During rapid intravenous induction of anaesthesia, a patient receives an opioid bolus and immediately develops severe truncal and chest wall muscle rigidity that impairs bag-mask ventilation. Which opioid is classically associated with this complication?
- A Morphine
- B Codeine
- C Fentanyl ✓
- D Pentazocine
Correct answer: C. Fentanyl
Explanation
Fentanyl and its short-acting congeners (alfentanil, sufentanil) can provoke chest wall and glottic rigidity when given as a rapid IV bolus, thought to be centrally mediated. It prevents adequate ventilation and is managed with a neuromuscular blocker or naloxone. Morphine, by contrast, produces hypotension and pruritus through histamine release rather than muscle rigidity, which eliminates the most tempting distractor.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.