title: Analysis of gastrointestinal sounds in infants with pyloric stenosis before and after pyloromyotomy.
abstract: BACKGROUND
  Although recent advances in computer technology enable us to analyze gastrointestinal sounds data objectively with ease, this clinical application has been investigated in only a few disorders. To investigate one potential role of this approach in pediatric practice, we recorded and analyzed 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 sound recording, using a marker dilution-double sampling method.
  
  
  RESULTS
  Before surgery, the mean SI was 4.6 +/- 1.0 mV per minute, significantly less than in healthy controls (31.7 +/- 8.4 mV per minute). The SI remained in a similar range until 12 hours after operation, after which it began 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 pyloromyotomy, increased by 4 to 5 times after surgery. There was a significant positive correlation between SI and gastric emptying. The incidence of postoperative symptoms (such as vomiting) were correlated significantly with SI at 24 hours after surgery.
  
  
  CONCLUSIONS
  This study found decreased gastrointestinal sounds to be among physical findings suggestive of HPS and a useful indicator of gastric emptying and bowel motility after pyloromyotomy. Computer-assisted analysis of gastrointestinal sounds might be helpful in clinical practice for pediatric patients with some gastrointestinal disorders.
authors.affiliation: Department of Pediatrics, Gunma University School of Medicine, Gunma 371, Japan. tomomasa@akagi.sb.gunma-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Tomomasa
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Nako
authors.forename: H
authors.initials: H
authors.lastname: Kaneko
authors.forename: M
authors.initials: M
authors.lastname: Tabata
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuchida
authors.forename: A
authors.initials: A
authors.lastname: Morikawa
mesh_terms: D000704:Analysis of Variance; D016022:Case-Control Studies; D004064:Digestive System / Q000503:physiopathology*; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D006984:Hypertrophy; D007223:Infant; D008297:Male; D011184:Postoperative Period; D011707:Pyloric Stenosis / Q000503:physiopathology* / Q000601:surgery; D011708:Pylorus / Q000601:surgery; D012815:Signal Processing, Computer-Assisted; D013016:Sound