title: Risk factors for postoperative mortality in congenital diaphragmatic hernia: a single-centre observational study.
abstract: BACKGROUND
  The management of congenital diaphragmatic hernia (CDH) is a major challenge. The mortality is dependent on associated malformations, the severity of pulmonary hypoplasia, pulmonary hypertension and iatrogenic lung injury associated with aggressive mechanical ventilation. The aims of the study were to investigate the mortality over time in a single paediatric surgical centre, to compare the results with recent reports and to define the risk factors for mortality.
  
  
  METHODS
  The medical records of infants with CDH from two time periods: 1995-2005 and 2006-2016 were reviewed. Cox regression was used for statistical analysis.
  
  
  RESULTS
  The study included 113 infants. The mortality rate was significantly decreased in the later time period, compared to the earlier, 4.4 and 17.9%, respectively. At the early time period five patients (7.5%) were treated with ECMO and in the later time period ECMO was used in three patients (6.5%). The mortality in ECMO-treated patients was 50% in both time periods. Prenatal diagnosis, intrathoracic liver, low Apgar score and low birth weight were defined as independent risk factors for mortality.
  
  
  CONCLUSIONS
  Despite no significant differences in the incidence of independent risk factors and the use of ECMO between the two time periods, mortality decreased over time. The mortality was lower than previously reported. The results indicate that there are many important factors involved in a successful outcome after CDH repair. Large multicentre studies are necessary to define those critical factors and to determine optimal treatment strategies.
authors.affiliation: Department of Women's and Children's Health, Section of Pediatric Surgery, Uppsala University, 751 85, Uppsala, Sweden.|Department of Pediatric Surgery, University Children's Hospital, Uppsala, Sweden.
authors.forename: Darya
authors.initials: D
authors.lastname: Kadir
authors.affiliation: Department of Women's and Children's Health, Section of Pediatric Surgery, Uppsala University, 751 85, Uppsala, Sweden. helene.lilja@kbh.uu.se.|Department of Pediatric Surgery, University Children's Hospital, Uppsala, Sweden. helene.lilja@kbh.uu.se.
authors.forename: Helene Engstrand
authors.identifier: http://orcid.org/0000-0002-1998-5212
authors.initials: HE
authors.lastname: Lilja
mesh_terms: D002648:Child; D002675:Child, Preschool; D015199:Extracorporeal Membrane Oxygenation / Q000706:statistics & numerical data; D005260:Female; D065630:Hernias, Diaphragmatic, Congenital / Q000401:mortality* / Q000601:surgery*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D011183:Postoperative Complications / Q000401:mortality*; D011247:Pregnancy; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013548:Sweden / Q000453:epidemiology
keywords: Congenital diaphragmatic hernia; Postoperative outcome; Risk factors