MLPAO MLPAO Medical Laboratory Calculations 2

Question 1

A patient's serum creatinine is 132 μmol/L. Convert this value to mg/dL. (Molecular weight of creatinine = 113.12 g/mol)

Accepted Answer

1.49 mg/dL

Answer

1.32 mg/dL

Answer

0.13 mg/dL

Answer

13.2 mg/dL

Question 2

A Levey-Jennings chart shows five consecutive QC values all falling above the mean on the same side. Which Westgard rule is violated?

Accepted Answer

10x rule

Answer

2s rule

Answer

R4s rule

Answer

1₃s rule

Question 3

You are preparing a working solution of NaCl at 0.9% (w/v). How many grams of NaCl are needed to prepare 500 mL of this solution?

Accepted Answer

4.5 g

Answer

9.0 g

Answer

0.9 g

Answer

45.0 g

Question 4

A urine microscopy report shows 15–20 RBCs per high-power field (HPF). This finding is best described as:

Accepted Answer

Microscopic hematuria

Answer

Gross hematuria

Answer

Normal finding

Answer

Pseudohematuria

Question 5

A laboratory receives a hemolyzed specimen for potassium analysis. The measured potassium is 6.8 mmol/L. What is the most appropriate course of action?

Accepted Answer

Reject the specimen, document hemolysis, and request a recollection

Answer

Report the result with a delta check notation

Answer

Dilute the specimen 1:2 and multiply the result by 2

Answer

Accept the result as potassium is stable in hemolyzed samples

Question 6

Using the formula: Clearance (mL/min) = (U × V) / P, where U = urine creatinine (8,800 μmol/L), V = urine volume per minute (1.0 mL/min), and P = plasma creatinine (88 μmol/L), calculate the creatinine clearance.

Accepted Answer

100 mL/min

Answer

88 mL/min

Answer

1000 mL/min

Answer

8.8 mL/min

Question 7

A technologist needs to dilute a patient sample that has a potassium result of 9.2 mmol/L (above linearity). After a 1:2 dilution with saline, the re-measured result is 4.8 mmol/L. What is the corrected patient potassium?

Accepted Answer

9.6 mmol/L

Answer

4.8 mmol/L

Answer

2.4 mmol/L

Answer

7.2 mmol/L