ABSTRACT
Refractory hypoxemia during veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may require an additional cannula (VV-V ECMO) to improve oxygenation. This intervention includes risk of recirculation and other various adverse events (AEs) such as injury to the lung, cannula malpositioning, bleeding, circuit or cannula thrombosis requiring intervention (i.e., clot), or cerebral injury. During the study period, 23 of 142 V-V ECMO patients were converted to VV-V utilizing two separate cannulas for bi-caval drainage with an additional upper extremity cannula placed for return. Of those, 21 had COVID-19. In the first 24 h after conversion, ECMO flow rates were higher (5.96 vs 5.24 L/min, p = .002) with no significant change in pump speed (3764 vs 3630 revolutions per minute [RPMs], p = .42). Arterial oxygenation (PaO2) increased (87 vs 64 mmHg, p < .0001) with comparable pre-oxygenator venous saturation (61 vs 53.3, p = .12). By day 5, flows were similar to pre-conversion values at lower pump speed but with improved PaO2. Unadjusted survival was similar in those converted to VV-V ECMO compared to V-V ECMO alone (70% [16/23] vs 66.4% [79/119], p = .77). In a mixed effect regression model, any incidence of AEs, demonstrated a negative impact on PaO2 in the first 48 h but not at day 5. VV-V ECMO improved oxygenation with increasing flows without a significant difference in AEs or pump speed. AEs transiently impacted oxygenation. VV-V ECMO is effective and feasible strategy for refractory hypoxemia on VV-ECMO allowing for higher flow rate and unchanged pump speed.
ABSTRACT
Amidst the pandemic, geographical boundaries presented challenges to those in need of higher levels of care from referral centers. Authors sought to evaluate potential predictors of treatment success; assess our transport and remote cannulation process; and identify transport associated complications.Retrospective series of critically ill adults with COVID-19 transferred by our Extracorporeal Membrane Oxygenation (ECMO) team 24 March 2020 through 8 June 2021. Descriptive statistics and associated interquartile ranges (IQR) were used to summarize the data.Sixty-three patients with COVID associated acute respiratory distress syndrome (ARDS) requiring ECMO support were admitted to our ECMO center. Mean age was 44 years old (SD 12; IQR 36-56). 59% (n = 37) of patients were male. Average body mass index was 39.7 (SD 11.3; IQR 31-48.5). Majority of patients (77.8%; n = 35) had severe ARDS. Predictors of treatment success were not observed.Transport distances ranged from 2.2 to 236 miles (median 22.5 miles; IQR 8.3-79); round trip times from 18 to 476 min (median 83 min; IQR 44-194). No transport associated complications occurred. Median duration of ECMO support was 17 days (IQR 9.5-34.5). Length of stay in the Intensive Care Unit (median 36 days; IQR 17-49) and hospital (median 39 days; IQR 25-57) varied. Amongst those discharged, 60% survived.
