PEDIATRICS Vol. 118 No. 2 August 2006, pp. 793-794 (doi:10.1542/10.1542/peds.2006-0643)
COMMENTARY |
Diagnosing Gastroesophageal Reflux in Preterm Infants
Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies & Children's Hospital, Cleveland, Ohio
Abbreviations: GER, gastroesophageal reflux
Preterm infants are exposed to a host of therapeutic agents, and drug therapy for presumed gastroesophageal reflux (GER) ranks high on any list. It was documented recently that 25% of all extremely low birth weight (<1 kg) infants are discharged on promotility and/or antacid therapy.1 The most common indications for these drugs comprise feeding intolerance and recurrent episodes of apnea/bradycardia/desaturation.2 Unfortunately, there is little evidence to support this widely practiced approach. The article by López-Alonso et al3 (in this month's issue of Pediatrics Electronic Pages) provides revealing new data to help us characterize GER in preterm infants.
Traditionally, GER has been quantified by measurement of esophageal pH. However, because frequent feeds in infants neutralize stomach contents, this measure is potentially unreliable. Intraluminal impedance, as used by López-Alonso et al, is pH-independent and measures reflux from retrograde flow of a liquid (or air) bolus as it passes from the stomach through the esophagus toward the oropharynx.3 When combined measurements are made, one would anticipate the incidence of impedance-based reflux to exceed acid reflux,4 and, in fact, only 25% of reflux events were strongly acidic (as defined by an esophageal pH < 4). Surprisingly, the esophageal mucosa was only exposed to refluxate 1% of the time (on the basis of impedance data), whereas the esophagus was exposed to acid 
5% of the time, as anticipated from previous studies.5 This is almost certainly because esophageal impedance rapidly normalizes after a bolus of refluxate, whereas pH stays low for a much longer time. The pathophysiologic relevance of these discordant results, which were based on measurement techniques, still needs to be determined.
Another point of interest is that in these preterm infants, all of whom were fed exclusively via nasogastric tube, reflux events tended to be relatively more common during feeding than nonfeeding periods, an observation that could not be revealed by pH monitoring because of neutralization of gastric contents. Data such as these are needed if we are to develop greater understanding of the pathophysiologic consequences of GER.
Where do we go from here? Several studies have failed to document a temporal relationship between apnea of prematurity and acid-based GER.6–8 Using the current impedance-based technology, Peter et al9 also failed to document a clear relationship between apnea and reflux. Therefore, pharmacologic management of GER should not play a prominent role in the management of episodic apnea/bradycardia/desaturation in preterm infants.10,11 However, other end points, such as growth and nutritional outcome, as well as increased airway reactivity, may benefit from pharmacologic approaches, especially in preterm infants at risk for neurodevelopmental or cardiorespiratory compromise. Unfortunately, the authors of a recent meta-analysis of antireflux strategies suggested that available data from randomized, clinical trials are largely inadequate and inconclusive.12 The Cochrane database indicates that metoclopramide reduces reflux symptoms but may increase adverse effects.13 In fact, there has been inadequate emphasis on potential long-term complications of such therapy. Incorporation into future trials of data derived from impedance, as well as pH-based, techniques for the diagnosis of GER should contribute greatly to future knowledge in this area.
 |
FOOTNOTES |
|---|
Accepted Mar 8, 2006.
Address correspondence to Richard J. Martin, MD, Rainbow Babies & Children's Hospital, Division of Neonatology, 11100 Euclid Ave, Cleveland, OH 44106-6010. E-mail: rxm6{at}case.edu
The authors have indicated they have no financial relationships relevant to this article to disclose.
Opinions expressed in these commentaries are those of the authors and not necessarily those of the American Academy of Pediatrics or its Committees.
|
REFERENCES |
|---|
 TOP REFERENCES |
|---|
- Malcolm W, Gantz M, Das A, Martin R, Goldberg R, Cotten C. Anti-reflux medications (ARM) at NICU discharge for extremely low birthweight (ELBW) infants [abstract]. Presented at: Annual Meeting of the Pediatric Academic Societies; April 29–May 2, 2006; San Francisco, CA
- Dhillon AS, Ewer AK. Diagnosis and management of gastro-oesophageal reflux in preterm infants in neonatal intensive care units. Acta Paediatr. 2004;93 :88 –93[CrossRef][Web of Science][Medline]
- López-Alonso M, Moya MJ, Cabo JA, et al. Twenty-four-hour esophageal impedance-pH monitoring in healthy preterm neonates: rate and characteristics of acid, weakly acidic, and weakly alkaline gastroesophageal reflux. Pediatrics. 2006;118(2) . Available at: www.pediatrics.org/cgi/content/full/118/2/e299
- Rosen R, Nurko S. The importance of multichannel intraluminal impedance in the evaluation of children with persistent respiratory symptoms. Am J Gastroenterol. 2004;99 :2452 –2458[CrossRef][Web of Science][Medline]
- Vandenplas Y, Goyvaerts H, Helven R, Sacre L. Gastroesophageal reflux, as measured by 24-hour pH monitoring, in 509 healthy infants screened for risk of sudden infant death syndrome.
Pediatrics. 1991;88
:834
–840
[Abstract/Free Full Text] - Di Fiore JM, Arko M, Whitehouse M, Kimball A, Martin RJ. Apnea is not prolonged by acid gastroesophageal reflux in preterm infants.
Pediatrics. 2005;116
:1059
–1063
[Abstract/Free Full Text] - Barrington KJ, Tan K, Rich W. Apnea at discharge and gastro-esophageal reflux in the preterm infant. J Perinatol. 2002;22 :8 –11[CrossRef][Medline]
- De Ajuriaguerra M, Radvanyi-Bouvet MF, Huon C, Moriette G. Gastroesophageal reflux and apnea in prematurely born infants during wakefulness and sleep.
Am J Dis Child. 1991;145
:1132
–1136
[Abstract/Free Full Text] - Peter CS, Sprodowski N, Bohnhorst B, Silny J, Poets CF. Gastroesophageal reflux and apnea of prematurity: no temporal relationship.
Pediatrics. 2002;109
:8
–11
[Abstract/Free Full Text] - Kimball AL, Carlton DP. Gastroesophageal reflux medications in the treatment of apnea in premature infants. J Pediatr. 2001;138 :355 –360[CrossRef][Web of Science][Medline]
- Molloy EJ, Di Fiore JM, Martin RJ. Does gastroesophageal reflux cause apnea in preterm infants? Biol Neonate. 2005;87 :254 –261[CrossRef][Web of Science][Medline]
- Hibbs AM, Lorch SA. Metoclopramide for the treatment of gastroesophageal reflux disease in infants: a systematic review.
Pediatrics. 2006;118
:746
–752
[Abstract/Free Full Text] - Craig WR, Hanlon-Dearman A, Sinclair C, Taback S, Moffatt M. Metoclopramide, thickened feedings, and positioning for gastro-oesophageal reflux in children under two years. Cochrane Database Syst Rev. 2005;(4) :CD003502
PEDIATRICS (ISSN 1098-4275). ©2006 by the American Academy of Pediatrics
CiteULike 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
