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Path 16
Laboratory Data
| Question | Answer |
|---|---|
| How is a reference interval defined | by limiting values within which a specified percentage (usually 95%) of apparently healthy intividuals' test results would fall |
| What is the parametric approach to determining reference intervals | the central 95% bounds are specified by the mean +/- 2 standard deviations |
| what is the non-parametric approach to determining reference intervals | central 95% bounds are determined by trimming off the lowest and highest 2.5% of observations |
| How can we reduce between person variation | make the reference group more homogeneous or by making serial measurements on each individual and letting them serve as their own control |
| What percent of healthy individuals would be expected to have "abnormal" results on any given test after 1 test | 5% |
| What is an accurate definition of fasting | 12-14 hours is the optimal time |
| True or False? In a healthy person plasma volume decreases by >4% with the change from lying to standing | false. In a healthy person it decreases by about 12% |
| Ideally all blood samples should be collected after a patient has been in the supine position for ? minutes | 60 |
| Where should you take the blood specimen from an arm with an IV | You should not take blood samples from arms with IVs |
| What are some causes of hemolysis in blood samples | 1) excessive suction 2) Rapid expulsion 3) Shaking |
| What can be seen when there is prolonged use of a tourniquet | increased number of plasma constituents |
| How soon after collection must urine samples for microbiological studies be cultured | within 1 hour |