Immediately after induction of anaesthesia with a high intravenous bolus of fentanyl, the anaesthetist finds it difficult to ventilate the patient despite an open airway. The most likely explanation is:

• A Truncal and chest wall muscle rigidity reducing compliance ✓
• B Fentanyl-induced bronchospasm from histamine release
• C Fentanyl-induced laryngospasm
• D Central apnoea with loss of diaphragmatic tone

Explanation

High-dose intravenous fentanyl can cause generalized truncal and chest wall rigidity severe enough to prevent bag-mask ventilation. It responds to neuromuscular blockade or naloxone. Unlike morphine, fentanyl causes minimal histamine release, so bronchospasm is unlikely. Laryngospasm is not a recognized effect of fentanyl, and the problem here is mechanical stiffness of the thorax rather than absent respiratory drive alone.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.