Neuronal Physiology, Physiology, USMLE Step 1 - Full Vignette with Extended Explanations

A 40-year-old woman with multiple medical conditions presents after recent travel to a tropical farm, developing sudden respiratory distress, vomiting, excessive secretions, muscle fasciculations, and altered mental status. On exam, she is hypoxemic, hypertensive, and has pinpoint pupils with marked bronchorrhea. What clinical considerations should guide airway management in a patient with suspected toxic exposure and cholinergic symptoms? How do underlying physiological mechanisms impact your intubation strategy? VIDEO INFO Category: Neuronal Physiology, Physiology, USMLE Step 1 Difficulty: Moderate - Intermediate level - Requires solid foundational knowledge Question Type: Clinical Pitfalls Case Type: ED Case Explore more ways to learn on this and other topics by going to https://endlessmedical.academy/auth?h... QUESTION A 40-year-old woman with primary myelofibrosis (JAK2 V617F), Sheehan syndrome on replacement therapy, HPV infection, and polymyalgia rheumatica presents to the ED with acute respiratory distress, copious salivation, vomiting, abdominal cramping, diaphoresis, and confusion that began 1 hour after returning from a 2-week trip where she visited family working on a tropical farm that recently sprayed organophosphate insecticide. She keeps exotic pets at home and works in a hospital laboratory.... OPTIONS A. Rocuronium 1.2 mg/kg IV ( 77 mg for a 64-kg adult) for rapid sequence intubation, avoiding succinylcholine and mivacurium because cholinesterase inhibition markedly prolongs their effect; continue antidotal therapy and mechanical ventilation. B. Succinylcholine 1.5 mg/kg IV for the fastest onset because apnea risk is high; accept the possibility of prolonged paralysis and provide bag-valve ventilation until recovery from cholinesterase inhibition. C. Mivacurium 0.2 mg/kg IV to minimize hemodynamic effects, relying on plasma cholinesterase metabolism to ensure a short block despite cholinesterase inhibitor toxicity. D. Cisatracurium 0.2 mg/kg IV because it undergoes Hofmann elimination and is unaffected by cholinesterase inhibition; choose it as the universal first-line agent for all toxic inhalational exposures regardless of urgency. CORRECT ANSWER A. Rocuronium 1.2 mg/kg IV ( 77 mg for a 64-kg adult) for rapid sequence intubation, avoiding succinylcholine and mivacurium because cholinesterase inhibition markedly prolongs their effect; continue antidotal therapy and mechanical ventilation. EXPLANATION Rocuronium 1.2 mg/kg IV ( 77 mg for a 64-kg adult) for rapid sequence intubation, avoiding succinylcholine and mivacurium because cholinesterase inhibition markedly prolongs their effect; continue antidotal therapy and mechanical ventilation. This is correct because organophosphate and related cholinesterase inhibitors profoundly reduce butyrylcholinesterase and acetylcholinesterase activity, causing dangerously prolonged paralysis with depolarizing (succinylcholine) and ester-metabolized nondepolarizing (mivacurium) agents. Rocuronium at RSI dosing achieves rapid onset independent of cholinesterase activity.... --------------------------------------------------- Our cases and questions come from the https://EndlessMedical.Academy quiz engine - multi-model platform. Each question and explanation is forged by consensus between multiple top AI models (GPT, Claude, Grok, etc.), with automated web searches for the latest research and verified references. Calculations (e.g. eGFR, dosages) are checked via code execution to eliminate errors, and all references are reviewed by several AIs to minimize hallucinations. Important note: This material is entirely AI-generated and has not been verified by human experts; despite stringent consensus checks, perfect accuracy cannot be guaranteed. Exercise caution - always corroborate the content with trusted references or qualified professionals, and never apply information from this book to patient care or clinical decisions without independent verification. Clinicians already rely on AI and online tools - myself included - so treat this book as an additional focused aid, not a replacement for proper medical education. Visit https://endlessmedical.academy for more AI-supported resources and cases. This material can not be treated as medical advice. May contain errors. ---------------------------------------------------