34 A. Saini et al.: J Extra Corpor Technol 2026, 58, 32 – 38
Table 1. Patient demographics and clinical characteristics of entire VA – ECLS cohort.
Variables |
Total cohort |
( n = 229) |
Age( months) |
2.5( 0.3, 19.0) |
Age group |
Neonates |
168( 73.4 %) |
Pediatrics |
61( 26.6 %) |
Weight( kg) |
4.4( 3.2, 10.7) |
BSA( m 2) |
0.3( 0.2, 0.5) |
Race |
Black |
104( 45.4 %) |
White |
87( 38.0 %) |
Hispanic |
26( 11.4 %) |
Other |
12( 5.2 %) |
Sex |
Female |
115( 50.2 %) |
Male |
114( 49.8 %) |
ECLS indication |
Cardiac |
112( 48.9 %) |
ECPR |
65( 28.4 %) |
Pulmonary |
52( 22.7 %) |
Time from admission to ECLS initiation |
78.5( 14.0, 356.0) |
( hours) |
Duration of ECLS run( hours) |
111.5( 65.5, 184.5) |
ECLS complications: |
Cardiovascular |
87( 45.8 %) |
Hemorrhagic |
86( 45.3 %) |
Mechanical |
75( 39.5 %) |
Renal |
103( 54.2 %) |
Neurologic |
46( 24.2 %) |
Metabolic |
29( 15.3 %) |
Infection |
9( 4.7 %) |
AKI Stage II or III |
160( 75.8 %) |
Mortality |
103( 45 %) |
Results Depicted in n(%), and Median( Interquartile Range / IQR). AKI: Acute Kidney Injury, BSA: Body Surface Area, ECLS: Extracorporeal Life Support; VA: Veno-Arterial.
( IQR 0.3, 19), and 4.4 kg( IQR 3.2, 10.7), respectively. Cardiac indications accounted for 48.9 % of the ECLS runs. The median time from admission to ECLS initiation was 78.5 h( IQR 14, 356), and the median duration of ECLS support was 111.5 h( IQR 65.5, 184.5). The overall in-hospital mortality rate was 45 % and Stage II or higher AKI was 75.8 %. Additional demographic and clinical variables are presented in Table 1.
A total of 181 patients( 79 %) experienced hyperoxia, with 87 patients( 37.9 %) exposed to moderate to severe hyperoxia. Table 2 summarizes demographic characteristics and clinical data stratified by hyperoxia severity. Patients with PaO 2 between 201 and 300 mmHg were older, with a median age of 7.9 months( IQR 0.5, 50.7) and a median weight of 7.4 Kg( IQR 3.5, 19.2). Moderate to severe hyperoxia was significantly associated with a cardiac indication for ECLS( p < 0.01). Patients with severe hyperoxia( PaO 2 > 300 mmHg) had the highest in-hospital mortality rate( 16 / 25, 64 %) and had the highest incidence of cardiovascular( 60 %), renal( 68 %) complications, and stage II or higher AKI( 95.2 %)( Table 2). The relationship between PaO 2 and patient survival is depicted in
Figure 1, which demonstrates a proportionately smaller number of survivors among patients exposed to severe hyperoxia.
In univariable analysis, severe hyperoxia compared to normoxia was associated with higher odds of in-hospital mortality( OR 2.7, 95 % CI 1.0 – 7.4, p = 0.04) and the composite outcome of cardiovascular or renal complications( OR 4.3, 95 % CI 0.9 – 20.7, p = 0.04). There was a trend towards a higher incidence of stage II or higher AKI, which did not reach statistical significance( OR 6.5, 95 % CI 0.8 – 53.9, p = 0.06). In multivariable regression analysis adjusted for age, body surface area( BSA), and indication for VA – ECLS, severe hyperoxia remained significantly associated with the composite outcome of cardiovascular or renal complications( OR 4.6, 95 % CI 0.9 – 23.0, p = 0.03). The association with in-hospital mortality trended towards but did not reach statistical significance( OR 2.5, 95 % CI 0.9 – 7.4, p = 0.1)( Table 3).
Subset analysis in neonates showed similar results, with higher odds of in-hospital mortality( OR 2.7, 95 % CI 0.9 – 8.1, p = 0.03) and cardiovascular or renal complications( OR 15.3, 95 % CI 1.9 – 124.1, p = 0.01) in univariate analysis when comparing the severe hyperoxia group to those without hyperoxia. The association remained significant for cardiovascular or renal complications( OR 11.9, 95 % CI 1.4 – 100.4, p = 0.03) in multivariable regression analysis. Severe hyperoxia was not associated with stage II or higher AKI, either in univariable( OR 11.3, 95 % CI 0.6 – 221.9, p = 0.11) or multivariable analysis( OR 19.4, 95 % CI 0.8 – 452.9, p = 0.07)( Table 4).
Among 126 survivors for whom functional status could be assessed, there was no statistically significant association between the severity of hyperoxia and adverse functional outcomes. The incidence of new morbidity and unfavorable outcomes was similar across all groups, p = 0.88 and p = 0.81, respectively( Table 5).
Discussion
Our study examines the outcomes of patients supported by VA – ECLS stratified by the severity of hyperoxia exposure. Nearly half of the VA – ECLS runs were performed for a cardiac indication. The overall in-hospital mortality was 45 % and Stage II or higher AKI was 75.8 %. Hyperoxia was more common in patients requiring VA – ECLS for a cardiac indication. Patients in the moderate hyperoxia group( PaO 2 = 201 – 300 mmHg) were older and, consequently, had a higher weight compared to the rest of the cohort. Patients in the severe hyperoxia group had the highest in-hospital mortality rate of 64 % and had the highest incidence of cardiovascular and renal complications, and stage II or higher AKI. Severe hyperoxia was associated with increased odds of composite outcome of cardiovascular or renal complications. Additionally, while severe hyperoxia was associated with higher odds of in-hospital mortality in univariable analysis, this association trended towards but did not reach statistical significance in multivariable regression analysis.
Hyperoxia potentiates the production of reactive oxygen species, which leads to lipid peroxidation, protein damage, and cell death [ 17 ]. It has been linked to adverse outcomes in various clinical scenarios. Studies have reported higher