Fasting in pediatric anesthesia: the art of making simple things complex

Abstract

Prolonged preoperative fasting times for children scheduled for general anesthesia and surgery continue to be reported despite a plethora of recent studies suggesting that fasting for clear fluids can be shortened without increasing the risk of pulmonary aspiration. The aim of this narrative review was to summarize knowledge about the known benefits and potential consequences of prolonged fasting in pediatric anesthesia and to discuss the difficult implementation of reduced fasting times in clinical practice. This narrative review is based on fifteen studies published in the databases PubMed, EMBASE and Cinahl from October 2009 to June 2020. Outcome measures assessed were divided into 4 overall domains: metabolism and hemodynamics (1), patient comfort and patient/parent satisfaction (2), gastric volume and/or emptying time (3) and risk of pulmonary aspiration (4). While incidences of pulmonary aspiration remain low after implementation of less restrictive recommendations, the duration of fasting times relates to negative outcomes (low post-induction blood pressure, increase of blood ketones, poor patient/parent satisfaction). Preoperative fasting times must balance the risk of aspiration during anesthesia against children’s wellbeing and metabolic homeostasis. Based on the current evidence on preoperative fasting in children, liberal fasting times with nil-per-mouth for solids and formulas, breast milk and clear fluids corresponding to 6, 4 and 1 hours respectively, are safe. However, a reduction in real fasting times is pending and requires a multifactorial approach.