Radionuclide scintigraphy in the evaluation of gastroesophageal reflux in symptomatic and asymptomatic pre-term infants.

PURPOSE: Gastroesophageal reflux (GER) is very common in pre-term infants. The diagnosis based on symptoms is always questionable. The incidence of GER in symptomatic babies varies from 22% to 85%, but literature regarding the incidence of reflux in asymptomatic pre-term infants is lacking. We used radionuclide scintigraphy to evaluate the incidence of GER in symptomatic as well as asymptomatic pre-term neonates and to assess whether symptoms have any relation with positive scintigraphy.

METHODS

We studied 106 pre-term infants (52 symptomatic, 54 asymptomatic) of less than 34 weeks of gestation, who fulfilled the eligibility criteria. Babies were considered symptomatic in the presence of vomiting, regurgitation, apnea, de-saturations, unexplained bradycardia and recurrent lung collapses. Radionuclide scintigraphy was conducted at post-conceptional age of 32-34 weeks when they were clinically stable for 72 h. Feeding was avoided for 2 h preceding the study. (99m)Tc sulphur colloid was administered in a dose of 1.85 MBq (0.05 mCi) in 1 ml, followed by milk (full feed) through an orogastric tube, prior to imaging under a gamma camera. Reflux was graded as low or high, and reflux episodes during the study were counted.

RESULTS

The incidence of GER in the symptomatic group was 71.2% and in asymptomatic babies 61.1% (p = 0.275). High-grade reflux was more common (71.4%) than low-grade (28.6%) in both groups (p = 0.449). Mean number of reflux episodes in 20 min was 4.4 +/- 2.4 in symptomatic babies and 4.9 +/- 2.2 in asymptomatic babies (p = 0.321). Babies with positive scintigraphy were similar in birth weight, gestation, time to achieve full feeds, weight and age at discharge to those with negative scintigraphy.

CONCLUSIONS

GER is common in pre-term infants of less than 34 weeks gestation. The incidence of positive scintigraphy and grade of reflux is not significantly different in symptomatic vs. asymptomatic babies. Though radionuclide scintigraphy is a simple, quick and non-invasive investigation in suspected cases of GER, positive scintigraphy has no correlation with symptoms.