Esophageal pH Study and Symptomatology of Gastroesophageal Reflux in Newborn Infants

A retrospective study was undertaken to assess the association between esophageal pH monitoring variables and signs such as regurgitation, vomiting, apnea, bradycardia, and cyanotic episodes attributable to gastroesophageal reflux (GER) in neonates. One hundred thirty-four infants with one or more of the above-described signs underwent 24-hour distal esophageal pH monitoring in the neonatal intensive care unit, and were divided into 2 groups by gestational age. Group 1 (preterm infant group) consisted of infants aged 25 to 36 weeks of gestation (n = 45) and group 2 (term infant group) consisted of infants aged 37 to 42 weeks gestation (n = 89). Esophageal pH monitoring variables were compared by gestational age group and within preterm infants by theophylline treatment and, separately, by nasogastric tube using the Mann-Whitney U test. Comparisons of nominal data were made using the chi square test. Logistic regression analysis was used to assess the net effect of each independent variable on the risk of developing GER. The prevalence of GER was not influenced by gestational age. The prevalence of gastrointestinal signs did not differ between groups. Cardiorespiratory signs attributed to GER were more frequent in preterm infants than in term infants. The number of episodes with pH < 4 in 24 hours was greater in the term compared with the preterm infant groups. Logistic regression analysis failed to detect an association between acid GER and gestational age, apnea, bradycardia, cyanotic episodes, vomiting, or regurgitation. Theophylline treatment and the presence of a nasogastric tube did not significantly affect the esophageal pH monitoring variables in preterm infants. Preterm infants have a smaller number of reflux episodes compared with term infants. In addition, treatment with theophylline for apnea of prematurity and the presence of a nasogastric tube in preterm infants did not significantly affect pH-monitoring variables in preterm infants.

KEYWORDS

Esophageal pH monitoring - infant - gestational age - gastroesophageal reflux - nasogastric tube - theophylline

REFERENCES

• 1 Newell S J, Booth I W, Morgan M EI, Durbin G M, McNeish A S. Gastro-oesophageal reflux in preterm infants.  Arch Dis Child Fetal Neonatal Ed. 1989;  64 780-786
• 2 Ewer A K, Durbin G M, Morgan M EI, Booth I W. Gastric emptying and gastro-oesophageal reflux in preterm infants.  Arch Dis Child Fetabl Neonatal Ed. 1996;  75 F117-F121
• 3 Diamant N E. Development of esophageal function.  Am Rev Respir Dis. 1985;  131(suppl) S29-S32
• 4 Boix-Ochoa J, Canals J. Maturation of lower oesophagus.  J Pediatr Surg. 1976;  11 749-756
• 5 Omari T I, Barnett C, Snel A et al.. Mechanisms of gastroesophageal reflux in healthy premature infants.  J Pediatr. 1998;  133 650-654
• 6 Ng S CY, Quak S H. Gastroesophageal reflux in preterm infants: norms for extended distal esophageal pH monitoring.  J Pediatr Gastroenterol Nutr. 1998;  27 411-414
• 7 Boix-Ochoa J, Lafuente J M, Gil-Vernet J M. Twenty-four hour esophageal pH monitoring in gastroesophageal reflux.  J Pediatr Surg. 1980;  15 74-78
• 8 Chen P H, Chang M H, Hsu H C. Gastroesophageal reflux: in children with chronic recurrent bronchopulmonary infection.  J Pediatr Gastroenterol Nutr. 1991;  13 16-22
• 9 Vandenplas Y, Sacre-Smits L. Continuous 24-hour esophageal monitoring in 285 asymptomatic infants 0-15 months old.  J Pediatr Gastroenterol Nutr. 1987;  6 220-224
• 10 Badriul H, Vandemaele K, Vandenplas Y. Esophageal pH monitoring in infants: elimination of gastric buffering does not modify reflux index.  J Pediatr Gastroenterol Nutr. 1999;  29 627-628
• 11 Lucas A, Bloom S R, Aynsley A. Postnatal surge in plasma gut hormones in term and preterm infants.  Biol Neonate. 1982;  41 63-67
• 12 Peter C S, Sprodowski N, Bohnhorst B, Silny J, Poets C F. Gastroesophageal reflux and apnea of prematurity: no temporal relationship.  Pediatrics. 2002;  109 8-11
• 13 de Ajuriaguerra M, Radvanyi-Bouvet M F, Huon C, Moriette G. Gastroesophageal reflux and apnea in prematurely born infants during wakefulness and sleep.  Am J Dis Child. 1991;  145 1132-1136
• 14 Arad-Cohen N, Cohen A, Tirosh E. The relationship between gastroesophageal reflux and apnea in infants.  J Pediatr. 2000;  137 321-326
• 15 Dennish G W, Castell D O. Caffeine and the lower esophageal sphincter.  Am J Dig Dis. 1972;  17 993-996
• 16 Cohen S, Booth G H. Gastric acid secretion and lower esophageal sphincter pressure in response to coffee and caffeine.  N Engl J Med. 1975;  293 897-899
• 17 Howell J, Clozel M, Aranda J V. Adverse effects of caffeine and theophylline in the newborn infant.  Semin Perinatol. 1981;  5 359-369
• 18 Stein M R, Towner T G, Weber R W et al.. The effect of theophylline on lower esophageal sphincter pressure.  Ann Allergy. 1980;  45 238-241
• 19 Vandenplas Y, De Wolf D, Sacre-Smits L. Influence of xanthines on gastroesophageal reflux in infants at risk for sudden infant death syndrome.  Pediatrics. 1986;  77 807-810
• 20 Noviski N, Ben-Yehuda Y, Serour F, Gorenstein A, Mandelberg A. Does the size of nasogastric tubes affect gastroesophageal reflux in children?.  J Pediatr Gastroenterol Nutr. 1999;  29 448-451
• 21 Mahajan L, Wyllie R, Oliva L, Balsells F, Steffen R, Kay M. Reproducibility of a 24-hour intraesophageal pH monitoring in pediatric patients.  Pediatrics. 1998;  101 260-263