GERD- ARE WE RIGHT IN CONTINUING WHAT WE KNOW?

The most noninvasive method used to assess for reflux burdenis the upper gastrointestinal tract series or bariumswallow test.Unfortunately, the sensitivityof this test is poorwhencomparedwith that ofpHmonitoring; in a study of infants, barium testing had a sensitivityof29%and a specificity of 50%, showing the inadequacy ofthe test to diagnose reflux.13 However, barium testing is helpful in detecting themasqueraders of reflux. In children with projectilevomiting,bilious vomiting, vomiting of undigested food, failure to thrive,or recurrent respiratory symptoms, barium testing will evaluate for anatomic abnormalities, such as pyloric stenosis, malrotation, tracheoesophagealfistulae, and other congenital anomalies of the uppergastrointestinal tract. If aspiration is suspected or if the infanthas recurrent wheezing, bronchiolitis, or wet cough, a modifiedbarium swallow test to focus on the mechanism of swallowing and the upper esophagus can also be performed to determine whetherbarium is aspirated. At present, the only utility of barium testing in the evaluation ofGERDin infants is to exclude anatomic abnormalities

Theoretically, the pH probe is more suited to assessing for the relationship between symptoms and reflux events; during the 24-hour testing, temporal correlation of acid reflux events, defined asdrops in pH levels to less than 4, with symptoms occurring duringthe test is possible. Unfortunately, the infant pH data suggest that,although occasional patients may clearly have reflux-related symptoms,most of the studies show no significant difference in acid re- flux urden between controls and infants undergoing evaluation forexcessive crying, apnea, bradycardia, respiratory symptoms, and regurgitation.19-23 Therefore, one must conclude that our diagnostictests are flawed (and some adult data suggest that thepHprobehas a reproducibility of only 70%) or that reflux is not to blame for these symptoms

Nonpharmacologic Therapies

Nonpharmacologic therapies include positioning, thickeningof feedings,changes in formula, and modifications in meal frequencies.Probably the most widespread intervention for the treatment ofGERD is positioning. Beginning with early pH probe studies, positioninghas had variable efficacy in reducing reflux. One of the earliestpositioning studies by Orenstein et al33 showed that positioning

children in car seats had no beneficial effect in reducing the acidreflux burden as measured by pH probe. Additional studies haveshown that acid reflux, measured by pH probe, is reduced to thegreatest degree in theproneposition followedby the left lateral, right lateral,andsupine positions indescendingorder of effectiveness.34,35Studies using pH-MII have confirmed that the prone and left lateralpositions reduce reflux to a greater degree36-38 than the supine andright lateral positions. However, supine positioning is still recommendedbecause of the risk of sudden infant death syndrome

Formula thickening has also been proposed as a therapy for reflux.EarlypHstudies44-46 suggest inconsistent benefits of thickeningto reduce acid burden. Some very elegant studies using pH-MIItesting have also been performed in which infants are fed standardand thickened formula in random order. Although thickening doesnot reduce the totalnumberof esophageal reflux episodes or symptoms,such as apnea, some benefit to parents may result in reducing the number of visible vomiting episodes, and improvements insleep and possibly failure to thrive may also result.40,45,47,48

Changingsmaller and more frequent feedings has also been proposed asa treatment for infant reflux. Studies sing pH-MII7 have suggestedthat the type of reflux may vary (acid vs nonacid reflux) dependingon the feeding frequency, but the total number of reflux episodesmay not differ greatly.

Finally, some data suggest formula or dietary changes may beused to treat reflux. In the NASPGHAN guidelines, a 2-week trial ofa hypoallergenic formula has been suggested to treat symptoms ofGER.Symptomsof milk protein intoleranceare similar to reflux Symptoms,including fussiness, regurgitation, arching, and colic. Althoughvery few data suggest that changing to a hydrolysate formula reduces the amount of reflux, clear evidence exists that a trialof a hypoallergenic formula improves colic, which is often mistakenforGERbecause of the symptom overlap.50

Pharmacologic Therapies

The mainstay of medical therapies for GERD in infants is acid suppression.The primary class of medications are histamine2 (H2) antagonistsand proton pump inhibitors, both of which have beenshown to reduce gastric acidity and heal esophagitis inchildren.14,54-56 However, relatively few patients undergo endoscopicevaluation compared with the number of children presenting

with GER symptoms in whom acid-suppression therapy is empirically Started.Thenumberof well-designed clinical trials including  infants who receive acid-suppression therapy for symptom relief issmall.

Three well-designed, randomized, placebo-controlled clinicaltrials59-61 of the proton pump inhibitors lansoprazole, pantoprazolesodium, and omeprazole magnesium have been conductedin infants, and all have failed to show any benefit in improvingthe classic reflux symptoms seen in infants, including crying, regurgitating, food refusal, arching, coughing, or wheezing. Furthermore, use of these therapies has been associated with an in- creased risk of gastrointestinal tract and pulmonary infections in infantsandchildren.62,63

Therefore, inlight of these randomizedclinical trials in Infants,NASPGHANguidelines3 haverecommended no acid suppression therapy in the otherwise healthy infant who spits up. They further recommenda trial of a hypoallergenic formula and then, at most, a short trial of acid-suppression therapy for patients with intractable or severe symptoms.3

Gastroesophageal Reflux in Infants More Than Just a pHenomenon

Rachel Rosen, MD, MPH

Author Affiliation: Aerodigestive Center, Boston Children’s Hospital,

Boston, Massachusetts