Association Between Tidal Volume in Invasive Mechanical Ventilation and Mortality in Children With Extracorporeal Membrane Oxygenation.

Mechanical ventilation (MV) strategies in children on extracorporeal membrane oxygenation (ECMO) have not been studied much and the ventilatory parameters to avoid greater lung damage are still unclear. Our objective was to determine the relationship between conventional tidal volume (4-8 ml/kg, CTV) versus low tidal volume (<4 ml/kg, LTV) and mortality in children with MV at the beginning of ECMO. This was a retrospective cohort study that included 101 (10.9 months interquartile range [IQR]: 6.0-24.0) children. Children with LTV had greater odds of hospital mortality (adjusted odds ratio [aOR]: 2.45; 95% confidence interval [CI]: 1.05-5.71; p = 0.03) regardless of age, reason for ECMO, and disease severity, as well as a longer duration of MV after ECMO. We found no differences between the groups in other MV settings. The CTV group required fewer fibrobronchoscopies than patients with LTV (aOR: 0.38; 95% CI: 0.15-0.99; p = 0.04). We found that a tidal volume (VT) lower than 4 ml/kg at the onset of ECMO support in children with MV was associated with higher odds of mortality, longer post-decannulation ventilation, and a greater need for fibrobronchoscopies. Lung-protective bundles in patients with ECMO and MV should consider the VT to maintain plateau and driving pressure that avoid major lung injury caused by MV.

Association between mechanical ventilation parameters and mortality in children with respiratory failure on ECMO: a systematic review and meta-analysis.

Background: In refractory respiratory failure (RF), extracorporeal membrane oxygenation (ECMO) is a salvage therapy that seeks to reduce lung injury induced by mechanical ventilation. The parameters of optimal mechanical ventilation in children during ECMO are not known. Pulmonary ventilatory management during this therapy may impact mortality. The objective of this study was to evaluate the association between ventilatory parameters in children during ECMO therapy and in-hospital mortality. Methods: A systematic search of PubMed/MEDLINE, Embase, Cochrane, and Google Scholar from January 2013 until May 2022 (PROSPERO 450744), including studies in children with ECMO-supported RF assessing mechanical ventilation parameters, was conducted. Risk of bias was assessed using the Newcastle-Ottawa scale; heterogeneity, with absence <25% and high >75%, was assessed using I2. Sensitivity and subgroup analyses using the Mantel-Haenszel random-effects model were performed to explore the impact of methodological quality on effect size. Results: Six studies were included. The median age was 3.4 years (IQR: 3.2-4.2). Survival in the 28-day studies was 69%. Mechanical ventilation parameters associated with higher mortality were a very low tidal volume ventilation (<4 ml/kg; OR: 4.70; 95% CI: 2.91-7.59; p < 0.01; I2: 38%), high plateau pressure (mean Dif: -0.70 95% CI: -0.18, -0.22; p < 0.01), and high driving pressure (mean Dif: -0.96 95% CI: -1.83, -0.09: p = 0.03). The inspired fraction of oxygen (p = 0.09) and end-expiratory pressure (p = 0.69) were not associated with higher mortality. Patients who survived had less multiple organ failure (p < 0.01). Conclusion: The mechanical ventilation variables associated with higher mortality in children with ECMO-supported respiratory failure are high plateau pressures, high driving pressure and very low tidal volume ventilation. No association between mortality and other parameters of the mechanical ventilator, such as the inspired fraction of oxygen or end-expiratory pressure, was found. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023450744, PROSPERO 2023 (CRD42023450744).