Background/purpose: Postoperative nausea and vomiting is common after general anesthesia. The timing of resuming oral input is arbitrary. This study aims to estimate the duration of emetic effects of general anesthesia after day surgery in children with electrogastrography (EGG).
Methods: Children between the age of 3 and 12 years undergoing elective nonabdominal surgery were recruited. The standard anesthesia protocol of thiopentone (5 mg/kg), O2 (30%), N2O (70%), and isoflurane (1.5%) was adopted. Caudal block was applied to the patients. A laryngeal mask was used. A mobile electrogastrogram (EGG) machine (Synectic; International Medtronic Synectics, Stockholm, Sweden) was attached to the epigastrium of the patient at least 1 hour before the operation and the recording continued through the operation and for a further 2 hours after the operation. The first half hour of preoperative recording was taken as normal control period. The results were analyzed using paired t test.
Results: Twenty patients who underwent circumcision under general anesthesia were studied. The mean age was 6.6 years. The mean anesthetic duration was 33.2 min. The tachygastria component (associated with nausea and vomiting) became prominent immediately after induction and returned to normal 1 half hour after cessation of general anesthesia. The dominant frequency instability coefficient of EGG (DFIC) and the dominant power instability coefficient (DPIC) peaked during the first half hour period postoperatively and returned to baseline 1 hour postoperatively (DPIC, P>.05). Bradygastria became prominent during the periods 1 half-hour before and 1 half-hour after the general anesthesia and returned to baseline 1 hour postoperatively (P<.05).
Conclusions: Significant EGG changes occur during day-surgery general anesthesia for children undergoing nonabdominal surgery. These changes return to baseline 1 hour after reversal of anesthesia. It is probably safe to restart feeding 1 hour later after day-surgery general anesthesia without causing nausea and vomiting.