NUR 155 COMPREHENSIVE EXAMS 2-4
MASTERY TEST QUESTIONS AND
ANSWERS
1. A nurse is caring for a patient with a potassium level of 2.8 mEq/L. Which assessment
finding is a priority for the nurse to report to the provider?
A. Muscle weakness in the lower extremities
B. Irregular heart rate and prominent U-waves on ECG
C. Decreased bowel sounds and constipation
D. Report of fatigue and lethargy
Answer: B
Conceptual Explanation: Hypokalemia (potassium < 3.5) significantly affects cardiac
electrical conduction. While muscle weakness and constipation are symptoms, cardiac
dysrhythmias and EKG changes are the most life-threatening priorities.
2. When assessing a pressure injury, the nurse notes full-thickness skin loss with visible
subcutaneous fat, but no bone, tendon, or muscle is exposed. How should this be staged?
A. Stage 2
B. Stage 4
,C. Stage 3
D. Unstageable
Answer: C
Conceptual Explanation: Stage 3 pressure injuries involve full-thickness skin loss where
adipose (fat) is visible in the ulcer and granulation tissue is often present. Stage 4 involves
exposed bone, tendon, or muscle.
3. A patient is admitted with suspected pulmonary tuberculosis. Which type of precautions
should the nurse implement immediately?
A. Droplet precautions
B. Airborne precautions
C. Contact precautions
D. Protective environment
Answer: B
Conceptual Explanation: Tuberculosis is transmitted via small droplets that remain
suspended in the air. This requires airborne precautions, including a negative-pressure
room and N95 respirator use.
4. A nurse interprets a patient’s arterial blood gas (ABG) results: pH 7.30, PaCO2 52 mmHg,
and HCO3 26 mEq/L. Which acid-base imbalance is occurring?
A. Metabolic Acidosis
, B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Answer: D
Conceptual Explanation: A pH below 7.35 indicates acidosis. A PaCO2 above 45 mmHg
indicates a respiratory cause. Since the HCO3 is within the normal range (22-26), it is
uncompensated respiratory acidosis.
5. Which intervention is most effective in preventing deep vein thrombosis (DVT) in a
postoperative patient?
A. Applying sequential compression devices (SCDs)
B. Massaging the legs twice daily
C. Limiting fluid intake to prevent edema
D. Keeping the knees in a flexed position with pillows
Answer: A
Conceptual Explanation: SCDs promote venous return and prevent stasis. Massaging legs
is contraindicated as it may dislodge a clot. Flexing the knees can actually impede venous
return.
MASTERY TEST QUESTIONS AND
ANSWERS
1. A nurse is caring for a patient with a potassium level of 2.8 mEq/L. Which assessment
finding is a priority for the nurse to report to the provider?
A. Muscle weakness in the lower extremities
B. Irregular heart rate and prominent U-waves on ECG
C. Decreased bowel sounds and constipation
D. Report of fatigue and lethargy
Answer: B
Conceptual Explanation: Hypokalemia (potassium < 3.5) significantly affects cardiac
electrical conduction. While muscle weakness and constipation are symptoms, cardiac
dysrhythmias and EKG changes are the most life-threatening priorities.
2. When assessing a pressure injury, the nurse notes full-thickness skin loss with visible
subcutaneous fat, but no bone, tendon, or muscle is exposed. How should this be staged?
A. Stage 2
B. Stage 4
,C. Stage 3
D. Unstageable
Answer: C
Conceptual Explanation: Stage 3 pressure injuries involve full-thickness skin loss where
adipose (fat) is visible in the ulcer and granulation tissue is often present. Stage 4 involves
exposed bone, tendon, or muscle.
3. A patient is admitted with suspected pulmonary tuberculosis. Which type of precautions
should the nurse implement immediately?
A. Droplet precautions
B. Airborne precautions
C. Contact precautions
D. Protective environment
Answer: B
Conceptual Explanation: Tuberculosis is transmitted via small droplets that remain
suspended in the air. This requires airborne precautions, including a negative-pressure
room and N95 respirator use.
4. A nurse interprets a patient’s arterial blood gas (ABG) results: pH 7.30, PaCO2 52 mmHg,
and HCO3 26 mEq/L. Which acid-base imbalance is occurring?
A. Metabolic Acidosis
, B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Answer: D
Conceptual Explanation: A pH below 7.35 indicates acidosis. A PaCO2 above 45 mmHg
indicates a respiratory cause. Since the HCO3 is within the normal range (22-26), it is
uncompensated respiratory acidosis.
5. Which intervention is most effective in preventing deep vein thrombosis (DVT) in a
postoperative patient?
A. Applying sequential compression devices (SCDs)
B. Massaging the legs twice daily
C. Limiting fluid intake to prevent edema
D. Keeping the knees in a flexed position with pillows
Answer: A
Conceptual Explanation: SCDs promote venous return and prevent stasis. Massaging legs
is contraindicated as it may dislodge a clot. Flexing the knees can actually impede venous
return.
