Post on 04-Jan-2016
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Chapter 46
Specimen Collection and Processing
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Urine Specimen
• First morning • Midstream clean-catch • 24-hour• Pediatric collection• Urinary catheterization
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Chain of Custody
• Collection of urine specimen for substance abuse analysis
• Detects the presence of illegal drugs and chemical substances
• Chain of custody forms must be filled out and procedure followed
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Pregnancy Testing
• Measures the amount of human chorionic gonadotropin (hCG) in urine or blood
• Most commonly performed on urine at home and in the POL
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Urinalysis
• Three components– Physical– Chemical– Microscopic
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Physical Urinalysis
• Color• Clarity• Volume• Odor
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Chemical Urinalysis
• Analyze specimen as soon as possible after collection
• Reagent strips provide qualitative and quantitative assessments
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Chemical Urinalysis
• Strips are compared to known values on the bottle for reporting
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Normal and Abnormal Values
• pH • Protein• Ketone• Bilirubin• Urobilinogen
• Hematuria• Nitrite• Leukocyte esterase• Glucose• Specific gravity
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Microscopic Examination
• MAs may prepare the slide for the provider to view and report results– Centrifuge urine tubes– Pour off supernatant– Collect sediment and place on slide
• The MA does not read or interpret results of microscopic urine specimen
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Fecal Specimen
• Used to check for occult blood, ova and parasites, bacterial and viral infections
• Stool specimen are difficult for patients to collect properly
• Instruct patients to obtain specimen at home and bring to lab for testing
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Fecal Specimen
• Occult blood specimen– Common screening tools for early detection of
colon cancer– Test uses a guaiac reagent
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Bacterial Specimen
• Bacteria, viruses, and fungi are extracted from specimen for identification, to determine the appropriate treatment
• Culture is taken from the part of the body that is infected– Collected in a culturette
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Bacterial Specimen
• Culture sites– Throat– Mouth– Ear– Eye
– Nose– Vagina– Anus– Infected Wounds
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Throat Culture
• Taken from patients complaining of sore throat, fever, swollen glands, and cough
• Rapid Group A strep kits provide results in minutes
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Blood Cultures
• Blood is drawn from patient directly into a particular formulated broth in a vacuum bottle
• When a blood culture is positive, this indicates a systemic infection and requires immediate attention
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Culture and Sensitivity
• Specimen is collected and inoculated in special media (agar) to encourage growth of microorganisms
• Sensitivity tests the organism against different types of antibiotics
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Culture and Sensitivity
• Media comes in petri dishes, tubes, and broths– Primary media encourages the growth of all
microorganisms– Selective media discourages the growth of certain
microorganisms
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Gram Staining and Microbiologic Smears
• Used to help identify a bacterial specimen• Bacteria specimen are sorted into two groups
– Gram positive• Dark blue to violet after staining
– Gram negative• Red or pink after staining• More dangerous connotation than Gram positive
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Morphologic Shapes
• Three basic shapes– Coccus– Bacillus– Spiral
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Morphologic Shapes
• Gram positive cocci in clusters– Staphylocci
• Gram positive cocci in chains– Streptococci
• Gram negative cocci in pairs– Neiserria gonorroeae
• Gram negative bacilli– Escherichia coli