[Association between gastroesophageal reflux and dips in the oxygen transcutaneous saturation of the hemoglobin in infants with chronic obstructive ventilatory disease]

OBJECTIVE: To verify the association between oxygen desaturation episodes and the dips in pH in infants with chronic obstructive respiratory symptoms. METHOD: Cross-sectional study with children 24 months old or younger hospitalized for investigation of chronic obstructive respiratory symptoms from 1997 to 1999. The patients underwent esophageal pH monitoring associated with transcutaneous oxygen saturation during the night. The patients were included in the study according to their need to be hospitalized and availability of equipment. The indices used to measure this association were reflux index, total number of refluxes, number of refluxes longer than 5 minutes, Euler index, ZMD index, 24-hour mean pH, and mean pH of desaturation. RESULTS: We studied 44 children. The mean age was 7.5 months, and 20% had desaturation below 93% during pH monitoring. We used the t test to compare the occurrence of desaturation with the pH monitoring parameters. We found higher significance with the reflux index (RI), number of episodes longer than 5 minutes, ZMD index, 24-hour mean pH, and mean pH of desaturation. The bivariate analysis, taking into account possible confounding factors and RI, showed PR equal to 6.61 (IC 95% 1.67 - 26.12) for an RI higher than 4%. CONCLUSION: Oxygen saturation monitoring associated with pH monitoring may be a useful tool to establish an association between GER and respiratory problems in patients with chronic or recurrent wheeze.