Clinical outcomes of venoarterial extracorporeal life support in 462 patients: Single‐center experience

Extracorporeal membrane oxygenation for cardiogenic shock: a meta-analysis of mortality and complications

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (va-ECMO) is an advanced life support for critically ill patients with refractory cardiogenic shock. This temporary support bridges time for recovery, permanent assist, or transplantation in patients with high risk of mortality. However, the benefit of this modality is still subject of discussion and despite the continuous development of critical care medicine, severe cardiogenic shock remains associated with high mortality. Therefore, this work aims to analyze the current literature regarding in-hospital mortality and complication rates of va-ECMO in patients with cardiogenic shock.

METHODS

We conducted a systematic review and meta-analysis of the most recent literature to analyze the outcomes of va-ECMO support. Using the PRISMA guidelines, Medline (PubMed) and Scopus (Elsevier) databases were systematically searched up to May 2022. Meta-analytic pooled estimation of publications variables was performed using a weighted random effects model for study size.

RESULTS

Thirty-two studies comprising 12756 patients were included in the final analysis. Between 1994 and 2019, 62% (pooled estimate, 8493/12756) of patients died in the hospital. More than one-third of patients died during ECMO support. The most frequent complications were renal failure (51%, 693/1351) with the need for renal replacement therapy (44%, 4879/11186) and bleeding (49%, 1971/4523), bearing the potential for permanent injury or death. Univariate meta-regression analyses identified age over 60 years, shorter ECMO duration and presence of infection as variables associated with in-hospital mortality, while the studies reporting a higher incidence of cannulation site bleeding were unexpectedly associated with a reduced in-hospital mortality.

CONCLUSIONS

Extracorporeal membrane oxygenation is an invasive life support with a high risk of complications. We identified a pooled in-hospital mortality of 62% with patient age, infection and ECMO support duration being associated with a higher mortality. Protocols and techniques must be developed to reduce the rate of adverse events. Finally, randomized trials are necessary to demonstrate the effectiveness of va-ECMO in cardiogenic shock.

Longitudinal Trends in Bleeding Complications on Extracorporeal Life Support Over the Past Two Decades—Extracorporeal Life Support Organization Registry Analysis

OBJECTIVES

Data about inhospital outcomes in bleeding complications during extracorporeal life support (ECLS) have been poorly investigated.

DESIGN

Retrospective observational study.

SETTING

Patients reported in Extracorporeal Life Support Organization Registry.

PATIENTS

Data of 53.644 adult patients (greater than or equal to 18 yr old) mean age 51.4 ± 15.9 years, 33.859 (64.5%) male supported with single ECLS run between 01.01.2000 and 31.03.2020, and 19.748 cannulated for venovenous (V-V) ECLS and 30.696 for venoarterial (V-A) ECLS.

INTERVENTIONS

Trends in bleeding complications, bleeding risk factors, and mortality.

MEASUREMENT AND MAIN RESULTS

Bleeding complications were reported in 14.786 patients (27.6%), more often in V-A ECLS compared with V-V (30.0% vs 21.9%; p < 0.001). Hospital survival in those who developed bleeding complications was lower in both V-V ECLS (49.6% vs 66.6%; p < 0.001) and V-A ECLS (33.9 vs 44.9%; p < 0.001). Steady decrease in bleeding complications in V-V and V-A ECLS was observed over the past 20 years (coef., -1.124; p < 0.001 and -1.661; p < 0.001). No change in mortality rates was reported over time in V-V or V-A ECLS (coef., -0.147; p = 0.442 and coef., -0.195; p = 0.139).Multivariate regression revealed advanced age, ecls duration, surgical cannulation, renal replacement therapy, prone positioning as independent bleeding predictors in v-v ecls and female gender, ecls duration, pre-ecls arrest or bridge to transplant, therapeutic hypothermia, and surgical cannulation in v-a ecls.

CONCLUSIONS

A steady decrease in bleeding over the last 20 years, mostly attributable to surgical and cannula-site-related bleeding has been found in this large cohort of patients receiving ECLS support. However, there is not enough data to attribute the decreasing trends in bleeding to technological refinements alone. Especially reduction in cannulation site bleeding is also due to changes in timing, patient selection, and ultrasound guided percutaneous cannulation. Other types of bleeding, such as CNS, have remained stable, and overall bleeding remains associated with a persistent increase in mortality.

Outcomes of extracorporeal membrane oxygenation in adults with active hematologic and nonhematologic malignancy

Although the number of cancer patients admitted to the intensive care unit is increasing, the data on the use of extracorporeal membrane oxygenation in patients with malignancy are limited. We applied extracorporeal membrane oxygenation to carefully selected patients with active hematologic malignancy or nonhematologic malignancy who experienced respiratory or cardiac failure despite maximal conventional therapy. Patients with active malignancy who underwent extracorporeal membrane oxygenation in our institution between January 2012 and December 2016 were included in this study. The primary outcome of this study was defined as survival to hospital discharge. We also investigated the factors associated with survival to hospital discharge. There were 30 (30.6%) and 68 (69.4%) patients in the hematologic malignancy group and the nonhematologic malignancy group, respectively. Patients in the hematologic malignancy group were younger, more neutropenic, more hypotensive, had a lower Charlson Comorbidity Index, higher sequential organ failure assessment score, and lower platelet count than those in the nonhematologic malignancy group. Forty-six (46.9%) patients were successfully weaned off extracorporeal membrane oxygenation, and 30 (30.6%) patients survived until hospital discharge. Hospital survival rate and survival status 6 months after hospital discharge were significantly lower in patients with hematologic malignancy than in those with nonhematologic malignancy (13.3% vs. 38.2%, P = .026 and 3.3% vs. 26.5%, P = .017, respectively). Multivariate analysis identified an active hematologic malignancy, older age, acidosis, thrombocytopenia, high vasoactive-inotrope score, and respiratory failure as the risk factors for in-hospital death. Patients with hematologic malignancy requiring extracorporeal membrane oxygenation support had significantly lower rates of hospital survival and 6-month survival after discharge than patients with nonhematologic malignancy. Therefore, extracorporeal membrane oxygenation for treating cardiac or respiratory failure should only be considered in highly selected patients with hematologic malignancy.

Outcomes of left ventricular assist device implantation for advanced heart failure in critically ill patients (INTERMACS 1 and 2): A retrospective study

The use of left ventricular assist devices (LVADs) for advanced heart failure is becoming increasingly common. However, optimal timing and patient selection remain controversial. The aim of this study was to investigate outcomes of LVAD implantation for advanced heart failure in critically ill patients (INTERMACS 1 and 2). Between August 2010 and January 2020, 207 consecutive patients underwent LVAD implantation. Overall survival, major adverse events, and laboratory parameters were compared between patients in INTERMACS 1-2 (n = 107) and INTERMACS 3-5 (n = 100). Preoperative white blood cells, C-reactive protein, procalcitonin, bilirubin, alanine transaminase, and lactate dehydrogenase were all significantly higher in INTERMACS 1-2 when compared to INTERMACS 3-5 (P < .05). During hospitalization following LVAD implantation, patients in INTERMACS 1-2 were more likely to develop major infections (41.1% vs. 23.0%, P = .005), respiratory failure (57.9% vs. 25.0%, P < .001), mild (20.6% vs. 8.0%, P = .010), and moderate (31.8% vs. 7.0%, P < .001) right heart failure, and acute renal dysfunction (56.1% vs. 6.0%, P < .001). During a median follow-up of 2.00 years (interquartile range (IQR) 0.24-3.39 years), they had a higher incidence of thoracic (15.9% vs. 4.0%, P = .005) and gastrointestinal bleeding (21.5% vs. 11.0%, P = .042), as well as right heart failure (18.7% vs. 1%, P < .001). Risk of death was significantly higher in the INTERMACS 1-2 group (hazards ratio (HR) 1.64, 95% CI 1.12-2.40, P = .011). LVAD implantation in critically ill patients is associated with increased morbidity and mortality. Our results suggest that decision for LVAD should be not be delayed until INTERMACS 1 and 2 levels whenever possible.

Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: A systematic review

Prolonged cardiac arrest (CA) may lead to neurologic deficit in survivors. Good outcome is especially rare when CA was unwitnessed. However, accidental hypothermia is a very specific cause of CA. Our goal was to describe the outcomes of patients who suffered from unwitnessed hypothermic cardiac arrest (UHCA) supported with Extracorporeal Life Support (ECLS). We included consecutive patients' cohorts identified by systematic literature review concerning patients suffering from UHCA and rewarmed with ECLS. Patients were divided into four subgroups regarding the mechanism of cooling, namely: air exposure; immersion; submersion; and avalanche. A statistical analysis was performed in order to identify the clinical parameters associated with good outcome (survival and absence of neurologic impairment). A total of 221 patients were included into the study. The overall survival rate was 27%. Most of the survivors (83%), had no neurologic deficit. Asystole was the presenting CA rhythm in 48% survivors, of which 79% survived with good neurologic outcome. Variables associated with survival included the following: female gender (P < .001); low core temperature (P = .005); non-asphyxia-related mechanism of cooling (P < .001); pulseless electrical activity as an initial rhythm (P < .001); high blood pH (P < .001); low lactate levels (P = .003); low serum potassium concentration (P < .001); and short resuscitation duration (P = .004). Severely hypothermic patients with unwitnessed CA may survive with good neurologic outcome, including those presenting as asystole. The initial blood pH, potassium, and lactate concentration may help predict outcome in hypothermic CA.

The impact of obesity on outcomes in patients receiving extracorporeal life support

Extracorporeal life support (ECLS) has been increasingly utilized to manage cardiac and pulmonary dysfunction. The impact of obesity on outcomes of ECLS is poorly defined. The purpose of the study was to compare in-hospital mortality, resource use, complications, and readmissions in obese versus non-obese patients receiving ECLS. We performed a retrospective cohort study of all adult ECLS patients with and without an obesity diagnosis using the 2010-2016 Nationwide Readmissions Database (NRD). Mortality, length of stay (LOS), hospital charges, complications, and readmissions were evaluated using multivariable logistic and linear regression. Of 23 876, patients who received ECLS, 1924 (8.1%) were obese. Obese patients received ECLS more frequently for respiratory failure (29.5% vs. 23.7%, P = .001). After adjustment for patient and hospital factors, obesity was not associated with increased odds of mortality (AOR = 1.06, P = .44) and was associated with decreased LOS (13.7 vs. 21.2 days, P < .001), hospital charges ($171 866 vs. $211 445, P < .001), and 30-day readmission (AOR = 0.71, P = .03). Obesity was also associated with reduced odds of hemorrhage (AOR = 0.43, P < .001), neurologic complications (AOR = 0.55, P = .004), and acute kidney injury (AOR=0.83, P = .04). After stratification by ECLS indication, obesity remained predictive of shorter LOS (AOR range: 0.53-0.78, all P < .05 ) and did not impact mortality (all P > .05). Respiratory support remains the most common indication for ECLS among obese patients. Among all patients, as well as by individual ECLS indication, obesity was not associated with increased odds of mortality. These findings suggest that obesity should not be considered a high-risk contraindication to ECLS.