Saunders Lab Values
Questions & Answers
1. A client with atrial fibrillation who is receiving maintenance therapy of warfarin sodium has a
prothrombin time (PT) of 35 seconds and an international normalized ratio (INR) of 3.5. On the basis of
these laboratory values, the nurse anticipates which prescription?
1. Adding a dose of heparin sodium
2. Holding the next dose of warfarin
3. Increasing the next dose of warfarin
4. Administering the next dose of warfarin
Correct answer: 2
Rationale: The normal PT is 11 to 12.5 seconds (conventional therapy and SI units). The normal INR is
2 to 3 for standard warfarin therapy, which is used for the treatment of atrial fibrillation, and 3 to 4.5 for
high-dose warfarin therapy, which is used for clients with mechanical heart valves. A therapeutic PT level
is 1.5 to 2 times higher than the normal level. Because the values of 35 seconds and 3.5 are high, the
nurse should anticipate that the client would not receive further doses at this time. Therefore, the
prescriptions noted in the remaining options are incorrect.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Analysis
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Clotting
2. A client has been admitted to the hospital for urinary tract infection and dehydration. The nurse
determines that the client has received adequate volume replacement if the blood urea nitrogen (BUN)
level drops to which value?
1. 3 mg/dL (1.05 mmol/L)
2. 15 mg/dL (5.25 mmol/L)
3. 29 mg/dL (10.15 mmol/L)
4. 35 mg/dL (12.25 mmol/L)
Correct answer: 2
Rationale: The normal BUN level is 6 to 20 mg/dL (2.1 to 7.1 mmol/L). Values of 29 mg/dL (10.15
mmol/L) and 35 mg/dL (12.25 mmol/L) reflect continued dehydration. A value of 3 mg/dL (1.05
mmol/L) reflects a lower than normal value, which may occur with fluid volume overload, among other
conditions.
,Cognitive Ability: Evaluating
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Evaluation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Fluid and Electrolyte Balance
3. A client is receiving a continuous intravenous infusion of heparin sodium to treat deep vein thrombosis.
The client's activated partial thromboplastin time (aPTT) is 65 seconds. The nurse anticipates that which
action is needed?
1. Discontinuing the heparin infusion
2. Increasing the rate of the heparin infusion
3. Decreasing the rate of the heparin infusion
4. Leaving the rate of the heparin infusion as is
Correct answer: 4
Rationale: The normal aPTT varies between 28 and 35 seconds (28 and 35 seconds), depending on the
type of activator used in testing. The therapeutic dose of heparin for treatment of deep vein thrombosis is
to keep the aPTT between 1.5 (42 to 52.5) and 2.5 (70 to 87.5) times normal. This means that the client's
value should not be less than 42 seconds or greater than 87.5 seconds. Thus the client's aPTT is within
the therapeutic range and the dose should remain unchanged.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Analysis
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Clotting
4. A client with a history of cardiac disease is due for a morning dose of furosemide. Which serum
potassium level, if noted in the client's laboratory report, should be reported before administering the
dose of furosemide?
1. 3.2 mEq/L (3.2 mmol/L)
2. 3.8 mEq/L (3.8 mmol/L)
3. 4.2 mEq/L (4.2 mmol/L)
4. 4.8 mEq/L (4.8 mmol/L)
Correct answer: 1
,Rationale: The normal serum potassium level in the adult is 3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L).
The correct option is the only value that falls below the therapeutic range. Administering furosemide
to a client with a low potassium level and a history of cardiac problems could precipitate ventricular
dysrhythmias. The remaining options are within the normal range.
Cognitive Ability: Applying
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Implementation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Fluid and Electrolyte Balance
5. Several laboratory tests are prescribed for a client, and the nurse reviews the results of the tests.
Which laboratory test results should the nurse report? Select all that apply.
1. Platelets 35,000 mm3 (35 × 109/L)
2. Sodium 150 mEq/L (150 mmol/L)
3. Potassium 5.0 mEq/L (5.0 mmol/L)
4. Segmented neutrophils 40% (0.40)
5. Serum creatinine, 1 mg/dL (88.3 mmol/L)
6. White blood cells, 3000 mm3 (3.0 ×
109/L)
Correct answer: 1, 2, 4, 6
Rationale: The normal values include the following: platelets 150,000-400,000 mm3 (150–400 × 109/L);
sodium 135–145 mEq/L (135–145 mmol/L); potassium 3.5–5.0 mEq/L (3.5–5.0 mmol/L); segmented
neutrophils 60%–70% (0.60–0.70); serum creatinine 0.6–1.3 mg/dL (53–115 mmol/L); and white blood
cells 5000-10,000 mm3 (5.0–10.0 × 109/L). The platelet level noted is low; the sodium level noted is high;
the potassium level noted is normal; the segmented neutrophil level noted is low; the serum creatinine
level noted is normal; and the white blood cell level is low.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Implementation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Collaboration
6. A client with diabetes mellitus has a glycosylated hemoglobin A1c level of 9%. On the basis of this test
result, the nurse plans to teach the client about the need for which measure?
1. Avoiding infection
, 2. Taking in adequate fluids
3. Preventing and recognizing hypoglycemia
4. Preventing and recognizing hyperglycemia
Correct answer: 4
Rationale: The normal reference range for the glycosylated hemoglobin A1c is 4.0% to 6.0%. This test
measures the amount of glucose that has become permanently bound to the red blood cells from
circulating glucose. Erythrocytes live for about 120 days, giving feedback about blood glucose for past
120 days. Elevations in the blood glucose level will cause elevations in the amount of glycosylation. Thus
the test is useful in identifying clients who have periods of hyperglycemia that are undetected in other
ways. The estimated average glucose for a glycosylated hemoglobin A1c of 9% is 212 mg/dL (11.8
mmol/L). Elevations indicate continued need for teaching related to the prevention of hyperglycemic
episodes.
Cognitive Ability: Applying
Client Needs: Health Promotion and Maintenance
Integrated Process: Teaching and Learning
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Client Education, Glucose Regulation
5. The nurse is caring for a client with a diagnosis of cancer who is immunosuppressed. The nurse would
consider implementing neutropenic precautions if the client's white blood cell count was which value?
1. 2000 mm3 (2.0 × 109/L)
2. 5800 mm3 (5.8 × 109/L)
3. 8400 mm3 (8.4 × 109/L)
4. 300,000 mm3 (11.5 × 109/L)
Correct answer: 1
Rationale: The normal WBC count ranges from 5000–10,000 mm3 (5–10 × 109/L). The client who has
a decrease in the number of circulating WBCs is immunosuppressed. The nurse implements neutropenic
precautions when the client's values fall sufficiently below the normal level. The specific value for
implementing neutropenic precautions usually is determined by agency policy. The remaining options
are normal values.
Cognitive Ability: Applying
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Planning
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Questions & Answers
1. A client with atrial fibrillation who is receiving maintenance therapy of warfarin sodium has a
prothrombin time (PT) of 35 seconds and an international normalized ratio (INR) of 3.5. On the basis of
these laboratory values, the nurse anticipates which prescription?
1. Adding a dose of heparin sodium
2. Holding the next dose of warfarin
3. Increasing the next dose of warfarin
4. Administering the next dose of warfarin
Correct answer: 2
Rationale: The normal PT is 11 to 12.5 seconds (conventional therapy and SI units). The normal INR is
2 to 3 for standard warfarin therapy, which is used for the treatment of atrial fibrillation, and 3 to 4.5 for
high-dose warfarin therapy, which is used for clients with mechanical heart valves. A therapeutic PT level
is 1.5 to 2 times higher than the normal level. Because the values of 35 seconds and 3.5 are high, the
nurse should anticipate that the client would not receive further doses at this time. Therefore, the
prescriptions noted in the remaining options are incorrect.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Analysis
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Clotting
2. A client has been admitted to the hospital for urinary tract infection and dehydration. The nurse
determines that the client has received adequate volume replacement if the blood urea nitrogen (BUN)
level drops to which value?
1. 3 mg/dL (1.05 mmol/L)
2. 15 mg/dL (5.25 mmol/L)
3. 29 mg/dL (10.15 mmol/L)
4. 35 mg/dL (12.25 mmol/L)
Correct answer: 2
Rationale: The normal BUN level is 6 to 20 mg/dL (2.1 to 7.1 mmol/L). Values of 29 mg/dL (10.15
mmol/L) and 35 mg/dL (12.25 mmol/L) reflect continued dehydration. A value of 3 mg/dL (1.05
mmol/L) reflects a lower than normal value, which may occur with fluid volume overload, among other
conditions.
,Cognitive Ability: Evaluating
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Evaluation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Fluid and Electrolyte Balance
3. A client is receiving a continuous intravenous infusion of heparin sodium to treat deep vein thrombosis.
The client's activated partial thromboplastin time (aPTT) is 65 seconds. The nurse anticipates that which
action is needed?
1. Discontinuing the heparin infusion
2. Increasing the rate of the heparin infusion
3. Decreasing the rate of the heparin infusion
4. Leaving the rate of the heparin infusion as is
Correct answer: 4
Rationale: The normal aPTT varies between 28 and 35 seconds (28 and 35 seconds), depending on the
type of activator used in testing. The therapeutic dose of heparin for treatment of deep vein thrombosis is
to keep the aPTT between 1.5 (42 to 52.5) and 2.5 (70 to 87.5) times normal. This means that the client's
value should not be less than 42 seconds or greater than 87.5 seconds. Thus the client's aPTT is within
the therapeutic range and the dose should remain unchanged.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Analysis
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Clotting
4. A client with a history of cardiac disease is due for a morning dose of furosemide. Which serum
potassium level, if noted in the client's laboratory report, should be reported before administering the
dose of furosemide?
1. 3.2 mEq/L (3.2 mmol/L)
2. 3.8 mEq/L (3.8 mmol/L)
3. 4.2 mEq/L (4.2 mmol/L)
4. 4.8 mEq/L (4.8 mmol/L)
Correct answer: 1
,Rationale: The normal serum potassium level in the adult is 3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L).
The correct option is the only value that falls below the therapeutic range. Administering furosemide
to a client with a low potassium level and a history of cardiac problems could precipitate ventricular
dysrhythmias. The remaining options are within the normal range.
Cognitive Ability: Applying
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Implementation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Fluid and Electrolyte Balance
5. Several laboratory tests are prescribed for a client, and the nurse reviews the results of the tests.
Which laboratory test results should the nurse report? Select all that apply.
1. Platelets 35,000 mm3 (35 × 109/L)
2. Sodium 150 mEq/L (150 mmol/L)
3. Potassium 5.0 mEq/L (5.0 mmol/L)
4. Segmented neutrophils 40% (0.40)
5. Serum creatinine, 1 mg/dL (88.3 mmol/L)
6. White blood cells, 3000 mm3 (3.0 ×
109/L)
Correct answer: 1, 2, 4, 6
Rationale: The normal values include the following: platelets 150,000-400,000 mm3 (150–400 × 109/L);
sodium 135–145 mEq/L (135–145 mmol/L); potassium 3.5–5.0 mEq/L (3.5–5.0 mmol/L); segmented
neutrophils 60%–70% (0.60–0.70); serum creatinine 0.6–1.3 mg/dL (53–115 mmol/L); and white blood
cells 5000-10,000 mm3 (5.0–10.0 × 109/L). The platelet level noted is low; the sodium level noted is high;
the potassium level noted is normal; the segmented neutrophil level noted is low; the serum creatinine
level noted is normal; and the white blood cell level is low.
Cognitive Ability: Analyzing
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Implementation
Content Area: Fundamentals of Care: Laboratory
Values Strategy(ies): Subject
Priority Concepts: Clinical Judgment, Collaboration
6. A client with diabetes mellitus has a glycosylated hemoglobin A1c level of 9%. On the basis of this test
result, the nurse plans to teach the client about the need for which measure?
1. Avoiding infection
, 2. Taking in adequate fluids
3. Preventing and recognizing hypoglycemia
4. Preventing and recognizing hyperglycemia
Correct answer: 4
Rationale: The normal reference range for the glycosylated hemoglobin A1c is 4.0% to 6.0%. This test
measures the amount of glucose that has become permanently bound to the red blood cells from
circulating glucose. Erythrocytes live for about 120 days, giving feedback about blood glucose for past
120 days. Elevations in the blood glucose level will cause elevations in the amount of glycosylation. Thus
the test is useful in identifying clients who have periods of hyperglycemia that are undetected in other
ways. The estimated average glucose for a glycosylated hemoglobin A1c of 9% is 212 mg/dL (11.8
mmol/L). Elevations indicate continued need for teaching related to the prevention of hyperglycemic
episodes.
Cognitive Ability: Applying
Client Needs: Health Promotion and Maintenance
Integrated Process: Teaching and Learning
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
Priority Concepts: Client Education, Glucose Regulation
5. The nurse is caring for a client with a diagnosis of cancer who is immunosuppressed. The nurse would
consider implementing neutropenic precautions if the client's white blood cell count was which value?
1. 2000 mm3 (2.0 × 109/L)
2. 5800 mm3 (5.8 × 109/L)
3. 8400 mm3 (8.4 × 109/L)
4. 300,000 mm3 (11.5 × 109/L)
Correct answer: 1
Rationale: The normal WBC count ranges from 5000–10,000 mm3 (5–10 × 109/L). The client who has
a decrease in the number of circulating WBCs is immunosuppressed. The nurse implements neutropenic
precautions when the client's values fall sufficiently below the normal level. The specific value for
implementing neutropenic precautions usually is determined by agency policy. The remaining options
are normal values.
Cognitive Ability: Applying
Client Needs: Physiological Integrity
Integrated Process: Nursing Process: Planning
Content Area: Fundamentals of Care: Laboratory Values
Strategy(ies): Subject
