03/09h Lab Tools of Evidence-Based Medicine II Flashcards
What is turnaround time?
The time interval between ordering a test (OR receiving a sample) and receiving/posting results
Varies based on the test, of course
Short - 10-15 minutes
Long - weeks to months
What are the three types of errors in laboratory data?
1) Pre-analytical
2) Analytical
3) Post-analytical
What are pre-analytical errors? What are some examples?
Errors and variables in the pre-laboratory analysis stage that can affect test results
Examples - patient variables, specimen collection techniques, sample identification, and specimen transport to the lab
What are some patient variables that can impact pre-analytical errors?
Age Sex Diet and exercise Tobacco smoking Stress Posture
What is the number one pre-analytical error in the emergency department?
MISIDENTIFICATION of the patient or MISLABELING or a specimen!
What are some examples of blood collection-associated pre-analytical errors?
Hemolysis cause by a too-small needle or traumatic venipuncture
Hemoconcentration caused by an improperly-applied tourniquet
Collecting different samples in the wrong tubes, or collecting tubes in the wrong order
What types of samples require special post-collection handling?
Platelets - do not put in pneumatic tubes
Blood gas - place in ice water or coolant
Bilirubin level - protect from UV light
What are analytical errors?
Errors that occur in the lab - can occur during specimen processing, reagent storage or use, or performance of the test itself (instrumentation)
What are some possible post-analytical errors?
Lack of verification of lab results
Errors in manual transcription of lab results
Excessive turnaround time
Delays in clinician receipt, reading, and interpretation
What is a pre-pre-analytical error?
Ordering the wrong test or failing to order the right test
What is a post-post-analytical error?
Error in interpreting reported results properly
