INHALATION ANESTHESIA WITH 30% NITROUS OXIDE PREMIXED GAS IN PERITONEOSCOPY

Abstract

Inhalation anesthesia with 30% nitrous oxide-70% oxygen pre-mixed gas was admini-stered to 88 patients subjected to peritoneoscopy. The anesthetic gas was inhaled through a face mask at a flow rate of 7.8 ± 0.21 per minute for 50.7 ± 24.4 minutes. The clinical efficacy of this inhalation anesthesia was compared with 47 patients not receiving the anesthetic as controls. The results are summarized as follows. Preanesthetic medication was the same in the two groups. 1) The proportion of patients who remained calm without any signs of excitement during operation was significantly greater in the group with the inhalation anesthesia (P < 0.05). 2) Pain felt at the time of puncturing with a syringe needle and of injecting a local anesthetic agent was relieved to a significantly greater extent in the group receiving the inhalation anesthesia (P<0.05). However, there was no significant difference between the two groups in respect of pain produced by manipulation of the endoscope. 3) The proportion of patients who were reported that they felt well during and after endoscopic examination or that endoscopy was performed without discomfort was signifi-cantly larger in the group with the inhalation anesthesia (P <0.01). 4) The physician's overall evaluation of clinical effect was good in a significantly greater proportion of cases in the group with the inhalation anesthesia (P <0.05). 5) No striking difference was observed between the two groups in the incidence of attendant symptoms. There was no evidence of adverse effect on the respiratory and circulatory systems as well as on liver function. 6) The premedication which proved to be nonemetic was a combination of a sedative and analgesic agents. These results led to the conclusion that inhalation of 30% nitrous oxide-70% oxygen pre-mixed gas is a useful anesthetic procedure providing a sedative-analgesic action adequate for peritoneoscopic purposes.