Multi-Lobar Atelectasis in Children Receiving Venoarterial Extracorporeal Membrane Oxygenation for Cardiac Indications

BACKGROUND: Respiratory complications are common in patients who require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for cardiac indications. We aimed to examine the frequency and characteristics of patients who develop multi-lobar atelectasis early in the course of VA ECMO and to identify factors associated with its occurrence.

METHODS: We performed a single-center retrospective review of consecutive pediatric subjects on VA ECMO in the cardiovascular ICU from 2014 to 2019. Chest radiographs before VA ECMO initiation and daily for up to 5 d of VA ECMO support were reviewed. Multi-lobar atelectasis was defined as the collapse of ≥2 lobes of the same lung. Patients with multi-lobar atelectasis before or immediately after VA ECMO cannulation were excluded. Bivariate comparisons and multivariable logistic regression analyses were performed to identify factors independently associated with lung collapse. Results of the multivariable analysis are provided as odds ratio (OR) with 95% CI.

RESULTS: We reviewed 119 VA ECMO runs in 101 unique subjects. Multi-lobar atelectasis occurred in 36 runs (30%), with an isolated collapse of the left lung occurring most frequently (no. runs = 20). VA ECMO runs complicated by multi-lobar atelectasis were significantly longer and associated with lower hospital survival (51% vs 77%, survival in subjects without multi-lobar atelectasis; P = .01). Multivariable logistic regression analysis identified a subsequent ECMO run during the same admission to be independently associated with multi-lobar atelectasis (OR 5.4, 95% CI 1.2–21.5). Subanalysis of the subjects with isolated left lung collapse revealed male sex (OR 8.9, 95% CI 1.6–48.2) and subsequent ECMO run during the same admission (OR 4.0, 95% CI 1.2–13.6) to be independently associated with this complication, and mechanical ventilation at least 12 h before ECMO may be protective (OR 0.22, 95% CI 0.07–0.76).

CONCLUSIONS: Multi-lobar atelectasis commonly occurred in children who were receiving VA ECMO for cardiac failure and was associated with worse outcomes. Male patients, a subsequent VA ECMO run during the same hospitalization, and patients in whom mechanical ventilation was initiated shortly before ECMO cannulation may be at increased risk for this complication.