Five days ago, a 60-year-old woman underwent pars plana vitrectomy with 14% C3F8 gas tamponade for a retinal detachment. She now requires emergency laparoscopic cholecystectomy under general anaesthesia. Which anaesthetic agent must be avoided?
- A Nitrous oxide ✓
- B Propofol
- C Sevoflurane
- D Rocuronium
Correct answer: A. Nitrous oxide
Explanation
Nitrous oxide is 46 times more soluble than nitrogen and diffuses rapidly into an intraocular gas bubble, expanding it massively within minutes and causing an acute, potentially blinding rise in intraocular pressure or central retinal artery occlusion. Nitrous oxide should be avoided until the bubble has fully absorbed, up to 6 to 8 weeks after C3F8. Sevoflurane, propofol and rocuronium have no such effect on intraocular gas volume.
Reference: Ryan's Retina, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.