Specimen Collection and Handling Flashcards
Used to preserve CSF samples
Fluoride oxalate
Withdraw needle if ____, _____, and _____.
Patient is experiencing excruciating pain
Hematoma begins to form
Patient begins to faint
Why should testing of CSF not be delayed?
Cells are rapidly lysed
Glucose is rapidly destroyed
CSF clots completely when
Spine is constricted
Tests affected by age
Cholesterol
Urate
Alkaline phosphatase
Pre-analytical factors
Physiological variables
Errors in specimen collection
Misidentification of samples
Post-analytical factors
Communication
Technical errors
Post-examination labeling and identification
Key issues in specimen collection
Consider differential diagnoses
Decide on tests to be conducted
Decide n clinical samples to be collected
Set the standards of practice
Clinical and Laboratory Standards Institute
Serum sample
Venous blood
Temperature and time for clot retraction
4-8 C
At least 1-2 hours
Purpose of collecting 24-hour urine specimen
Evaluation of kidney function
Why should repeated freeze-thaw cycles be avoided?
This causes destruction of IgM.
Screens substances which are indicators of kidney infection or other pathology
Random urine specimen
How do we avoid hemolysis of blood?
Do not freeze unseparated blood.
Content of case investigation forms
Patient information
Clinical information
Laboratory information
Line listing
Tests affected by food intake
Glucose
Triglycerides
Phosphate
Temperature requirement if serum sample is stored for weeks or months
-20 C
Characteristic of purulent meningitis
Large clots
Test tubes of fresh blood should be
Rinsed in cold water
Left to soak in detergent solution
Tests affected by stress
Cortisol Prolactin Growth hormone Catecholamines Glucose
Laboratory investigation standards
Advance planning Collection of adequate and appropriate specimens Sufficient documentation Biosafety and decontamination Correct packaging Rapid transport Choice of laboratory that can accurately perform the tests Timely communication of results
Test tubes of old blood should be
Filled with 10% solution of household bleach
Left for 12 hours
Rinsed and cleaned
Affect triglycerides
Body mass
Most concentrated sample for urine
Early morning urine specimen
Temperature requirement for transport that lasts less than 10 days
4-8 C
Test tubes of old blood kept for several days may contain
Microorganisms
Effusion collection sites
Pleural cavity Peritoneal cavity Pericardial cavity Synovial joint Bursa
Characteristic of tuberculous meningitis
Single or numerous fine clots
Cerebrospinal fluid collection
Lumbar puncture
Sterile tubes
Aseptic conditions
Trained person
Patient Observations
Patient alertness Patient emotional and mental status IV lines Injuries Prior mastectomy Presence of edema Medications
Tests affected by posture
Renin
Aldosterone
Plasma proteins
Inherent on the methods of analysis
Analytical factors
Tests affected by time
Cortisol (diurnal variation)
Gonadotrophins (catamenial variation in women)
25-hydroxycholecalciferol (seasonal variation)
Tests affected by sex
Gonadal steroids
Gonadotrophins
HDL cholesterol
