Showing posts with label SOP. Show all posts
Showing posts with label SOP. Show all posts

Membaca hasil lab urin

Warna urin

Nilai normal: kekuningan jernih
Dalam keadaan normal, warna urin pagi (yang diambil sesaat setelah bangun pagi) sedikit lebih gelap dibanding urin di waktu lainnya. Perubahan warna urin dapat terjadi karena beberapa hal.
Hitam: baru mengkonsumsi tablet besi (ferri sulfat), sedang minum obat parkinson (levodopa), methemoglobunuria.
Biru: mengkonsumsi obat antidepresi (amitriptilin), antibiotik saluran kemih (nitrofurantoin), atau karena infeksi Pseudomonas pada saluran kemih.
Coklat: gangguan fungsi ginjal, mengkonsumsi antibiotik (sulfonamid atau metronidazol), dan konsumsi obat parkinson (levodopa).
Kuning gelap (seperti teh): hepatitis fase akut, ikterus obstruktif, kelebihan vitamin B2 / riboflavin, antibiotika (nitrofurantoin dan kuinakrin).
Oranye-merah: dehidrasi sedang, demam, konsumsi antikoagulan oral, trauma ginjal, konsumsi deferoksamin mesilat, rifampisin, sulfasalazin, laksatif (fenolftalein).
Hijau: infeksi bakteri, kelebihan biliverdin, konsumsi vitamin tertentu.
Bening (tidak berwarna sama sekali): terlalu banyak minum, sedang minum obat diuretik, minum alkohol, atau diabetes insipidus.
Seperti susu (disebut juga chyluria): filariasis atau tumor jaringan limfatik.
Berat jenis
Nilai normal: 1.003 s/d 1.030 g/mL
Nilai ini dipengaruhi sejumlah variasi, antara lain umur. Berat jenis urin dewasa berkisar pada 1.016-1.022, neonatus (bayi baru lahir) berkisar pada 1.012, dan bayi antara 1.002 sampai 1.006.
Urin pagi memiliki berat jenis lebih tinggi daripada urin di waktu lain, yaitu sekitar 1.026.
Abnormalitas:
Berat jenis urin yang lebih dari normal menunjukkan gangguan fungsi ginjal, infeksi saluran kemih, kelebihan hormon antidiuretik, demam, diabetes melitus, diare / dehidrasi.
Berat jenis urin yang kurang dari normal menunjukkan gangguan fungsi ginjal berat, diabetes insipidus, atau konsumsi antibiotika (aminoglikosida).
pH
Nilai normal: 5.0-6.0 (urin pagi), 4.5-8.0 (urin sewaktu)
pH lebih basa: habis muntah-muntah, infeksi atau batu saluran kemih, dan penurunan fungsi ginjal. Dari faktor obat-obatan: natrium bikarbonat, dan amfoterisin B.
pH lebih asam: diet tinggi protein atau diet tanpa kalori, diabetes melitus, asidosis tuberkulosis ginjal, dan fenilketonuria. Dari faktor obat-obatan: diazoksid dan vitamin C.
Glukosa
Nilai normal: negatif
Di Indonesia, glukosa urin biasanya diuji secara semikuantitatif dengan uji reduktor (Benedict).


Pemeriksaan Benedict ini sebenarnya ditujukan untuk mendeteksi adanya glukosa, asam homogentisat, dan substansi reduktor lainnya (misalnya vitamin C) dalam urin; sesuai dengan mekanisme reaksi yaitu reduksi tembaga sulfat. Asam homogentisat bisa ada dalam urin dalam jumlah besar pada individu dengan gangguan metabolisme asam amino alkohol (fenilalanin dan tirosin). Karena faktor ini pemeriksaan glukosuria di negara maju telah diganti dengan Clinistix.
Glukosa urin positif tidak selalu berarti diabetes melitus, walaupun memang penyakit ini yang paling sering memberi hasil positif pada uji glukosa urin. Makna lain yang mungkin:
-Penyakit ginjal (glomerulonefritis, nefritis tubular, sindroma Fanconi).
-Penyakit hepar dan keracunan logam berat.
-Faktor farmakologis (indometasin, isoniazid, asam nikotinat, diuretik tiazid, karbamazepin).
-Nutrisi parenteral total yang berlebihan (hiperalimentasi) dengan infus glukosa.
Protein
Nilai normal: negatif (uji semikuantitatif), 0.03-0.15 mg/24 jam (uji kuantitatif)
Protein dapat diuji dengan asam sulfosalisilat 20%, asam sulfat 6%, atau dengan reagen strip. Pemeriksaan dengan reagen strip lebih banyak digunakan saat ini. Untuk anak-anak di bawah 10 tahun nilai kuantitatif normal protein dalam urin sedikit lebih rendah daripada dewasa, yaitu <100>
Hasil abnormal (positif) dalam uji proteinuria dapat berarti:
Masalah nonginjal (gagal jantung kongestif, asites, infeksi bakteri, keracunan).
Keganasan (leukemia dan keganasan tulang yang bermetastasis).
Proteinuria sementara (pada dehidrasi, diet tinggi protein, stres, demam, post-pendarahan). Penyakit ginjal (lupus, infeksi saluran kemih, nekrosis tubular ginjal).
Pada anak-anak sering karena sindroma nefrotik atau penyakit bawaan (ginjal polikistik). Faktor farmakologis (amfoterisin B, semua aminoglikosida, fenilbutazon, sulfonamid).
Keton
Nilai normal: negatif
Uji ketonuria dimaksudkan untuk mendeteksi adanya produk sampingan penguraian karbohidrat dalam urin. Ketonuria dulu diperiksa dengan metode Rothera, dan sekarang digunakan dipstik. Hasil positif dapat ditemukan pada ketoasidosis diabetik, alkoholisme, diet tinggi lemak, penyakit glikogen, dan konsumsi obat-obatan tertentu (levodopa dan obat-obat anestetik).
Urobilinogen
Nilai normal: 0.1-1 Ehrlich U/dL (dipstik), atau positif s/d pengenceran 1/20 (Wallace-Diamond) Urobilinogen klasik diperiksa dengan uji pengenceran Wallace-Diamond. Cara ini sudah banyak digantikan oleh uji dipstik modern yang bersifat kualitatif.
Urobilinogenuria dapat disebabkan oleh
Penyakit hepar dan empedu (hepatitis akut, sirosis, kolangitis)
Infeksi tertentu (malaria, mononukleosis)
Polisitemia vera ataupun anemia
Keracunan timah hitam
Tidak ada urobilinogen sama sekali dalam urin bermakna ada obstruksi komplit pada saluran empedu (kolelitiasis atau karsinoma pankreas). Dari faktor farmakologis: kloramfenikol dan vitamin C menyebabkan urobilinogen urin berkurang.
Bilirubin
Nilai normal: negatif, maksimal 0.34 μmol/L. Bilirubinuria dapat disebabkan oleh:
Penyakit hepar (sirosis, hepatitis alkoholik), termasuk efek hepatotoksisitas.
Infeksi atau sepsis.
Keganasan (terutama hepatoma dan karsinoma saluran empedu).
Nitrit
Nilai normal: negatif (kurang dari 0.1 mg/dL, atau kurang dari 100.000 mikroorganisme/mL) Nitrit urin digunakan untuk skrining infeksi saluran kemih.
Eritrosit
Nilai normal: 0-3 sel per lapang pandang besar Eritrosit dalam urin yang berlebihan (mikrohematuria) dapat ditemukan pada urin wanita menstruasi dan perlukaan pada saluran kemih; baik oleh batu, infeksi, faktor trauma, maupun karena kebocoran glomerulus.
Leukosit
Nilai normal: 2-4 sel per lapang pandang besar Leukosit yang berlebihan dalam urin (piuria) biasanya menandakan adanya infeksi saluran kemih atau kondisi inflamasi lainnya, misalnya penolakan transplantasi ginjal. Sel epitel Nilai normal: sekitar 10 sel per lapang pandang besar, berbentuk skuamosa. Sel epitel yang lebih daripada jumlah normal berkaitan dengan infeksi saluran kemih dan glomerulonefritis. Sedangkan bentuk sel epitel abnormal dikaitkan dengan keganasan setempat.
Cast / inklusi
Nilai normal: ditemukan cast hialin dalam jumlah sedang, tanpa adanya inklusi. Cast merupakan kumpulan sel-sel yang dikelilingi suatu membran. Biasanya cast selain hialin (misalnya cast eritrosit atau cast leukosit) menunjukkan kerusakan pada glomerulus (glomerulonefritis kronik). Inklusi sitomegalik menunjukkan infeksi sitomegalovirus (CMV) atau campak.
Kristal
Nilai normal: ditemukan kristal dalam jumlah kecil Kristal yang ditemukan dalam urin tergantung pada pH urin yang diperiksa. Pada urin asam dapat ditemukan kristal asam urat. Pada urin netral ditemukan kristal kalsium oksalat. Pada urin basa mungkin terlihat kristal kalsium karbonat dan kalsium fosfat. Ada juga sejumlah kristal yang dalam keadaan normal tidak ada; antara lain kristal tirosin, sistin, kolesterol, dan bilirubin.
Bakteri, jamur, dan parasit
Nilai normal bakteri: negatif. Kecuali untuk urin midstream: <>
Nilai normal jamur dan parasit: negatif Bakteri yang dapat menimbulkan infeksi saluran kemih mungkin ditemukan dalam urinalisa, antara lain E.coli, Proteus vulgaris, Neisseria gonorrhoea dan Pseudomonas aeruginosa. Sedangkan parasit yang mungkin ditemukan dalam urin adalah Schistosoma haematobium dan mikrofilaria spesies tertentu.
Referensi Chernecky CC & Berger BJ. Laboratory Tests and Diagnostic Procedure. Philadelphia: Saunders Elsevier, 2008. Kasper DL et.al (eds). Harrison’s Principles of Internal Medicine. New York: McGraw-Hill, 2007. (hnz)

Pengecatan Gram dan Pengecatan BTA

1. Pengecatan Gram

Pengertian : adalah tata cara laboratorium untuk mengindentifikasi kuman melalui pengecatan Gram.


Tujuan : Diagnosis

Sampel : Swab, pus, urine, darah faeces, liquor, pleura, ascites, sputum, dll ciran darah.

Alat :

- Lampu spiritus
- Pipet Pasteur
- Obyek Glass
- Jembatan pengecatan
- Mikroskop

Reagen :
1. Larutan Gram A (Carbol Gentian Violet) :
a. Gentian Violet 1 gr
b. Alkohol 96% 10 ml
c. Phenol Kristal 1 gr
d. Aquadest 90 ml

2. Larutan Gram B (lugol)
a. Yodium 1 gr
b. Kalium Yodida 2 gr
c. Aquadest 300 ml

3. Larutan gram C (Alkohol 96%)

4. Larutan Gram D ( Solution fuchsin 1%)
a. Basic Fuchsin 1 gr
b. Aquadest 100 ml

Cara kerja :
a. Mempersiapkan alat-alat yang akan diperlukan
b. Mempersiakan reagensia yang diperlukan
c. Membuat preparat / sediaaan
d. Mengeringkan dan memfiksasi preparat diatas nyla api spiritus

e. Melakukan pengecatan :
1. Meletakan preparat diatas jembatan pengecatan
2. Menuanggi preparat dengan larutan Gram A selama 4 menit
3. Mencuci preparat dengan air mengalir sebentar lalu menuangginya dengan larutan Gram b selama 1 menit
4. Mencuci preparat deangan air mengalir sebentar lalu menuanginya dengan larutan Gram C goyang-goyang
5. Mencuci preparat deangan air mengalir sebentar lalu menuanginya dengan larutan Gram D selama 5 menit
6. Mencuci preparat deangan air mengalir lalu membiarkan mongering di udara ( kering angin)
f. Mengamati preparat dibawah mikroskop dengan perbesaran kuat untuk mencari adanya bakteri gram ( + ) dan Gram ( - ).

2.
Pengecatan BTA
Pengertian : Cara mengidentifikasi Bakteri Tahan Asam melalui pengecatan menurut Ziehl Nielsen
Tujuan : Diagnosis
Sampel : sputum, lesi, Swab, pus, urine, darah, faeces, liquor, pleura, ascites
Alat :
- Spirtus
- Obyek glass
- Jembatan pengecatan
- Ose dan mikroskop
- Pipet pasteur
Reagen :
1. Carbol fuchsin :
- Basic fuchsin 3,0 gr
- Etanol/methanol 100 ml
- Kristal phenol 45 gr
- Aquadest 900 ml
2. larutan dekolorisasi :
- HCl pekat 30 ml
- Etanol 970 ml
3. pewarna kontras :
- Methylen blue khlorida 30 ml
- Air suling/aquadest 1000 ml
Cara kerja :
a. Mempersiapkan alat-alatnyang di perlukan
b. Mempersiapkan reagensia
c. Membuat preparat/sediaan dari bagian spesimen yang purulen/berdarah, menghapus spesimen pada bagian tengah obyek glass ukuran 2 x 3 cm, menulis nomor urut sesuai register Lab TB 04 di sebelah pinggir obyek glass
d. Membakar ose sampai membara setelah setiap mengerjakan 1 spesimen
e. Mengeringkan dan memfiksasi preparat di atas nyala api lampu spirtus
f. Melakukan pengecatan :
1. Meletakkan preparat diatas jembatan pengecatan
2. Menuangi preparat dengan carbol fuchsin
3. Memanaskan dari bawah setiap sediaan dengan lampu spirtus sampai keluar uap, api harus selalu di gerakkan, dihentikan bila sudah timbul uap
4. Mendinginkan selama 5 menit atau lebih, jangan sampai pewarna kering
5. Mencuci dengan air mengalir, memiringkan setiap sediaan untuk mengalirkn air yang berlebih
6. Mencuci sediaan dengan decolorasi sampai tidak ada pewarna carbol fuchsin, maksimal 3 menit
7. Mencuci dengan air mengalir
8. Menggenangi tiap sediaan dengan pewarna kontras 30 menit
9. Mencuci lagi setiap sediaan dengan air mengalir, memiringkan sediaan untuk mengurangi air yang berlebih, mengeringkan di udara terbuka
10. Mengamati preparat di bawah mikroskop dengan pembesaran kuat (100x) untuk mencari adanya bakteri tahan asam (BTA)

sumber:
http://sodiycxacun.blogspot.com/2010/04/pengambilan-darah-dengan-vacutainer.html

Cara Menggunakan Mikroskop

Sebagai seorang yang ingin berkerja di laboratorium, ilmu pertama yang harus dipelajari dan wajib bisa adalah menggunakan Mikroskop, karena hampir semua bagian ilmu seperti, Hematologi, Parasitologi, Bakteriologi, Kimia dan lainnya beberapa pemeriksaannya di lakukan dengan menggunakan mikroskop.

Nah sekarang saya ingin berbagi ilmu yang berhubungan dengan Mikroskop, diantaranya adalah bagian-bagian dari Mikroskop dan bagaimana cara menggunakannya.

Berikut adalah gambar bagian dari Mikroskop :



A. Struktur Mikroskop beserta Komponen-komponennya, terdiri dari:

1. Lensa okuler.
Merupakan bagian yang dekat dengan mata pengamat saat mengamati objek. Lensa okuler terpasang pada tabung atas mikroskop. Perbesaran pada lensa okuler ada tiga macam, yaitu 5x, 10x, dan 12,5x.

2. Tabung mikroskop.
Merupakan penghubung lensa okuler dan lensa objektif.
Tabung terpasang pada bagian bergerigi yang melekat pada pegangan mikroskop sebelah atas. Melalui bagian yang bergerigi, tabung dapat digerakkan ke atas dan ke bawah.

3. Makrometer (sekrup pengarah kasar).
Merupakan komponen untuk menggerakkan tabung mikroskop ke atas dan ke bawah dengan pergeseran besar.

4. Mikrometer (sekrup pengarah halus).
Merupakan komponen untuk menggerakkan tabung ke atas dan ke bawah dengan pergeseran halus.

5. Revolver.
Merupakan pemutar lensa untuk menempatkan lensa objektif yang dikehendaki.

6. Lensa objektif.
Merupakan komponen yang langsung berhubungan dengan objek atau specimen. Lensa objektif terpasang pada bagian bawah revolver. Perbesaran pada lensa objektif bervariasi, bergantung pada banyaknya lensa objektif pada mikroskop. Misalnya, ada perbesaran lensa objektif 10x dan 40x (mikroskop dengan dua lensa objektif); 4x, 10x, dan 40x (mikroskop dengan tiga lensa objektif); dan 4x, 10x, 45x, dan 400x (mikroskop dengan empat lensa objektif).

7. Panggung mikroskop.
Merupakan meja preparat atau tempat sediaan obek/specimen. Pada bagian tengah panggung mikroskop terdapat lubang untuk jalan masuk cahaya ke mata pengamat. Panggung digunakan untuk meletakkan sediaan objek atau specimen. Pada panggung terdapat dua penjepit untuk menjepit object glass. Pada beberapa mikroskop lain, panggung dapat digerakkan ke atas dan ke bawah.

8. Diafragma.
Merupakan komponen untuk mengatur banyak sedikitnya cahaya yang masuk melalui lubang pada panggung mikroskop. Diafragma ini terpasang pada bagian bawah panggung mikroskop.

9. Kondensor.
Merupakan alat untuk memfokuskan cahaya pada objek atau specimen. Alat ini terdapat di bawah panggung.

10. Lengan mikroskop.
Merupakan bagian yang dapat dipegang waktu mengangkat atau menggeser mikroskop.

11. Cermin reflektor.
Digunakan untuk menangkap cahaya yang masuk melalui lubang pada panggung mikroskop, yakni dengan cara mengubah-ubah letaknya. Cermin ini memiliki permukaan datar dan permukaan cekung. Permukaan datar digunakan jika sumber cahaya cukup terang dan permukaan cekung digunakan jika cahaya kurang terang.
Pada Mikroskop yang lebih canggih, cermin reflektor digantikan oleh sinar lampu listrik (light illuminator)
12. Kaki mikroskop.
Merupakan tempat mikroskop bertumpu. Kebanyakan kaki mikroskop berbentuk seperti tapal kuda.

B. Mempersiapkan Mikroskop

1. Mikroskop diambil dari tempat penyimpanan mikroskop dengan menggunakan kedua tangan saat mengambil dan membawa mikroskop ke meja. Satu tangan memegang lengan mikroskop dan tangan lain memegang kaki mikroskop.
2. Mikroskop ditempatkan di meja dengan kedudukan datar dan dihadapkan kearah cahaya.
3. Sekrup pemutar besar diputar hingga tabung mikroskop turun sampai ke batas bawah.
4. Revolver diputar sehingga lensa objektif dengan pembesaran lemah (missal 10x) tepat pada posisinya atau tepat berada di atas lubang panggung.
5. Diafragma dibuka secara penuh. Kedudukan cermin diatur agar cahaya yang masuk terpantul melalui lubang pada panggung sehingga melalui lensa okuler akan tampak lingkaran cahaya yang terangnya merata. Lingkaran cahaya tersebut dikenal sebagai bidang pandang.

C. Cara Penggunaan Mikroskop

1. Jarak mata-okuler: Untuk mencegah kelelahan mata, diperlukan penjagaan jarak antara mata dan okuler. Untuk menentukan jarak ini, mata mendekati okuler dari suatu jarak maksimum sekitar 1 cm. Jarak optimum dicapai pada saat medan pandang tampak sebesar-besarnya dan setajam-tajamnya. Selain itu, mata yang sebelah lagi harus tetap terbuka.

2. Pengamatan dimulai dengan menggunakan lensa objektif dengan pembesaran lemah (misal 10x).

3. Sambil mengamati melalui lensa okuler, sekrup pemutar kasar diputar secara perlahan agar tabung mikroskop naik. Pada saat demikian, gambar dapat teramati meskipun belum begitu jelas. Untuk memperoleh gambit yang lebih jelas, sekrup pemutar halus diputar sehingga dapat diamati gambar yang lebih jelas dan lebih fokus.

4. Setelah mengamati gambar dengan menggunakan lensa objektif dengan pembesaran lemah (10x), objek yang sama coba diamati dengan menggunakan lensa dengan pembesaran yang lebih kuat (missal 40x) dengan cara memutar revolver sehingga lensa objektif 40x tepat mengarah ke lubang pada panggung. Hal yang perlu diingat: selama pengamatan dengan pembesaran kuat tidak boleh mempergunakan sekrup pemutar kasar, untuk mendapatkan gambar yang baik (fokus) cukup digunakan sekrup pemutar halus.

D. Perawatan Mikroskop
1. Memegang mikroskop dengan kedua tangan ketika mengangkatnya.
2. Memulai pengamatan dengan pembesaran lemah sebelum menggunakan pembesaran kuat.
3. Tidak memutar tombol dengan kasar.
4. Menghilangkan kotoran pada lensa mikroskop: Seringkali gambar mikroskop tetap kabur meski telah diusahakan penyetelan focus halus. Ini seringkali disebabkan lensa depan objektif yang kotor dan/atau lensa okuler. Untuk memastikan pada bagian mana lensa kotor, pertama-tama lensa okuler diputar, dan kemudian, bila perlu, lensa objektif diputar sambil mengamati cuplikan untuk menentukan kapan lapisan kotoran yang kabur bergerak. Kemudian lensa yang kotor dibersihkan dengan kertas transerat atau kertas lensa. Kondensor yang kotor pun dapat mengaburkan gambar. Ketika membersihkan lensa depan objektif, harus diingat bahwa lensa terpasang pada perekat yang dapat melarut dalam pelarut organic. Oleh karena itu, lebih baik jika digunakan air suling untuk menghilangkan kotoran; jika tidak bisa, digunakan pelarut organik yang mudah menguap sesedikit mungkin, misalnya benzene atau eter minyak bumi.
5. Memastikan mikroskop dalam keadaan kering, sebelum dan sesudah digunakan.

E. Menghitung Pembesaran Gambar

Telah dijelaskan sebelumnya bahwa sebuah mikroskop memiliki dua macam lensa, yaitu lensa okuler dan lensa objektif. Kedua lensa tersebut memiliki ukuran pembesaran tertentu. Pembesaran total untuk panjang tabung yang digunakan diperoleh dari pembesaran pada objektif dikalikan dengan pembesaran yang tertera pada okuler.
Perbesaran objektif x perbesaran okuler = perbesaran total
10 x 8 = 80 x
10 x 12,5 = 125 x
40 x 8 = 320 x
40 x 12,5 = 500 x

Perbesaran total 80-125x (perbesaran rendah) dan 320-500x (perbesaran tinggi) yang diberikan pada contoh sudah cukup untuk memenuhi persyaratan normal.
Perbesaran rendah (3,5 x 8 atau 3,5 x 12,5, yaitu perbesaran total 30-40x) dapat memperlihatkan tampak umum dari suatu cuplikan dan biasanya digunakan untuk pengamatan pertama pada seluruh cuplikan.

F. Preparasi Sampel

1. Setetes air ditempatkan pada object glass.
2. Objek/spesimen diletakkan pada air tersebut.
3. Cover glass ditempatkan pada bagian atasnya dengan cara miring dan turunkan secara perlahan serta diusahakan agar tidak terbentuk gelembung udara. Pembentukan gelembung udara dapat menyebabkan kualitas gambar menjadi kurang bagus atau tidak jelas.
4. Air harus mengisi ruang antara object glass dan cover glass; jika air tersebar ke bagian lain dari object glass, kelebihan ini harus dikeringkan (misal dengan tisu) dengan hati-hati.
5. Jika objek sudah terdapat dalam bentuk suspense cairan, tetesan suspense dapat digunakan tanpa harus meneteskan air terlebih dahulu pada permukaan object glass.

Phlebotomy Procedures Materials Required


The following equipment should be assembled before proceeding with the venipuncture procedure:

Blood Drawing Site: The blood drawing site should provide a chair with a wide, flat, clean surface on the arms, or the patient may be lying in bed. The area should be wide enough for the patient's arm to rest comfortably. The patient's elbow should be supported so that it remains straight.
Some outpatients may prefer lying down, in which case an examination table may be used.

Blood Collection Safety Needles: "Puncture-guard" needles by BioPlexus are available in sizes 21 gauge and 22 gauge, 1 inch to 1.5 inches. We also have available safety "winged" sets in sizes of 21 ga, 23ga, 25 ga and 27 ga.

Plastic Tube/Needle Holders: The plastic holders are used to hold the needle on one end, and the vacuum tube for collection on the other. Regular, and blood culture sizes are available.

Blood Collection Vacuum Tubes: The vacuum tubes are designed to draw a predetermined volume of blood. Regular, pediatric tubes, and microtainers are available in a variety of sizes. Tubes with different additives are used for collecting blood specimens for specific types of tests. The color of the rubber stopper capping the tube is used to identify these additives, which, in turn, dictate the function of the tube.

Tourniquets: Tourniquets are used to help distend the veins for ease in venipuncture. Easy to use Velcro lined tourniquets are available in adult and pediatric sizes. Most commonly used type is 1"x16" non-latex band.

Antiseptics: Individually packaged 70% isopropyl alcohol wipes may be used to clean the venipuncture site for most specimens. Cepti Seal Blood Culture Prep kits must be used when collecting specimens for blood cultures. (See "Collection of Blood Cultures" section for further explanation).

Gauze: 2 x 2 inch gauze squares can be folded and taped to the puncture site to control the bleeding after the blood specimen is collected.

Sharps Disposal Container: An OSHA acceptable, puncture proof, container marked "Biohazardous" with a top for unscrewing needles must be used for needle disposal, or for partially filled capillary tubes.

Ammonia Inhalants: Ammonia inhalants may be used to revive patients who faint or become dizzy.

Cold Compress: Cold compresses may be used to revive patients who faint or become dizzy.
Disinfectant: A plastic wash bottle with an ASCEND solution should be available for cleaning up small blood spills.

Adhesive Labels: 1.0 x 2.5-inch adhesive labels and a permanent marking pen should be available for labeling the specimens.

Non-Powdered Gloves: Latex gloves may be found in various sizes. Also available are various types of non-latex gloves.

TRICHROME STAIN PROCEDURE

PRINCIPLE

It is generally recognized that stained fecal films are the single most productive means of stool examination for intestinal protozoa. The permanent stained smear facilitates detection and identification of cysts and trophozoites and affords a permanent record of the protozoa encountered. Small protozoa, missed by wet mount examinations (of either unconcentrated or concentrated samples) are often seen on the stained smear. The Wheatley Trichrome technique for fecal specimens is a modification of Gomori’s original staining procedure for tissue. It is a rapid, simple procedure, which produces uniformly well-stained smears of the intestinal protozoa, human cells, yeast, and artifact material.

SPECIMEN

The specimens usually consist of fresh stool or stool fixed in PVA or MIF smeared on microscope slides and allowed to air dry or dry on a slide warmer at 60°C. Stool preserved in 10% -formalin or some of the one-vial fixatives can also be used.

REAGENTS

There are seven steps to this procedure, requiring the following solutions:
1. 70% Ethanol plus iodine: prepare a stock solution by adding iodine crystals to 70% alcohol until you obtain a dark solution. To use, dilute the stock with 70% alcohol until a dark reddish brown color or strong tea color is obtained.
2. 70% Ethanol
3. Trichrome Stain: may be purchased commercially
4. 90% Acid Ethanol
90% ethanol 99.5 ml
Acetic acid (glacial) 0.5 ml
5. 95% ethanol
6. 100% ethanol
7. Xylene or xylene substitute

QUALITY CONTROL

A control slide of a known protozoan such as Giardia spp. from a PVA preserved specimen should be included with each staining run. When the smear is thoroughly fixed and the stain is performed correctly, the cytoplasm of protozoan trophozoites will have a blue green color sometimes with a tinge of purple. Cysts tend to be slightly more purple. Nuclei and inclusions (chromatoid bodies, red blood cells, bacteria) and Charcot-Leyden crystals have a red color sometimes tinged with purple. Glycogen is dissolved by the solvents and appears as a clear area in the organism. The background material usually stains green providing a nice color contrast with the protozoa.

PROCEDURE
1. For PVA smears, place the slide in 70% ethanol plus iodine for 10 minutes. For other fixatives, follow the manufacturer's instructions. Omit the iodine step for preservatives that do not contain mercuric chloride.
2. Place slide in 70% Ethanol for 5 minutes.
3. Place in second 70% Ethanol for 3 minutes
4. Place in Trichrome stain for 10 minutes.
5. Destain in 90% ethanol plus acetic acid for 1 to 3 seconds.
6. Rinse several times in 100% ethanol.
7. Place in two changes of 100% ethanol for 3 minutes each.
8. Place in two changes of xylene or xylene substitute for 10 minutes.
9. Mount with coverslip using mounting medium (e.g., permount).
10. Examine the smear microscopically utilizing the 100× objective. Examine at least 200 to 300 oil immersion fields.

INTERPRETATION

The cytoplasm of organisms stains blue-green tinged with purple, whereas nuclear chromatin, chromatoid bodies, erythrocytes, and bacteria stain red or purplish-red. Background material will stain green to blue-green. Organisms undergoing degeneration take a pale stain, and incompletely fixed organisms may stain red. Yeasts and molds may stain either green or red. Cryptosporidium and Cyclospora oocysts are not satisfactorily stained in Trichrome smears and can easily be overlooked; sometimes they appear as “ghosts” in this stain, which can serve as a clue to their presence.

REFERENCE

Ash, Lawarence and Thomas Orihel. Atlas of Human Parasitology. ASCP. 4th Edition. 1997.

LABORATORY SAFETY


Safety is vitally important for the laboratory. It is imperative that the entire laboratory staff understands the importance of safety training and the proper implementation of safety policies and procedures. By following a few simple precautions, potentially dangerous accidents can be prevented.

Maintain training records demonstrating that all laboratory staff have been trained in safety procedures, including infectious waste disposal, fire safety, electrical hazards, and general personal and technical safety procedures.

SAFETY OF PATIENTS

Patients should be prohibited form entering laboratory areas of the laboratory.

STANDARD PRECAUTIONS FOR SPECIMEN HANDLING

Use barrier protection to prevent skin and mucous membrane contamination while handling the following human body fluids.

Blood
Semen and vaginal secretions
Tissues, cerebral spinal fluid, synovial, pleural, peritoneal, pericardial, amniotic)

Standard precautions are not mandated for handling urine, feces, nasal secretions, sputum, saliva, sweat, tears, or vomitus unless the specimen is bloody. However, a laboratorian should consider all body fluids to be a source of infection and take appropriate precautions when handling them.

GENERAL LABORATORY SAFETY

- Handwashing is the single most important safety practice in the laboratory.
Wash hands:

After removing gloves or other personal protective equipment.
Before touching your eyes or mouth.
Immediately, if a specimen or reagent has been spilled on your bare hands.
Before eating, drinking, or smoking.

- Wear gloves whenever you:

Handle blood, body fluids, mucous membranes, or open wounds.
Touch items or surfaces soiled with blood or body fluids, including dried blood and body fluids.
Perform venipuncture, fingersticks, and other vascular access procedures.
Have cuts, scratches, dermatitis, or other breaks in your skin.
Universal Precaution: No gloves should be re-used. Replace when damaged.

- Wear protective clothing and equipment while performing laboratory procedures involving potentially infectious materials. Remove protective clothing and equipment before leaving the laboratory.

- Every laboratory should have easy access to an eyewash. The device should contain or accommodate enough water to flush the eyes and facial area continuously for 15 to 30 minutes.

- DO NOT recap, bend, or break needles after drawing blood. If it is necessary to recap, a one-handed, passive technique should be used.

- Do not eat, drink, smoke, handle contact lenses, or apply cosmetics or lip balm in the laboratory.

- Employers must offer the Hepatitis B vaccine series (free of charge) to any employee that is exposed on the job to the potentially infectious materials listed above. Employees who choose not to receive the Hepatitis B vaccination must sign a declination form.

- Use laboratory refrigerators ONLY for storage of reagents, controls, or specimens. No food or drink is allowed in laboratory refrigerators.

- Disinfect laboratory countertops daily. A 10% solution of household bleach and water (1 part bleach plus 9 parts water) is an effective disinfectant with both bacterial and viral organisms. Work areas should be wiped and allowed to soak. To retain potency and effectiveness, the 10% solution must be prepared daily. Wear utility gloves when cleaning.

- Clean spills up immediately. Spills that involve blood, urine, and reagents can be cleaned up with paper towels and by applying a 10% bleach solution to most spill sites. Gloves must be worn and other tools must be used to prevent personal and environmental contamination and cuts.

- Whenever possible, use disposable plastics rather than glass. Broken glass gives rise to “sharps” that may need to be handled in the same manner as needles.

- Pipette reagents with a mechanical pipette or a bulb. NEVER PIPETTE BY MOUTH!

- Never open a running centrifuge or slow it down using your hands, a pencil, or similar device. Disinfect all centrifuges regularly, following manufacturer’s instructions. Disinfect the centrifuge immediately after a spill. Centrifuges must be covered when in use (i.e., centrifuges must have a lid). Always balance specimens in the centrifuge.

- When operating a centrifuge, ensure proper balance is maintained. Imbalance of the rotor causes vibration, which increases wear on the centrifuge, and causes tubes to break more frequently.

- Inspect all tubes before centrifugation. Do not use cracked or scratched tubes.

- Pick up broken glass using a hemostat or other device, wearing puncture-resistant gloves. Do not simply use gloved hands to pick up potentially contaminated sharps. If a tube breaks inside the centrifuge, use forceps to remove any broken glass and clean the interior with a 1:10 dilution of chlorine bleach. Allow to stand for 5 minutes then rinse with water and dry.

- Clearly label all reagents and other materials. If caustic or volatile materials are used, store only minimal quantities on the premises. Establish a clean-up procedure to be followed in case of a spill or broken container. Sand or other absorbent material may be used to clean up chemical spills. Refer to the Material Safety Data Sheets in your laboratory's Hazardous Chemical Control Manual and train employees in their proper use.

INFECTIOUS WASTE HANDLING AND DISPOSAL

-Decontaminate infectious waste before disposal.

-Infectious waste (biohazard) containers, sharps and biohazard bags, should be conveniently located and of sufficient volume to accommodate the infectious waste generated by the laboratory. They must be labeled or color-coded in red to warn of biohazardous material.

-Biohazard containers should be handled with gloved hands.

-Microbiological cultures should not be discarded in sanitary sewers.

ELECTRICAL EQUIPMENT

-Have an adequate number of grounded electrical outlets and enough lighting for safe laboratory operations. Be familiar with the location of circuit breakers for your laboratory. Electrical equipment must have safe cords and three prong grounded plugs.

-Maintain equipment properly to avoid electrical hazards. IF an electrical problem with a piece of equipment is suspected, immediately turn the equipment off, disconnect it from the outlet, and have it repaired.

FIRE SAFETY

-Mount a small, multi-use (ABC) fire extinguisher on the laboratory wall. The fire extinguisher should be tested and maintained by your Facilities officer, and all laboratory staff should know how to use it.

-Clearly mark exits from the building. All office personnel should know how to leave the building quickly in case of fire.

IN CASE OF ACCIDENT

-Notify the your officer as soon as possible after the incident. If an accident involves exposure to potentially infectious materials (e.g., a needle stick).

-Specific policies should be developed by each laboratory for the following items:

A list of the names and telephone numbers of persons incharge at the lab to contact in an emergency.
Procedures for cleanup of reagent and specimen spills (see your Hazardous Chemical Control Plan)
An accident log where the person’s name, type of accident, and the date are included.
Office evacuation plan.

URINE CULTURES

PRINCIPLE

Urine specimens are submitted for culture from patients with symptoms of urinary tract infections and from asymptomatic patients with a high risk of infection. The most common gram-negative bacteria found in a urine culture are: Escherichia coli, Enterobacteriaceae sp. Klebsiella spp., Proteus spp., and Staphylococcus saprophyticus.

Quantitative cultures of urine specimens are critical for diagnosis of UTI. The criteria to be used for distinguishing significant from non-significant growth may vary depending on the patient and type of urine specimen received for culture.

MATERIALS AND EQUIPMENT

1. Media
BA
MAC

2. Supplies
Sterile urine collection cups
Platinum or plastic disposable calibrated loops (0.001-ml for colony counts>1,000 CFU/ml)

3. Reagents
Gram stain reagents
Reagents specified in preliminary identification protocol
API 20E

4. Equipment
Non-CO2 incubator
Microscope

SPECIMEN

1. Specimen collection – Urine is normally a sterile body fluid. However, unless it is collected properly, it can become contaminated with normal flora from the urethra, vagina, prostate or perineum. Laboratory staff must provide detailed instructions to the patients to ensure proper specimen collection.

Clean-catch midstream urine or catheter urine. See Specimen Collection section of this manual for more complete instructions.

2. Timing and transport
a. First morning specimen is best. Excessive fluid intake will dilute the colony count to <105>

b. Transport urine to laboratory as soon as possible after collection.
c. Culture urine specimens within 2 h, or refrigerate and culture within 24 h. Bacterial counts usually remain stable for 24 h at 4oC.
d. Request a repeat specimen when the collection time and method of collection have not been provided.
e. If an improperly collected, transported, or handled specimen cannot be replaced, document in the final report that specimen quality may have been compromised.
QUALITY CONTROL
Inspect calibrated loops regularly to confirm that they remain round and are free of bends, dents, corrosion, or incinerated material. Additionally, at least monthly, check the loops to ensure that the delivery volume is accurate using the drill bit method: Drill bit method: Obtain two twist drill bits (no. 53 or 54). Carefully slip the 0.001-ml loop over the end of the no. 54 bit. If the loop is calibrated, it will fit over the bit. Repeat the procedure with the no. 53 bit. If the loop is calibrated, it will not fit over the end. Discard the loop if it fits over the no. 53 bit. Perform media, reagent, and stain quality control as directed in the Quality Control SOP.
GRAM STAIN (done by request only)
1. The Gram stain method can detect the presence of both bacteria and WBC’s in urine specimens. If an order is received consult with medical provider.
2. If the intent is to determine if there is a high colony count infection, place 0.01 ml of well mixed, uncentrifuged urine onto a glass slide, allow it to air dry without spreading, and Gram stain. (Refer to Gram Stain SOP). Report the number of microorganisms per oil immersion field (OIF). The presence of one or more microorganisms per OIF correlates with a colony count of > 105 CFU/mL. Report and quantitate WBC’s and organisms seen. The presence of many squamous epithelial cells and different microbial morphotypes indicates contamination or “dirty-catch”. Request a repeat specimen.
3. If the intent of the requisition is to establish whether the infection is Gram-positive or Gram
negative, Grams stain the sediment of urine that has been centrifuged at 1500 g for 5 minutes. Evaluate the organisms OIF. Report whether the organisms are Gram-positive or Gram-negative.

INOCULATION AND INCUBATION

SURFACE STREAK METHOD

The standard choice of media used for initial inoculation of urine is: BA (non-selective media), and MAC. The proper procedure for inoculating urine specimens with a calibrated loop onto culture medium is as follows:

1. Flame and cool a platinum loop calibrated to deliver 0.001 ml (alternatively, a commercially purchased calibrated disposable plastic loop delivering 0.001 ml may be used.)

2. After mixing the urine, remove the top of the container.

3. Holding the cooled loop vertically, immerse the loop below the surface of the urine specimen and subsequently remove the loop vertically.

4. Inoculate the urine on the agar by making a single line steak down the middle of the plate from top to bottom.

5. Beginning at the top of the plate, streak the urine back and forth across the inoculum line, filling the plate with streak lines.

6. Then streak the plate at right angles to the initial streak to produce isolated colonies.
7. Incubate both culture plates at 35 to 37o C in an aerobic atmosphere for 18-24 h.



EXAMINATION OF CULTURE MEDIA

1. Examine cultures that have been incubated overnight.

2. If there is no visible growth and the specimen was collected by voiding or with a catheter, report as follows: “No growth at 24 hours”

3. Re-incubate culture plates with tiny or scant colonies that are not discernible.

4. For positive cultures, examine culture plates for the quantity and morphological type of organisms present. The BA plate is used for the total bacterial count. MAC is inhibitory and could give erroneous quantitative results. MAC should only be used for the presumptive identification of gram-negative rods. A total colony count is performed and the CFU/mL of urine is calculated. Using a 0.001-ml loop, one colony equals 1,000 or 103 CFU/mL (10 colonies would be equal to 10,000 or 104 CFU/ml).

5. Perform additional testing based on the colony count and morphology, method of urine collection, and clinical condition. In routine “clean catch” urine specimens colony counts of 100,000 or 105 CFU/mL or greater are considered significant. Counts of 103 – 105 CFU/mL may also be considered significant from patients on antimicrobial agents, female patients with urethritis, symptomatic males, and dilute urines. Consult with the medical provider as required.

6. In general when there are three or more colony types of organisms grown, regardless of the colony count, it indicates that the specimen was contaminated during collection. This is especially true if the organisms are common vaginal flora such as Lactobacillus sp. Other common contaminants include diphtheroids, viridans streptococci, and coagulase negative staphylococci other than Staphylococcus saprophyticus.

INTERPRETATION

Colony counts should be correlated with clinical criteria to confirm a diagnosis of urinary tract infection (UTI).

1. No Growth

Final report: “No growth at 48 hours”.

2. Colony count <>
3. Colony count of 5,000 to 50,000 CFU/ml (10 to 50 colonies)
a. If mixed: Final report: “Multiple microorganisms present: probable contamination; please repeat culture”. NOTE: A colony count is reflective of one organism. Each organism has its own colony count. Do not use a total cumulative count when more than one organism is isolated.
b. If pure culture of one or two potential pathogens equally predominant
· For patients on antimicrobial agents, female patients with urethritis, and symptomatic males, enumerate and perform definitive identification and antimicrobial susceptibility testing (AST), if indicated. (Refer to Antimicrobial Sensitivity SOP).
· If one organism is predominant and the other is “few”, work up only the predominant organism). Final report: Enumeration CFU/ml and report organism ID and AST results for each organism.
· If no clinical information is provided, enumerate and provide a descriptive identification of colony morphology for organism present. Hold the culture at room temperature for possible further workup if requested by medical provider.
4. Colony count 50,000 to >100,000 CFU/ml (more than 50 colonies)

a. If mixed:

Final report: “Multiple microorganisms present: probable contamination; please repeat culture”.

b. If pure culture of one or two potential pathogens equally predominant

· Perform definitive identification and antimicrobial susceptibility testing (AST), if indicated. (Refer to Antimicrobial Sensitivity SOP).

· If one organism is predominant and the other is “few”, work up only the predominant organism).

Final report: Enumeration CFU/ml and report organism ID and AST results for each organism.

PROCEDURE NOTES

1. Bacteria in urine may settle to the bottom of the specimen container. Therefore, mixing the specimen prior to sampling is extremely important.

2. A quick visual estimation of the number of colonies of each organism is sufficient.

3. If there is a question on which guideline applies to a given culture result, choose the guideline involving more identification and sensitivity testing.

4. The guidelines for working up cultures are only approximations. They must be modified to fit unusual clinical situations.

5. Do not perform AST directly from the urine specimen.

IDENTIFICATION

1. For any urine cultures that grow a significant Stahyococcus coagulase negative, Staph. saprophyticus should be ruled out. It is a very important pathogen among young sexually active females. Staph. Saprophyticus is novobiocin resistant by Kirby-Bauer testing using a disc of 5 ug (<16>
2. If growth occurs on both plates and the colonies are morphologically similar, then it is safe to assume the organism is of the Enterobacteriaceae family (gram negative). Identification may be made using the API test procedure. Perform antibiotic sensitivity.
3. Quick ID’s: The colony morphology and spot indole test can be used to make presumptive identifications of E. coli, Klebsiella-Enterobacter spp., and Proteus (Refer to Spot Indol procedure in SOP). Refer to flowcharts found in “Processing Culture” procedure and/or Table 1.
· E. coli – Will have a flat pink colony morphology on MAC, and will sometimes be beta hemolytic on BA. E.coli will also be indole positive. If the isolate has these characteristics and a typical smell and colony morphology the isolate may be called an E.coli.
· Proteus spp. – Produce a foul odor and tend to produce a film of swarming growth that covers the surface of the BA plate. On MAC, these organisms are non-lactose fermenters colonies (colorless) and may be either indole-positive or indole-negative when tested from blood agar. If indole positive, it can be called P. vulgaris. If indole negative, it can be called P. mirabilis.
· Klebsiella spp. and Enterobacter spp. – Usually large, mucoid, and pink on MAC. These species are usually spot indole negative.
4. Quick ID - Pseudomonas aeruginosa – Will be a non-lactose fermenter on MAC and will have a very typical colony morphology on BA. On BA the organism may or may not b beta hemoloytic, it will have blue or green pigment, “grape-like” odor, and a spreading colony type. The isolate will also be oxidase positive. If the organism has these characteristics, it can be called a P. aeruginosa.
5. If there is growth on the BA but not on MAC, a gram stain should be done on the organism to determine its gram reaction. See Table 2.
6. For Enterococcus sp., susceptibilities should not be done for outpatients. Simply report the drugs of choice and hold the plates for 3 days. If heavy growth on a repeat culture, a sensitivity can probably be done on a MH plate. Drugs of choice are for an uncomplicated UTI is ampicillin. Alternates are nitrofurantoin and levofloxacin.
7. Gram-positive rods frequently isolated but rarely involved in urinary tract infections are Corynebacterium sp. (diphtheroids) and Lactobacillus sp. These organisms will appear as tiny, nondescript colonies on BA and will not grow on MAC.
8. When yeast are isolated that have “spiking” or “feet” around the colonies, this will give a presumptive identification of C. albicans. For yeast that are very tiny on the BA (even after two days incubation) and the individual yeast cells are quite small (by gram stain or wet prep), a presumptive identification can be determined for Torulopsis glabrata. If possible, differentiate between the two yeasts; it could be clinically significant and very helpful to the medical provider. Report only when the amount is moderate to many. Report the yeast only when the amount is moderate-many.
9. Report any amount of Group B streptococcus isolated on women known to be pregnant or on any woman of child bearing age.
LIMITATIONS
1. Because most antibiotics concentrate in urine, negative urine cultures are possible following treatment of a urinary tract infection by an antibiotic that is only partially effective. For this reason, urine cultures collected to determine whether a course of therapy was effective should be collected 7 days after discontinuance of the antibiotic.
2. Improper specimen collection and/or allowing the urine to remain at room temperature for extended periods of time results in false positive cultures. The laboratory can prevent issuance of false positive reports, to a degree, by rejecting polymicrobial specimens.
3. Failure to obtain separation of colonies on primary plating will produce erroneous colony counts.
REFERENCE
1. Barry, A.L. et al. Cumitech 2. Laboratory diagnosis of urinary tract infections. Washington, American Society for Microbiology, 1975.
2. Baron, E.J., and S.M. Finegold. Bailey and Scott’s Diagnostic Microbiology, 8th ed. St. Louis, C.V. Mosby Co., 1990.
3. Clarridge, J.E., Johnson, J.R., Pezzlo, M.T. 1998. Cumitech 2B, laboratory Diagnosis of Urinary Tract Infections, Coordinating ed., A.S. Weissfield. ASM, Washington, D.C.
4. Miller, J.M.: B.B. Wentworth. Methods for quality control in diagnostic microbiology. APHA, Washington, D.C., 1985, pp. 89-134.
5. Miller, J.M. Handbook of Specimen Collection and handling in Microbiology. Atlanta, Centers for Disease Control, PHS, HHS, 1985.
6. Murray, P., Baron, E.J., Pfaller, M.A., Tenover, F.C., Yolken, R.H. 1999. Manual of Clinical Microbiology, 7th Edition. The ASM Press, Washington, D.C.

SCREENING AND DIAGNOSIS OF GESTATIONAL

INTRODUCTION

Glucose intolerance during pregnancy is associated with an increase in perinatal morbidity and mortality, especially in women who are:

• Aged >25 years
• Member of an ethnic group with high prevalence of diabetes (e.g., Hispanic, African, Native American, South or East Asian, Pacific islander)
• Body mass index > 25
• Previous unexplained perinatal loss or birth of a malformed child
• History of abnormal glucose tolerance
• Previous large baby (greater than 9 lbs.)
• Family history of diabetes, especially in first degree relatives
• Abnormal birth weight (<> 9 lbs)
• Polycystic ovary syndrome

Hyperglycemia during pregnancy affects 2-3% of pregnant women; most will return to normal after delivery. Most patients with GDM have normal fasting glucose levels, thus some challenge of glucose tolerance must be undertaken. It is therefore recommended that universal screening and diagnosis be performed between 24 and 28 weeks gestation on all pregnant women not identified as having glucose intolerance. Women with a family history of diabetes or previous gestational diabetes should undergo the screening test earlier in pregnancy (14 to 20 weeks) and again at 24 to 28 weeks of gestation.

SCREENING PROCEDURE

1. Patient Preparation:
Explain test purpose (to evaluate abnormal carbohydrate metabolism) and the procedure. No fasting is required. Test performed without regard to time of day or time of last meal. Patient should not eat, drink, or chew gum during the test. She may void if necessary.

2. Have patient ingest 50 gm of oral glucose (usually chilled glucola).

3. One hour after ingestion, measure patient’s serum glucose.

4. Patient aftercare: Normal activities, eating, and drinking may be resumed.

5. Normal Values: <> 140 mg/dL (nonfasting) / > 130 mg/dL (fasting) and <> 126 mg/dL are diagnostic of diabetes.

DIAGNOSIS PROCEDURE

1. Perform in the morning after a 10-16 hour fast.
Note: This is often done after a 3-day 150-gm carbohydrate/day diet.

2. Measure fasting serum glucose

3. Have patient ingest 100 gm of glucose orally within 5 minutes

4. Measure serum glucose hourly for 3 hours – Fasting, 1 hour, 2 hour, 3 hour

5. The patient should not smoke, drink coffee, or exercise during the testing process other than to walk around. If autonomic nervous system responses develop during testing (pallor, sweating, nausea, fainting, etc.), testing should be discontinued after a sample is taken. The test should be repeated at another time.

6. Normal venous glucose values:

Fasting <95 mg/dL
1 hour <180 mg/dL
2 hour <155 mg/dL
3 hour <140 mg/dL

7. If two or more of the four values are met or exceeded a diagnosis of gestational diabetes can be made.

8. If results are normal in a clinically suspicious situation, repeat during the third trimester.

REFERENCE

1. Fischback, T, Dunning, MB III. Manual of Laboratory Diagnostic Tests, LW & W, Philadelphia, PA, 7th Ed, 2003.

2. Star, Winifred. Ambulatory Obstetrics, Univ. of California San Francisco; 3rd Ed, 1999.

3. Tietz NW. Textbook of clinical Chemistry, 3rd Ed. WB Saunders. Philadelphia: 1815; 1999.

4. Wallace, J. Interpretation of Laboratory Tests, LW & W, Philadelphia, PA, 7th ed. 2000.

MICRO HEMATOCRIT

PRINCIPLE

The micro hematocrit represents the volume of circulating blood that is occupied by erythrocytes and is expressed as a percentage. The micro hematocrit test helps the medical provider identify patients at risk of developing anemia and manage patients who have anemia. Anemia is a less than normal number of erythrocytes in the volume of packed cells. The most common cause of anemia throughout the world is iron deficiency. A decrease in the micro hematocrit value results in a lack of energy, a reduced resistance to infections, and an increased risk of abnormality in pregnancy. An increased micro hematocrit value can result from polycythemia, hemoconcentration, and/or cardiac disease.

SUPPLIES AND EQUIPMENT

1. Equipment
High-speed centrifuge
Micro hematocrit tube reader
Timer

2. Materials/Reagents
Capillary tubes (heparinized) if finger stick specimens used
Capillary tubes (nonheparinized) if whole blood is used
Clay to seal tubes
Laboratory tissues
Gloves

3. Preparation– If room temperature EDTA blood is being used the blood should be placed on the blood rocker for 10-15 minutes to allow adequate mixing of the blood cells. If the blood was refrigerated, mix the tube for at least 20 minutes.

4. Performance Parameters–N/A

5. Storage Requirements–Store at room temperature.

SPECIMEN

1. Patient Preparation–N/A

2. Type–Free-flowing capillary or thoroughly mixed anticoagulated venous blood. EDTA is the anticoagulant of choice.

Finger Stick

Refer to detailed description of this technique in Specimen Collection Section.

1. Put on gloves
2. Wipe the finger with alcohol and allow it to dry.
3. Make a puncture wound with a sterile lancet.
4. Check that the patient’s hand is relaxed. Some patients will hold their hand open, but it will be tense. This will prevent blood flow to the small capillaries and will prevent sample collection. It may be necessary to shake the patient’s hand to make it loose.
5. Do not squeeze the finger excessively. This radically alters the relationship between the plasma and the RBCs and will therefore change the micro hematocrit.
6. Wipe away the first drop of blood with a gauze pad.
7. Hold the capillary tube to the puncture site, tilting it in a downward direction. This will allow the tubes to fill much faster.
8. Fill the capillary tube at least three-quarters full, and insert the end of the tube into the clay sealant. Either end of the tube can be put into the sealant, but using the clean end will keep the sealant surface clean. If the other end is used, it should be wiped with a gauze to clean off excess blood from the outer surface of the tube.
9. Repeat the above steps with a second capillary tube.

Heel Stick

Refer to detailed description of the infant heel-stick technique in Specimen Collection Section.

EDTA-Anticoagulated Blood Tube

An accurate micro hematocrit can be obtained using EDTA-anticoagulated blood for up to 24 hours after its collection as long as the sample has been refrigerated. If left at room temperature it is good for only 6 hours.

1. Examine anticoagulated specimens carefully for clots. If the blood has clotted, the test cannot be accurately performed. Blood should be mixed well and at room temperature.
2. Put on gloves.
3. Hold a 2x2 inch gauze around the stopper and gently remove the stopper from the tube. Try to avoid splashing blood.
4. Put the micro hematocrit capillary tubes into the purple-top tube and collect the blood sample. Hold the tube as close to horizontal as possible without spilling the blood. Blood should rise into the tube by capillary action. If this does not happen, tap the top of the capillary tubes several times to speed up the process.
5. Wipe the blood off the outside of the capillary tube with gauze.
6. Place the capillary tubes into the sealant after they are at least three-fourths filled with blood. The more blood in the tube the easier the result is to read and the more accurate is the result.

QUALITY CONTROL

Test is performed in duplicate and results must agree within 2.0%. If not, repeat test.

Paired studies–Run a patient’s blood and send the patient’s sample to a reference laboratory for a complete blood count. The automated hematology equipment calculates the micro hematocrit from the red cell size and the red cell number. This calculated micro hematocrit value would be about 3% less than the micro hematocrit. This is due to the 3% plasma trapping that occurs in even the ideal micro hematocrit technique.

Participation in a proficiency testing survey.

CALIBRATION

It is necessary to perform periodic calibration of the timer (with a stopwatch) and of the centrifuge speed (rotations per minute, RPM). Speed may be calibrated using a tachometer device. If such a device is not available, the performance of the centrifuge can be checked by determining the “constant packing time.” Fill and seal a micro hematocrit tube and take a reading after 2 minutes of centrifugation. Centrifuge again for an additional minute and take a reading. Repeat centrifugation for another minute until there is no change in readings. The results should be recorded. For scheduled cleaning and maintenance, follow the manufacturer’s directions.

PROCEDURE

STANDARD PRECAUTION: Patient specimens and all materials coming into contact with them should be handled as if capable of transmitting infections and disposed of with proper precautions. Gloves should be worn when handling all specimens.

1. Place both capillary tubes in the centrifuge across from each other. The sealed end should be on the outside, as the centrifugal forces press the cells toward the outside of the centrifuge.

2. Place the lid on the centrifuge head. Most centrifuges have a special spin-on head to prevent the capillary tubes from flying out of the head during the centrifugation.

3. Centrifuge the capillary tubes for 5 minutes at a minimum of 15,000 g.

4. Remove the capillary tubes after spinning has stopped. To read the micro hematocrit, place the tube at the right edge of the reader card (see Figure 1) with the top of the plasma line at the 100% mark. Slide the tube to the left until the top of the clay sealant is at the bottom line (0). Check that the top of the plasma is at the 100% line, the bottom of the red cell column is at the 0 line, and the capillary tube is parallel to the edge of the reading card.

5. Carefully find the point where the top of the red cell column crosses the line on the reader card. Do not include the gray buffy coat just above the red cell column as part of the reading. The identified line corresponds to the micro hematocrit value. It may be necessary to use a magnifying glass to accurately identify the top of the red cell column.

6. Repeat the reading process for the second capillary tube. The results should agree within two percentage points. The reported value is the average of those values. If the two values differ by greater than 3 points, the entire procedure should be repeated.

INTERPRETATION

Examination of the micro hematocrit:


· Top of tube – fatty layer and normally barely visible. With lipemia, the layer is several mm thick.
· Second layer is plasma – pale yellow and fairly clear. Excessive hemolysis results in reddish color, and can lower the micro hematocrit. A new specimen should be obtained. Jaundice results in a yellow color.
· Third layer is buffy coat – 0.5 to 1.0 mm thick. If WBC count is over 10,000/cu mm, the layer is usually over 1 mm thick. Packed platelets are found in upper part of the layer and WBC in the lower part.
· Fourth layer is packed red cells – read as the micro hematocrit. A consistent technique for the micro hematocrit should produce a test-to-test variation of only + 2 percent. The largest source of error is the variation between readers in the reading step of the procedure.



FIGURE 1.


CALCULATIONS – N/A

REPORTING

Normal Values
The reference intervals based on Texas Department of Health (TDH) values are:

40-54% males
38-47% females
44-64% newborns
35-49% 14-90 days
30-40% 6 months – 1 year
31-43% 1 year – 10years

PROCEDURE NOTES

1. When collecting the fingertip blood, care should be taken not to squeeze the finger so as to contaminate the collection with tissue juice. This will decrease the micro hematocrit.

2. Capillary tubes should be centrifuged at 15,000g. A decreased centrifuged force will trap plasma between the RBC and cannot be corrected by increasing time. Inadequate centrifugation has stopped, will give falsely elevated readings. The time and speed of centrifugation, therefore, are extremely important in order to obtain maximal red cell packing.

3. An office laboratory may be 3% higher than the calculated hematocrit obtained from a reference laboratory. This is because of the small volume of plasma that is trapped between the red cells during the packing procedure.

4. Air bubbles that occur when filling the micro hematocrit tubes will not affect the final value because the bubbles will be expelled by the red cells as they migrate during the centrifugation process.

5. The microhematocrit is greatly affected by abnormally shaped cells because such cells trap plasma and artificially elevate the value of the micro hematocrit. Patients with distorted cells such as in sickle cell disease should therefore be followed by hemoglobin levels rather than microhematocrit values.

6. A good relationship to keep in mind is that the micro hematocrit is usually three times the value of the hemoglobin value. Another way to describe this relationship is that 1 hematocrit point is equivalent to 0.34 g Hb/dL.

SOURCES OF ERROR

Falsely Low Values

1. Improper reading of the micro hematocrit value from the reader chart
2. Inadequate mixing of an EDTA-anticoagulated tube and drawing of the specimen from the plasma-rich area at the top of the tube
3. Inadequately filling an EDTA tube with blood so that the anticoagulant over dilutes the blood sample
4. Reading the micro hematocrit a long period after the sample has been spun

Falsely High Values

1. Incorrect reading of the micro hematocrit from the reader chart
2. Inclusion of the buffy coat in the reading of the red cell column
3. Inadequate mixing of an EDTA-anticoagulated tube and drawing of the specimen from the cell-rich area at the bottom of the tube
4. Inadequate centrifuge speed or time, resulting in less than maximal packing of the red blood cells
5. Increased plasma trapping because of unusually shaped cells (e.g., macrocytes, sickle cells, poikilocytosis). This can result in as great an increase as 20 percent in extreme cases, such as sickled cells.
6. The use of EDTA-anticoagulated blood that has been stored for greater than 24 hours

REFERENCES

1. Clinical Diagnostics & Management, 18th Ed., Mar 1995, Pg. 583 by J.B. Henry, M.D.

2. Laboratory Test Handbook, 3rd Ed. With Key Word index, 1994, Pg. 578, 581, and 582-583 by Jacobs, Demott, Finley, Horvatm Kasten, Tilzer

3. National Committee for Clinical Laboratory Standards (NCCLS), Physician’s Office Laboratory Guidelines, 2nd ed. Document POL1-T2. Villanova, PA: June, 1995

Diagnostic Procedures for Stool Specimens

Microscopic Examination


Calibration of Microscopes Using an Ocular Micrometer:

A correctly calibrated microscope is crucial because size is an important characteristic for identification of parasites. This section assumes that an ocular micrometer disk has been installed in one of the oculars and that a stage micrometer is available for calibrating the ocular micrometer. This calibration should be done for each of the microscope's objectives.

Place the stage micrometer on the microscope stage and focus on the micrometer scale, until you can distinguish between the large (0.1 mm) and the small (0.01 mm) divisions of the scale. Adjust the stage micrometer so that the "0" line on the ocular micrometer is superimposed with the "0" line on the stage micrometer. Without changing the stage adjustment, find a point as distant as possible from the two superimposed "0" lines where two other lines are also exactly superimposed. Determine the number of ocular micrometer spaces, as well as the number of millimeters on the stage micrometer, between the two points of superimposition.

For example: Suppose 48 ocular micrometer spaces (units) equal 0.6 mm. Calculate the number of mm/ocular micrometer space.

0.6 mm × 48 ocular micrometer spaces = 0.0125 mm/ocular micrometer space

Since most measurements of microorganisms are given in µm rather than mm, the value calculated above must be converted to µm by multiplying it by 1000 µm/mm.

For example:
0.125 mm ocular space × 1000 µm/mm = 12.5 µm/ocular micrometer space

Thus in this case, 1 ocular micrometer space (unit) is the equivalent of 12.5 µm.

Follow the above steps for each objective. Calibration readings should be posted on each microscope and the microscope should be recalibrated after every cleaning or changing of objectives or oculars.


Before preparing a wet mount slide, the microscope should be calibrated. The objectives and oculars used for the calibration procedure should be used for all measurements on the microscope. The calibration factors should always be posted on the side of the microscope.

Protozoan trophozoites, cysts, oocysts, and helminth eggs and larvae may be seen and identified using a wet mount identification technique. To prepare a wet mount, obtain a microscope slide and the stool specimen. Take a small amount of the specimen and place it on a microscope slide. If the stool specimen is still somewhat solid, add a drop or two of saline to the specimen and mix. Ideally, two smears can be prepared on one slide, of which one can be stained with iodine. Thickness of the wet mount should be as the image below illustrates.
If desired the coverslip(s) can be sealed. A preparation of petroleum jelly and paraffin in a 1:1 ratio can be applied with a cotton tip swab as illustrated. It must be heated to approximately 70°C to both mix and use. Sealing the coverslip keeps organisms from moving when using oil immersion objectives and prevents the preparation from drying out. To seal, secure the four corners by placing a drop of hot sealant to anchor the coverslip. Spread a thin layer around the edges. Other suitable sealing preparations can be used if desired.

Systematically scan the entire coverslip area using the 10× objective as illustrated. If something suspicious is seen, a higher magnification may be necessary.
CAUTION: Bringing high power objectives too near the edge of the slide will result in the sealant smearing the objective and interfering with the optors.
Permanent stained slides are used for identification of protozoan trophozoites and cysts and for confirmation of species. It also permits consultation reference and diagnosis when needed as well as providing a permanent record of organism(s) observed. The microscope should be calibrated before examination begins. Positive microscope slides as well as reference material (plates, photographs, digital images) should be available by the workstation to compare morphological details and organisms. Refer to the staining section of stools for additional information regarding which stains to use.
Normally 3 × 1 slides are used to prepare permanent stained slides. If the specimen is unpreserved, prepare a thin, even smear of the material by streaking the material back and forth on the slide with an applicator stick. If necessary dilute feces with saline. For PVA fixed specimens, apply two or three drops of the specimen to the slide and with a rolling motion or an up and down dabbing motion spread the specimen evenly to cover an area roughly the size of a 22 by 22 mm coverslip. For other fixatives, check manufacturers instructions.
After the staining process is complete, systematically examine the smear microscopically utilizing the 100× oil objective. Examine at least 200 to 300 oil immersion fields. Report protozoa seen as either trophozoites and/or cysts as applicable.
The demonstration of Cyclospora oocysts in wet preparations is greatly enhanced by using UV fluorescence microscopy. Despite the age of the specimen or sample, Cyclospora oocysts exhibit intense blue color when observed under a fluorescence microscope (UV excitation filter set at 330-365 nm). If this filter set is not available, a less intense green fluorescence can be obtained with blue excitation (450-490 nm). Under bright-field (differential interference contrast or DIC) microscopy, Cyclospora oocysts appear as refractile spheres (8-10 µm) with a distinct oocyst wall. The utilization of both bright-field (DIC) and fluorescence microscopy provides an efficient and reliable approach to diagnosis. However, it does not provide a permanent stained slide that can be archived.

CHEMSTRIP 10SG CHEMICAL ANALYSIS OF URINE



PRINCIPLE

The chemical analysis of urine is a vital part of the routine urinalysis. The Chemstrip 10SG urine test strips are inert plastic strips to which are attached different chemically impregnated test sites on an absorbent pad for determining specific gravity, pH, leukocytes, nitrite, protein, glucose, ketones, urobilinogen, bilirubin, and blood/hemoglobin in urine. Refer to the package insert for the specific test principles and parameters. When the dry reagents come in contact with urine or a suitable control solution, the reagents are activated and a chemical reaction occurs. The chemical reaction is a specific color change. This is observed visually and compared with a special color chart provided by the manufacturer. The intensity of the color formed is generally proportional to the amount of substance present in the specimen at a specific time. Some tests are used as screening tests (presence or absence) while others are used to estimate (semiquantitate) the amount of substance present and reported in a plus system or in numerical values.

SPECIMEN

Fresh, uncentrifuged, well mixed urine or QC solutions at room temperature.

1. Patient Preparation—N/A

2. Type
Random specimens
First morning void – most concentrated
Timed specimens (such as complete 24-hour collections
Double-voided specimens
Midstream-voided specimens (used for routine urinalysis)
Clean-catch midstream – specimen of choice
Catheterized urine – performed when the patient has dysuria or is incontinent.

The patient should receive oral and detailed written instructions for the desired urine collection technique. See urine specimen collection procedure.

3. Handling Conditions—Specimens should be tested within one hour of collection or immediately refrigerated at 2-8oC.

4. Rejection criteria for samples
Specimens without acceptable labels.
Discrepant information on labels and requisitions.
Insufficient quantity for test requested (1mL or less)
Grossly contaminated (i.e. foreign materials, fecal matter) are to be rejected for testing.

EQUIPMENT AND MATERIALS

1. Equipment
Timer

2. Materials
Chemstrip 10SG dipsticks

3. Preparation—If this is the first specimen of the day, perform QUALITY CONTROL.

4. Performance Parameters—N/A

5. Storage Requirements
· The Chemstrip 10SG dipsticks must be kept in tightly capped or stoppered containers. Strips will deteriorate when exposed to moisture, direct sunlight, heat, or volatile substances.
· Do not remove the desiccant from the container. Store at room temperature.
· Remove only the number of strips needed at a time, and keep the container tightly closed at all times. Do not touch test areas.

CALIBRATION – N/A

QUALITY CONTROL

Quality control testing with 2 levels of liquid control material (Bio Rad Liquichek level 1 & 2 Controls) should be conducted prior to daily testing. Distilled water may be used as a negative control. The control system is used to determine accuracy and precision in the measurement of the physical and chemical tests commonly employed in semiquantitative urine testing. Quality control results must be recorded and available for reference.

1. If the product has been refrigerated, warm one vial of each level of control to room temperature, 18o-30oC (15-30 minutes). Verify that the lot number indicated on each control bottle matches the assay sheet enclosed.

2. Remove the dropper tip cap. Holding the dipstick reagent strip in one hand, invert the control bottle and apply control material directly across each pad by gently squeezing the bottle.

3. Remove excess control by tilting the dipstick on its edge and blotting on an absorbent towel.

4. If reading the results visually, follow the manufacturer’s instructions completely, comparing the color reactions at the designated times to the appropriate strip area.

5. Wipe the tip of the control bottle and recap.

6. Control stability—The Bio Rad control is stable after opening for 31 days at room temperature. When refrigerated, the product is stable until it’s expiration date. Freeze aliquots of each control before the expiration date for use after the material has expired.

7. Record the reaction of each test on the appropriate quality control chart.

Proficiency Testing: Successful participation in the USDOS PT Program.

PROCEDURE

1. Test fresh, well-mixed, uncentrifuged urine.

2. Remove one reagent strip. Recap the bottle promptly. Briefly (no longer than 1 second) dip test strip into the urine. Ensure that the chemically impregnated patches on the test strip are totally immersed.

3. Draw the edge of the strip over the rim of the specimen container to remove excess urine.

4. Turn the test strip on its side and tap once on a piece of absorbent paper to remove any remaining urine, and to prevent the possible mixing of chemicals.

5. After the appropriate time read the test as follows: hold strip close to color blocks and match carefully, ensuring that the strip is properly oriented to the color chart on the vial label.


Specific Gravity 60 sec Glucose 60 sec
pH Immediate Ketones 60 sec
Leukocytes 60-120 sec Urobilinogen 10-30 sec
Nitrite 30 sec Bilirubin 30-60 sec
Protein 30-60 sec Blood 60 sec

For convenience, all values on the strip may be read between 1 and 2 minutes after immersion in the urine. The colors are stable up to 120 seconds after immersion in the urine. Color changes that occur after 2 minutes from immersion are not of clinical value. Color changes that occur only along the edge of the test area should be ignored.

CALCULATIONS – N/A

REPORTING RESULTS

1. Reference Ranges—Normal Urine Values

Glucose Negative
Bilirubin Negative
Ketones Negative
Specific Gravity 1.010-1.025
Blood Negative
PH 4.5-8.0
Protein Negative-Trace
Urobilinogen 1EU/dL or less
Nitrite Negative
Leukocyte Negative

2. Procedures for Abnormal Results

If any of the above tests fail to fall within the acceptable normal ranges, they must have the appropriate confirmatory tests performed and recorded on the result slip prior to reporting results.

Chemistrip Dipstick Test Confirmatory Test

Glucose Clinitest
Bilirubin Ictotest
Ketones Acetest*
Specific Gravity Refractometer
Blood Microscopic
pH pH
Protein SSA
Urobilinogen None
Nitrite Microscopic
Leukocytes Microscopic

LIMITATIONS

The limitations including interfering substances for each reagent are shown below.

1. Specific Gravity—Results may vary between urine concentration measuring methodologies due to their differing principles and limitations. Urines above 1.025 are not reliably measured with correct relative ionic concentration methodology. Test samples with results above 1.025 should be retested with a refractometer. The chemical principle of this test may also cause slightly different results compared with other urine concentration measuring methods when elevated amounts of certain urine constituents are present. Glucose and urea concentrations greater than 1% may cause a low specific gravity reading relative to other methods. In the presence of moderate amounts of protein (100-500 mg/dL) or ketoacidosis, readings tend to be elevated.

2. pH Test—No known interference’s when handled according to instructions

3. Leukocytes Test—Test is not affected by erythrocytes in concentration up to 10,000/ul or by bacteria common in urine. Specimens should not be collected in containers that have been cleaned with strong oxidizing agents. Do not use preservatives. The drugs cephalexin and gentamicin have been found to interfere with this test. In addition nitrofurantoin colors the urine and this effect interferes with visual interpretation of the test strip. High levels of albumin (> 500 mg/dL) in the urine may interfere with the test results.

4. Nitrite Test—Large amounts of ascorbic acid decrease the sensitivity of the test. False-positive readings may be produced by medication that colors the urine red or which turns red in an acid medium (e.g. phenazopyridine)

5. Protein Test—False-positive results may be found:
· In strongly basic urine (pH 9 or higher)
· During therapy with phenazopyridine
· When infusions of polyvinylpyrrolidone (blood substitutes) are administered
· When residues of disinfectants containing quaternary ammonium groups or chlorohexidine are present in the urine container

6. Glucose Test—The effect of ascorbic acid (vitamin C) retained in the urine due to ingestion of vitamin tablets, antibiotics or fruit juices has been eliminated at glucose concentrations of 100 mg/dL and above so that false-negative readings may only rarely occur, even at high concentration of ascorbic acid. False-positive readings may be produced by strong oxidizing cleaning agents in the urine container.

7. Ketone Test—Red-orange to red color shades, which are, however readily distinguishable form the colors obtained with ketone bodies can be produced by phenylketone or phthalein compounds that be administered for liver and kidney function tests. Mercaptoethane sulphonate sodium or other sulfhydryl containing compounds may cause false-positives.

8. Urobilinogen Test—The total absence of urobilinogen cannot be detected. Most normal urines give a slight pink reaction. The test gives the same color reaction with urobilinogen as with stercobilinogen; however, the differentiation is not of diagnostic importance. Urine treated with phenazopyridine may show a false-positive reaction. Nitrite concentrations above 5 mg/dl or formalin concentrations above 200 mg/dL (as preservative) may cause a decrease in the color reaction.

9. Bilirubin Test—Large amounts of ascorbic acid present in the urine following the ingestion of vitamin C or fruit juices lower the sensitivity of the test. In case of doubt, the test should be repeated on the urine voided at least 10 hours after the last administration of vitamin C. Elevated concentrations of nitrite, as in urinary tract infections, may result in lower bilirubin values. Large amounts of urobilinogen in the urine affect the color change of the bilirubin test, but not enough to give a positive result. False-positives readings may be produced by medication that colors the urine red, or which turns red in acid medium.

10. Blood Test—False-negative readings are obtained when formalin is used to preserve the urine. Nitrite in excess of 10 mg/dL in the urine (which is rare in urinary tract infections) delays the reaction. False-positive results can be produced by residues of strongly oxidizing cleaning agents in the urine container. Urine from menstruating females will occasionally yield a positive result. This test has not been found to be affected by the ingestion of reasonable quantities of ascorbic acid.

REFERENCES

1. Clinical Diagnosis and Management by Laboratory Methods, 18th ed., 1995, pg. 431-432, by J.B. Henry.

2. Chemstrip 10SG by ROCHE package insert.

3. Urinalysis and Body Fluids, 1995, by Karen Munson Ringsrud and Jean Jorgenson Linne.

Trichomonas vaginalis / Wet prep test



Trikomoniasis dan Penatalaksanaannya

AM Adam, Hardy Suwita
SMF Kulit dan Kelamin RSUD Lambuang Baji, Makassar

Trikomoniasis adalah infeksi Trichomonas vaginalis yang merupakan protozoa patogen pada saluran genito-urinaria manusia. Berbagai macam gejala klinis dapat ditemukan baik pada wanita maupun pria dan diagnosis pasti adalah dengan menemukan organisme ini. Hingga saat ini metronidasol masih merupakan obat pilihan untuk trikomoniasis.

ETIOLOGI Trikomonas adalah suatu organisme eukaryotik yang termasuk kelompokmastigophora, mempunyai flagel, dengan ordo trichomonadida. Terdapat lebih dari 100 spesies, sebagian besar trichomonas merupakan organisme komensal pada usus mamalia dan burung. Terdapat 3 spesies yang sering ditemukan pada manusia yaitu Trichomonas vaginalis yang merupakan parasit pada saluran genitourianaria, Trichomonas tenax dan Pentatrichomonas hominis merupa-kan trichomonas non patogen yang ditemukan di rongga mulut untuk Trichomonas tenax dan usus besar untuk Pentatrichomonas
hominis .

Nama Trichomonas vaginalis sebenarnya salah, karena juga ditemukan di uretra wanita dan tidak jarang ditemukan di uretra pria.

Organisme ini berbentuk oval atau fusiformi, atau seperti buah pir dengan panjang rata-rata 15 mm dengan tanda khas selalu berpindah tempat. Intinya terletak anterior, antara inti dan permukaan ujung yang lebih luas terdapat 1 atau lebih struktur yang membulat yang disebut blepharoplasts dan dari tempat inilah keluar keempat flagel. Flagel kelima berbentuk membran bergelombang yang berasal dari kompleks kinetosomal dan terbentang sepanjang setengah dari organisme ini

Pergerakannya dengan kedutan yang didorong oleh keempat flagel anterior, kecepatan dan aktivitas hentakannya yang khas menyebabkan organisme ini mudah diidentifikasi pada sediaan segar.

Trichomonas vaginalis tumbuh di lingkungan yang basah dengan suhu 35-37º C dengan pH antara 4,9-7,5

Trichomonas vaginalis tidak menyerang jaringan di sebelah bawah dinding vagina, ia hanya ada di rongga vagina; sangat jarang ditemui di tempat lain. Lingkungan vagina sangat disukai oleh organisme ini

Trichomonas vaginalis dapat menimbulkan reaksi radang pada rongga vagina yang didominasi oleh sel lekosit polymorphonuclear (PMN). Trichomonas vaginalis dan ekstraknya dapat merangsang kemotaktik sel lekosit PMN, yang mungkin mempengaruhi perkembangan gejalanya.

Mekanisme lengkap penghancuran sel epitel vagina yang diserang oleh Trichomonas vaginalis belum diketahui dengan pasti.

Pria yang mengandung Trichomonas vaginalis sebagian besar asimtomatik dan respon radang pada uretra pria biasanya tidak ditemukan. Hal ini berhubungan dengan epitel kuboid pada uretra. Trichomonas vaginalis dapat menginfeksi epitel skuamosa pada vagina tetapi hanya yang rentan saja.

Cara menghilangkan Trichomonas vaginalis dari saluran urogenital pria belum diketahui pasti, tetapi mungkin organisme hilang secara mekanik pada waktu buang air kecil dan adanya seng di dalam cairan normal prostat dapat dengan cepat membunuh trichomonas

PENULARAN
Trichomonas vaginalis menular melalui hubungan seksual meskipun masih diperdebatkan

Trichomonas vaginalis dapat hidup pada obyek yang basah selama 45 menit pada kloset duduk, kain lap pencuci badan, baju, air mandi dan cairan tubuh

Penularan perinatal terjadi kira-kira 5% dari ibu yang terinfeksi tetapi biasanya sembuh sendiri dengan metabolisme yang progresif dari hormon ibu

Infeksi Trichomonas vaginalis mempunyai masa inkubasi selama 4-21 hari

LABORATORIUM
Pemeriksaan mikroskop secara langsung
Dengan sediaan basah dapat ditemukan protozoa dengan 4-5 flagel dan ukuran 10-20 µm yang motil

Pada wanita metode ini mempunyai sensitifitas 50- 70% dan spesimen harus diambil dari vagina karena agen penyebab hanya menyerang epitel skuamosa

Pada pria cara penemuan Trichomonas vaginalis tidak selalu berhasil dan Trichomonas vaginalis dapat dideteksi dengan menggunakan sedimen urin

Cara lain menggunakan pewarnaan Gram, Giemsa, Papa-nicolaou, Periodic acid schiff, Acridine orange, Fluorescein, Neutral red dan Imunoperoxidase

Kultur
Teknik kultur menggunakan berbagai cairan dan media semi solid yang merupakan baku emas untuk diagnosis Biasanya dengan menggunakan medium Feinberg-Whittington memberikan hasil yang dapat dipercaya
Teknik kultur ini mempunyai sensitifitas kira-kira 97%

Metode serologi
Beberapa studi mengatakan bahwa uji serologis kurang sensitif daripada kultur atau pemeriksaan sediaan basah
Pada metode serologi ini dapat digunakan teknik ELISA, tes latex agglutination yang menggunakan antibodi poliklonal
Antigen detection immunoassay yang menggunakan antibodi
monoklonal dan nucleic acid base test

http://www.kalbe.co.id


Article in English:

Purpose: Definitive diagnosis of Trichomonas vaginalis in genital secretions because clinical symptoms and signs or cellular charateristics of the exudate are not reliable evidence of trichomonal infections in either sex.

Equipment and Materials required:
Light microscope
microscope slides and cover slip
0.85% Saline, isotonic

Quality Control:

Specimen Collection and Handling: Specimens are collected by the health care practitioner. Follow Universal Precautions

1. Using a sterile swab , collect vaginal or, prostatic fluid, urethral discharges or centrifuge a fresh urine sample from either sex.
2. Specimen is mixed with a drop of isotonic saline solution. Cover slip the mixture.
3. Transport slide directly to the laboratory for examination.

Reporting:
1. Examine the slide microscopically using the 10 x objective for scanning and the 40 or 45 objective for confirmation and count estimation.
2. Trophozoites of T. Vaginalis may be incredibly numerous or only a few may be found. Motile and non-motile flagellates may be present, resembling small WBCs and epithelial debris.
3. Organisms are large, 15 to 18.5 by 5-15 um., pyriform, flagellate exhibiting rapid and jerky motility ( in fresh samples only). The wave-like motion of the undulating membrane is often apparent. There is not cyst stage of this parasite.
4. Report as follows:
*Presence of T. vaginalis, crystals and yeast as : Observe several fields under high power (400X) Report the presence as: Rare or Occasional or Many

*WBC, RBC, Epithelial cells, Renal cells – report lowest to the highest number of each element found as range/ HPF. Example: WBC 0-5/HPF

*Casts- observe several fields under low power (100X) report the lowest to highest number of each type of case found as range /LPF, Example: Granular cast 0-5/LPF

Reference:
1.Current Medial Diagnosis & Treatment ,1997
2. Saunders Manual of Clinical Laboratory Science, Lehmann, 1998