Current fasting guidelines for elective procedures that require anesthesia are poorly implemented, resulting in negative metabolic sequelae. A prospective quality improvement study evaluated the implementation of a liberal clear-fluid fasting policy in adults scheduled for procedures requiring anesthesia with a focus on fasting duration, well-being, and safety.

In the standard fasting policy, clear fluids were allowed until two hours before the start of anesthesia. In the liberal policy, intake of up to one glass of water per hour was permitted until arrival in the operating room. Of 76,451 patients (mean age, 56 years; 52% men) included in the study, 59,036 followed the standard fasting policy and 16,815 followed the liberal policy. After implementation of the liberal policy, overall median fasting time decreased significantly, from 3.07 hours to 1.20 hours.

In the liberal policy group, the incidence of regurgitation was 24 in 10,000 patients compared with 18 in 10,000 patients in the standard policy group. The incidence of aspiration was 2.4 in 10,000 patients in the liberal policy group compared with 1.7 in 10,000 patients in the standard policy group. The incidence of aspiration pneumonia was 1.8 in 10,000 patients in the liberal policy group and 0.7 in 10,000 patients in the standard policy group.

The incidence of postoperative nausea and vomiting was lower in the liberal policy group than in the standard policy group (9.4% versus 10.6%, respectively), and fewer patients in the liberal policy group received antiemetics compared with those in the standard policy group (9.5% versus 11%, respectively). In the liberal policy group, 37% felt thirsty before surgery compared with 46% of those in the standard policy group.

Among the limitations of this study, according to the authors, was that it was underpowered to draw conclusions on the safety of the liberal fasting policy regarding regurgitation and aspiration. Additionally, because of the observational design, residual confounding was possible. The authors conclude that wider implementation of the liberal fasting policy may be advocated despite a slightly increased risk of regurgitation. Their results suggest that procedures shouldn't be postponed or canceled if patients drink clear fluids within two hours of anticipated anesthesia.