Combined oesophageal impedance‐pH monitoring in preterm newborn: comparison of two options for layout analysis

Abstract

Gastro-oesophageal reflux (GOR) is common in preterm infants. Combined multichannel intraluminal impedance and pH monitoring (pH-MII) is emerging as an useful tool to study both acid and non-acid GOR in this population. We aimed to highlight main advantages and limits of pH-MII in preterm infants and to test whether the inclusion of GOR episodes detected only by pH monitoring details better the features of GOR. Fifty-two symptomatic preterm infants underwent a 24-hour, continuous and simultaneous measurement of pH-MII. Each layout was analyzed using two different options: option 1 included GOR episodes detected by MII and then classified as acid or non-acid according to the associated pH change; option 2 included GOR episodes detected by MII and also GOR episodes detected only by pH sensor. By adopting option 1, a total number of 2834 GOR episodes was detected by MII: 2162 of them were characterized as non-acid and 672 were characterized as acid. The median (range) number of acid MII-GOR episodes was 10 (1-52); the median (range) number of non-acid MII-GOR episodes was 36.5 (2-119). Median (range) acid MII-GOR-bolus exposure index was 0.28% (0.02-2.73%); median (range) non-acid MII-GOR-bolus exposure index was 1.03% (0.06-38.15%). By adopting option 2, an average of 53.2 acid GOR episodes and an average of 11% oesophageal exposure to acid GOR more than by option 1 was detected. An accurate and detailed description of GOR in preterm infants can be obtained only by including in the analysis all acid GOR episodes detected by pH sensor.

A Thickened Formula Does Not Reduce Apneas Related to Gastroesophageal Reflux in Preterm Infants

“…The relationship between AOP and gastroesophageal reflux (GER) is still controversial [2,3,4]: in a previous study, we have shown that the proportion of apneas triggered by GER is highly variable among preterm infants [4], while other studies have failed to show a causal relationship between the two events [2]. In our experience, non-acid GER appears to be a more effective trigger for apnea than acid GER [5]; it occurs mainly soon after feeding [6], and is often associated with breathing irregularities [7]. …”

“…Combined multichannel intraluminal impedance and pH monitoring (pH-MII; Sandhill Scientific, Inc., Highland Ranch, Colo., USA) and PSG (System Plus; Micromed, Mogliano Veneto, Italy) were performed as previously described [6]. The clocks of the two instruments were synchronized at minute-second before starting each recording, and the recording of the two layouts was started simultaneously.…”

High Prevalence of Esophageal Acid Exposure in Very Low Birth Weight Infants Presenting or Not Bronchopulmonary Dysplasia: A Prospective Cross-Sectional Study

“…In the last decade, combined esophageal impedance-pH monitoring is the most widely used method for the identification of acid and non-acid reflux [8,10,13,14,20,21]. However, this technology does not detect a substantial part of the acid events in premature infants [14,22].…”

The efficacy of sodium alginate (Gaviscon) for the treatment of gastro-oesophageal reflux in preterm infants

“…pH-MII was performed as previously described. 13 The single use, flexible pH-MII probe (Comfortec; pH-MII Sandhill Scientific) contains seven impedance rings, which constitute six dipolar impedance channels and one antimony electrode for pH detection, located in the middle of the distal impedance dipole. The distance between each of the impedance rings is 1.5 cm, except for the distance between the two distal ones, which is 2 cm.…”

“…13 For this reason, our first hypothesis was that sodium alginate could act mainly by lowering non-acid GER indexes. However, we found that in preterm infants the efficacy of sodium alginate in treating GER is mainly related to the decrease in acid GER indexes, which suggests that the alginate preparation remains inside the stomach for a quite long period after feeding.…”