Examkin

Question

Difficulty: Very hardPharmacological Therapies

During morning rounds, a practical nurse (PN) evaluates a client with cirrhosis and hepatic encephalopathy who is prescribed oral lactulose and oral spironolactone. The electronic health record reveals a morning serum potassium level of 2.8 mEq/L. The client currently exhibits bilateral asterixis and reports having three soft bowel movements over the past 12 hours. Which action should the PN take first?

  1. A
    Document the potassium level in the medical record and administer the lactulose to treat the asterixis
  2. B
    Administer the spironolactone, but independently discontinue the lactulose prescription due to the hypokalemia
  3. Withhold the scheduled lactulose dose and immediately report the serum potassium results to the supervising registered nurse (RN)Answer
  4. D
    Administer the scheduled medications, as the three bowel movements indicate the lactulose is achieving its expected therapeutic effect

Answer

The correct action is to withhold the scheduled lactulose dose and immediately report the critical serum potassium results to the supervising registered nurse.
The client's potassium level of 2.8 mEq/L is critically low. Because lactulose induces osmotic diarrhea to eliminate ammonia, it inherently causes additional potassium loss through the gastrointestinal tract. Administering lactulose in the presence of severe hypokalemia places the client at imminent risk for lethal cardiac dysrhythmias. Furthermore, hypokalemia directly increases renal ammonia production, which ultimately worsens hepatic encephalopathy. The safest and most appropriate action within the practical nurse's scope of practice is to withhold the medication and immediately escalate the critical laboratory finding to the registered nurse for urgent intervention.

Step-by-Step Solution

1
Analyze the clinical laboratory data and physical assessment findings
The serum potassium is 2.8 mEq/L (critical hypokalemia). Asterixis is present (indicating active encephalopathy). Three soft stools indicate the lactulose is effectively increasing bowel motility.
Establishing the client's baseline physiological status is required before administering high-risk medications.
2
Evaluate the pharmacological mechanism and adverse effects of lactulose
Lactulose acts as an osmotic laxative to trap and excrete ammonia in the stool; however, this mechanism inherently causes significant gastrointestinal loss of water and electrolytes, specifically potassium.
Understanding the mechanism of action highlights the direct conflict between the medication's effect and the client's current potassium deficit.
3
Synthesize the physiological risks
Administering lactulose will worsen the severe hypokalemia, placing the client at imminent risk for lethal cardiac dysrhythmias. Additionally, severe hypokalemia actually increases renal ammonia production, paradoxically worsening the encephalopathy.
Clinical judgment requires balancing the therapeutic need (treating encephalopathy) against immediate life-threatening physiological risks (cardiac dysrhythmia from hypokalemia).
4
Determine the appropriate intervention within the PN scope of practice
The PN must withhold the unsafe medication and urgently escalate the critical potassium value to the RN for medical intervention.
A PN cannot independently alter medical prescriptions, but has a duty to withhold harmful medications and report critical findings.

Key Concept

Recognizing severe hypokalemia as an absolute contraindication for administering osmotic laxatives, and adhering to the PN scope of practice by withholding the drug and escalating critical labs.
Rate this question

Topics

Pharmacological Therapies

More questions from this topic