RESUMO
The effect of orally administered cimetidine 7.5 mg/kg (group 1), ranitidine 1.5 mg/kg (group 2), ranitidine 2.0 mg/kg (group 3), or a placebo (group 4) on gastric pH and gastric residual volume of 60 healthy children 2-6 yr of age admitted for elective surgery was evaluated. Both cimetidine and ranitidine administered 1-2 h prior to induction of anesthesia effectively increased the gastric pH:5,47 - 1.85 ml/kg (group 1), 4.92 +/- 2.1 ml/kg (group 2), 5.30 +/- 1.82 ml/kg (group 3) compared with 1.75 +/- 0.58 ml/kg (group 4) (P less than 0.001). A single dose of ranitidine 1.5 mg/kg was an effective as ranitidine 2.0 mg/kg and cimetidine 7.5 mg/kg. Neither drug decreased the gastric residual volume: 0.32 +/- 0.33 ml/kg (group 1), 0.31 +/- 0.06 ml/kg (group 2), 0.23 +/- 0.05 ml/kg (group 3), and 0.33 +/- 0.05 ml/kg (group 4). The combination of a volume greater than 0.4 ml/kg and a pH less than 2.5 was found in 33% (five of 15) of patients in the placebo group (group 4). In contrast, there were no patients with this combination in groups 1, 2, or 3 (P less than 0.001).
