Hyperthermia - alternate approach

🔥 Hyperthermia Syndromes in the ICU – Comparison of Symptoms and Treatment

Comparative Table

Syndrome	Key Triggers	Core Features	Muscle Involvement	Labs	Main Treatments
Neuroleptic Malignant Syndrome (NMS)	Dopamine antagonists (e.g., haloperidol); abrupt withdrawal of dopaminergic drugs	Gradual onset (1–3 days), fever, rigidity, mental status changes, autonomic instability	Lead-pipe rigidity	↑ CK, ↑ WBC, ↑ LFTs, metabolic acidosis	Stop offending agent, dantrolene, bromocriptine, supportive care
Serotonin Syndrome	SSRIs, MAOIs, TCAs, linezolid, fentanyl, tramadol	Rapid onset (<24h), fever, agitation, tremor, hyperreflexia, clonus	Hyperreflexia, clonus	Mild ↑ CK, ↑ WBC	Stop agent, benzodiazepines, cyproheptadine, cooling
Malignant Hyperthermia (MH)	Inhaled anesthetics (e.g., halothane), succinylcholine	Acute onset during/after anesthesia, fever, rigidity, tachycardia, hypercarbia	Generalized rigidity, masseter spasm	↑↑ CK, ↑ K+, metabolic/resp acidosis	Stop agent, dantrolene, cooling, manage acidosis
Heat Stroke	Environmental heat + exertion or impaired thermoregulation	Sudden collapse, AMS, anhidrosis or sweating, core temp >40°C	Possible rigidity or flaccidity	↑ LFTs, ↑ CK, coagulopathy, DIC	Rapid cooling, IV fluids, ICU support
Thyroid Storm	Untreated or undertreated hyperthyroidism, stress, infection	Fever, agitation, tremor, tachycardia, diarrhea, AMS	No rigidity	↑ T3/T4, ↓ TSH	Beta-blockers, PTU, iodine, steroids, cooling
Sepsis/Septic Shock	Infection (bacterial, fungal, etc.)	Fever (or hypothermia), hypotension, AMS, multi-organ dysfunction	No rigidity	↑ lactate, ↑ WBC, positive cultures	Broad-spectrum antibiotics, fluids, vasopressors

🔬 Key Diagnostic Clues & Distinctions

• NMS: Dopamine blockade, rigidity without clonus, onset over days, bromocriptine responsive.
• Serotonin Syndrome: Serotonergic drugs, clonus/hyperreflexia, rapid onset, responds to cyproheptadine.
• MH: Genetic predisposition, intraoperative onset, masseter rigidity, requires dantrolene emergently.
• Heat Stroke: History of heat exposure, absence of drug triggers, rapid cooling is essential.
• Thyroid Storm: History of hyperthyroidism, systemic symptoms, thyroid panel essential.
• Sepsis: Infection signs, positive cultures, lactic acidosis, systemic organ dysfunction.

💊 Medications Summary

Medication	Used In	Mechanism
Dantrolene	NMS, MH	Inhibits Ca²⁺ release from sarcoplasmic reticulum
Bromocriptine	NMS	Dopamine agonist
Cyproheptadine	Serotonin Syndrome	5-HT₂A antagonist
Propranolol / Esmolol	Thyroid Storm	Controls tachycardia, blocks T4 → T3 conversion
PTU / Methimazole	Thyroid Storm	Inhibit thyroid hormone synthesis
Antibiotics	Sepsis	Treat underlying infection