The actual duration of preoperative fasting in pediatric patients, and its effects on hunger and thirst: a prospective observational study

Background: Preoperative fasting time for food and clear liquid was recommended as 2 and 6 h to prevent pulmonary aspiration. Prolonged fasting led to ketosis, hypotension, and patient discomfort. This study aimed to investigate the actual duration of preoperative fasting in pediatric patients, its effects on hunger and thirst, and factors that influence hunger and thirst. Methods: This prospective observational study recruited participants aged 0-15 years who were scheduled for elective surgery or for other procedures to be performed under general anesthesia in a tertiary care center. All parents or participants were asked to report the fasting time for food and clear liquid. Participants aged 7-15 years self-rated their degree of hunger and thirst using a 0-10 scale. For participants aged less than 7 years, parents were asked to rate their child's degree of hunger based on the child's behavior. Dextrose-containing intravenous fluid administration and anesthesia start time were collected. Results: Three hundred and nine participants were included. The overall median [interquartile range; IQR] fasting duration for food and clear liquid was 11.1 h [IQR: 8.0, 14.0] and 10.0 h [IQR: 7.2, 12.5], respectively. The overall median hunger and thirst score was 7 [IQR: 5, 9] and 5 [IQR: 0, 7.5], respectively. High hunger score was reported in 76.4% of participants. There was no correlation between fasting time for food and hunger score [Spearman's rank correlation coefficient (Rho): -0.150, P=0.008], or between fasting time for clear liquid and thirst score (Rho: 0.007, P=0.955). Zero to 2-year-old participants had a significantly higher hunger score compared to older participants (P<0.001) and a higher proportion (80-90%) of high hunger score regardless of anesthesia start time. Although dextrose-containing fluid was administered ≥10 mL/kg, 85.7% of this group still reported high hunger score (P=0.008). Ninety percent of participants who had anesthesia start time after 12:00 PM reported high hunger score (P=0.044). Conclusions: The actual duration of preoperative fasting was found to be longer than the recommendation for both food and liquid in pediatric surgical population. Younger age group and anesthesia start time in the afternoon were factors associated with high hunger score.