Preoperative clear fluid fasting and endoscopy‐measured gastric fluid volume in children

Abstract

Background:In light of new recommendations to shorten clear fluid fasting time before anesthesia, our study aimed at exploring residual fluid volume in the stomach after different fasting times. We intended to perform direct endoscopic aspiration of stomach contents under vision, as part of routine gastroscopy assessment. Hereby we would be able to quantify true residual gastric fluid volume and acidity in children and measure their correlation with fasting times. Methods:The study was performed as a single-center, prospective study in pediatric perioperative day care at a university-affiliated tertiary care center. Aspiration of gastric fluid contents was performed in anesthetized children aged 1-18 years undergoing an elective gastroscopy. Recorded data included patient fast time, last meal content, last clear fluid content, and aspirated gastric volume and pH, as well as patient characteristics. Results:We included 253 gastroscopies, performed in 245 children. Mean fasting time for clear fluids was 6.9 h (range 1 h 40 min -18 h 35 min) (SD 4.5). Mean age was 9.8 years (SD 5.1) and mean body weight was 33.2 kg (SD 18.7). Mean residual gastric volume was 12 mL (0-90) (SD 13.5) or 0.34 mL/kg (SD 0.37) and mean pH was 1.5 (SD 0.9). No significant correlation was observed between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight (r = −.103, p = .1), nor between clear fluid fasting time and the pH of the residual gastric fluid (r = −.07, p = .3). In more than half of the patients the residual gastric volume was less than 10 mL, unrelated to fasting time. Conclusions: In children undergoing gastroscopy, we could not demonstrate any association between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight. Since we did not see a clinically relevant association between clear fluids fasting time and gastric residual volume, this study may support the recommendation to shorten clear fluids fasting time.

Assessing Residual Gastric Fluid Volume after Administering Diluted Oral Contrast until One Hour Prior to Anesthesia in Children: An Observational Cohort Study

“…Our approach to measuring the gastric fluid volume via CT imaging, which is a standard and accepted technique for volume measurement in radiology [ 9 , 10 ] and bariatric surgery [ 11 ], was different from the methods used in previous studies, which measured gastric fluid volumes by using blind aspiration of the gastric contents [ 21 , 22 ], ultrasound assessment [ 28 , 29 , 31 ], or magnetic resonance imaging [ 27 ]. This was a practical choice because all our study patients were undergoing abdominal CT scans.…”

“…The mean pH of the residual gastric fluid was 1.5 (SD 0.9). A reverse correlation (r = −0.236, p = 0.01) between residual gastric volume and pH indicates that a lower pH was correlated with larger volumes [ 31 ]. Another prospective clinical trial comparing gastric pH and residual volume after one vs. two hours of preoperative clear fluid fasting in 131 children (ASA I or II) aged 1.01 to 16.23 years showed that one hour of clear fluid fasting does not alter gastric pH or residual volume significantly compared with fasting for two hours [ 30 ] The mean gastric pH in the one-hour fasting group was 1.44 (SD 0.26) [ 30 ] The mean pH of the residual gastric fluid in our study was higher, at 2.14 (SD 1.23), than the previously mentioned studies and did not correlate with age, weight, or time from the end of contrast [ 5 ].…”

Liberal Preoperative Fasting in Adults Undergoing Elective Surgery: A Scoping Review Protocol

“…In 1986, Maltby et al [ 10 ] challenged the overnight fasting routine, who found no correlation between gastric volume or pH values with the ingestion-surgery interval in patients given 150 ml of water. Aschkenasy et al [ 11 ] also found that drinking water at different fasting times did not have a significant correlation with gastric residual fluid. Although aspiration can lead to aspiration pneumonia and ultimately death, the incidence is relatively very low at around 0.014% [ 12 , 13 ].…”