Analysis of gastrointestinal sounds in infants with pyloric stenosis before and after pyloromyotomy

Background. Although recent advances in computer technology enable us to an alyze gastrointestinal sounds data objectively with ease, this clinical app lication has been investigated in only a few disorders. To investigate one potential role of this approach in pediatric practice, we recorded and anal yzed gastrointestinal sounds in infants with hypertrophic pyloric stenosis (HPS), a motility-related disorder that is common in children. Methods. In 15 infants with pyloric stenosis, gastrointestinal sounds were collected with a microphone placed 3 cm below the umbilicus for 60 minutes before pyloromyotomy and at 9 to 12 hours, 20 to 24 hours, 40 to 48 hours, and 112 to 120 hours after the operation. Data were entered into a computer to sum the amplitude of sound signals as a sound index (SI; mV per minute) . In 12 infants, gastric emptying was measured immediately before each soun d recording, using a marker dilution-double sampling method. Results. Before surgery, the mean SI was 4.6 +/- 1.0 mV per minute, signifi cantly less than in healthy controls (31.7 +/- 8.4 mV per minute). The SI r emained in a similar range until 12 hours after operation, after which it b egan increasing to reach the normal range by 48 hours after operation (30.0 +/- 9.4 mV per minute). Gastric emptying, also low in HPS before pyloromyo tomy, increased by 4 to 5 times after surgery. There was a significant posi tive correlation between SI and gastric emptying. The incidence of postoper ative symptoms (such as vomiting) were correlated significantly with SI at 24 hours after surgery. Conclusion. This study found decreased gastrointestinal sounds to be among physical findings suggestive of HPS and a useful indicator of gastric empty ing and bowel motility after pyloromyotomy. Computer-assisted analysis of g astrointestinal sounds might be helpful in clinical practice for pediatric patients with some gastrointestinal disorders.