## Understanding RSI Pharmacology and Technique ### The Correct Answer: Rocuronium Onset vs Succinylcholine **Key Point:** Rocuronium, even at high doses (1.2 mg/kg), has an onset of 60–90 seconds, which is SLOWER than succinylcholine's 30–45 seconds. Rocuronium is NOT faster than succinylcholine for RSI. **High-Yield:** While rocuronium is increasingly used in RSI (especially in patients with contraindications to succinylcholine), the statement that rocuronium provides "faster onset" is factually incorrect and is the wrong statement in this question. ### Why the Other Options Are Correct | Aspect | Detail | |--------|--------| | **Cricoid Pressure** | Applied at loss of consciousness, maintained until cuff inflation and position confirmed; prevents passive regurgitation | | **Succinylcholine** | Gold standard for RSI: onset 30–45 sec, duration 5–10 min; depolarizing agent with rapid metabolism by pseudocholinesterase | | **Pre-oxygenation** | 3–5 min continuous or 8 vital capacity breaths achieves FiO₂ >90%; extends safe apnea time to 8–10 min in non-obese adults | **Clinical Pearl:** Rocuronium's advantage lies in its lack of hyperkalemia risk and absence of malignant hyperthermia trigger, not speed of onset. When rocuronium IS chosen for RSI, sugammadex (reversal agent) must be available. **Mnemonic:** **SUCK-cinyl = QUICK** — Succinylcholine is the quick choice for RSI onset; Rocuronium is the safer choice when contraindications exist. [cite:Stoelting's Pharmacology and Physiology in Anesthetic Practice Ch 8]
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