Esophageal multichannel intraluminal impedance and pH testing in the study of apparent life threatening episode incidents in infants

The conventional 24-hour pH monitoring is the gold standard for the diagnosis of gastro-esophageal reflux (GER), a possible cause of Apparent Life Threatening Episodes (ALTE). However, multichannel intraluminal impedance (MII) may provide advantages. Comparison of the results of MII and pH monitoring in patients undergoing MII-pH monitoring in the 3-year study period because of having suffered from ALTE. Prospective study of MII-pH monitoring performed in our unit to infants < 12 months of ageadmitted for ALTE for a 3-year period. Thirty nine patients studied. 2,692 pH monitoring episodes, with median of 24 (IQ: 15-44) episodes/patient, 1.30 (IQ: 0.80-2.60) reflux/hour, 1 (IQ: 0-4) reflux episode > 5 min per patient and clearance of 1.20 (IQ: 0.70-2.20) min/reflux. With pH monitoring analysis, 14 children (35.9 %) could have been diagnosed as GER (8 mild, 4 moderate and 2 severe) based on the classical criteria. MII identified a total of 8,895 events; only 3,219 among them were refluxes, with a median of 75 (IQ: 54-111) per patient, 1.30 (IQ: 1.3-2.6) episodes/hour). With MII-pH monitoring combination there were 21.60 (SD 15.21) acid reflux episodes, 67.33 weekly acid (SD 32.09) and 3.34 (SD 7.23) non-acid, being finally diagnosed 33 patients as GER. The association of pH monitoring and MII provides additional information that improves GER diagnostic performance without posing any additional risk to the infant patient. The non-acid/weekly acid refluxes, not detected by pH monitoring, account for a high percentage of episodes, this may have diagnostic and therapeutic significance, especially in infants. Further studies are needed to assess the normality of MMI in pediatric patients.