title: Nasal continuous positive airway pressure inhibits gastroesophageal reflux in newborn lambs.
abstract: 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.
authors.affiliation: Neonatal Respiratory Research Unit, Departments of Pediatrics and Physiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada; Pediatric Department, Amiens University Medical Center, Amiens, France.
authors.forename: Djamal
authors.initials: D
authors.lastname: Djeddi
authors.affiliation: Neonatal Respiratory Research Unit, Departments of Pediatrics and Physiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Danny
authors.initials: D
authors.lastname: Cantin
authors.affiliation: Neonatal Respiratory Research Unit, Departments of Pediatrics and Physiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Samson
authors.affiliation: Neonatal Respiratory Research Unit, Departments of Pediatrics and Physiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Praud
mesh_terms: D000818:Animals; D045422:Continuous Positive Airway Pressure / Q000379:methods; D004195:Disease Models, Animal; D005764:Gastroesophageal Reflux / Q000628:therapy*; D006801:Humans; D007231:Infant, Newborn; D008365:Manometry; D012756:Sheep