Core Nursing Explanation
This question tests the critical nursing skill of
prioritization in a patient with severe
Anorexia Nervosa (AN). The core theme is recognizing that the most immediate threat to life is not the psychiatric disorder itself, but the severe
physiological complications of starvation. The patient's data paints a picture of a body in a state of severe energy conservation and metabolic compromise.
Key Concept Analysis
The patient presents with multiple red flags indicating medical instability:
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Severe Bradycardia (HR 48 bpm): In AN, the heart muscle atrophies and metabolic rate plummets. The body slows the heart to conserve energy, but this bradycardia is pathological and can progress to fatal arrhythmias like
asystole.
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Hypotension (BP 90/55 mmHg): Caused by dehydration, reduced cardiac output, and loss of vascular tone.
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Cachexia and
Low BMI (15.8 kg/m²): Indicates severe malnutrition and protein-energy wasting.
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Electrolyte Imbalances (Hypomagnesemia, Hypophosphatemia): These are critical. Magnesium and phosphate are essential for cardiac muscle function and cellular energy production (ATP). Deficits directly increase the risk of
Key Point! life-threatening cardiac arrhythmias (e.g., torsades de pointes) and are hallmarks of impending
Refeeding Syndrome.
Answer Rationale
Key Point! The priority nursing intervention is
Implement continuous cardiac monitoring immediately. This is based on the
ABCs (Airway, Breathing, Circulation) of prioritization. The patient's circulation is critically compromised by bradycardia, hypotension, and electrolyte disturbances that create a perfect storm for sudden cardiac arrest. Continuous monitoring allows for immediate detection and intervention for arrhythmias, making it a life-saving action. This intervention directly addresses the
greatest and most immediate risk to patient safety.
Distractor Analysis
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Watch out for confusion! Option ② (Group therapy) and ④ (Therapeutic relationship) are essential
psychiatric nursing interventions for AN, addressing the core psychological issues. However, according to
Maslow's Hierarchy of Needs and nursing prioritization principles, physiological safety (circulation) must be secured before addressing psychosocial needs.
* Option ③ (Nutritional education) is a crucial component of long-term recovery but is
contraindicated as an initial priority. Initiating aggressive nutritional counseling or refeeding without first stabilizing the patient and monitoring for refeeding syndrome can be dangerous. The priority is to medically stabilize the patient so that nutritional rehabilitation can be done safely.
Related Concepts
This case integrates concepts from medical-surgical nursing (cardiac monitoring, electrolyte management) and psychiatric nursing. The nurse must function as an integrator, recognizing when a psychiatric patient requires acute medical intervention. Understanding
Refeeding Syndrome—a potentially fatal shift of electrolytes and fluids that occurs when nutrition is restarted in a severely malnourished patient—is critical. Hypophosphatemia is its hallmark.
Concept Summary
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Primary Threat: Physiological instability (cardiac arrhythmia, refeeding syndrome) over psychological symptoms.
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NCLEX Priority Framework: ABCs (Airway, Breathing, Circulation) & Maslow's Physiological Needs.
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Key Lab Values: Monitor K+, Mg2+, PO4- (Phosphate), Na+.
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Underlying Pathophysiology: Starvation → Body conserves energy (↓HR, ↓BP, ↓Temp) → Cardiac muscle wasting & electrolyte depletion → High risk for arrhythmia/cardiac arrest.
Side-by-Side Comparison!
| Priority in Acute Medical Instability (This Case) | Priority in Stabilized Psychiatric Care |
|---|
| 1. Continuous cardiac monitoring | 1. Establish therapeutic relationship |
| 2. Monitor vital signs & electrolytes | 2. Supervised meals & nutritional support |
| 3. Implement refeeding protocol cautiously | 3. Cognitive-behavioral therapy (CBT) |
| 4. Ensure physical safety (fall risk) | 4. Address body image distortion |
Anatomy, Physiology & Pharmacology Points
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Cardiac Physiology: The heart requires magnesium for proper electrical conduction and phosphate for ATP production. Deficiencies lead to prolonged QT interval and weak cardiac contractions.
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Endocrine Physiology: Starvation lowers thyroid hormone (T3), contributing to bradycardia, hypotension, and cold intolerance.
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Pharmacology: Electrolyte replacements (IV Magnesium sulfate, Potassium phosphate) may be administered, but slowly and with close monitoring to avoid overload.
Memory Tips
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Acronym "HEART": In Anorexia, monitor
Heart rate (Bradycardia),
Electrolytes,
Arrhythmia risk,
Refeed carefully,
Temperature (Hypothermia).
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Rule of Thumb: If the patient with an eating disorder has a heart rate <
50 bpm, systolic BP <
90 mmHg, or critical electrolyte imbalances, think "
MEDICAL EMERGENCY, not just therapy."
High-Frequency NCLEX Topics
This is a classic NCLEX "priority" or "first" question. The exam loves to test your ability to distinguish between a
psychosocial need and a
physiological emergency in psychiatric patients. Always assess physiological stability (ABCs, vital signs, labs) first.
Watch Out for Question Variations!
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Shift from Symptom to Intervention: "The nurse notes the client's heart rate is 44 bpm. Which action should the nurse take
first?" (Answer: Assess blood pressure and attach cardiac monitor).
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Shift to Refeeding Syndrome: "The client with anorexia has started nutritional supplements. Which finding requires immediate intervention?" (Answer: Serum phosphate level of
1.5 mg/dL).
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Shift to Discharge Planning: "Which outcome indicates the client is ready for outpatient treatment?" (Answer: Vital signs and electrolyte levels have been stable within normal range for one week).