title: Effects of permissive hypercapnia on pulmonary and neurodevelopmental sequelae in extremely low birth weight infants: a meta-analysis.
abstract: OBJECTIVE
  To perform a systematic review and meta-analysis of the efficacy and safety of permissive hypercapnia in extremely low birth weight infants.
  
  
  METHODS
  A systematic search of MEDLINE, EMBASE, the Cochrane Database of randomized trials. Eligibility and quality of trials were assessed, and data on study design, patient characteristics, and relevant outcomes were extracted.
  
  
  RESULTS
  Four studies that enrolled a total of 693 participants were selected. Meta-analysis revealed no effect of permissive hypercapnia on decreasing rates of bronchopulmonary dysplasia (BPD). Permissive hypercapnia also had no significant effect on mortality, intraventricular haemorrhage (IVH), IVH (grade 3-4), periventricular leukomalacia (PVL), necrotising enterocolitis (NEC), retinopathy of prematurity (ROP) or air leaks in extremely low birth weight infants. Neurodevelopmental outcomes were comparable at 18-22 months' corrected age in two studies. permissive hypercapnia did not increase the risk of cerebral palsy, Mental Developmental Index <70, Psychomotor Developmental Index <70, visual deficit, or hearing deficit.
  
  
  CONCLUSIONS
  Permissive hypercapnia did not reduce the rate of BPD in extremely low birth weight infants. The rates of mortality, IVH, PVL, NEC, ROP and neurodevelopmental outcomes did not differ between these two groups. These results suggest that permissive hypercapnia does not bring extra benefits in extremely low birth weight infants.
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310000 People's Republic of China.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Pediatrics, Taizhou First People's Hospital, Taizhou, 318020 People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ye
keywords: Extremely low birth weight infants; Lung protection; Meta-analysis; Neurodevelopmental sequelae; Permissive hypercapnia