Patients can chew gum immediately before surgery. I guess

A study presented at the American Society of Anesthesiologists (ASA) meeting in October of this year found that patients who chew gum in the immediate preoperative period may safely undergo surgery.

The authors, based at the University of Pennsylvania, found that gum chewing increases saliva production and the volume of fluid in the stomach, but stomach acidity was equivalent to that of non-gum chewers. An article about the study said The mean gastric volume, or total amount of liquid in the stomach, was statistically higher in patients who chewed gum before their procedure (13ml) versus those who did not (6ml). A 7 mL difference might be statistically significant, but surely is not clinically important.

The research differed from previous studies because it involved patients who underwent upper gastrointestinal endoscopy, which enabled the investigators to recover all of the fluid in the stomach for testing. Prior studies had been done using nasogastric tubes, and it was impossible to determine whether all gastric fluid was recovered when the tubes were suctioned.

The study involved 34 gum chewers who were allowed to chew any type or any amount of gum compared to 33 patients who did not chew gum.

Preoperative fasting and evidence-based medicine

The other day Mike Blackburn, a South African anesthesiologist I follow on Twitter, posted this: "Colleague just fb’d about a surgeon who said, 'I know we should wait 6 h but she ate at 12 and looks like a fast digester.'"

This was followed by a tweet from someone who calls him- or herself @LessIsMoreMed who said, "funnier still is the lack of evidence re: pre-op fasting" and included links to two references on the subject.

This reminded me of an incident that occurred about three years ago. I was working as a surgical hospitalist and had admitted a patient with acute cholecystitis in the middle of the night. I put her on the add-on OR schedule for that day.

By and by the patient was called for and when I got to the operating room holding area, the anesthesiologist met me with a frown on his face and told me the case would have to be postponed for a minimum of 6 hours.

I asked why. He told me that when he interviewed the patient, he noticed that the patient had a piece of hard candy in her mouth. He informed me that, in terms of gastric secretion, the act of sucking on a piece of hard candy was equivalent to having a eaten a full meal of solid food.