Which inhalational agent uniquely causes non-shivering thermogenesis to be impaired, contributing to the greatest degree of intraoperative hypothermia compared with other volatile agents at equipotent concentrations?
- A Isoflurane
- B Desflurane
- C Halothane ✓
- D Sevoflurane
Correct answer: C. Halothane
Explanation
Halothane inhibits non-shivering thermogenesis more profoundly than the newer fluorinated agents by directly uncoupling mitochondrial oxidative phosphorylation in brown adipose tissue, thereby preventing adaptive heat production. All volatiles impair thermoregulation centrally, but halothane's direct mitochondrial action on thermogenin (UCP1) is more pronounced. Desflurane and isoflurane primarily impair the central thermoregulatory setpoint but leave peripheral thermogenesis relatively intact.
Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.