A 5 Year Prospective Study to Evaluate The Effects of Position on Gastro-Oesophageal Reflux (GOR) in Infants

Abstract □ 49

The positioning therapy in GOR is subjected to discussion, since the prone position has been cited as a risk factor for sudden infant death. Therefore in 1992 a prospective study was started to evaluate the effects of position on GOR.

PATIENTS: All infants (n=691) under the age of 1 year with regurgitations, vomiting, recurrent respiratory infections or apparent life threatening events (ALTE) were included. 5 days prior to and during pH monitoring prokinetic or antisecretory drugs were prohibited. Excluded were patients with major malformations of thorax or abdomen. METHODS: Oesophageal pH monitoring was performed using a glass microelectrode and a cutaneous Ag/Ag CI reference electrode connected with a pH-meter. The infant was positioned successively for 6h in upright (30° antitrendelenburg or infant seat),for 6h in flat supine and for 6h in flat prone position.X Ray examination was performed to control the exact location. For each of the 3 positions separately the total number of episodes with pH < 4 were counted and the position reflux index (PRI);(PRI: % of the investigation time in a certain position with pH <4) and total reflux index (TRI);(TRI:% of the total investigation time with pH <4) was calculated. Statistics were done with the unpaired student t-test.

RESULTS: Three groups were observed: G1: PRI < 6%: 260 infants or 37,6% had normal measurements; G2: PRI > 6% in one position only: 209 infants or 30,3%; G3: PRI > 6% in more than one position: 222 infants or 32,1%. The 431 infants with pathological GOR were distributed according to the position in which they were having the highest RI (RI > 6% in this specific position alone or in > 1 position but predominantly in this specific position): the most abnormal results were found subsequently for the prone 42,7% (184/431), the supine 33,9% (146/431) and the upright 23,4% (101/431). When the group of the 65 infants referred for ALTE were distributed according to the position in which they had the highest RI a slight difference could be seen (prone 24/65 or 37%, supine 22/65 or 34% and upright 19/65 or 29%).

CONCLUSIONS:

• 1 1/3 of the infants had physiological values whatever the position.

• 2 1/3 of the infants had pathological values in only one position.

• 3 1/3 of the infants had pathological values in 2 or more positions.

• 4 In G2 and G3 the pathological refluxes occur mainly in prone position, being responsible for 42,7% pathological readings.

• 5 If GOR is present in more than one position, there is no preferential position.

• 6 If GOR is only present in one position, the prone position is significantly worse than the other two.

• 7 In the group of children specifically referred for ALTE Prone position was associated with the highest RI.

Finally this study shows that recommendation on position as therapy for GOR could only be ethical after failure of treatment with thickening of feeding and use of prokinetics based on individual data.