Conventional mechanical ventilation versus high-frequency oscillatory ventilation in congenital diaphragmatic hernia of neonates: a systematic review

Background: Neonates with congenital diaphragmatic hernia (CDH) present with respiratory distress and circulatory insufficiency, requiring immediate intubation and mechanical ventilation. Studies in the literature present contradictory results regarding the optimal ventilation mode for neonates with congenital diaphragmatic hernia. We present a systematic review of the selected literature regarding high-frequency oscillatory ventilation (HFOV) compared to conventional mechanical ventilation (CMV) in congenital diaphragmatic hernia. Methodology: PubMed, SCOPUS, EBSCOhost, and ProQuest databases were used to identify literature regarding HFOV compared to CMV in a CDH. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies and the Joanna Briggs Institute critical appraisal tool for randomized clinical trials. The search was conducted between the 23rd of October 2020 to November 2020. Articles that were included were published within the last twenty years (2000-2020). The following search and Boolean terms were used for the search of relevant articles: "Congenital Diaphragmatic Hernia" AND "high frequency" AND neonate AND "conventional mechanical ventilation". Results: Four studies were identified and considered eligible for the study. One study was a randomized clinical trial, and the other three cohort studies. Patients in the high-frequency oscillatory (HFO) group presented with a higher length of ventilation and hospital stay. There was a lack of evidence regarding any significant difference in the mortality rate. Conclusion: We cannot make an evidence-based recommendation regarding the superiority of either CMV or HFOV as the optimal ventilation method in neonates with CDH. However, almost all studies observed a lengthened period of ventilation and time required before surgical repair in the HFOV group. Abbreviations: CDH: congenital diaphragmatic hernia; CLD: chronic lung disease; CMV: conventional mechanical ventilation; GER: gastroesophageal reflux; HFOV: high-frequency oscillatory ventilation; NOS: Newcastle-Ottawa Scale; RDS: respiratory distress syndrome.