(1064) Factors Associated With Access Insufficiency in VV ECMO

Introduction: Access insufficiency is the sudden decrease or cessation of ECMO flows, a common complication affecting patients with severe respiratory failure managed with VV ECMO, which in severe cases can result in dangerous hypoxemia and hemodynamic instability. The interventions directed at stopping access insufficiency in the acute setting, including volume resuscitation and increased sedation, are also potentially deleterious to patients being managed for severe respiratory failure. We sought to determine what patient and procedural factors were associated with access insufficiency in adult patients with severe respiratory failure cannulated for VV ECMO.

Methods: We analyzed a retrospective cohort of adults ≥ 18 years from the University of Maryland Medical Center’s ECMO database from January 1, 2016, to December 31, 2022. All patients were placed on VV ECMO for severe respiratory failure and remained alive and on ECMO for at least 96 hours. The episodes of severe access insufficiency that warranted documentation in the daily progress note were recorded. Multivariable Poisson regression models were created to estimate relative risks and their 95% confidence intervals for the association between patient and procedural factors and access insufficiency.

Results: A total of 303 patients with severe respiratory failure cannulated for VV ECMO were analyzed. Episodes of access insufficiency occurred in 34.3% of patients. Multivariable modelling indicated that episodes of access insufficiency were significantly associated with durations of VV ECMO exceeding 2 weeks (RR = 3.10, 95% CI: 1.68-5.73, p< 0.001), failed attempts at prone positioning (RR = 2.48, 95% CI: 1.03-5.98, p = 0.04) and the need for non-sterile drainage cannula repositioning (RR= 2.00, 95% CI: 1.20-3.33, p = 0.008). No statistically significant association was observed between access insufficiency and the type of imaging guidance used during cannulation, cannula configuration, size of drainage cannula, patient age, BMI, or gender.

Conclusions: We identified several factors associated with access insufficiency, including duration of VV ECMO, failed prone positioning, and the need for non-sterile cannula repositioning.