Intraoral moisture during operation under general anesthesia

BACKGROUND: Intra-operative intraoral moisture was examined using a moisture checker, on the hypothesis that as an operation is prolonged, the intraoral moisture decreases; consequently, intraoral drying level should increase. METHODS: This hypothesis was tested on 27 adult patients undergoing a regular operation. The subjects having fasted since 0:00 o'clock of the operation day entered the operating room, where their intraoral moisture was measured using an intraoral moisture checker (Life Co. Ltd., Tokyo) (the unit is % index). Then, propofol administration was started with simulated blood concentration of 4 microg x ml(-1). Anesthesia was induced with vecuronium 1 mg x kg(-1) and fentanyl 1.5 microg x mg(-1). Every hour from anesthesia induction to the end of operation, intraoral moisture was checked. The propofol simulated blood concentration during operation was set to remain at 2-3.5 microg x ml(-1), with fentanyl administered. Statistical analysis was done by two factor factorial ANOVA. P < 0.05 was considered significant. RESULTS AND CONCLUSIONS: The intraoral moisture during operation under general anesthesia showed no chronologically significant difference.