Effect of a constant rate infusion of lidocaine on the quality of recovery from sevoflurane or isoflurane general anaesthesia in horses.

REASONS FOR PERFORMING STUDY

Lidocaine constant rate infusions (CRIs) are common as an intraoperative adjunct to general anaesthesia, but their influence on quality of recovery has not been thoroughly determined.

OBJECTIVES

To determine the effects of an intraoperative i.v. CRI of lidocaine on the quality of recovery from isoflurane or sevoflurane anaesthesia in horses undergoing various surgical procedures, using a modified recovery score system.

HYPOTHESIS

The administration of intraoperative lidocaine CRI decreases the quality of recovery in horses.

METHODS

Lidocaine (2 mg/kg bwt bolus followed by 50 microg/kg bwt/min) or saline was administered for the duration of surgery or until 30 mins before the end of surgery under isoflurane (n = 27) and sevoflurane (n = 27).

RESULTS

Horses receiving lidocaine until the end of surgery had a significantly higher degree of ataxia and a tendency towards significance for a lower quality of recovery. There was no correlation between lidocaine plasma concentrations at recovery and the quality of recovery.

CONCLUSIONS

Intraoperative CRI of lidocaine affects the degree of ataxia and may decrease the quality of recovery.

POTENTIAL RELEVANCE

Discontinuing lidocaine CRI 30 mins before the end of surgery is recommended to reduce ataxia during the recovery period.