Ultrasound dynamics of gastric content volumes after the ingestion of coconut water or a meat sandwich. A randomized controlled crossover study in healthy volunteers

Abstract

Background: Adequate preoperative fasting is critical in preventing pulmonary aspiration of gastric content. We proposed to study the sonographic gastric content dynamics after the ingestion of liquid or solid food in healthy volunteers and confront it with current guidelines for preoperative fasting times. Methods: We performed a prospective, crossover, evaluator-blinded study involving 17 healthy volunteers of both sexes. Each participant fasted for 10 h and was subjected to a baseline gastric ultrasound, intake of 400 mL of coconut water or a 145 g, 355 kcal meat sandwich, and sonographic gastric evaluations after 10 min and every hour until the stomach was completely empty. Results: At baseline, all subjects had an empty stomach. At 10 min, gastric content [mean + standard deviation (SD)] was 240.4 + 69.3 and 248.2 + 119.2 mL for liquid and solid foods, respectively (p > 0.05). Mean + SD gastric emptying times were 2.5 + 0.7 and 4.5 + 0.9 h for liquid and solid foods, respectively (p 0,05). Os tempos médios de esvaziamento gástrico + DP foram de 2,5 + 0,7 e 4,5 + 0,9 horas para alimentos líquidos e sólidos, respectivamente (p < 0,001). Para a bebida, o estômago ficou completamente vazio em 59% e 100% dos sujeitos após duas e quatro horas; para o sanduíche, o estômago ficou completamente vazio em 65% e 100% dos sujeitos após quatro e sete horas, respectivamente. Conclusões: A dinâmica ultrassonográfica do volume gástrico para água de coco e sanduíche de carne resultou em tempos totais de esvaziamento gástrico maiores e menores, respectivamente, do que os sugeridos pelas diretrizes atuais para o jejum pré-operatório. Keywords: Ultrasound, Gastric content, Gastric dynamics, Preoperative fasting, Palavras-chave: Ultrassom, Conteúdo gástrico, Dinâmica gástrica, Jejum pré-operatório