Postoperative vomiting following strabismus surgery in paediatric outpatients: spontaneous versus controlled ventilation

The study was designed to compare the frequency and severity of postoperative vomiting in paediatric out-patients receiving controlled ventilation (IPPV) or breathing spontaneously (SV) during anaesthesia for strabismus repair. One hundred and twenty unpremedicated children (ages 2-12 years) were studied in a randomized fashion. After intravenous induction of anaesthesia and tracheal intubation, patients breathed halothane 1-1.5 per cent inspired and N2O 66 per cent in O2 spontaneously (n = 60), or received IPPV, halothane 0.5-1 per cent, N2O 66 per cent, and pancuronium 0.05 mg.kg-1, which was reversed with neostigmine and atropine (n = 60). The incidence of vomiting with SV was 50 per cent (95 per cent confidence limits: 34.5-65.5 per cent) compared with 40 per cent (24.5-55.5 per cent) with IPPV (p greater than 0.25). Patients in the SV group experiencing emesis had longer operations than those not vomiting (mean +/- SEM = 1.5 +/- 0.1 vs 1.2 +/- 0.1 hours, p less than 0.005). This was not the case with IPPV. There was no correlation between age, sex, duration of surgery, or number of extraocular muscles repaired, and frequency or severity of vomiting or time to discharge. No significant advantage was afforded by IPPV over SV in the present study.