A Retrospective Study of Infection in Patients Requiring Extracorporeal Membrane Oxygenation Support.

BACKGROUND: Healthcare-associated infections (HAIs) in critically ill patients are a serious public health problem. Extracorporeal membrane oxygenation (ECMO) has been used increasingly for patients with severe cardiac or respiratory failure, but it may increase HAI risk. The goal of our study was to characterize HAIs in ECMO patients at an ECMO referral center. METHODS: This institutional review board-approved study identified all consecutive adult ECMO patients admitted to the cardiac surgery intensive care unit (CSICU) between January 1, 2015, and December 31, 2017. Demographic data, diagnosis, ECMO cannulation technique, and survival were collected. Urinary tract infection, pneumonia, and bacteremia incidence during ECMO and within 3 months of decannulation were collected. Outcomes of patients with HAIs were compared with noninfected patients, the CSICU infection incidence, and overall Extracorporeal Life Support Organization survival data. RESULTS: There were 288 ECMO patients and 3396 CSICU admissions during this period. Survival was 72.3% for venoarterial ECMO, 85.3% for venovenous ECMO, and 57.1% for multimodality or veno-arteriovenous ECMO, with discharge survival of 60.2%, 72.0%, and 28.6%, respectively. Bacteremia incidence while cannulated was 6.8% for venoarterial ECMO and 9.3% for venovenous ECMO. Bacteremia occurred in 22 of 288 (7.6%) ECMO patients, compared with 48 of 3109 (1.5%) in non-ECMO CSICU patients, which was statistically significant (P < .002). Bacteremia and pneumonia were associated with decreased VA-ECMO survival, with prolonged overall requirements for ECMO support. CONCLUSIONS: Nosocomial ECMO infections are significantly higher than in other CSICU patients. Infection risk remains significant even after decannulation. Infection is associated with increased mortality and longer duration of ECMO support. Further efforts are needed to determine HAI reduction strategies in this high-risk patient population.

High-efficiency, high-flux in-line hemofiltration using a high blood flow extracorporeal circuit.

The ability of current renal replacement therapy modalities to achieve rapid solute removal is limited by membrane surface area and blood flow rate. Extracorporeal membrane oxygenation offers high blood flow and hemodynamic support that may be harnessed to overcome limitations in traditional renal replacement therapy. Using an extracorporeal membrane oxygenation circuit, we describe a high blood flow, high-efficiency hemofiltration technique using in-line hemofilters (hemoconcentrators) and standard replacement fluid to enhance solute clearance. Using this approach and a total of 5 L of replacement volume per treatment, creatinine (Cr) clearances of 8.3 L/hour and 11.2 L/hour using one and two hemoconcentrators, respectively, were achieved. With use of a high blood flow rate of up to 5 L/min, this hemofiltration technique can potentially offer clearance of 30 times that of continuous renal replacement therapy and of 6 times that of hemodialysis which may expand the ability to remove substances traditionally not considered removable via existing extracorporeal therapies.

Long-Term Venovenous Extracorporeal Membrane Oxygenation Support for Acute Respiratory Distress Syndrome.

BACKGROUND: Given substantial advances in venovenous extracorporeal membrane oxygenation (ECMO) technology, long-term support is increasingly feasible. Although the benefits of short-term ECMO as a bridge to recovery in acute respiratory distress syndrome (ARDS) are well described, the utility and outcomes of long-term support remain unclear. METHODS: Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed and analyzed separately for those requiring ECMO support for less than 3 weeks or for 3 weeks or longer. Demographic factors, ECMO variables, and outcomes were assessed. RESULTS: Fifty-five patients with ARDS received ECMO during the study period, with 11 patients requiring long-term ECMO support and a median duration of 36 (interquartile range: 24 to 68) days. Recovery was the initial goal in all patients. Pre-ECMO mechanical ventilatory support, indices of disease severity, and the ECMO cannulation strategy were similar between the two groups. Eight (73%) patients receiving long-term support were bridged to recovery, and 1 patient was bridged to transplantation after a refractory course. Eight (73%) patients receiving long-term support and 25 (57%) patients receiving short-term support survived to 30 days and hospital discharge. CONCLUSIONS: Previously, long-term ECMO support was thought to be associated with unfavorable outcomes. This study, however, may provide support for the efficacy of ECMO support even for 3 weeks or more as a bridge to recovery or transplantation.

Class III Obesity is Not a Contraindication to Venovenous Extracorporeal Membrane Oxygenation Support.

BACKGROUND: The use of venovenous extracorporeal membrane oxygenation (ECMO) has increased as a bridge to recovery for acute respiratory distress syndrome (ARDS) refractory to conventional support. Morbid obesity can pose a significant challenge to obtaining indexed flows, and outcomes in this population are not well described. METHODS: Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed. Demographics, ECMO variables, and outcomes were assessed. Morbid obesity and super obesity were defined as a body mass index (BMI) greater than 40 kg/m(2) and greater than 50 kg/m(2), respectively. RESULTS: Fifty-five patients with ARDS were placed on ECMO during the study period. Twelve were morbidly obese with a BMI of 49.0 kg/m(2) (interquartile range [IQR]: 45.4-57.3 kg/m(2)). Pre-ECMO mechanical ventilatory support and indices of disease severity were similar between the 2 groups, as were cannulation strategy and duration of ECMO support. Nine (75%) morbidly obese patients and 27 (63%) non-morbidly obese patients were successfully weaned from ECMO support, and patient survival to time of discharge was 67% and 58%, respectively. In the subset of super obese patients (n = 6; BMI, 57.3 kg/m(2) [IQR: 51.3-66.5 kg/m(2)]), recovery and midterm survival was 100%. CONCLUSIONS: In this review, class III obesity was not associated with poorer outcomes, and based on these data, ECMO support should not be withheld from this patient population.