Effects of preoperative anxiety on gastric fluid acidity and volume

The aim of this study was to evaluate the effect of preoperative anxiety on the gastric pH and volume. We studied 96 female patients aged 16-60 yr who underwent elective gynecological surgery. We classified the subjects into 2 groups, those presenting preoperative anxiety scores using visual analogue scale (VAS, 0-10) less than 5 (L-group, n=59), and those with 5 and more (H-group, n=37). Immediately after tracheal intubation, gastric contents were aspirated using a 14-F multiorifice nasogastric tube. The gastric acidity and volume of the two groups were not statistically different. Mean pH were 3.0 +/-1.8 and 3.0 +/-2.0 in each group (L-group and H-group) and mean gastric volume (mL) were 15.3 +/-11.7 and 11.8 +/-11.8, respectively. Nine (15.3%) patients in the L-group were considered to be 'at risk i.e. gastric pH <2.5 and volume >25 mL' and one patient (2.7%) in the H-group (p <0.05). The mean serum gastrin concentrations in both groups were similar (21.6 +/-9.8 vs. 20.2 +/-11.0 pg/mL). The pH and volume of preoperative gastric contents were not correlated with the preoperative anxiety. The results suggest that a low level of preoperative anxiety can be considered a risk factor for aspiration pneumonitis.