[Gastric fluid volume and pH in scheduled surgical patients following unrestricted oral fluid intake until two hours before surgery].

BACKGROUND

In scheduled surgery, drinking is generally restricted for 6-8 hours before operation to avoid aspiration pneumonia induced by aspiration of residual gastric contents. However, the restriction is hard for patients and also there is no evidence of reduction of such a risk. We examined the correlation between water intake and residual gastric content.

METHODS

We studied 60 patients scheduled for gynecological operations (ASA 1 or 2). They were allowed to drink clear water freely until two hours before operation, and timing and volume of their drinking were recorded. In addition, volume and pH of the residual gastric content were measured at induction of anesthesia.

RESULTS

The mean volumes of fluids they had are 157 ml (range 0-750 ml) in the morning, and 486 ml (range 80-1300 ml) in the afternoon. The patients took more water as the scheduled time of operation became nearer. There was no correlation between the volume of preoperative drinking with the volume and pH of gastric content.

CONCLUSIONS

Intake of clear water until two hours before surgery has been shown to be safe and contribute to patients' satisfaction.