Factors associated with outcomes of patients on extracorporeal membrane oxygenation support: a 5-year cohort study.

INTRODUCTION: Mortality of patients on extracorporeal membrane oxygenation (ECMO) remains high. The objectives of this study were to assess the factors associated with outcome of patients undergoing ECMO in a large ECMO referral centre and to compare veno-arterial ECMO (VA ECMO) with veno-venous ECMO (VV ECMO). METHODS: We reviewed a prospectively obtained ECMO database and patients' medical records between January 2005 and June 2011. Demographic characteristics, illness severity at admission, ECMO indication, organ failure scores before ECMO and the ECMO mode and configuration were recorded. Bleeding, neurological, vascular and infectious complications that occurred on ECMO were also collected. Demographic, illness, ECMO support descriptors and complications associated with hospital mortality were analysed. RESULTS: ECMO was initiated 158 times in 151 patients. VA ECMO (66.5%) was twice as common as VV ECMO (33.5%) with a median duration significantly shorter than for VV ECMO (7 days (first and third quartiles: 5; 10 days) versus 10 days (first and third quartiles: 6; 16 days)). The most frequent complications during ECMO support were bleeding and bloodstream infections regardless of ECMO type. More than 70% of the ECMO episodes were successfully weaned in each ECMO group. The overall mortality was 37.3% (37.1% for the patients who underwent VA ECMO, and 37.7% for the patients who underwent VV ECMO). Haemorrhagic events, assessed by the total of red blood cell units received during ECMO, were associated with hospital mortality for both ECMO types. CONCLUSIONS: Among neurologic, vascular, infectious and bleeding events that occurred on ECMO, bleeding was the most frequent and had a significant impact on mortality. Further studies are needed to better investigate bleeding and coagulopathy in these patients. Interventions that reduce these complications may improve outcome.

A pilot feasibility trial of allocation of freshest available red blood cells versus standard care in critically ill patients.

BACKGROUND: Prolonged storage of red blood cells (RBCs) may increase posttransfusion adverse events in critically ill patients. We aimed to evaluate in intensive care unit (ICU) patients 1) the feasibility of allocating freshest available compatible RBCs versus standard care and 2) the suitability of this approach in the design of a large randomized controlled trial (RCT). STUDY DESIGN AND METHODS: Eligible patients from two adult ICUs were randomly assigned to receive either the freshest available compatible RBCs or the standard care (the oldest compatible available RBCs) for all transfusions during their ICU stay. Study group allocation was concealed from patients and bedside clinicians, but the transfusion service was unblinded. The study endpoints were the feasibility of the study procedures, including success of the ICU Web randomization, the ICU staff blinding, and the correct delivery of the RBC units by the transfusion service in accordance with the allocated study group. In addition, we measured the difference in age of RBC units between the two groups. RESULTS: During a 3-month period, 177 RBC units were delivered to 51 patients. All study procedures, including randomization, blinding, and delivery of blood in accordance with the study group were successful. The mean (±SD) of the mean age of the RBC received by each patient was lower in the "fresher blood" group compared with the standard care group (12.1 [±3.8] days vs. 23 [±8.4] days; p<0.001). CONCLUSION: Randomized delivery of the freshest available RBCs versus standard care to ICU patients who were prescribed transfusion for clinical reasons is feasible, with a clinically relevant degree of storage duration separation achievable between the two study groups. These findings support the feasibility of a future large pragmatic RCT.

Duration of red blood cells storage and outcome in critically ill patients.

PURPOSE: There is conflicting evidence on the effect of red blood cells (RBC) storage duration and clinical outcomes. We aimed to investigate the association between RBC storage duration and clinical outcomes in patients admitted to the intensive care unit (ICU). MATERIALS AND METHODS: We retrospectively (2001-2011) studied adults admitted to the ICUs of 2 hospitals who received RBC. Using the mean, maximum and minimum age of RBC units transfused, we evaluated the association between RBC storage duration and mortality. We also analyzed the association between mean age of RBC units and length of stay (LOS) in survivors. We performed sensitivity analyses in patients who only received RBC in ICU and who only received leukodepleted RBC. RESULTS: We studied 8416 patients who received a median of 4 (interquartile range, 2-7) RBC units. After multivariate analysis, age of RBC was not independently associated with mortality, including in the subgroup analyses. Furthermore, there was no clinically relevant relationship between mean RBC age and LOS. CONCLUSIONS: RBC storage duration was not associated with increased mortality nor ICU and hospital LOS. These results support the view that the effect of RBC storage duration on outcomes in critically ill patients is uncertain.

Infections acquired by adults who receive extracorporeal membrane oxygenation: risk factors and outcome.

OBJECTIVES: To analyze infectious complications that occur in patients who receive extracorporeal membrane oxygenation (ECMO), associated risk factors, and consequences on patient outcome. DESIGN: Retrospective observational survey from 2005 through 2011. PARTICIPANTS AND SETTING: Patients who required ECMO in an Australian referral center. METHODS: Cases of bloodstream infection (BSI), catheter-associated urinary tract infection (CAUTI), and ventilator-associated pneumonia (VAP) that occurred in patients who received ECMO were analyzed. RESULTS: A total of 146 ECMO procedures were performed for more than 48 hours in 139 patients, and 36 patients had a total of 46 infections (30.1 infectious episodes per 1,000 days of ECMO). They included 24 cases of BSI, 6 of them secondary to VAP; 23 cases of VAP; and 5 cases of CAUTI. The most frequent pathogens were Enterobacteriaceae (found in 16 of 46 cases), and Candida was the most common cause of BSI (in 9 of 24 cases). The Sequential Organ Failure Assessment score before ECMO initiation and the number of days of support were independently associated with a risk of BSI, with odds ratios of 1.23 (95% confidence interval [CI], 1.03-1.47; [Formula: see text]) and 1.08 (95% CI, 1.03-1.19]; [Formula: see text]), respectively. Infected patients did not have a significantly higher mortality compared with uninfected patients (41.7% vs 32%; [Formula: see text]), but intensive care unit length of stay (16 days [interquartile range, 8-26 days] vs 11 days [IQR, 4-19 days]; [Formula: see text]) and hospital length of stay (33.5 days [interquartile range, 15.5-55.5] vs 24 days [interquartile range, 9-42 days]; [Formula: see text]) were longer. CONCLUSION: The probability of infection increased with the duration of support and the severity of illness before initiation of ECMO. Infections affected length of stay but did not have an impact on mortality.

Total leukocyte control for elective coronary bypass surgery does not improve short-term outcome.

BACKGROUND: Despite early promise as a means of reducing the inflammatory response to surgery and subsequent organ damage, the evidence of the clinical value of leukocyte filtration remains equivocal. METHODS: Three hundred patients presenting for routine coronary artery bypass surgery were randomized to a total leukocyte filtration group (filters in five different locations) and a control group with a standard 40-mum filter in the bypass return line only. Data on efficacy and safety of leukocyte filtration were collected by research and postoperative care staff who were blinded to the mode of filtration. RESULTS: Leukofiltration achieved a transient fall in white cells immediately after surgery (p = 0.07) and a sustained fall in platelets, which was still significant on the second postoperative day (p = 0.0001). However, there were no significant differences in postoperative hospital stay, the primary outcome variable (p = 0.35), in ICU stay (p = 0.92), or mortality (p = 1.0). There were no differences in postoperative cardiac status including cardiac output (p = 0.16), inotrope (p = 0.93) or balloon pump (p = 0.48) requirement, or 24-hour troponin (p = 0.60). Similarly there were no differences in pulmonary or renal function (intubation time (p = 0.83), respiratory index (p = 0.19) rise in creatinine (p = 0.13) or hemofiltration (1.0)). Leukofitration was not associated with a statistically significant increase in bleeding or requirement for blood or blood products. It was associated with a decrease approaching significance (p = 0.1) in number and severity of postoperative wound infections. Three filters were blocked during use but were changed without incident or compromise to patient safety. CONCLUSIONS: Leukocyte filtration is safe but not efficacious in improving short-term outcome.