title: Surfactant deficiency in full-term newborns with transient tachypnea delivered by elective C-section.
abstract: BACKGROUND
  Previous studies have suggested that full-term newborns delivered by elective cesarean section who develop transient tachypnea have low gastric microbubble counts. In the present study, microbubble concentrations in oral fluid samples were used to evaluate pulmonary maturity.
  
  
  OBJECTIVE
  To evaluate lung maturity in full-term newborns delivered by elective caesarean section using the stable microbubble test in oral aspirates collected at birth.
  
  
  METHODS
  The study involved newborns with gestational age >37 weeks delivered by elective cesarean section. Oral fluid samples were obtained in the delivery room immediately after birth, and gastric fluid was collected within the first hour of life. Samples were frozen and analyzed by two blinded researchers.
  
  
  RESULTS
  The sample comprised 544 newborns. Twenty-two were diagnosed with transient tachypnea of the newborn by the assisting physician, and required admission to the Neonatal Intensive or Intermediate Care Unit. The median (interquartile range) of the number of microbubbles in the oral samples of these patients was 67.5 (45-150) microbubbles/mm(2) . The remaining 498 newborns without respiratory difficulties had a count of 350 (150-750) microbubbles/mm(2) -P < 0.001. Gastric fluid tests revealed a count of 150 (82.5-700) microbubbles/mm(2) for neonates with respiratory difficulties, and of 600 (216-1125) microbubbles/mm(2) -P < 0.05 for those without respiratory symptoms.
  
  
  CONCLUSIONS
  The present results suggest that transient tachypnea of the newborn is associated with surfactant dysfunction. Pediatr Pulmonol. 2016;51:596-600. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Graduate Program in Medicine-Pediatrics and Child Health, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
authors.forename: Geovana Rhoden
authors.initials: GR
authors.lastname: Estorgato
authors.affiliation: Department of Pediatrics, PUCRS, Porto Alegre, Brazil.
authors.forename: Humberto Holmer
authors.initials: HH
authors.lastname: Fiori
authors.affiliation: Department of Pediatrics, PUCRS, Porto Alegre, Brazil.
authors.forename: Manoel Antonio
authors.initials: MA
authors.lastname: da Silva Ribeiro
authors.affiliation: Neonatal Intensive Care Unit, Hospital da Unimed, Novo Hamburgo, Brazil.
authors.forename: Davi
authors.initials: D
authors.lastname: de Paula
authors.affiliation: Department of Pediatrics, PUCRS, Porto Alegre, Brazil.
authors.forename: Pedro Celiny Ramos
authors.initials: PC
authors.lastname: Garcia
authors.affiliation: Department of Pediatrics, PUCRS, Porto Alegre, Brazil.
authors.forename: Rita
authors.initials: R
authors.lastname: Mattiello
authors.affiliation: Department of Pediatrics, PUCRS, Porto Alegre, Brazil.
authors.forename: Renato Machado
authors.initials: RM
authors.lastname: Fiori
mesh_terms: D001826:Body Fluids / Q000737:chemistry*; D002585:Cesarean Section; D005260:Female; D005750:Gastric Juice / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000378:metabolism* / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D045423:Microbubbles; D009055:Mouth / Q000737:chemistry*; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000032:analysis* / Q000378:metabolism; D047929:Term Birth; D059245:Transient Tachypnea of the Newborn / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D011663:Pulmonary Surfactants
keywords: Microbubbles; diseases; infant; newborn; term birth