Complications of general anesthesia using nitrous oxide in eyes with preexisting gas bubbles.

Purpose: To present the visual and anatomical outcomes for patients with intraocular gas placed during vitreoretinal surgery who subsequently underwent surgery wherein general anesthesia with nitrous oxide was used.

Methods: The authors reviewed the charts of patients who had undergone vitreoretinal surgery where a long-acting gas tamponade had been used. These patients underwent additional surgery for a variety of reasons at five different institutions and had nitrous oxide used during general anesthesia. The authors reviewed the preoperative and postoperative findings for patients receiving nitrous oxide following vitreoretinal surgery with gas tamponade.

Results: The authors reviewed findings for five eyes of five patients. All eyes that underwent general anesthesia using nitrous oxide had significant preexisting intraocular gas bubbles ranging from 40% to 90%, and the surgical procedures lasted from 1 to 4 hours. These eyes were followed from 2 months to 9 years (median follow-up, 4 years). Four of five eyes had a final vision of 20/200 or worse and significant optic atrophy at the time of the last follow-up examination. Three eyes had no light perception.

Conclusion: The use of nitrous oxide during general anesthesia in gas-filled eyes may have disastrous visual results caused by gas expansion and elevated intraocular pressure. Patients must be advised of the potentially catastrophic results of undergoing general anesthesia before their intraocular gas bubble has resorbed. The use of nitrous oxide for patients with intraocular gas should be avoided. It may be prudent for patients with intraocular gas to wear notification bracelets warning anesthesiologists about the presence of intraocular gas lest emergency surgery be needed by a patient unable to advise anesthesia personnel about the potential danger.