Vomiting, retching, headache and restlessness after halothane-, isoflurane- and enflurane-based anaesthesia. An analysis of pooled data following ear, nose, throat and eye surgery.
BACKGROUND
Isoflurane has exceeded halothane and enflurane in usage. A literature search, however, revealed no data comparing the effects on emesis, headache and restlessness of these three agents.


METHODS
With hospital ethics committee approval and patient consent, a prospective, randomised, double-blind study of 556 patients undergoing ENT and eye surgery was undertaken to evaluate the effects of halothane, isoflurane and enflurane on vomiting, retching, headache and restlessness until 24 h after anaesthesia. Balanced general anaesthesia was administered comprising benzodiazepine premedication, induction with thiopentone-atracurium-morphine (ENT patients) or fentanyl (eye patients), controlled ventilation and maintenance with either halothane 0.4-0.6 vol% (n = 186), isoflurane 0.6-0.8 vol% (n = 184) or enflurane 0.8-1 vol% (n = 186) in nitrous oxide 67% and oxygen.


RESULTS
The three study groups were comparable, and comprised comparable subgroups having ear, nose, throat, intraocular and non-intraocular surgery. During early recovery from anaesthesia, the respective requirements for halothane, isoflurane and enflurane for analgesia (7%, 9% and 10%), frequency of emesis (6%, 8% and 8%), antiemetic requirements (1%, 1% and 2%), restlessness-pain scores and time spent in the recovery ward (27 SD 10, 31 SD 12 and 26 SD 9 min) were similar. During the ensuing 24-h postoperative period, patients who had isoflurane experienced emesis less often than those who had halothane (36% vs 46%, P < 0.025) but did so with similar frequency to those who had enflurane (46% vs 41%). Antiemetic requirements were least in those given isoflurane (isoflurane 12%, halothane and enflurane 23% each, P < 0.005), but headache and analgesic requirements were similar.


CONCLUSIONS
Isoflurane induces less postoperative emesis than halothane, but headache is similarly frequent after anaesthesia with any of these agents.
Department of Anaesthesia, Riyadh Armed Forces Hospital, Kingdom of Saudi Arabia.
A A
AA
van den Berg
N M
NM
Honjol
T
T
Mphanza
C J
CJ
Rozario
D
D
Joseph
D000328:Adult; D017109:Akathisia, Drug-Induced / Q000209:etiology; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D000932:Antiemetics / Q000627:therapeutic use; D004311:Double-Blind Method; D004737:Enflurane / Q000009:adverse effects*; D005260:Female; D006221:Halothane / Q000009:adverse effects*; D006261:Headache / Q000139:chemically induced*; D006801:Humans; D007530:Isoflurane / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D013517:Otorhinolaryngologic Surgical Procedures; D011446:Prospective Studies; D014839:Vomiting / Q000175:diagnosis* / Q000188:drug therapy
D018685:Anesthetics, Inhalation; D000932:Antiemetics; D004737:Enflurane; D007530:Isoflurane; D006221:Halothane