Neurologic Complications in Adult Post-cardiotomy Cardiogenic Shock Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation: A Cohort Study

Anticoagulation and associated complications in veno-arterial extracorporeal membrane oxygenation in adult patients: A systematic review and meta-analysis

Objective

To describe the incidence of bleeding and thrombotic complications in VA-ECMO according to anticoagulation strategy.

Design

This systematic review and meta-analysis included randomised controlled trials (RCTs) and observational studies reporting bleeding and thrombotic complications in VA-ECMO. The incidence of primary outcomes according to anticoagulation drug and monitoring test was described.

Data sources

CENTRAL, MEDLINE, Embase and CINAHL (2010-January 2024).

Review methods

Data was extracted using Covidence. A meta-analysis of proportions was performed using STATA MP v18.1 metaprop.

Results

We included 159 studies with 21,942 patients. No studies were at low risk of bias. The incidence of major bleeding or thrombotic events was similar among heparin-, bivalirudin- and anticoagulation-free cohorts. The pooled incidence of major bleeding and thrombotic complications were 40% (95%CI 36-44, I2 = 97.12) and 17% (95%CI 14-19, I 2  = 92.60%), respectively. The most common bleeding site was thoracic. The most common ischaemic complication was limb ischaemia. The incidences of major bleeding or thrombotic events, intracranial haemorrhage and ischaemic stroke were similar among all monitoring tests. Mechanical unloading was associated with a high incidence of major bleeding events (60%, 95%CI 43-77, I2 = 93.32), and ischaemic strokes (13%, 95%CI 7-19, I2 = 81.80).

Conclusions

Available literature assessing the association between anticoagulation strategies in VA-ECMO, and bleeding and thrombosis is of limited quality. We identified a substantially higher incidence of major bleeding events than a previous meta-analysis. Limited numbers of patients anticoagulated with alternatives to heparin were reported. Patients with additional mechanical LV unloading represent a cohort at particular risk of bleeding and thrombotic complications.

Epidemiology of Seizures and Association With Mortality in Adult Patients Undergoing ECMO: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) provides lifesaving support to patients with cardiopulmonary failure. Although seizures increase mortality risks among critically ill patients broadly, studies specific to adult ECMO patients have largely been limited to single-center studies. Thus, we aimed to perform a systematic review and meta-analyses of seizure prevalence, mortality, and their associations in adult ECMO patients.

METHODS

PubMed, EMBASE, Cochrane trial registry, Web of Science, and SCOPUS were searched on August 5, 2023. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we included studies of adults undergoing venovenous ECMO (VV-ECMO), venoarterial ECMO (VA-ECMO), or extracorporeal cardiopulmonary resuscitation (ECPR) that reported seizures during ECMO. The extracted data included study characteristics, patient demographics, ECMO support, EEG monitoring, and seizures, organized by ECMO types. Forest plot and meta-regression analyses were performed. Bias assessment was performed with the Egger test and Newcastle-Ottawa Scale.

RESULTS

Twenty-three studies (n = 40,420, mean age = 51.8 years, male = 62%) were included. Data were extracted by ECMO type as follows: VV-ECMO (n = 16,633), non-ECPR VA-ECMO (n = 11,082), ECPR (n = 3,369), combination of VA-ECMO and ECPR (n = 240), and combination of all types (n = 9,096). The pooled seizure prevalence for all ECMO types was 3.0%, not significantly different across ECMO types (VV-ECMO = 2.0% [95% CI 0.8-4.5]; VA-ECMO = 3.5% [95% CI 1.7-7.0]; ECPR = 4.9% [95% CI 1.3-17.2]). The pooled mortality was lower for VV-ECMO (46.2% [95% CI 39.3-53.2]) than VA-ECMO (63.4% [95% CI 56.6-69.6]) and ECPR (61.5% [95% CI 57.3-65.6]). Specifically, for VV-ECMO, the pooled mortality of patients with and without seizures was 55.1% and 36.7%, respectively (relative risk = 1.5 [95% CI 1.3-1.7]). Similarly, for VA-ECMO, the pooled mortality of patients with and without seizures was 74.4% and 56.1%, respectively (relative risk = 1.3 [95% CI 1.2-1.5]). Meta-regression analyses demonstrated that seizure prevalence was not associated with prior neurologic comorbidities, adjusted for ECMO type and study year.

DISCUSSION

Seizures are infrequent during ECMO support. However, they were associated with increased mortality when present. Multi-institutional, larger-scale studies using standardized EEG monitoring are necessary to further understand the risk factors of specific classes of seizures for individual ECMO types, and their effects on mortality. Limitations of our study include missing data for details on seizure types, sedating/antiseizure medications used during ECMO, other ECMO-related complications, and EEG recording protocols.

Comparing Outcomes of Post-Cardiotomy Cardiogenic Shock Patients: On-Site Cannulation vs. Retrieval for V-A ECMO Support

Background: Post-cardiotomy cardiogenic shock (PCCS) remains a life-threatening complication after cardiac surgery. Extracorporeal membrane oxygenation (ECMO) represents the mainstay of mechanical circulatory support for PCCS; however, its availability is limited to larger experienced centers, leading to a mismatch between centers performing cardiac surgery and hospitals offering ECMO management beyond cannulation. We sought to evaluate the outcomes and complications of PCCS patients requiring veno-arterial (V-A) ECMO cannulated at our hospital compared to those cannulated at referral hospitals. Methods: A retrospective analysis of PCCS patients requiring V-A ECMO was conducted between October 2014 to December 2022. Results: A total of 121 PCCS patients required V-A ECMO support, of which 62 (51%) patients were cannulated at the referring institutions and retrieved (retrieved group), and 59 (49%) were cannulated at our hospital (on-site group). The baseline demographics and pre-ECMO variables were similar between groups, except retrieved patients had higher lactic acid levels (retrieved group: 8.5 mmol/L ± 5.8 vs. on-site group: 6.6 ± 5; p = 0.04). Coronary artery bypass graft was the most common surgical intervention (51% in the retrieved group vs. 47% in the on-site group). There was no difference in survival-to-discharge rates between the groups (45% in the retrieved group vs. 51% in the on-site group; p = 0.53) or in the rate of patient-related complications. Conclusions: PCCS patients retrieved on V-A ECMO can achieve similar outcomes as those cannulated at experienced centers. An established network in a hub-and-spoke model is critical for the PCCS patients managed at hospitals without ECMO abilities to improve outcomes.

Predictors of Neurological Complications of Pediatric Post-Cardiotomy Extracorporeal Life Support

Background

Post-cardiotomy extracorporeal membrane oxygenation (ECMO) was associated with significant neurological complications affecting the overall outcome. The aim of the work is to determine the incidence and the predictors of neurological events during pediatric extracorporeal life support after cardiac surgery.

Patients & Methods

This is a retrospective study that encompassed all neonates, infants, and children (<18 years of age) who need extracorporeal life support following cardiac surgery between January 2015 and December 2018 at San Donato Hospital, Italy. Data as regards surgical procedure of congenital heart disease, in-hospital mortality, length of ECMO, hospital stay durations, short-term neurological ECMO complications and outcome were analyzed.

Results

The sixty-three patients who received post-cardiotomy ECMO, Neurological complications were evident in 31.7% in the form of ischemic stroke in 17.5% and hemorrhagic stroke in 11.1%. By multivariable analysis, the older age of cyanotic cases, the need for a venting cannula, and the rapid CO2 drop in the first 24 h were the most independent risk factors for neurological complications. Prolonged ECMO support and hospital stay duration were associated with neurological sequelae.

Conclusion

Neurological complications either ischemic or hemorrhagic strokes were common during pediatric post-cardiotomy ECMO and were significantly related to prolonged ECMO support and hospital stay. Predictors of these neurological sequelae are the older cyanotic cases, the need for a venting cannula, the oxygenator thrombosis, and the rapid CO2 drop in the first 24 h of ECMO.

Development of an acute kidney injury risk prediction model for patients undergoing extracorporeal membrane oxygenation

Background

Some studies have reported to use some predictors before extracorporeal membrane oxygenation (ECMO) initiation to predict the acute kidney injury (AKI) risk. However, injury during the ECMO operation and the response of patients to ECMO may significantly influence the prognosis, and they are unpredictable before ECMO initiation. This study aims to develop a potential model based clinical characteristics at the 2-hour time point during ECMO for the early prediction of AKI in patients receiving ECMO.

Methods

139 patients who underwent ECMO were enrolled in this study. The clinical characteristics and the laboratory examinations at 2-hour time point during ECMO were recorded. The least absolute shrinkage and selection operator (LASSO) regression method was performed to select predictors, and logistic regression and a nomogram were used to establish the prediction model. The area under curve (AUC) of the receiver operating characteristic and calibration curve were used to analyze the discrimination and calibration of the model. K-fold cross-validation method was performed to validate the accuracy of this model.

Results

Among the 139 patients receiving ECMO, 106 participants (76.26%) developed AKI. Four predictive variables including ECMO model, serum creatinine (Scr-2h), uric acid(UA-2h), and serum lactate (Lac-2h) at the 2-hour time point during ECMO were filtered from 39 clinical parameters by LASSO regression. These four predictors were incorporated to develop a model for predicting AKI risk using logistic regression. The AUC of the model was 0.905 (0.845-0.965), corresponding to 81.1% sensitivity, 90.9% specificity and 83.5% accuracy. Moreover, this model showed good consistency between observed and predicted probability based on the calibration curve (P > 0.05). The validation performed by K-fold cross-validation method showed that the accuracy was 0.874 ± 0.006 in training sets, 0.827 ± 0.053 in test sets, indicating a good capability for AKI risk prediction. Finally, a nomogram based on this model was constructed to facilitate its use in clinical practice.

Conclusion

The nomogram incorporating Scr-2h,Lac-2h, UA-2h, and ECMO model may facilitate the individualized prediction of the AKI risk among patients undergoing ECMO.

Weaning from venous-arterial extracorporeal membrane oxygenation: The hemodynamic and clinical aspects of flow challenge test

The cardiac function reserve is crucial for the successful weaning of V-A ECMO. During the V-A ECMO weaning phase, the gradual reduction in pump flow converts the blood flow originally driven by the pump to native cardiac output and also transforms afterload (caused by retrograde flow) into ventricular preload, thus introducing a “flow challenge” to the native heart. In this perspective, we propose to use this flow challenge as a test to simulate the preload-to-afterload conversion to assess cardiac functional reserve quantitatively. With this short article we offer the hemodynamic and clinical aspects regarding the flow challenge test.