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Gastric pH and residual volume after 1 and 2 h fasting time for clear fluids in children†
A R Schmidt1, P Buehler2, L Seglias2
1Department of Anaesthesia, University Children's Hospital, Steinwiesstrasse 75, Zurich CH-8032, Switzerland alexander.schmidt@kispi.uzh.ch.
Insights
One hour of clear fluid fasting before anesthesia is safe for children, showing no significant difference in gastric pH or residual volume compared to two hours. This finding supports potentially shorter fasting times to improve patient comfort.
Area of Science:
- Pediatric Anesthesiology
- Gastroenterology
- Clinical Trial Research
Background:
- Current guidelines recommend 2-hour fasting for clear fluids before anesthesia, often exceeded in practice.
- Prolonged fasting can cause patient discomfort, dehydration, and stress, particularly in pediatric patients.
- Shorter fluid fasting durations have not been adequately investigated for their impact on gastric parameters.
Purpose of the Study:
- To compare gastric pH and residual volume in children after 1 hour versus 2 hours of preoperative clear fluid fasting.
- To evaluate the safety and efficacy of reduced fasting times in pediatric anesthesia.
- To provide evidence for optimizing preoperative fasting protocols.
Main Methods:
- A prospective clinical trial randomized 131 children (ages 1-16) into two groups: 60-minute (Group A) or 120-minute (Group B) clear fluid fasting.
- Gastric content was sampled via an oro-gastric tube after intubation to determine gastric pH and residual volume.
- Data were analyzed using median and interquartile range, with statistical significance set at P<0.05.
Main Results:
- Despite significantly shorter fasting times in Group A (76 min) versus Group B (136 min), no significant differences were found in gastric pH [1.43 vs 1.44] or residual volume [0.43 vs 0.46 ml kg(-1)].
- Patient characteristics were similar between groups, with a slight difference noted in gender distribution.
- The study included 120 children for gastric pH determination and reported P-values of 0.66 for pH and 0.47 for residual volume.
Conclusions:
- One hour of clear fluid fasting does not significantly alter gastric pH or residual volume compared to two hours in pediatric patients.
- This suggests that shorter preoperative fluid fasting times may be a viable option without compromising gastric safety.
- The findings support potential revisions to current fasting guidelines to enhance pediatric patient comfort.
Introduction:
Current guidelines suggest a fasting time of 2 h for clear fluids, which is often exceeded in clinical practice, leading to discomfort, dehydration and stressful anaesthesia induction to patients, especially in the paediatric population. Shorter fluid fasting might be a strategy to improve patient comfort but has not been investigated yet. This prospective clinical trial compares gastric pH and residual volume after 1 vs 2 h of preoperative clear fluid fasting.
Methods:
Children (1-16 yr, ASA I or II) undergoing elective procedures in general anaesthesia requiring tracheal intubation were randomized into group A with 60 min or B with 120 min preoperative clear fluid fasting. To determine gastric pH and residual volume, the gastric content was sampled in supine, left and right lateral patient position using an oro-gastric tube after intubation. Data are median (interquartile range) for group A or B (P<0.05).
Results:
In total, 131 children aged 1.01-16.23 yr were included; gastric pH was determined in 120 cases. Patient characteristic data were similar between the two groups, except for gender (46/33 males in group A/B; P=0.02). Despite significantly shorter fasting times for clear fluids in group A compared with group B (76/136 min; P<0.001), no significant difference was observed regarding gastric pH [1.43 (1.30-1.56)/1.44 (1.29-1.68), P=0.66] or residual volume [0.43 (0.21-0.84)/0.46 (0.19-0.78) ml kg(-1), P=0.47].
Conclusion:
One hour clear fluid fasting does not alter gastric pH or residual volume significantly compared with 2 h fasting.
Clinical Trial Registration:
The study was approved by the local ethics committee (KEK-ZH-Nr. 2011-0034) and registered with ClinicalTrials.gov (NCT01516775).
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