- Door Han Franssen
- In ARDS
- 2016-01-30 10:53:15
Mortality from pediatric respiratory failure treated with extracorporeal life support (ECLS) remains high at 43%.1 Studies evaluating predictors of mortality for pediatric ECLS for respiratory failure have identified patient diagnosis,1-3 presence of co-morbidities,1 pre-ECLS oxygenation,1, 2, 4, 5 and pre-ECLS length of mechanical ventilation1-3, 5, 6 as associated with higher mortality. Stratified analyses have suggested that the effect on mortality is not apparent until pre-ECLS mechanical ventilation exceeds 14 days.1, 5 Prolonged ECLS is associated with poor outcomes.2, 3, 7, 8 Analysis of 1489 pediatric patients with pneumonia in the Extracorporeal Life Support Organization (ELSO) registry between 1985 and 2010 showed predicted mortality decreasing by 1.3% daily until day 14, after which mortality increased by 1.8% per day.2 Separately, ELSO patients between 1993 and 2007 receiving > 21 days of ECLS for respiratory failure had higher mortality (62%) relative to those on for _ 14 days (39%).8 Time on ECLS may be either a marker for illness severity, reversibility of underlying disease, or recoverability of cardiopulmonary function. It is unknown whether therapies aimed at decreasing time on ECLS will improve outcomes. Pulmonary management during ECLS may affect duration of support. Traditional “rest settings” may risk unnecessary atelectasis and derecruitment in the attempt to limit ventilator induced lung injury during ECLS. A single neonatal study suggests that higher levels of positive end-expiratory pressure during ECLS may shorten the duration of extracorporeal support,9 but otherwise there is no literature to guide ventilator management. Additionally, flexible bronchoscopy on ECLS10-12 has been reported to improve pulmonary function leading to reductions of ECLS flows.11, 12 However, the optimal role of bronchoscopy during ECLS is undefined.
Since May, 2011, our pediatric intensive care unit (PICU) has approached ECLS for respiratory failure with a focus on improved secretion clearance and early recruitment. To this end, the initial and predominant mode of ventilation utilized on ECLS was changed to high frequency percussive ventilation (HFPV), which has been well-described in inhalational injury for its ability to safely oxygenate and ventilate, with continuous pneumatically-powered high frequency percussions to facilitate clearance of airway debris.13-16 An increase in therapeutic bronchoscopies was also instituted. The purpose of this study is to compare the outcomes of the patients who underwent HFPV and therapeutic bronchoscopies while on ECLS with a samecenter control population immediately prior to these interventions. We hypothesized that use of HFPV and bronchoscopies were associated with shorter ECLS runs and improved outcomes.