Ten RCTs (n=323) were included. These were 2 parallel-group trials (n=44) and 8 crossover trials (n=279).
Positioning.
One RCT found that placement in an infant seat (inclined at 60 degrees) was detrimental with respect to GERD. Infants in the seat spent a greater proportion of time in a state of reflux (28.2%) than did those in the prone position (12.8%); they also had significantly more episodes of reflux (16.0 versus 10.1). Another RCT found no difference in any measure of reflux between infants in the prone position and those in the prone position with the head of the bed inclined at 30 degrees.
Nonnutritive sucking.
One study assessed infants randomised to a prone or seated position. In each position, the infants underwent the pH probe examination with and without pacifiers, in random order, for 3 hours. In the prone position, pacifier use increased the number of episodes of reflux in 2 hours from 7.2 to 12.8 (p=0.04). In the seated position, pacifier use decreased the number of reflux episodes in 2 hours from 21.1 to 14.8 (p=0.03), but this was insufficient to compensate for the negative effects of the seated position. The total reflux time and reflux clearance were not significantly affected by pacifier use in either position.
Thickened infant food.
Four RCTs assessed the effect of thickened food on GERD. Two studies compared formula thickened with rice flour to placebo, one compared carob bean gum-thickened formula with placebo, and one compared 2 different thickening agents. Thickening with rice flour.
The first RCT assessed infants given both thickened or non-thickened apple juice in the 4 positions of prone, prone and elevated 30 degrees, supine or unrestricted. There was no difference between the 2 types of juice in any position, except in the 30 degree elevated prone position, in which reflux time was increased with thickened juice. The second RCT compared thickened with normal infant formula. The type of formula had no statistically-significant impact on the amount of reflux. However, a significant decrease was found in the number of episodes of frank emesis (1.2 versus 3.9 per 90 postprandial minutes).
Thickening with carob bean gum.
There were improvements noted in both the group randomised to the control formula (80% casein and 20% whey) and the thickened formula. However, no significant differences were found between the two groups in terms of the pH monitoring results.
Carob bean gum versus rice flour thickening.
Parental diaries showed a reduction over time in the symptomatic scores for both formulas. However, the carob bean gum-thickened formula showed a significant reduction in both symptomatic score (70.4% versus 48.7%; p<0.01) and episodes of emesis (58.1% versus 34.1%; p<0.05).
Formula changes.
Two RCTs investigated the effect of the formula composition on GERD. The first study randomised the infants to receive casein predominant, soy-based, and whey-predominant formulas. No differences were noted on the outcome measures of spitting and vomiting and reflux between the formulas. The second small RCT examined casein versus whey-based formulas. All 3 infants showed improvement in emesis while receiving the whey-based formulas (1.3 versus 4.3; p<0.01), but the difference between the formulas was not significant when based on the results of the pH probe test.
Caloric density or osmolality changes.
One RCT assessed the effect of using dextrose 5% water (D5W), dextrose 10% water (D10W) and a glucose polymer solution when rehydrating children with carbohydrate solutions. The total minutes of oesophageal reflux were significantly lower while receiving the D5W and glucose polymer solutions than while receiving the D10W solution: the mean values were 12.0 (D5W) and 12.6 (glucose polymer) minutes, respectively, versus 28.6 minutes (D10W) (p<0.05). No significant difference was found in the results in the first postprandial hour, but the results became significant when observed for 2 hours postprandially.