The Utility of Risk Scores in Postcardiotomy Extracorporeal Membrane Oxygenation

BACKGROUND

The use of a venoarterial extracorporeal membrane oxygenation (ECMO) in the postcardiotomy shock setting (PC-ECMO) can be life-saving. Risk stratification for patients under PC-ECMO is currently challenging. The aim of this study was to assess the discriminatory ability of the different available risk scores for mortality in PC-ECMO patients.

METHODS

Patients aged >18 years undergoing coronary artery bypass, valve surgery, or a combination of these procedures and implanted an ECMO for postcardiotomy shock between January 2017 and June 2022 in a single ELSO registered center were retrospectively included. The STS, Euroscore II, SAVE, modified SAVE, APACHE II, and VIS scores were compared for their discriminatory ability concerning weaning and 30-day survival.

RESULTS

During the study period, 7342 patients underwent coronary bypass or valve surgery, of whom 109 patients with PC-ECMO were included in the analysis. The Euroscore II and STS scores were not associated significantly with 30-day mortality, whereas the SAVE, the modified SAVE, APACHE II, and VIS scores significantly predicted 30-day mortality. The SAVE and the modified SAVE scores showed moderate discrimination ability with AUCs of 0.672 and 0.695, while the APACHE and VIS scores had a satisfactory discriminatory ability with AUCs of 0.727 and 0.844, respectively.

CONCLUSION

Currently used risk scores for PC-ECMO patients do not provide satisfactory predictions for weaning and survival. VIS at the 24th hour can be a valuable parameter for risk analysis and prospective studies can investigate novel PC-ECMO risk scoring systems.

Postcardiotomy Shock Syndrome: A Narrative Review of Perioperative Diagnosis and Management

Postcardiotomy shock (PCS) is generally described as the inability to separate from cardiopulmonary bypass due to ineffective cardiac output after cardiotomy, which is caused by a primary cardiac disorder, resulting in inadequate tissue perfusion. Postcardiotomy shock occurs in 0.5% to 1.5% of contemporary cardiac surgery cases, and is accompanied by an in-hospital mortality of approximately 67%. In the last 2 decades, the incidence of PCS has increased, likely due to the increased age and baseline morbidity of patients requiring cardiac surgery. In this narrative review, the authors discuss the epidemiology and pathophysiology of PCS, the rationale and evidence behind the initiation, continuation, escalation, and discontinuation of mechanical support devices in PCS, and the anesthetic implications.

Extracorporeal Membrane Oxygenation in Postcardiotomy Cardiogenic Shock

Postcardiotomy extracorporeal membrane oxygenation (PC-ECMO), the most frequent indication for ECMO in the United States, is increasingly used as the first-line mechanical circulatory support in patients who are refractory to conventional treatment. Despite increasing use of PC-ECMO, limited evidence is available regarding its safety, efficacy, and optimal timing for initiation and weaning. The decision to use PC-ECMO often is made in the absence of robust clinical data, leading to variability in patient selection, management, and outcomes across different institutions. This article summarizes current evidence on ECMO use in postcardiotomy cardiogenic shock and discusses its potential benefits, management, complications, and outcomes.

Benefits of Intra-Aortic Balloon Pump Support in Patients with Postcardiotomy Shock Requiring Venoarterial Extracorporeal Membrane Oxygenation

Background: The benefit of the combined use of an intra-aortic balloon pump (IABP) and venoarterial extracorporeal membrane oxygenation (VA-ECMO) for postcardiotomy shock remains unclear. We aimed to analyse the potential benefits and safety of combining these two devices. Methods: We enrolled 200 patients treated with either VA-ECMO only or in combination with IABP (ECMO-I group) between January 2012 and January 2021. To adjust the patients’ backgrounds, we used propensity score matching for additional analyses, resulting in 57 pairs. The primary endpoint was 30-day survival. Secondary endpoints included successful weaning and complication rates. We also analysed hemodynamic parameters in both groups. Results: After propensity score matching, 30-day survival was better in the ECMO-I group (log-rank p = 0.004). The ECMO-I and ECMO-only groups differed regarding the secondary endpoints, including successful weaning (50.9% and 26.3%, respectively; p = 0.012) and the need for continuous renal replacement therapy (28.1% and 50.9%, p = 0.021). Complication rates were not statistically different between the two groups. Conclusion: Compared to VA-ECMO alone, the combined use of VA-ECMO and IABP is beneficial regarding 30-day survival in selected patients with postcardiotomy shock; successful ECMO weaning and freedom from renal replacement therapy is more common in patients supported with VA-ECMO plus IABP.

Postcardiotomy Extracorporeal Membrane Oxygenation: Narrative Review Navigating the Ethical Issues

Postcardiotomy shock (PCS) is an uncommon and life-threatening surgical complication. Extracorporeal membrane oxygenation (ECMO) is the first line of mechanical circulatory support for treating PCS when medical therapies are insufficient. Reaching a "therapeutic ceiling" or a "bridge to nowhere" is a common clinical scenario in which medical avenues for recovery have been exhausted. These situations pose emotional and ethical challenges for patients, their surrogates, and clinicians. To shed light on these ethically challenging situations in PCS and potential approaches, the authors conducted a narrative review of the literature. Publications were utilized to describe current trends in the diagnosis and management of the patient with PCS, with particular emphasis on the therapeutic ceiling for life support. Most of the recommendations came from practice parameters or expert opinions to support specific interventions. The authors proposed a stepwise multidisciplinary approach to reduce PCS-associated ethical and emotional challenges. Their proposed algorithm was based on the likelihood of the need for ECMO support based on the mortality risk stratification of cardiac surgery. They suggested focused discussions around the commencement of ECMO or other life-sustaining therapies-ideally preoperatively at the time of consent-through shared decision-making and, subsequently, proactive multidisciplinary education and updates to the surrogate decision-makers relying on realistic prognosis and consideration of the patient wishes during the ECMO run.

Neurologic Injury in Patients Treated With Extracorporeal Membrane Oxygenation for Postcardiotomy Cardiogenic Shock

OBJECTIVE

To investigate the frequency, predictors, and outcomes of neurologic injury in adults treated with postcardiotomy extracorporeal membrane oxygenation (PC-ECMO).

DESIGN

A retrospective multicenter registry study.

SETTING

Twenty-one European institutions where cardiac surgery is performed.

PARTICIPANTS

A total of 781 adult patients who required PC-ECMO during 2010 to 2018 were divided into patients with neurologic injury (NI) and patients without neurologic injury (NNI).

MEASUREMENTS AND MAIN RESULTS

Baseline and operative data, in-hospital outcomes, and long-term survival were compared between the NI and the NNI groups. Predictors of neurologic injury were identified. A subgroup analysis according to the type of neurologic injury was performed. Overall, NI occurred in 19% of patients in the overall series, but the proportion of patients with NI ranged from 0% to 65% among the centers. Ischemic stroke occurred in 84 patients and hemorrhagic stroke in 47 patients. Emergency procedure was the sole independent predictor of NI. In-hospital mortality was higher in the NI group than in the NNI group (79% v 61%, p < 0.001). The one-year survival was lower in the NI group (17%) compared with the NNI group (37%). Long-term survival did not differ between patients with ischemic stroke and those with hemorrhagic stroke.

CONCLUSION

Neurologic injury during PC-ECMO is common and associated with a dismal prognosis. There is considerable interinstitutional variation in the proportion of neurologic injury in PC-ECMO-treated adults. Well-known risk factors for stroke are not associated with neurologic injury in this setting.

Postcardiotomy extracorporeal membrane oxygenator: No longer a bridge to no where?

BACKGROUND

Postcardiotomy extracorporeal membrane oxygenation (PC-ECMO) represents a unique subset of critically ill patients, with a paucity of data regarding long-term survival and correlated characteristics. We present a retrospective cohort of PC-ECMO patients, with outcomes at 1 and 3 years.

METHODS

Data were collected retrospectively for all patients requiring ECMO within 72 hours of an index cardiac operation (excluding assist devices and transplants). Primary outcomes were the ability to wean from ECMO, hospital survival, and long-term survival.

RESULTS

Thirty-one patients required PC-ECMO, representing a total of 172 days of ECMO support. Overall survival data were the ability to wean 58%, hospital survival 52%, 1-month survival 42%. The estimated 12- and 36-month survival for all PC-ECMO patients was 35% and 29%, respectively. Twelve and 36-month survival for all hospital survivors was 62% and 56%. Operative times, the Society of Thoracic Surgeons risk scores, type of operation, open chest status, hemorrhage, and cannulation location, and timing were all compared. Centrally cannulated patients were more likely to wean from ECMO (83% vs 44%; P = .03), and survive hospitalization (75% vs 36%; P = .04) and trended toward long-term survival benefit (67% vs 33%; P = .06). Otherwise, no statistically significant relationships were observed.

CONCLUSIONS

Central cannulation may provide benefits in the postcardiotomy patient, compared to peripheral strategies. Twelve and 36-month survival for all PC-ECMO patients was 35% and 29%. For hospital survivors, 12 and 36-month survival 62% 56% at 36. These data support PC-ECMO as a reasonable salvage strategy, with midterm survival comparable to other surgically treated diseases.

Cardiogenic Shock in Perioperative and Intraoperative Settings: A Team Approach

Cardiogenic shock (CS) is a multifactorial disease process with high morbidity and mortality. When it occurs in a peri- or intraoperative setting, factors such as surgery, anesthesia, and post-surgical physiology can negatively affect patient outcomes. Since patient needs often escalate during CS-from medications to mechanical support to palliative care-this disease demands a multidisciplinary approach that encompasses all aspects of medical delivery. Preliminary studies have indicated that a multidisciplinary team approach to CS results in earlier diagnosis and treatment and improves patient outcomes. Here we discuss various management strategies for CS from an anesthesiology, surgery, and critical care perspective.

Neutrophil-to-lymphocyte ratio for early renal failure under extracorporeal membrane oxygenation support for postcardiotomy shock

Background

This study aims to investigate the relationship between the neutrophil-to-lymphocyte ratio and renal injury in patients under extracorporeal membrane oxygenation support for postcardiotomy shock.

Methods

Between January 2007 and July 2018, a total of 119 patients (38 males, 81 females; mean age 54.4±13.0 years; range, 24 to 74 years) who received extracorporeal membrane oxygenation support for postcardiotomy shock and survived at least 48 hours in our center were retrospectively analyzed. Pre- and postoperative neutrophil-to-lymphocyte ratios, demographic characteristics, renal function parameters, and extracorporeal membrane oxygenationrelated data of the patients were recorded. Occurrence and stages of renal injury was determined using the revised Acute Kidney Injury Network and Kidney Disease Improving Global Outcomes criteria.

Results

No significant relationship was found between preoperative neutrophil-to-lymphocyte ratio and renal injury (p>0.05). Postoperative neutrophil-to-lymphocyte ratio was higher in patients who developed renal injury, compared to patients without renal injury (8.68 [0.84-42.00] vs. 4.02 [1.04-21.21], respectively, p=0.004). When patients were grouped for renal injury stage according to the revised Acute Kidney Injury Network (p=0.015) and Kidney Disease Improving Global Outcomes (p=0.006) criteria, the patients with more severe renal injury had higher neutrophil-to-lymphocyte ratio. The receiver operating characteristics analysis revealed a cut-off value of 6.71 for the neutrophil-to-lymphocyte ratio for the detection of renal injury. Patients with a value above 6.71 had an odds ratio of 5.941 for occurrence of renal injury.

Conclusion

Postoperative, but not preoperative neutrophil-tolymphocyte ratio is associated with presence and severity of renal injury in patients under extracorporeal membrane oxygenation support for postcardiotomy shock. Neutrophil-to-lymphocyte ratio is a simple and inexpensive marker of inflammation in this patient population.

The Impella Device: Historical Background, Clinical Applications and Future Directions

The Impella device is a catheter-based miniaturized ventricular assist device. Using a retrograde femoral artery access, it is placed in the left ventricle across the aortic valve. The device pumps blood from left ventricle into ascending aorta and helps to maintain a systemic circulation at an upper rate between 2.5 and 5.0 L/min. This results in almost immediate and sustained unloading of the left ventricle, while increasing overall systemic cardiac output. The most common indications for using the Impella device are in the treatment of acute myocardial infarction complicated by cardiogenic shock and to facilitate high risk coronary angioplasty. Other indications include the treatment of cardiomyopathy with acute decompensation, postcardiotomy shock, and off-pump coronary bypass surgery. A growing body of observational and registry data suggest a potentially valuable role for the Impella system in reducing the mortality associated with cardiogenic shock. However, there are, as of yet, no randomized controlled trial data supporting this observation.