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Assessing the effect of sugar-free chewing gum use on the residual gastric volume of patients fasting for gastroscopy: A randomised controlled trial

journal contribution
posted on 2023-05-20, 09:47 authored by Best, GWJ, Fanning, SB, Iain RobertsonIain Robertson, Blackford, D, Mitchell, BL
There is no clear consensus in the current guidelines published by major international anaesthetic associations on what is the most appropriate time for a patient to stop chewing gum. This open-label balanced-group randomised controlled trial aimed to evaluate whether the chewing of sugar-free gum caused an increased volume or reduced pH of residual gastric fluid in fasting patients. For this study 212 patients undergoing elective gastroscopy were randomised into a control group who followed routine fasting instructions and an intervention group who were asked to chew gum while fasting. Residual gastric fluid was aspirated under direct vision via a gastroscope under anaesthesia. The primary outcome was the incidence of a gastric residual volume >50 ml in participants who chewed gum compared with a control group. Secondary outcomes were variability in the overall gastric volume distribution and gastric pH distribution between the two groups. Nine out of 110 (8.2%) in the chewing gum group and six out of 102 (5.9%) in the control group had a residual gastric fluid volume >50 ml: incidence rate ratio 1.39 (95% confidence intervals (CI) 0.51–3.77; P = 0.60). However, only one patient (in the control group) had a residual gastric volume >73 ml. There was no statistically significant difference in gastric volume distribution between groups, odds ratio 1.60 (95% CI 0.99–2.58; P = 0.054) or in the distribution of gastric pH measurement, odds ratio 0.90 (95% CI 0.57–1.44; P = 0.67). These results indicate that if there is an increase in the incidence of residual gastric volume >50 ml in patients who chew gum preoperatively, it is likely to be small. Moreover, the absence of any patients in our chewing gum group with a residual gastric volume >73 ml is reassuring.


Publication title

Anaesthesia and Intensive Care










School of Health Sciences


SAGE Publications

Place of publication

United States

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Copyright The Author(s) 2019

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  • Restricted

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Expanding knowledge in the health sciences

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