Gastric fluid volume in infants for pyloromyotomy.

PURPOSE: To quantify gastric fluid volumes in infants with pyloric stenosis presenting for pyloromyotomy and to demonstrate endoscopically the efficacy of blind aspiration for gastric fluid recovery. We hypothesized that previous diagnostic contrast studies, preoperative nasogastric suction, and fasting interval would not affect these volumes.

METHODS: Seventy-five infants scheduled for pyloromyotomy were given atropine before induction of anaesthesia. For those who had undergone preoperative nasogastric suction, the nasogastric tube was aspirated and removed. A 14 F multiorificed orogastric catheter was blindly passed to aspirate gastric fluid for measurement. Following tracheal intubation, 15/75 subjects underwent gastroscopy to measure residual gastric fluid.

RESULTS: Gastric fluid volume removed by blind aspiration averaged 4.8 +/- 4.3 ml.kg-1 with 83% of patients having > 1.25 ml.kg-1. Although 14 of the 15 patients evaluated by endoscope had < or = 1 ml residual gastric fluid, one had 1.8 ml.kg-1. Recovery of total gastric fluid volume by blind aspiration averaged 96 +/- 7%. The large gastric fluid volumes were independent of a history of barium study, preoperative nasogastric suction, and fasting interval.

CONCLUSION: Infants with pyloric stenosis have large gastric fluid volumes which are not substantially reduced by preoperative nasogastric suction. Blind aspiration of gastric contents prior to induction of anaesthesia provides a reliable estimate of total gastric fluid for most of these infants, although the occasional infant may retain a small amount of gastric fluid. The clinical importance of such a residual volume is uncertain.