EFFECTS OF FASTING AND ORAL PREMEDICATION ON THE pH AND VOLUME OF GASTRIC ASPIRATE IN CHILDREN

Abstract

The pH and volume of gastric aspirate were measured immediately after the induction of anaesthesia in 224 healthy children to determine the effects of decreasing the period of fasting and of giving oral premedicants before anaesthesia. Fasting for less than 4 h was found to increase the volume of gastric aspirate and the risk of developing pulmonary aspiration syndrome. Trimeprazine syrup was found to increase the pH of the gastric contents, and decrease the likelihood of the pulmonary aspiration syndrome. There was a significant increase in gastric volume in patients premedicated with temazepam elixir which did not occur in patients given temazepam capsules. These results support the custom of fasting patients for at least 4 h before anaesthesia and indicate that oral premedicants and their vehicles can have significant effects on the stomach.

Preoperative anxiety and gastric fluid secretion in healthy children scheduled for outpatient surgery

“…Twentyone percent of our patients had a gastric volume > 0.4 ml-kg-' and pH ~2.5. This compares well with the observation of Meakin, Dingwall & Addison (1987) who noted that 22% of unpremedicated healthy children awaiting minor surgery had gastric aspirates with pH <2.5 and volume >0.4 m1.kg-l. They also noted a variable effect of premedication.…”

“…(Cot6 et al. 1982;Manchikanti et al 1985;Meakin, Dingwall & Addison 1987;Sandhar et al 1989;Crawford et al 1990;Schreiner, Triebwasser & Keon 1990;Splinter, Stewart & Muir 1990). Twentyone percent of our patients had a gastric volume > 0.4 ml-kg-' and pH ~2.5.…”

Oral drug absorption in pediatrics: the intestinal wall, its developmental changes and current tools for predictions

“…The drug solubility normalized to the dose and to the gastric volume is given by the Dose number D 0 . When normalized per kg body weight, the fasted gastric content volume is broadly similar in children (0.25-0.56 ml/kg, [25][26][27]) and adults (0.36-0.50 ml/kg, [28,29]) while the drug dosage may differ. As a result, some drugs have a BCS solubility class that changes with age.…”

Aspiration Prevention and Prophylaxis

“…11 A preliminary experiment by Roberts and Shirley, involving gastric fluid instillation into the right main stem number of patients with gastric contents more voluminous than 0.4 mL/kg. 77 Hyperosmolar glucose solutions are also associated with delayed gastric emptying. [73][74][75][76] Ingestion of clear liquids alone therefore appears to pose no demonstrable hazard if taken no later than 2 hours before anesthesia by children without gastrointestinal pathology.…”