Impact of clear fluids fasting on pulmonary aspiration in children undergoing general anesthesia: Results of the German prospective multicenter observational (NiKs) study.

Background A preliminary national audit of real fasting times including 3324 children showed that the fasting times for clear fluids and light meals were frequently shorter than recommended in current guidelines, but the sample size was too small for subgroup analyses. Aims Therefore, the primary aim of this extended study with more participating centers and a larger sample size was to determine whether shortened fasting times for clear fluids or light meals have an impact on the incidence of regurgitation or pulmonary aspiration during general anesthesia in children. The secondary aim was to evaluate the impact of age, emergent status, ASA classification, induction method, airway management or surgical procedure. Methods After the Ethics Committee's approval, at least more than 10 000 children in total were planned to be enrolled for this analysis. Patient demographics, real fasting times, anesthetic and surgical procedures, and occurrence of target adverse events defined as regurgitation or pulmonary aspiration were documented using a standardized case report form. Results At fifteen pediatric centers, 12 093 children scheduled for surgery or interventional procedures were included between October 2018 and December 2019. Fasting times were shorter than recommended in current guidelines for large meals in 2.5%, for light meals in 22.4%, for formula milk in 5.3%, for breastmilk in 10.9%, and for clear fluids in 39.2%. Thirty-one cases (0.26%) of regurgitation, ten cases (0.08%) of suspected pulmonary aspiration, and four cases (0.03%) of confirmed pulmonary aspiration were reported, and all of them recovered quickly without any consequences. Fasting times for clear fluids shortened from 2 hours to 1 hour did not affect the incidence of adverse events (upper limit 95% CI 0.08%). The sample size of the cohort with fasting times for light meals shorter than 6 hours was too small for a subgroup analysis. An age between one and 3 years (odds ratio 2.7,95% CI 1.3 to 5.8%;P < .01) and emergent procedures (odds ratio 2.8,95% CI 1.4 to 5.7;P < .01) increased the incidence of adverse events, whereas ASA classification, induction method, or surgical procedure had no influence. The clear fluid fasting times were shortest under 6/4/0 as compared to 6/4/1 and 6/4/2 fasting regimens, all with an incidence of 0.3% for adverse events. Conclusion This study shows that a clear fluid fasting time shortened from 2 hours to 1 hour does not affect the incidence of regurgitation or pulmonary aspiration, that an age between one and 3 years and emergent status increase the incidence of regurgitation or pulmonary aspiration, and that pulmonary aspiration followed by postoperative respiratory distress is rare and usually shows a quick recovery.