Sussex Eye Hospital, Brighton BN2 5BF, UK E-mail: edwardlee{at}doctors.org.uk
Accepted for publication May 5, 2004.
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Abstract |
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Keywords: anaesthetics gases, nitrous oxide ; complications, visual loss ; eye, intraocular gas
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Introduction |
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Case report |
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He was making good postoperative progress until 37 days later when he underwent elective revision of a femoral-popliteal bypass under general anaesthetic. This was performed in the same healthcare trust but in a different hospital, using separate case notes from those used in the eye hospital. His recent ocular surgery was noted in the preoperative assessment but the use of intraocular gas was not. It had, however, been recorded in his ophthalmology case notes 1 week previously that he still had a 30% intraocular gas fill. The general anaesthetic given for his vascular procedure was uneventful. He was induced with fentanyl and propofol, and intubated after administration of vecuronium. Maintenance of anaesthesia was achieved with a 50:50 mixture of oxygen and nitrous oxide, and sevoflurane. Three litres of crystalloid were given. A small amount of ephedrine and metaraminol was also administered. Morphine was given towards the end of the operation for postoperative pain relief. The operation lasted 2 h and 37 min. On waking, the patient noticed that he could not see from his left eye and examination at that time demonstrated no perception of light. Ophthalmological review showed that the intraocular pressure was normal but the retina was white, the arteries were attenuated, and a gas bubble was still present. There was no significant blood loss or prolonged hypotension during the vascular surgery that could have caused the visual loss. The patient was diagnosed with central retinal artery occlusion secondary to bubble expansion during general anaesthesia. In the following 3 months, his vision has improved slightly to hand movements only in the left eye. The optic disc has become pale and the arteries remain very attenuated. As a consequence of this event and his diabetic retinopathy, he no longer reaches the legal limit of vision for driving in the UK.
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Discussion |
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Patients who have intraocular gas inserted should be advised of the risks of general anaesthesia whilst the gas bubble remains, and should be told to warn the anaesthetist if they are undergoing a subsequent general anaesthetic. It would also be advisable to use alternative agents to nitrous oxide. Air should be used as a carrier gas during anaesthetics for any patient who has undergone vitreoretinal surgery within the preceding 3 months, unless the notes are available and confirm that either intraocular gas was not used or that it has subsequently been completely reabsorbed. In our hospital, we have now introduced ID bracelets that are placed on the patient's wrist at the time of intraocular gas insertion, and are only removed once an ophthalmologist has determined that the gas has been fully absorbed. This idea has been suggested previously. It is intended to help prevent the use of nitrous oxide not only in elective surgery, but also in the event of the patient being unable to give a history before an emergency anaesthetic.2 6
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References |
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2 Fu AD, McDonald HR, Eliot D, et al. Complications of general anesthesia using nitrous oxide in eyes with preexisting gas bubbles. Retina 2002; 22: 56974[CrossRef][ISI][Medline]
3 Vote BJ, Hart R, Worsley DR, Borthwick JH, Laurent S, McGeorge AJ. Visual loss after use of nitrous oxide gas with general anesthetic in patients with intraocular gas still persistent up to 30 days after vitrectomy. Anesthesiology 2002; 97: 13058[ISI][Medline]
4 Lincoff H, Coleman J, Kressig I, Richard G, Chang S, Wilcox LM. The perfluorocarbon gases in the treatment of retinal detachment. Ophthalmology 1983; 90: 54651[ISI][Medline]
5 Hayreh SS, Kolder HE. Central retinal artery occlusion and retinal tolerance time. Ophthalmology 1980; 87: 758[ISI][Medline]
6 Hart RH, Vote BJ, Borthwick JH, McGeorge AJ, Worsley DR. Loss of vision caused by expansion of intraocular perfluoropropane (C(3)F(8)) gas during nitrous oxide anesthesia. Am J Ophthalmol 2002; 134: 7613[CrossRef][ISI][Medline]