7.5 Urinalysis and Body Fluids Problem-Solving

Question 1

Given the following dry reagent strip urinalysis results, select the most appropriate course of action:

Answer 1

Perform a turbidimetric protein test, instead of the dipstick protein test, and report

Question 2

Given the following urinalysis results, select the most appropriate course of action:

Answer 2

No indication of error is present; results indicate a UTI

Question 3

SITUATION: A 6-mL pediatric urine sample is processed for routine urinalysis in the usual manner. The sediment is prepared by centrifuging all of the urine remaining after performing the biochemical tests. The following results are obtained:

Select the most appropriate course of action.

Answer 3

Report biochemical results only; request a new sample for the microscopic examination

Question 4

Given the following urinalysis results, select the most appropriate course of action:

Answer 4

Recheck urine pH

Question 5

Given the following urinalysis results, select the most appropriate first course of action:

Answer 5

Repeat the dry reagent strip test for bilirubin

Question 6

A biochemical profile gives the following results:

Creatinine = 1.4 mg/dL
BUN = 35 mg/dL
K = 5.5 mmol/L

All other results are normal, and all tests are in control. Urine from the patient has an osmolality of 975 mOsm/kg. Select the most appropriate course of action.

Answer 6

Report these results

Question 7

A 2 p.m. urinalysis shows trace glucose on the dry reagent strip test. Fasting blood glucose drawn 8 hours earlier is 100 mg/dL. No other results are abnormal. Select the most appropriate course of action.

Answer 7

Repeat the urine glucose, and report if positive

Question 8

Following a transfusion reaction, urine from a patient gives positive test results for blood and protein. The SG is 1.015. No RBCs or WBCs are seen in the microscopic examination. These results:

Answer 8

Support the finding of an intravascular transfusion reaction

Question 9

A urine sample taken after a suspected transfusion reaction has a positive test result for blood, but intact RBCs are not seen on microscopic examination. Which test result would rule out an intravascular hemolytic transfusion reaction?

Answer 9

Normal plasma haptoglobin

Question 10

Given the following urinalysis results, select the most appropriate course of action:

Answer 10

Call for a list of medications administered to the patient

Question 11

Urinalysis results from a 35-year-old woman are as follows:

Select the most appropriate course of action.

Answer 11

Recheck the blood reaction; if negative, look for budding yeast

Question 12

A routine urinalysis gives the following results:

These results are most likely explained by:

Answer 12

Pseudocasts of urate mistaken for true casts

Question 13

SITUATION: When examining a urinary sediment under 400× magnification, the medical laboratory scientist (MLS) noted many RBCs to have cytoplasmic blebs and an irregular distribution of the hemoglobin. This phenomenon is most often caused by:

Answer 13

Glomerular disease

Question 14

SITUATION: A urine specimen is dark orange and turns brown after storage in the refrigerator overnight. The MLS requests a new specimen. The second specimen is bright orange and is tested immediately. Which test result would differ between the two specimens?

Answer 14

Urobilinogen

Question 15

A patient’s random urine sample consistently contains a trace of protein but no casts, cells, or other biochemical abnormality. The first voided morning sample is consistently negative for protein. These findings can be explained by:

Answer 15

Orthostatic or postural albuminuria

Question 16

A urine sample with a pH of 8.0 and a specific gravity of 1.005 had a small positive blood reaction but is negative for protein, and no RBCs are present in the microscopic examination of urinary sediment. What best explains these findings?

Answer 16

Hemoglobin is present without intact RBCs because of hemolysis

Question 17

A urine sample has a negative blood reaction and 5 to 10 cells per high-power field that resemble RBCs. What is the best course of action?

Answer 17

Mix a drop of sediment with 1 drop of WBC counting fluid and re-examine

Question 18

A toluidine blue chamber count on CSF gives the following values:

After correcting the WBC count in CSF, the MLS should next:

Answer 18

Concentrate CSF using a cytocentrifuge and perform a differential

Question 19

A blood-tainted pleural fluid is submitted for culture. Which test result would be most conclusive in classifying the fluid as an exudate?

Answer 19

A. LD fluid/serum; 0.65

Question 20

A pleural fluid submitted to the laboratory is milky in appearance. Which test would be most useful in differentiating between a chylous and pseudochylous effusion?

Answer 20

Fluid to serum triglyceride ratio

Question 21

A CSF sample from an 8-year-old child with a fever of unknown origin was tested for glucose, total protein, lactate, and IgG index. Glucose was 180 mg/dL, but all other results were within the reference range. The CSF WBC count was 9 × 106/L, and the RBC count was 10 × 106/L. The differential showed 50% lymphocytes, 35% monocytes,
10% macrophages, 3% neutrophils, and 2% neuroectodermal cells. What is the most likely cause of these results?

Answer 21

Hyperglycemia

Question 22

A WBC count and differential performed on ascites fluid gave a WBC count of 20,000/ µL with 90% macrophages. The gross appearance of the fluid was described by the MLS as “thick and bloody.” It was noted on the report that several clusters of these cells were observed and that the majority of the cells contained many vacuoles resembling paper-punch holes. What do the observations above suggest?

Answer 22

Malignant mesothelial cells were counted as macrophages

Question 23

Given the following data for creatinine clearance, select the most appropriate course of action.

Volume = 2.8 L/day
Surface area = 1.73 m2
Urine creatinine = 100 mg/dL
Serum creatinine = 1.2 mg/dL

Answer 23

Request a new 24-hour urine sample

Question 24

An elevated amylase is obtained on a stat serum collected at 8 p.m. An amylase performed at 8 a.m. that morning was within normal limits. The MLS also noted that urine amylase was measured at 6 p.m. Select the most appropriate course of action.

Answer 24

Review the amylase result on the 6 p.m. urine sample; if elevated, report the stat amylase

Question 25

Results of an FLM study from a patient with diabetes mellitus are as follows: L/S ratio = 2.0 Phosphatidyl glycerol = Neg Creatinine = 2.5 mg/dL Given these results, the MLS should:

Answer 25

Report the result and recommend repeating the L/S ratio in 24 hours

Question 26

A 24-hour urine sample from an adult submitted for catecholamines gives a result of 140 µg/day (upper reference limit 150 µg/day). The 24-hour urine creatinine level is 0.6 g/day. Select the best course of action.

Answer 26

Request a new 24-hour urine sample

Question 27

A sperm motility test was performed and 200 sperm were evaluated in each of two duplicates. The first sample showed progressive movement in 50% and nonprogressive movement in 35%, and 15% were immotile. The second showed progressive movement in 35% and nonprogressive movement in 35%, and 30% were immotile. What is the best course of action?

Answer 27

Repeat the motility test

Question 28

A quantitative serum hCG is ordered on a male patient. The technologist should:

Answer 28

Perform the test and report the result

Question 29

SITUATION: A lamellar body count (LBC) was performed on an amniotic fluid sample that was slightly pink within 1 hour of specimen collection. The sample was stored at 4°C prior to analysis. The result was 25,000/µL, classified as intermediate risk of RDS. The physician waited 24 hours and collected a new sample that was counted within 2 hours of collection on the same instrument. The LCB count of the new sample was 14,000/µL and the patient was reclassified as high risk for delivery. Which statement best explains these results?

Answer 29

Blood caused a falsely elevated result for the first sample

Question 30

When testing for drugs of abuse in urine, which of the following test results indicate dilution and would be cause for rejecting the sample?

Answer 30

SG 1.002; creatinine 15 mg/dL,

Question 31

SITUATION: A urine specimen has an SG of 1.025 and is strongly positive for nitrite. All other dry reagent strip test results are normal, and the microscopic examination was unremarkable, showing no WBCs or bacteria. The urine sample was submitted as part of a pre-employment physical examination that also includes drug testing. Which most likely caused these results?

Answer 31

An adulterated urine specimen

Question 32

A CSF sample submitted for cell counts has a visible clot. What is the best course of action?

Answer 32

Request a new sample

Question 33

Total hemolytic complement and glucose are ordered on a synovial fluid sample that is too viscous to pipet. What is the best course of action?

Answer 33

Add 1 mg/mL hyaluronidase to the sample, and incubate at room temperature for 30 minutes

Question 34

A CSF cytospin smear shows many smudge cells and macrophages with torn cell membranes. What most likely caused this problem?

Answer 34

Failure to add albumin to the cytospin cup

Question 35

An automated electronic blood cell counter was used to count RBCs and WBCs in a turbid pleural fluid sample. The WBC count was 5 × 1010/L (50,000/µL) and the RBC count was 5.5 × 1010/L (55,000/µL). What is the significance of the RBC count?

Answer 35

The RBC count is not significant and should be reported as 5,000/µL