Lab Values

The nurse determines that the blood urea nitrogen (BUN) level is normal if which value is noted on the laboratory report?

20 mg/dL (7.1 mmol/L)

A client is undergoing a series of diagnostic tests. The laboratory results indicate an increased blood urea nitrogen (BUN) to creatinine ratio. The nurse determines that which potential conditions could contribute to these results? Select all that apply. 1. Dehydration 2. Catabolic state 3. High-protein diet 4. Fluid volume excess 5. Obstructive uropathy 6. Acute renal tubular acidosis

1. Dehydration 2. Catabolic state 3. High-protein diet 5. Obstructive uropathy Rationale: Causes of an increased BUN to creatinine ratio include dehydration, a catabolic state, a high-protein diet, and obstructive uropathy. A decreased ratio is caused by fluid volume excess or acute renal tubular acidosis.

The nurse is reviewing the white blood cell (WBC) count and differential on a client and notes that the results indicate a left shift. What are the possible indications for these laboratory results? Select all that apply. 1. The total number of WBCs 2. An increased number of bands 3. The presence of an acute infectious process 4. An increased number of mature neutrophils 5. An increased number of immature neutrophils

1. The total number of WBCs 2. An increased number of bands 3. The presence of an acute infectious process 5. An increased number of immature neutrophils Rationale: The differential count reflects the percentage of the total number of WBCs. A left shift indicates an increased number of immature neutrophils, or an increased number of bands. This signals the presence of an acute infectious process. A right shift represents an increased number of mature neutrophils

The nurse caring for a client with a diagnosis of gastrointestinal (GI) bleeding reviews the client's laboratory results and notes a hematocrit level of 30% (0.30). Which action should the nurse take? 1. Report the abnormally low level. 2. Report the abnormally high level. 3. Inform the client that the laboratory result is normal. 4. Place the normal report in the client's medical record.

1.Report the abnormally low level. Rationale: The normal hematocrit level ranges from 42% to 52% (0.42 to 0.52) in a male and from 37% to 47% (0.37 to 0.47) in a female, depending on age. A hematocrit level of 30% (0.30) is a low level and would be reported to the health care provider because it indicates blood loss. Therefore, the remaining options are incorrect.

A client is undergoing a 2-hour glucose tolerance test. The nurse assesses for which client factors that can interfere with the test period results? Select all that apply. 1.Experiencing stress 2.Fasting before the test period 3.Voiding during the test period 4.Eating a small snack or candy during the test period 5.Having an episode of diarrhea before the test period 6.Being unable to eat the entire test meal or vomiting some or all of the meal

1. Experiencing stress 4.Eating a small snack or candy during the test period 6.Being unable to eat the entire test meal or vomiting some or all of the meal Rationale: Some interfering factors that can result in inaccurate test findings include experiencing stress, being unable to eat the entire test meal or vomiting during the test period, and eating a small snack or candy during the test period. Voiding during the test period, fasting for 4 hours before the test period, and having an episode of diarrhea before the test period would not interfere with the test results.

A client is receiving oral anticoagulant therapy with warfarin. The result of a newly drawn prothrombin time (PT) is 40 seconds. The nurse should anticipate which prescription to be prescribed for this client? 1. Hold the next dose of warfarin. 2. Increase the next dose of warfarin. 3. Administer the next dose of warfarin. 4. Stop the warfarin, and administer heparin.

1. Hold the next dose of warfarin. Rationale: The normal PT is 11 to 12.5 seconds for adults. Appropriate therapy for full anticoagulation should prolong the PT by 1.5 to 2 times. Because the value stated is extremely high, the nurse should anticipate that the client would not receive further doses at this time. If the level were too high, the antidote (vitamin K) could also be prescribed. It would be dangerous to add a different anticoagulant to the client's regimen at this time, as in option 4.

The nurse is evaluating the laboratory test results for a client with diabetes mellitus seen in the health care clinic. The nurse determines that which glycosylated hemoglobin level value shows poor adherence to therapy? 1. 6% 2. 7% 3. 7.5% 4. 10%

10% Rationale: The normal glycosylated hemoglobin in an adult without diabetes is <6%. Levels >8% indicate poor diabetic control and need for adherence to regimen or changes in therapy. The results in the remaining options indicate adequate control.

The nurse in the respiratory care unit completes a lung assessment and reviews the laboratory results of a serum medication level assay for a client receiving theophylline. The nurse determines that a therapeutic medication level has been achieved by indication of which value? 1. 8 mcg/mL (44 mcmol/L) 2. 9 mcg/mL (50 mcmol/L) 3. 18 mcg/mL (100 mcmol/L) 4. 26 mcg/mL (144 mcmol/L)

18 mcg/mL (100 mcmol/L) Rationale: The therapeutic range for serum theophylline is 10 to 20 mcg/mL (55.5 to 111 mcmol/L). If the level is less than the therapeutic range, the client may experience frequent exacerbations of the respiratory disorder. If the level is too high, the medication may need to be stopped or the dose may need to be lowered. Values of 8 and 9 mcg/dL (44 and 50 mcmol/L) indicate low values, while 26 mcg/dL (144 mcmol/L) indicates an elevated value.

The nurse is reviewing the laboratory test results for a client seen in the health care clinic. The nurse determines that the serum lipase level is normal if which value is noted on the laboratory report? 1. 4 U/L (4 U/L) 2. 100 U/L (100 U/L) 3. 210 U/L (210 U/L) 4. 360 U/L (360 U/L)

2. 100 U/L (100 U/L) Rationale: The normal serum lipase level is 0 to 160 U/L (0 to 160 U/L). The remaining options reflect either low or elevated serum lipase levels.

The nurse checks the laboratory results of a serum medication level assay for a newly admitted client taking digoxin 0.125 mg orally daily. Which value would indicate a therapeutic level? 1. 0.1 ng/mL (0.13 nmol/L) 2. 0.6 ng/mL (0.76 nmol/L) 3. 1.8 ng/mL (2.30 nmol/L) 4. 2.4 ng/mL (3.07 nmol/L)

2. 0.6 ng/mL (0.76 nmol/L) Rationale: The normal therapeutic range for digoxin is 0.5 to 0.8 ng/mL (0.6 to 1.0 nmol/L). A value of 0.6 ng/mL (0.76 nmol/L) falls within the therapeutic range, and the medication would be continued as at home. A values of 0.1 (0.13 nmol/L) is lower than the therapeutic range and would require additional medication to be given. A value of 1.8 ng/mL (2.30 nmol/L) and 2.4 ng/mL (3.07 nmol/L) exceeds the therapeutic range, could be toxic to the client, and would be held.

The nurse is reviewing the laboratory test results for a client seen in the health care clinic and notes that the red blood cell (RBC) count is decreased. The nurse determines that this finding occurs in which condition? 1. Dehydration 2. Iron deficiency 3. Severe diarrhea 4. Polycythemia vera

2. Iron deficiency Rationale: Decreased RBC counts occur in clients with vitamin B6 and B12 deficiencies, iron deficiency, chronic infection, bone marrow depression, multiple myeloma, leukemia, hemolytic anemia, and pernicious anemia. A decrease in the RBC count also may be noted in the older client. Increased RBC counts are noted in clients with the disorders in the remaining options.

The nurse is reviewing the laboratory blood test results for a client and notes that the hemoglobin S (Hgb S) value is elevated. The nurse determines that this laboratory finding is associated with which condition? 1. Aplastic anemia 2. Sickle cell anemia 3. Infectious mononucleosis 4. Acute lymphocytic leukemia

2. Sickle cell anemia Rationale: Sickle cell anemia is a severe anemia that predominantly affects African Americans. It is characterized by the presence of Hgb S. The client must have 2 abnormal genes encoding Hgb S to have sickle cell disease. A client could have sickle cell trait by carrying 1 hemoglobin A gene and 1 Hgb S gene. Hgb S is not associated with aplastic anemia, infectious mononucleosis, or acute lymphocytic leukemia.

A client's laboratory test results reveal an increased transferrin level and a decreased iron-binding capacity. The nurse interprets that these laboratory results are compatible with anemia because of which problem? 1. Infection 2. Malnutrition 3. Iron deficiency 4. Sickle cell disease

3. Iron deficiency Rationale: Iron deficiency anemia usually is characterized by decreased iron-binding capacity and increased transferrin saturation. Infection is not associated with these laboratory values. Malnutrition can cause reductions in both iron-binding capacity and transferrin saturation. Sickle cell anemia is diagnosed by determining that the client has hemoglobin S.

The evening shift nurse is reviewing the laboratory results of a client's urine culture showing 100,000 bacterial units/mL of urine. What should be the nurse's action? 1. Notify the HCP during rounds in the morning. 2. No action is needed because this is normal value. 3. Page the health care provider (HCP) with the results. 4. Collect another urine specimen to confirm the results.

3. Page the health care provider (HCP) with the results. Rationale: The HCP needs to be notified. A colony count of 100,000 is considered a positive culture and could be indicative of pyelonephritis if accompanied by fever and flank pain. A positive culture that is accompanied by dysuria, frequency, and urgency is indicative of cystitis. The other options are not correct and delay necessary intervention.

After completing an assessment and reviewing the laboratory test results of a client admitted to the hospital with acute abdominal pain, the nurse should take action for which noted serum amylase level? 1. 60 Somogyi units/dL (27 U/L) 2. 100 Somogyi units/dL (50 U/L) 3. 120 Somogyi units/dL (60 U/L) 4. 200 Somogyi units/dL (100 U/L)

4. 200 Somogyi units/dL (100 U/L) Rationale: The normal serum amylase level ranges from 60 to 120 Somogyi units/dL (30 to 220 U/L), depending on the laboratory running the test. Option 4 is out of range for a serum amylase level and would require action by the nurse. The values in the remaining options are normal serum amylase levels and would not require any action.

The nurse receives a telephone laboratory report indicating that a diabetic client has a glycosylated hemoglobin (HgbA1c) level of 7.6%. In which priority area should the nurse plan to provide diabetic teaching? 1. Avoidance of infection 2. Rotation of insulin injection sites 3. Measures to prevent hyperglycemia 4. Avoidance of hypoglycemic episodes

3.Measures to prevent hyperglycemia Rationale: The normal level for HgbA1c is <6% in an adult without diabetes. Regardless, a level of 7.6% is elevated. This test measures the amount of glucose that has become permanently bound to the red blood cells from circulating glucose. Elevations in the blood glucose level will cause elevations in the amount of glycosylation, helping to detect otherwise unknown episodes of hyperglycemia. Elevations indicate continued need for teaching related to the prevention of hyperglycemic episodes because the results are reflective of the blood glucose levels over the preceding 2- to 3-month period.

A client is admitted with possible hepatic encephalopathy. The nurse determines that which noted serum laboratory abnormality supports this suspicion? 1. Protein level of 72 g/L (7.2 g/dL) 2. Ammonia level of 98 mcg/dL (60 mcmol/L) 3. Magnesium level of 1.7 mEq/L (0.85 mmol/L) 4. Total bilirubin level of 1.2 mg/dL (20.5 mcmol/L)

4. Total bilirubin level of 1.2 mg/dL (20.5 mcmol/L) Rationale: The normal serum ammonia level ranges from 10 to 80 mcg/dL (6 to 47 mcmol/L). High levels of ammonia can result in encephalopathy and coma. The other blood levels are not related to hepatic encephalopathy and are also normal values.

A client who has a serum potassium (K+) level of 2.9 mEq/L (2.9 mmol/L) tells the nurse that he does not feel like eating lunch. The nurse checks his serum digoxin level from that morning and notes that it is 1.0 ng/mL (1.2 nmol/L). What should the nurse determine about this digoxin level? 1. Low 2. Extremely toxic 3. Within the therapeutic range 4. Just above the high end of the therapeutic range

4. Just above the high end of the therapeutic range Rationale: Digoxin is a cardiac glycoside that is used to treat dysrhythmias such as atrial fibrillation in clients with heart failure. Digoxin blood levels need to be checked while the client is taking this medication to monitor for toxicity. The normal therapeutic range for digoxin is 0.5 to 0.8 ng/mL (0.6 to 1.0 nmol/L). Therefore, a blood level of 1.0 ng/mL (1.2 nmol/L) is just above the high end of the therapeutic range. It is important to be aware that a low K+ level has an additive effect in increasing the risk of digoxin toxicity. The normal K+ level is 3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L).

The nurse is reviewing the laboratory results from a lumbar puncture performed in a client with a diagnosis of meningitis. Which laboratory findings are expected to be noted with bacterial meningitis? Select all that apply. 1. Increased glucose level 2. Elevated protein level 3. Increased white blood cells (WBCs) 4. Clear appearance of the cerebrospinal fluid (CSF) 5. Elevated cerebrospinal fluid pressure

Calcium 4.0 mg/dL (1.0 mmol/L) Rationale: The normal reference level for calcium is 9 to 10.5 mg/dL (2.25 to 2.75 mmol/L). The reported level is low, requiring immediate notification of the HCP. The normal electrolyte levels for an adult client are sodium 135 to 145 mEq/L (135 to 145 mmol/L), potassium 3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L), and magnesium 1.3 to 2.1 mEq/L (0.65 to 1.05 mmol/L).