Residual gastric fluid volume and chewing gum before surgery

In this study we sought to determine if chewing gum preoperatively increases gastric fluid volume (GFV) and changes gastric acidity. Children, 5-17 yr old, were randomized to one of three groups: a control group that was not given any gum, a group that was given sugarless bubble gum, and a group that was given sugared bubble gum. Patients in the two gum groups were instructed to chew their gum for a period of 30 min. After induction of anesthesia and tracheal intubation, the stomach was suctioned with a salem sump orogastric tube. We found that children who did not chew gum had significantly smaller GFV as compared with children who chewed sugared and sugarless gum (0.35 [0.2-0.5] mL/kg versus 0.88 [0.6-1.4] mL/kg versus 0.69 [0.4-1.6] mL/kg; P = 0.0001). Children who did not chew gum also had a significantly lower gastric fluid pH as compared with children chewing sugared and sugarless gum (geometric mean, 1.91 versus 2.25 versus 2.19; P = 0.007). We conclude that children who present for surgery while chewing gum have significantly larger GFV and higher pH.