[Controversies in the therapeutical management of congenital diaphragmatic hernia: update by means of evidence-based medicine].

INTRODUCTION: Congenital diaphragmatic hernia (CDH) is one of the high-risk diseases in neonatal surgery. The aim of this article is to make an update of the controversies about the therapeutic management (time of surgery and modalities of medical stabilization) of CDH, by means of a systematic and critical review of the best scientific evidence in bibliography.

METHODS: Systematic and structured review of the articles about therapeutic management of CDH (surgery, mechanical ventilation, inhaled nitric oxide, extracorporeal membrane oxygenation, surfactant, etc) published in secondary (TRIPdatabase, systematic review in Cochrane Collaboration, clinical practice guidelines, health technology assessment database, etc) and primary (bibliographic databases, biomedical journals, books, etc) publications and critical appraisal by means of methodology of the Evidence-Based Medicine Working Group. We selected the publications with the main scientific evidence in therapeutical articles (clinical trial, systematic review, meta-analysis and clinical practice guideline).

RESULTS: The main secondary information is found in The Cochrane Library: 3 systematic review in the Neonatal Group (one specific about the time of surgery, and two related to the use of nitric oxide and extracorporeal membrane oxygenation in neonatal severe respiratory failure). But we found the main relevant articles in Pubmed database, mainly published in Journal Pediatric Surgery and with some clusters of investigation (Congenital Diaphragmatic Hernia Study Group in Texas University and Buffalo Institute of Fetal Therapy in New York University).

CONCLUSIONS: From the evidence-based analysis, the results of CDH management between immediate versus delayed surgery were unclear, but delayed surgical (with pre-operative stabilization) has become preferred approach in many centers, and foetal surgery is not better than neonatal one. Opinion regarding the time of surgery has gradually shifted from early repair to a policy of stabilization and delayed repair. Because of associated persistent pulmonary hypertension and/or pulmonary hypoplasia in CDH, medical therapy is focused toward optimizing oxygenation while avoiding barotrauma, using gentle ventilation and permissive hypercarbia. High frequency oscillatory ventilation, inhaled nitric oxide and extracorporeal membrane oxygenation are used in severe cases, but these treatments do not clearly improve the outcome in neonates with CDH. The usefulness of surfactant and partial liquid ventilation are based in animal model experimentation, because the clinical trials in newborns are little and non-conclusive. Challenges for the future in this thematic area include the need for bigger and better trials of therapy in this field, with long-term outcomes among surviving children.