Summary of the review “Neuroleptic Malignant Syndrome”
6 Oct, 2024 | 16:20h | UTCIn a comprehensive review published in the New England Journal of Medicine, Wijdicks and Ropper discuss neuroleptic malignant syndrome (NMS), a rare but potentially fatal complication of antipsychotic therapy characterized by fever, muscle rigidity, and autonomic dysfunction. Given the widespread use of dopamine-blocking agents across various medical specialties, it is crucial for practicing physicians to recognize and manage this syndrome promptly to improve patient outcomes.
Key Aspects Influencing Patient Care:
- Epidemiology and Risk Factors:
- NMS occurs in approximately 0.02 to 3% of patients exposed to dopamine-blocking agents.
- Risk factors include dehydration, high doses of antipsychotics, rapid dose escalation, intramuscular administration, and prior episodes of NMS.
- Both first-generation (typical) and second-generation (atypical) antipsychotics can cause NMS, though it may be less severe with atypical agents.
- Clinical Presentation:
- Hyperthermia: Elevated temperatures often exceeding 40°C.
- Muscle Rigidity: Lead-pipe rigidity leading to rhabdomyolysis and elevated creatine kinase levels.
- Autonomic Dysfunction: Tachycardia, fluctuating blood pressure, diaphoresis.
- Altered Mental Status: Ranges from agitation to stupor or catatonia.
- Laboratory Findings: Leukocytosis, electrolyte imbalances, and signs of renal impairment.
- Diagnosis:
- Based on clinical criteria including recent exposure to dopamine antagonists and presence of key symptoms.
- Important to differentiate from serotonin syndrome, malignant hyperthermia, heat stroke, and severe catatonia.
- Management:
- Immediate Discontinuation of the offending agent.
- Supportive Care in ICU:
- Stabilize vital signs and manage autonomic instability.
- Aggressive hydration to prevent renal failure from rhabdomyolysis.
- Cooling measures for hyperthermia.
- Pharmacologic Interventions:
- Dantrolene: Reduces muscle rigidity and hyperthermia.
- Dopamine Agonists: Bromocriptine or amantadine may reverse dopamine blockade.
- Benzodiazepines: Lorazepam for sedation and muscle relaxation.
- Monitoring for Complications:
- Watch for respiratory failure, renal dysfunction, electrolyte disturbances, and cardiac arrhythmias.
- Electroconvulsive Therapy (ECT):
- Considered in refractory cases unresponsive to medical management.
- Outcome and Prognosis:
- Recovery typically occurs within 7 to 11 days with appropriate treatment.
- Mortality rates have decreased but can reach up to 15% within one year due to complications.
- Rechallenge with Antipsychotics:
- If necessary, reintroduce antipsychotics cautiously after full recovery, using low doses and slow titration.
- Prefer atypical agents and monitor closely for recurrence.
Clinical Implications:
- Early Recognition: Timely identification of NMS is critical for initiating life-saving interventions.
- Interdisciplinary Approach: Collaboration among psychiatrists, intensivists, neurologists, and other specialists enhances patient care.
- Education and Prevention:
- Educate healthcare providers about the signs and risk factors of NMS.
- Monitor patients on antipsychotics closely, especially during dose changes or when using high-potency agents.