Atracurium infusions in major ophthalmic surgery

Fifteen patients who were undergoing major ophthalmic surgery were anaesthetized using controlled ventilation with nitrous oxide, oxygen, midazolam and fentanyl after induction with thiopentone. Each was then given a bolus dose of 0.6 mg kg-1 atracurium followed immediately by an infusion of the drug at the rate of 0.6 mg kg-1 h-1, neuromuscular function being monitored throughout. Even slight movement can jeopardize the success of this type of surgery but good control of neuromuscular blockade was achieved without inhalational supplementation. The mean duration of the atracurium infusion was 118 min (range 30-247 min). The mean time from stopping the infusion to recovery of the first twitch of the train of four (TOF) to 20% was 25 min (range 11-44 min). Atropine (1.2 mg) and 5.0 mg neostigmine were then given in divided doses and a rapid and complete recovery was achieved. This technique can be used safely even in bad-risk patients but the infusion should be discontinued about 25 min before the end of surgery.