Background: Using esophageal pHmetry, nasal CPAP (nCPAP) has been shown to decrease acid gastroesophageal reflux (GER) in adult humans. Although both GER (mainly non-acid) and nCPAP use are very frequent in newborns, the effect of nCPAP on GER in early life is unknown. Having recently shown that the newborn lamb is a unique model for studying neonatal GER, our main objective was to assess the effect of nCPAP on GER in newborn lambs.
Methods: Eight newborn lambs, aged 2-3 days, were studied. Continuous esophageal pH-Impedance monitoring and polysomnography were performed for six hours during both spontaneous breathing and nCPAP application at 6 cmH2O (nCPAP(6)), in a randomized order. Results were compared in the two experimental conditions, as well as without CPAP during the following 6 hours.
Results: i) nCPAP(6) virtually abolished GER [mean ± SD reflux number for 6 h = 9.1 ± 8.6 without nCPAP(6) vs. 0.6 ± 1 with nCPAP(6), P<0.05]; ii) GER number was also reduced during the 6 h-period following nCPAP(6) application (18 ± 16 without nCPAP(6) vs. 7 ± 8.1 with nCPAP(6), P<0.05); iii) nCPAP(6) decreased the depth and duration of lower esophageal sphincter relaxation.
Conclusions: nCPAP inhibits GER in the newborn lamb. Further clinical studies using different levels of nasal CPAP are needed to confirm this result in human infants.