Association of Respiratory Parameters at Venovenous Extracorporeal Membrane Oxygenation Liberation With Duration of Mechanical Ventilation and ICU Length of Stay: A Prospective Cohort Study

OBJECTIVES: Although the criteria for initiation of venovenous extracorporeal membrane oxygenation (VV ECMO) are well defined, the criteria and timing for VV ECMO decannulation are less certain. The aim of this study was to describe the ventilation and physiologic factors at the time of VV ECMO decannulation and to determine if these factors have association with mechanical ventilation or ICU length of stay after ECMO decannulation. DESIGN: Multicenter, prospective cohort study. SETTING: Eleven ICUs in Australia. PATIENTS: Adult patients treated with VV ECMO from March 19, 2019, to September 20, 2020. INTERVENTIONS: Liberation from VV ECMO. RESULTS: Of 87 patients receiving VV ECMO, the median age was 49 years (interquartile range, 37–59 yr), 61 of 87 (70%) were male, and 52/87 (60%) had a diagnosis of acute respiratory distress syndrome. There were 24 of 87 patients (28%) who died prior to day 90. No patient required a second run of VV ECMO. In a multivariate models, a higher partial pressure of arterial carbon dioxide (p < 0.01) and respiratory rate at the time of decannulation (p = 0.01) were predictive of a longer duration of mechanical ventilation and ICU length of stay postdecannulation in survivors. Higher positive end-expiratory pressure at ECMO decannulation was associated with shorter duration of ICU length of stay post-ECMO decannulation in survivors (p = 0.01). CONCLUSIONS: A higher partial pressure of arterial carbon dioxide and higher respiratory rate at ECMO decannulation were associated with increased duration of mechanical ventilation and increased duration of ICU stay postdecannulation, and increased positive end-expiratory pressure at decannulation was associated with decreased duration of ICU stay postdecannulation. Future research should further investigate these associations to establish the optimal ventilator settings and timing of liberation from VV ECMO.