Extra-corporeal membrane oxygenation for refractory cardiogenic shock after adult cardiac surgery: a systematic review and meta-analysis

Outcome and complications in postcardiotomy cardiogenic shock treated with extracorporeal life support - a systematic review and meta-analysis

BACKGROUND

Postcardiotomy cardiogenic shock (PCCS) in cardiac surgery is associated with a high rate of morbidity and mortality. Beside other therapeutic measures (e.g. intraaortic balloon pump (IABP)), extracorporeal life support is being increasingly used in this particular form of shock. Objectives of this meta-analysis were to determine mortality and complications of extracorporeal life support treatment (ECLS) in cardiac surgery patients, and if outcomes were influenced by a preexisting cardiovascular risk profile.

METHODS

MEDLINE and EMBASE were searched for studies in English, published between January 1st 2000 and January 16th 2023, reporting mortality and morbidity in patients aged ≥ 18 treated with ECLS for PCCS. Supplementary data were requested from the respective corresponding authors. Outcomes were weaning from extracorporeal life support, hospital survival and complications.

RESULTS

Two thousand, seven hundred seventy-four papers were screened, of which 132 full text articles were assessed for suitability. 70 remaining studies were included for further evaluation and data analysis. Five studies could be included in the final analysis since the corresponding authors provided additional necessary information. Successful weaning from extracorporeal life support was accomplished in 52.8% (30.8%-57.4%) and 31.1% were discharged alive (mortality of 25.0 - 56.2% after weaning). 95.1% of all treated patients suffered from at least one complication. Diabetes mellitus and obesity seem to be independent risk factors for poor outcome.

CONCLUSIONS

Extracorporeal life support for PCCS is associated with a substantial mortality and complication rate. Diabetes mellitus and obesity seem to be independent risk factors. Therefore, until future work has elucidated which patients benefit at all, the risks of ECLS-treatment must be critically weighed up against a possible benefit.

Vascular Complications After Venoarterial Extracorporeal Membrane Oxygenation Support: A CT Study

OBJECTIVES

Vascular complications after venoarterial extracorporeal membrane oxygenation (ECMO) remains poorly studied, although they may highly impact patient management after ECMO removal. Our aim was to assess their frequency, predictors, and management.

DESIGN

Retrospective, observational cohort study.

SETTING

Two ICUs from a tertiary referral academic hospital.

PATIENTS

Adult patients who were successfully weaned from venoarterial ECMO between January 2021 and January 2022.

INTERVENTIONS

None.

PRIMARY OUTCOME

Vascular complications frequency related to ECMO cannula.

MEASUREMENTS AND MAIN RESULTS

A total of 288 patients were implanted with venoarterial ECMO during the inclusion period. One hundred ninety-four patients were successfully weaned, and 109 underwent a CT examination to assess for vascular complications until 4 days after the weaning procedure. The median age of the cohort was 58 years (interquartile range [IQR], 46-64 yr), with a median duration of ECMO support of 7 days (IQR, 5-12 d). Vascular complications were observed in 88 patients (81%). The most frequent complication was thrombosis, either cannula-associated deep vein thrombosis (CaDVT) ( n = 63, 58%) or arterial thrombosis ( n = 36, 33%). Nonthrombotic arterial complications were observed in 48 patients (44%), with 35 (31%) presenting with bleeding. The most common site of CaDVT was the inferior vena cava, occurring in 33 (50%) of cases, with 20% of patients presenting with pulmonary embolism. There was no association between thrombotic complications and ECMO duration, anticoagulation level, or ECMO rotation flow. CT scans influenced management in 83% of patients. In-hospital mortality was 17% regardless of vascular complications.

CONCLUSIONS

Vascular complications related to venoarterial ECMO cannula are common after ECMO implantation. CT allows early detection of complications after weaning and impacts patient management. Patients should be routinely screened for vascular complications by CT after decannulation.

The early and mid-term outcomes of acute type A aortic dissection patients with ECMO

Background

Acute type A aortic dissection (ATAAD) poses significant challenges in cardiovascular management due to its high morbidity and mortality rates. Postcardiotomy cardiogenic shock (PCS) is a severe complication following ATAAD repair that complicates postoperative recovery. Extracorporeal membrane oxygenation (ECMO) has emerged as a potential life-saving intervention in this context, yet the specific outcomes related to ECMO in ATAAD patients remain insufficiently studied.

Methods

This retrospective single-center study reviewed the medical records of 479 patients who underwent ATAAD surgery from September 2017 to June 2021. Patients were stratified into those requiring postoperative ECMO support and those who did not. Data collected included demographics, operative details, and postoperative outcomes.

Results

Of the cohort, 19 patients (4.0%) required ECMO support. The ECMO group exhibited significantly higher mortality rates (57.9% vs. 5.4%, p < 0.001) and increased complications, including a higher rate of continuous renal replacement therapy (84.2% vs. 24.3%, p < 0.001) and prolonged ICU stays (14.5 days vs. 7.6 days, p = 0.009). Survival analysis demonstrated a stark contrast in 3-year survival rates, with 36.8% for the ECMO group vs. 92.8% for non-ECMO patients (p < 0.001).

Conclusions

ECMO can be a crucial intervention for ATAAD patients suffering from PCS; however, it is associated with significantly higher mortality and complications. Despite lower long-term survival rates compared to non-ECMO patients, ECMO may offer a survival benefit as a salvage therapy. Interpretation is limited by the retrospective single-center design, small ECMO cohort size, and lack of post-discharge quality-of-life data.

Obesity Is Associated With Increased Mortality in Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVES

To determine the relationship between all-cause hospital mortality and morbidity in patients treated with venoarterial extracorporeal membrane oxygenation (ECMO) and to assess whether this relationship is mediated via body mass index (BMI).

DESIGN

Using the Extracorporeal Life Support Organization (ELSO) registry, venoarterial ECMO runs from 2015 to 2021 were retrospectively analyzed. Patient demographics, ECMO indications, and complications for survivors and decedents were univariately compared. Logistic regression with fractional polynomials was used to estimate the relationship between BMI and both mortality and complications in venoarterial ECMO patients.

SETTING

Contributing centers to the ELSO ECMO registry.

PATIENTS

Patients that underwent venoarterial ECMO at an ELSO contributing ECMO center.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-two thousand eight hundred twenty-five venoarterial ECMO runs met inclusion criteria for analysis. The mean BMI for survivors was 28.4 ± 6.5 vs. 29.5 ± 6.9 kg/m2 for decedents. BMI was significantly associated with mortality (p < 0.001), with the proportion of patients dying increasing with increasing BMI: 47% of underweight patients died, increasing to 50% for the normal range, to 53%, 56%, 58%, and 65% for preobese, class 1, class 2, and class 3 obese patients, respectively. Relative to a BMI of 25, a BMI of 35 had an odds ratio (OR) of death of 1.15 (1.09-1.18), and a BMI of 45 an OR of 1.46 (1.25-1.57). BMI was significantly associated with increased mechanical and renal complications, but decreased pulmonary complications.

CONCLUSIONS

In patients undergoing venoarterial ECMO, increasing BMI was associated with increasing all-cause mortality and mechanical and renal complications.

Hypoalbuminemia is a predictor of mortality in patients with cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation

INTRODUCTION

Hypoalbuminemia is predictive of mortality in critically ill patients, especially those with cardiac etiologies of illness. The objective of this study was to determine the association of albumin level pre-cannulation for veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) and important clinical hospital outcomes.

METHODS

This was a retrospective, observational cohort study of albumin levels in patients with cardiogenic shock requiring V-A ECMO between December 2015 and August 2021 in a single, high-volume ECMO center. The primary outcome was in-hospital mortality.

RESULTS

Of 434 patients assessed, 318 were included. The overall mean pre-ECMO albumin was 3 ± 0.8 g/dL and mean albumin at 72 hours post-cannulation was 2.7 ± 0.5 g/dL. For patients with pre-ECMO albumin ≤3 g/dL vs. >3 g/dL, in-hospital mortality was 44.9% vs. 27.5%, respectively (p = .002). In multivariable logistic regression analysis, higher albumin (per 1 g/dL increase) at time of V-A ECMO initiation was associated with decreased odds of in-hospital mortality (OR, 0.68; 95% CI, 0.48-0.96; p = .03). Patients with a pre-ECMO albumin ≤3 g/dL required significantly more platelet transfusions and had higher incidence of gastrointestinal bleeding during V-A ECMO support (both p < .05).

CONCLUSIONS

Hypoalbuminemia at time of cannulation is significantly associated with in-hospital mortality and ECMO-related complications including platelet transfusion and gastrointestinal bleeding. Albumin levels at the time of consideration of V-A ECMO may serve as a key prognostic indicator and may assist in effective decision-making regarding this invasive and costly resource.

Epigenomic biomarkers insights in PBMCs for prognostic assessment of ECMO-treated cardiogenic shock patients

OBJECTIVE

As the global use of extracorporeal membrane oxygenation (ECMO) treatment increases, survival rates have not correspondingly improved, emphasizing the need for refined patient selection to optimize resource allocation. Currently, prognostic markers at the molecular level are limited.

METHODS

Thirty-four cardiogenic shock (CS) patients were prospectively enrolled, and peripheral blood mononuclear cells (PBMCs) were collected at the initiation of ECMO (t0), two-hour post-installation (t2), and upon removal of ECMO (tr). The PBMCs were analyzed by comprehensive epigenomic assays. Using the Wilcoxon signed-rank test and least absolute shrinkage and selection operator (LASSO) regression, 485,577 DNA methylation features were analyzed and selected from the t0 and tr datasets. A random forest classifier was developed using the t0 dataset and evaluated on the t2 dataset. Two models based on DNA methylation features were constructed and assessed using receiver operating characteristic (ROC) curves and Kaplan-Meier survival analyses.

RESULTS

The ten-feature and four-feature models for predicting in-hospital mortality attained area under the curve (AUC) values of 0.78 and 0.72, respectively, with LASSO alpha values of 0.2 and 0.25. In contrast, clinical evaluation systems, including ICU scoring systems and the survival after venoarterial ECMO (SAVE) score, did not achieve statistical significance. Moreover, our models showed significant associations with in-hospital survival (p < 0.05, log-rank test).

CONCLUSIONS

This study identifies DNA methylation features in PBMCs as potent prognostic markers for ECMO-treated CS patients. Demonstrating significant predictive accuracy for in-hospital mortality, these markers offer a substantial advancement in patient stratification and might improve treatment outcomes.

Characteristics and Outcomes of Prolonged Venoarterial Extracorporeal Membrane Oxygenation After Cardiac Surgery: The Post-Cardiotomy Extracorporeal Life Support (PELS-1) Cohort Study

OBJECTIVES

Most post-cardiotomy (PC) extracorporeal membrane oxygenation (ECMO) runs last less than 7 days. Studies on the outcomes of longer runs have provided conflicting results. This study investigates patient characteristics and short- and long-term outcomes in relation to PC ECMO duration, with a focus on prolonged (> 7 d) ECMO.

DESIGN

Retrospective observational cohort study.

SETTING

Thirty-four centers from 16 countries between January 2000 and December 2020.

PATIENTS

Adults requiring post PC ECMO between 2000 and 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Characteristics, in-hospital, and post-discharge outcomes were compared among patients categorized by ECMO duration. Survivors and nonsurvivors were compared in the subgroup of patients with ECMO duration greater than 7 days. The primary outcome was in-hospital mortality. Two thousand twenty-one patients were included who required PC ECMO for 0-3 days ( n = 649 [32.1%]), 4-7 days ( n = 776 [38.3%]), 8-10 days ( n = 263 [13.0%]), and greater than 10 days ( n = 333 [16.5%]). There were no major differences in the investigated preoperative and procedural characteristics among ECMO duration groups. However, the longer ECMO duration category was associated with multiple complications including bleeding, acute kidney injury, arrhythmias, and sepsis. Hospital mortality followed a U-shape curve, with lowest mortality in patients with ECMO duration of 4-7 days ( n = 394, 50.8%) and highest in patients with greater than 10 days ECMO support ( n = 242, 72.7%). There was no significant difference in post-discharge survival between ECMO duration groups. In patients with ECMO duration greater than 7 days, age, comorbidities, valvular diseases, and complex procedures were associated with nonsurvival.

CONCLUSIONS

Nearly 30% of PC ECMO patients were supported for greater than 7 days. In-hospital mortality increased after 7 days of support, especially in patients undergoing valvular and complex surgery, or who had complications, although the long-term post-discharge prognosis was comparable to PC ECMO patients with shorter support duration.

Age-Related Quality of Life in Cardiac Surgical Patients with Extracorporeal Life Support

BACKGROUND

 The rationale of the study was to analyze the impact of age on quality of life (QoL) in patients who had undergone cardiac surgery with consecutive extracorporeal life support (ECLS) treatment.

METHODS

 The study population consisted of 200 patients, operated upon between August 2006 and December 2018. The patient cohort was divided into two groups following an arbitrary cutoff age of 70 years. Comparative outcome analysis was calculated utilizing the European Quality of Life-5-Dimensions-5-Level Version (EQ-5D-5L).

RESULTS

 A total of 113 patients were 70 years or less old (group young), whereas 87 patients were older than 70 years (group old). In 45.7% of cases, the ECLS system was established during cardiogenic shock and external cardiac massage. The overall survival-to-discharge was 31.5% (n = 63), with a significantly better survival in the younger patient group (young = 38.9%; old = 21.8%, p = 0.01). Forty-two patients (66%) responded to the QoL survey after a median follow-up of 4.3 years. Older patients reported more problems with mobility (y = 52%; o = 88%, p = 0.02) and self-care (y = 24%; o = 76%, p = 0.01). However, the patients' self-rated health status utilizing the Visual Analogue Scale revealed no differences (y = 70% [50-80%]; o = 70% [60-80%], p = 0.38). Likewise, the comparison with an age-adjusted German reference population revealed similar QoL indices. There were no statistically significant differences in the EQ-5D-5L index values related to sex, number of comorbidities, and emergency procedures.

CONCLUSION

 Despite the limited sample size due to the high mortality rate especially in elderly, the present study suggests that QoL of elderly patients surviving ECLS treatment is almost comparable to younger patients.

Adverse Technical Events During Aortic Root Replacement

BACKGROUND

Although adverse technical events during aortic root replacement (ARR) are not uncommon and are extremely challenging, there is scant literature to help surgeons prepare for such situations. We describe our experience of outstanding technical events during ARR.

METHODS

This is a retrospective study of 830 consecutive ARRs at a single center from 2012 to 2022. Technical events were defined as intraoperative events that led to an unplanned cardiac procedure, need for mechanical circulatory support, or additional aortic cross-clamping. Logistic regression identified factors associated with operative mortality and technical events.

RESULTS

Technical events occurred in 90 patients (10.8%) and were attributed to bleeding (n = 26), nonischemic ventricular dysfunction (n = 23), residual valve disease (n = 20), myocardial ischemia (n = 19), and iatrogenic dissection (n = 2). Prior sternotomy (odds ratio [OR], 2.38; 95% CI, 1.36-4.19; P = .002) and complex aortic valve disease (OR, 3.09; 95% CI, 1.09-8.75; P = .03) were associated with technical events. Patients with technical events had higher rates of operative mortality (6.7% vs 2.3%, P = .03) and all major postoperative complications. Surgical indications of dissection (OR, 13.57; 95% CI, 4.95-37.23; P < .001) and complex aortic valve disease (OR, 14.09; 95% CI, 3.67-54.02; P < .001) but not adverse technical events (OR, 2.42; 95% CI, 0.81-7.26; P = .11) were associated with operative mortality.

CONCLUSIONS

Adverse technical events occurred in 10.8% of ARRs and were associated with reoperative sternotomies. Technical events are associated with increased postoperative complications.

Temporary Mechanical Circulatory Support after Cardiac Surgery

Postcardiotomy shock in the cardiac surgical patient is a highly morbid condition characterized by profound myocardial impairment and decreased systemic perfusion inadequate to meet end-organ metabolic demand. Postcardiotomy shock is associated with significant morbidity and mortality. Poor outcomes motivate the increased use of mechanical circulatory support (MCS) to restore perfusion in an effort to prevent multiorgan injury and improve patient survival. Despite growing acceptance and adoption of MCS for postcardiotomy shock, criteria for initiation, clinical management, and future areas of clinical investigation remain a topic of ongoing debate. This article seeks to (1) define critical cardiac dysfunction in the patient after cardiotomy, (2) provide an overview of commonly used MCS devices, and (3) summarize the relevant clinical experience for various MCS devices available in the literature, with additional recognition for the role of MCS as a part of a modified approach to the cardiac arrest algorithm in the cardiac surgical patient.

Relationship between indexed surgery and postcardiotomy extracorporeal life support outcomes

OBJECTIVES

Veno-arterial extracorporeal life support (V-A ECLS) is increasingly being utilized for postcardiotomy shock (PCS), though data describing the relationship between type of indexed operation and outcomes are limited. This study compared V-A ECLS outcomes across four major cardiovascular surgical procedures.

METHODS

This was a single-center retrospective study of patients who required V-A ECLS for PCS between 2015 and 2022. Patients were stratified by the type of indexed operation, which included aortic surgery (AoS), coronary artery bypass grafting (CABG), valve surgery (Valve), and combined CABG and valve surgery (CABG + Valve). Factors associated with postoperative outcomes were assessed using logistic regression.

RESULTS

Among 149 PCS patients who received V-A ECLS, there were 35 AoS patients (23.5%), 29 (19.5%) CABG patients, 59 (39.6%) Valve patients, and 26 (17.4%) CABG + Valve patients. Cardiopulmonary bypass times were longest in the AoS group (p < 0.01). Regarding causes of PCS, AoS patients had a greater incidence of ventricular failure, while the CABG group had a higher incidence of ventricular arrhythmia (p = 0.04). Left ventricular venting was most frequently utilized in the Valve group (p = 0.07). In-hospital mortality was worst among CABG + Valve patients (p < 0.01), and the incidence of acute kidney injury was highest in the AoS group (p = 0.03). In multivariable logistic regression, CABG + Valve surgery (odds ratio (OR) 4.20, 95% confidence interval 1.30-13.6, p = 0.02) and lactate level at ECLS initiation (OR, 1.17; 95% CI, 1.06-1.29; p < 0.01) were independently associated with mortality.

CONCLUSIONS

We demonstrate that indications, management, and outcomes of V-A ECLS for PCS vary by type of indexed cardiovascular surgery.

Haemodynamic support with percutaneous devices in patients with cardiogenic shock: the current evidence of mechanical circulatory support

INTRODUCTION

Cardiogenic shock (CS) is a complex life-threatening condition that results from primary cardiac dysfunction, leading to persistent hypotension and systemic hypoperfusion. Among the therapeutic options for CS are various percutaneous mechanical circulatory support (MCS) devices that have emerged as an increasingly effective hemodynamic support option. Percutaneous therapies can act as short-term mechanical circulatory assistance and can be split into intra-aortic balloon pump (IABP) and non-IABP percutaneous mechanical devices.

AREAS COVERED

This review will evaluate the MCS value while considering the mortality rate improvements. We also aim to outline the function of pharmacotherapies and percutaneous hemodynamic MCS devices in managing CS patients to avoid the onset of end-organ dysfunction and improve both early and late outcomes.

EXPERT OPINION

Given the complexity, acuity and high mortality associated with CS, and despite the availability and efficacy of pharmacological management, MCS is required to achieve hemodynamic stability and improve survival. Various percutaneous MCS devices are available with varying indications and clinical outcomes. The rates of early mortality and complications were found to be comparable between the four devices, yet, IABP seemed to show the most optimal clinical profile whilst ECMO demonstrated its more long-term efficacy.

Phenotyping Refractory Cardiogenic Shock Patients Receiving Venous-Arterial Extracorporeal Membrane Oxygenation Using Machine Learning Algorithms

Background

This study used machine learning to categorize cardiogenic shock (CS) patients treated with venous-arterial extracorporeal membrane oxygenation (VA-ECMO) into distinct phenotypes. Subsequently, it aimed to clarify the wide mortality variance observed in refractory CS, attributing it to the condition's inherent heterogeneity.

Methods

This study enrolled a cohort of CS patients who received VA-ECMO support. By employing rigorous machine learning (ML) techniques, we generated and validated clusters based on determinants identified through algorithmic analysis. These clusters, characterized by distinct clinical outcomes, facilitated the examination of clinical and laboratory profiles to enhance the understanding of patient responses to VA-ECMO treatment.

Results

In a study of 210 CS patients undergoing VA-ECMO treatment, 70.5% were male with a median age of 62, ranging from 53 to 67 years. Survival rates were 67.6% during VA-ECMO and 49.5% post-discharge. Patients were classified into three phenotypes based on the clinical and laboratory findings: "platelet preserved (I)", those with stable platelet counts, "hyperinflammatory (II)", those indicating significant inflammation, and "hepatic-renal (III)", those showing compromised liver and kidney functions. Mortality rates (25.0%, 52.8%, and 55.9% for phenotypes I, Ⅱ, and Ⅲ, respectively (p = 0.005)) varied significantly among these groups, highlighting the importance of phenotype identification in patient management.

Conclusions

This study identified three distinct phenotypes among refractory CS patients treated using VA-ECMO, each with unique clinical characteristics and mortality risks. Thus, highlighting the importance of early detection and targeted intervention, these findings suggest that proactive management could improve outcomes for those showing critical signs.

What is the weakest point of a secured aortic cannula in central extracorporeal membrane oxygenation?

PURPOSE

The purpose of this study was to compare techniques for securing the aortic extracorporeal membrane oxygenation (ECMO) cannula, using in vitro models.

METHODS

Two models were studied: a tissue model using porcine aortas and a stand model replacing the aorta with a metal stand to study the system independent of the tissue. Interventions in each model were divided into three experimental groups: Group 1 (3-0 Prolene® + 20-French Medtronic Arterial Cannula EOPA™), Group 2 (4-0 Prolene® + 16-French Medtronic Arterial Cannula DLP Pediatric), and Group 3 (5-0 Prolene® + 8-French Medtronic Arterial Cannula DLP Pediatric). In separate experiments, both gradual and rapid forces were applied to the cannulas, starting with 9.8 Newtons and increasing exponentially if the cannula remained secured. Additionally, the method of securing the tourniquet and the number of ties securing the tourniquet to the cannula were evaluated.

RESULTS

In the tissue model, even with a minimum force of 9.8 Newtons, the suture pulled through the aortic tissue, leaving sutures and ties intact. In the stand model, two purse-string sutures secured by two ligaclips held the cannula reliably and withstood higher total force. Dislodgement was prevented at forces close to 60 Newtons with only two hemostatic clips included in cannulation.

CONCLUSIONS

The weakest part of the aortic ECMO cannulation system using in vitro experiments was the tissue. Assuming that these experiments translate in vivo, it is therefore critical to prevent any pull on the cannulas by securing ECMO cannulas and ECMO tubing to both the patient and the patient's bed. Sutures with a larger diameter withstand more force. Two medium hemostatic clips can secure Prolene® sutures within snares as safely as a mosquito hemostat. Two polypropylene purse-string sutures secured by two hemostatic clips were most reliable at greater forces. The rationale for publishing our experiments in this manuscript is to (1) communicate our quantification of possible contributing factors to this rare and likely catastrophic complication of unintended decannulation, (2) increase awareness about this potential complication, and (3) increase vigilance to assure prevention of this dreaded complication.

Lactate Profile Assessment-A Good Predictor of Prognosis in Patients with COVID-19 and Septic Shock Requiring Continuous Renal Therapy

INTRODUCTION

Lactate is a useful prognostic marker, as its level increases in hypoxic tissue and/or during accelerated aerobic glycolysis due to excessive beta-adrenergic stimulation and decreased lactate clearance. The Surviving Sepsis Campaign Bundle 2018 Update suggests premeasurement of lactate within 2-4 h so that physicians perform, assist, administer, and introduce lactate-guided resuscitation to reduce mortality due to sepsis.

METHODS

A total of 108 patients with septic shock who underwent continuous renal replacement therapy (CRRT) for acute kidney injury were enrolled in this observational study. Demographic, clinical, and laboratory data were collected, and patients were divided into two groups: survivors and non-survivors.

RESULTS

Multivariate analysis demonstrated that lactate levels at 24 h after initiation of CRRT treatment, but not lactate levels at intensive care unit (ICU) admission, were associated with mortality. Lactate clearance was associated with lower mortality among the survivors (OR = 0.140) at 6 h after ICU admission and late mortality (OR = 0.260) after 24 h. The area under the ROC curves for mortality was 0.682 for initial lactate; 0.797 for lactate at 24 h; and 0.816 for lactate clearance at 24 h.

CONCLUSIONS

Our result reinforces that the determination of lactate dynamics represents a good predictor for mortality, and serial lactate measurements may be more useful prognostic markers than initial lactate in patients with septic shock.

Mid-Term Outcome after Extracorporeal Life Support in Postcardiotomy Cardiogenic Shock: Recovery and Quality of Life

Background: Extracorporeal life support (ECLS) therapy for refractory postcardiotomy cardiogenic shock (rPCS) is associated with high early mortality rates. This study aimed to identify negative predictors of mid-term survival and to assess health-related quality of life (HRQoL) and recovery of the survivors. Methods: Between 2017 and 2020, 142 consecutive patients received ECLS therapy following cardiac surgery. The median age was 66.0 [57.0-73.0] years, 67.6% were male and the median EuroSCORE II was 10.5% [4.2-21.3]. In 48 patients, HRQoL was examined using the 36-Item Short Form Survey (SF-36) and the modified Rankin-Scale (mRS) at a median follow-up time of 2.2 [1.9-3.2] years. Results: Estimated survival rates at 3, 12, 24 and 36 months were 47%, 46%, 43% and 43% (SE: 4%). Multivariable Cox Proportional Hazard regression analysis revealed preoperative EuroSCORE II (p = 0.013), impaired renal function (p = 0.010), cardiopulmonary bypass duration (p = 0.015) and pre-ECLS lactate levels (p = 0.004) as independent predictors of mid-term mortality. At the time of follow-up, 83.3% of the survivors were free of moderate to severe disability (mRS < 3). SF-36 analysis showed a physical component summary of 45.5 ± 10.2 and a mental component summary of 50.6 ± 12.5. Conclusions: Considering the disease to be treated, ECLS for rPCS is associated with acceptable mid-term survival, health-related quality of life and functional status. Preoperative EuroSCORE II, impaired renal function, cardiopulmonary bypass duration and lactate levels prior to ECLS implantation were identified as negative predictors and should be included in the decision-making process.

Mortality in patients with normal left ventricular function requiring emergency VA-ECMO for postcardiotomy cardiogenic shock due to coronary malperfusion

OBJECTIVES

To analyze outcomes in patients with normal preoperative left ventricular ejection fraction (LVEF) undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) therapy due to postcardiotomy cardiogenic shock (PCCS) related to coronary malperfusion.

METHODS

Retrospective single-center analysis in patients with normal preoperative LVEF treated with VA-ECMO for coronary malperfusion-related PCCS between May 1998 and May 2018. The primary outcome was 30-day mortality, which was compared using the Kaplan-Meier method and the log-rank test. Multivariable logistic regression was performed to identify predictors of mortality.

RESULTS

During the study period, a total of 62,125 patients underwent cardiac surgery at our institution. Amongst them, 59 patients (0.1%) with normal preoperative LVEF required VA-ECMO support due to coronary malperfusion-related PCCS. The mean duration of VA-ECMO support was 6 days (interquartile range 4-7 days). The 30-day mortality was 50.8%. Under VA-ECMO therapy, a complication composite outcome of bleeding, re-exploration for bleeding, acute renal failure, acute liver failure, and sepsis occurred in 51 (86.4%) patients. Independent predictors of 30-day mortality were lactate levels > 9.9 mmol/l before VA-ECMO implantation (odds ratio [OR]: 3.3; 95% confidence interval [CI] 1.5-7.0; p = 0.002), delay until revascularization > 278 minutes (OR: 2.9; 95% CI 1.3-6.4; p = 0.008) and peripheral arterial artery disease (OR: 3.3; 95% 1.6-7.5; p = 0.001).

CONCLUSIONS

Mortality rates are high in patients with normal preoperative LVEF who develop PCCS due to coronary malperfusion. The early implantation of VA-ECMO before the development of profound tissue hypoxia and early coronary revascularization increases the likelihood of survival. Lactate levels are useful to define optimal timing for the VA-ECMO initiation.

Prognostic impact of preoperative atrial fibrillation in patients undergoing heart surgery in cardiogenic shock

Surgical intervention in the setting of cardiogenic shock (CS) is burdened with high mortality. Due to acute condition, detailed diagnoses and risk assessment is often precluded. Atrial fibrillation (AF) is a risk factor for perioperative complications and worse survival but little is known about AF patients operated in CS. Current analysis aimed to determine prognostic impact of preoperative AF in patients undergoing heart surgery in CS. We analyzed data from the Polish National Registry of Cardiac Surgery (KROK) Procedures. Between 2012 and 2021, 332,109 patients underwent cardiac surgery in 37 centers; 4852 (1.5%) patients presented with CS. Of those 624 (13%) patients had AF history. Cox proportional hazards models were used for computations. Propensity score (nearest neighbor) matching for the comparison of patients with and without AF was performed. Median follow-up was 4.6 years (max.10.0), mean age was 62 (± 15) years and 68% patients were men. Thirty-day mortality was 36% (1728 patients). The origin of CS included acute myocardial infarction (1751 patients, 36%), acute aortic dissection (1075 patients, 22%) and valvular dysfunction (610 patients, 13%). In an unadjusted analysis, patients with underlying AF had almost 20% higher mortality risk (HR 1.19, 95% CIs 1.06-1.34; P = 0.004). Propensity score matching returned 597 pairs with similar baseline characteristics; AF remained a significant prognostic factor for worse survival (HR 1.19, 95% CI 1.00-1.40; P = 0.045). Among patients with CS referred for cardiac surgery, history of AF was a significant risk factor for mortality. Role of concomitant AF ablation and/or left atrial appendage occlusion or more aggressive perioperative circulatory support should be addressed in the future.

Aortic thrombosis with visceral malperfusion during circulatory support with a combination of Impella and extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock

Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used to aid myocardial recovery in patients with postcardiotomy cardiogenic shock (PCCS), it has been associated with adverse effects. The combined use of VA-ECMO and Impella (ECPELLA) for PCCS, however, has been reported to be efficacious with few reports of thromboembolic events. We present a case of aortic thrombosis with visceral malperfusion during ECPELLA management for PCCS. We performed the Bentall procedure, mitral valve repair, tricuspid annuloplasty, and coronary artery bypass graft on a 73-year-old man admitted with congestive heart failure caused by annuloaortic ectasia, along with severe aortic and mitral regurgitation. VA-ECMO and Impella were required, since the cardiopulmonary bypass weaning was difficult. Impella was removed on postoperative day 4. On postoperative days 5 and 6, laboratory data showed worsening renal dysfunction, lactate levels, and acidosis. Contrast-enhanced computed tomography showed thrombosis in the celiac and superior mesenteric arteries. Aortic thrombectomy was performed. Hyperkalemia, caused by a reperfusion injury, resulted in ventricular fibrillation. Continuous hemodiafiltration improved the hyperkalemia. However, irreversible acidosis progressed, and the VA-ECMO flow rate could not be sustained. On postoperative day 7, the patient died. Perioperative use of Impella for PCCS may be effective in improving postoperative cardiac function. When sudden organ failure is observed after surgery, it is necessary to not only keep the exacerbation of cardiogenic shock in mind, but also the possibility of thrombosis.

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.

Right Axillary Artery Cannulation for Veno-Arterial Extracorporeal Membrane Oxygenation in Postcardiotomy Patients: A Single-Center Experience

Background and Objectives: To analyze the patient outcome and complication rate of axillary artery cannulation for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients who could not be weaned from cardiopulmonary bypass after cardiothoracic surgery. Materials and Methods: We analyzed the data of 179 patients who were supported with VA-ECMO with femoral-axillary access (FA VA-ECMO) after cardiothoracic surgery between January 2014 and January 2019 in our department. Patients requiring central aortic cannulation and patients with respiratory failure requiring veno-venous ECMO were excluded. Primary outcomes were in-hospital mortality and 1-year survival rate of patients who were weaned from VA-ECMO support. Secondary outcomes were cannulation-related complications at the axillary site, VA-ECMO-related complications, and systemic complications. Results: In our cohort, 60 (33.5%) patients were female. Mean age was 67.0 ± 10.9 years. Overall, 78 (43.5%) patients were operated upon electively, 37 (20.7%) patients underwent urgent surgery, and 64 (35.8%) patients underwent emergency surgical treatment. Sixty-seven patients (37.4%) were resuscitated preoperatively. The mean duration of VA-ECMO support was 8.4 ± 5.1 days. Weaning from VA-ECMO was successful in 87 (48.6%) patients; 62 (34.6%) patients survived the hospital stay. The 1-year survival rate was 74%. Subclavian bleeding occurred in 24 (13.4%) patients, femoral bleeding in 4 (2.2%) patients, ischemia of the upper limb in 11 (6.1%) patients, intracerebral bleeding in 9 (5%) patients, and stroke in 19 (10.6%) patients. Conclusions: In patients with acute LV dysfunction after cardiothoracic surgery who cannot be weaned from cardiopulmonary bypass, right axillary artery cannulation is a safe and reliable method for VA-ECMO support with an acceptable complication rate.

Extracorporeal Membrane Oxygenation Uses in Refractory Cardiogenic Shock After Open-Heart Surgery

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is the first-line therapy for temporary mechanical circulatory support allowing cardiac and pulmonary recovery or as a bridge to further therapeutic alternatives. The aim of this study was to report clinical outcomes in adult patients with refractory cardiac failure after open-heart surgery undergoing ECMO in a single center with an ECMO unit in Chile.

METHODS

We retrospectively analyzed adults with refractory cardiac failure after open-heart surgery who required a venoarterial (VA) ECMO between 2016 and 2021.

RESULTS

Of 16 patients with VA ECMO, 60% were men (n=10), 90% had hypertension (n=14), 69% had < 30% of left ventricular ejection fraction (n=11), and the mean European System for Cardiac Operative Risk Evaluation II score was 12 ± 11%. ECMO support with central cannulation accounts for 81% (n=13), and an intra-aortic balloon pump was used in nine patients (56%). The mean time of support was 4.7 ± 2.6 days (1.5 - 12 days). ECMO weaning was achieved in 88% of patients, and in-hospital mortality was 44% (n=7) after discharge. The freedom from all-cause mortality at one year of follow-up of the entire cohort was 38% (n=6).

CONCLUSION

VA ECMO is now a well-known life-saving therapeutic option, but mortality and morbidity remain high. Implementation of an ECMO program with educational training is mandatory in order to find the proper balance between patient benefits, ethical considerations, and public health financial input in South America.

Positive association between arterial blood lactate level before extra-corporeal membrane oxygenation and 30-day mortality in pediatric patients with severe cardiopulmonary failure

INTRODUCTION

This study aimed to investigate the relationship between blood lactate level and mortality in pediatric patients receiving extracorporeal membrane oxygenation (ECMO) for severe cardiopulmonary failure.

METHODS

A retrospective observational study was conducted on pediatric patients who received ECMO from January 2013 to December 2021 at the Seventh Medical Center of PLA General Hospital. Patient demographic characteristics, arterial blood lactate level prior to ECMO (pre-ECMO), ECMO settings, ECMO duration, and 30-days mortality were retrieved from patients' medical records. The relationships between pre-ECMO blood lactate level and mortality were interpreted using the logistic regression analysis and Kaplan-Meier survival analysis.

RESULTS

A total of 160 pediatric patients who had either refractory respiratory failure (n = 89) or circulatory failure (n = 71) and received ECMO were included in this study. In both the respiratory failure and circulatory failure groups, the non-survivors showed a higher mean pre-ECMO arterial blood lactate level than the survivors. In the respiratory failure group, a pre-ECMO lactate concentration at ≥11.6 mmol/L had a sensitivity of 51% and a specificity of 82% for predicting mortality. In the circulatory failure group, a pre-ECMO lactate concentration at ≥7.2 mmol/L had a sensitivity of 90% and a specificity of 57% for predicting mortality. The Kaplan-Meier survival curves showed that respiratory failure patients with a pre-ECMO lactate level over 11.6 mmol/L or circulatory failure patients with a pre-ECMO lactate level over 7.2 mmol/L had a higher 30-days mortality rate than those with a lower lactate level.

CONCLUSIONS

High pre-ECMO arterial blood lactate level serves as an independent risk factor for mortality in pediatric patients who receive ECMO for severe cardiopulmonary failure.

Veno-arterial extracorporeal membrane oxygenation for post-infarction ventricular septal defect in a low-volume center

Managing patients with post-ischaemic ventricular septal defects (VSD) and postcardiotomy cardiogenic shock can be extremely challenging in a low-volume cardiac surgery unit. We present a case of a 68-year-old patient who received veno-arterial extracorporeal membrane oxygenation support due to cardiogenic shock after VSD repair. The patient was successfully weaned off support after 86 h. In the postoperative period, mediastinitis occurred, and negative pressure wound therapy was instituted.

Percutaneous dilatation tracheotomy in patients on extracorporeal membrane oxygenation after cardiac surgery

BACKGROUND

Current practices regarding percutaneous dilatational tracheostomy in adult patients treated with extracorporeal membrane oxygenation (ECMO) after cardiac surgery is not completely defined. This study aimed to evaluate the safety of the percutaneous dilatational tracheostomy in patients with ECMO after cardiac surgery.

METHODS

Between July 2017 and May 2021, 371 ECMO procedures were performed in more than 35,000 adult patients who underwent cardiac surgery in our hospital. Sixty-two patients underwent percutaneous dilatational tracheostomy (PDT) during or after ECMO. A retrospective analysis was performed comparing the incidence of complications and clinical outcomes of the two groups.

RESULTS

Of the 371 patients treated with ECMO after adult cardiac surgery during the enrollment period, 22 (7.1%) and 40 (12.8%) underwent PDT during or after ECMO, respectively. The platelet count (PLT) of the day was significantly lower in the PDT during ECMO group (54 (34, 68) vs. 108 (69, 162) (thousands), p < 0.001)). The prothrombin time (PT) and activated partial thromboplastin time (APTT) of the day were longer in the PDT during ECMO group (15.8 (14.6, 19.9) vs. 13.8 (13.2, 15.2) seconds, p = 0.001, 43.8 (38.0, 49.4) vs. 35.2 (28.2, 40.9) seconds, p < 0.001, respectively). There was no significant difference in tracheotomy-related complications between the two groups. Significantly decreased ventilator time was observed in the PDT during ECMO group.

CONCLUSIONS

Despite poor coagulation of the day, PDT during ECMO is safe and can appropriately reduce the duration of mechanical ventilation compared with PDT after ECMO weaning in adult patients who have undergone cardiac surgery.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

Cardiogenic shock is a critical condition of low cardiac output resulting in insufficient systemic perfusion and end-organ dysfunction. Though significant advances have been achieved in reperfusion therapy and mechanical circulatory support, cardiogenic shock continues to be a life-threatening condition associated with a high rate of complications and excessively high patient mortality, reported to be between 35% and 50%. Extracorporeal membrane oxygenation can provide full cardiopulmonary support, has been increasingly used in the last two decades, and can be used to restore systemic end-organ hypoperfusion. However, a paucity of randomized controlled trials in combination with high complication and mortality rates suggest the need for more research to better define its efficacy, safety, and optimal patient selection. In this review, we provide an updated review on VA-ECMO, with an emphasis on its application in cardiogenic shock, including indications and contraindications, expected hemodynamic and echocardiographic findings, recommendations for weaning, complications, and outcomes. Furthermore, specific emphasis will be devoted to the two published randomized controlled trials recently presented in this setting.

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.

Increased Drop in Activity of Alkaline Phosphatase in Plasma from Patients with Endocarditis

(1) Infective endocarditis is a severe inflammatory disease associated with substantial mortality and morbidity. Alkaline phosphatase (AP) levels have been shown to change significantly during sepsis. Additionally, we previously found that a higher initial AP drop after cardiac surgery is associated with unfavorable outcomes. Therefore, the course of AP after surgery for endocarditis is of special interest. (2) A total of 314 patients with active isolated left-sided infective endocarditis at the Department of Cardiac Surgery (Medical University of Vienna, Vienna, Austria) between 2009 and 2018 were enrolled in this retrospective analysis. Blood samples were analyzed at different time points (baseline, postoperative days 1-7, postoperative days 14 and 30). Patients were categorized according to relative alkaline phosphatase drop (≥30% vs. <30%). (3) A higher rate of postoperative renal replacement therapy with or without prior renal replacement therapy (7.4 vs. 21.8%; p = 0.001 and 6.7 vs. 15.6%; p = 0.015, respectively) and extracorporeal membrane oxygenation (2.2 vs. 19.0%; p = 0.000) was observed after a higher initial alkaline phosphatase drop. Short-term (30-day mortality 3.0 vs. 10.6%; p = 0.010) and long-term mortality (p = 0.008) were significantly impaired after a higher initial alkaline phosphatase drop. (4) The higher initial alkaline phosphatase drop was accompanied by impaired short- and long-term outcomes after cardiac surgery for endocarditis. Future risk assessment scores for cardiac surgery should consider alkaline phosphatase.

Construction and evaluation of prognostic models of ECMO in elderly patients with cardiogenic shock based on BP neural network, random forest, and decision tree

OBJECTIVE

To analyze the predictive effect of a back propagation (BP) neural network, random forest (RF) and decision tree model on the prognosis of elderly patients with cardiogenic shock after extracorporeal membrane oxygenation (ECMO).

METHODS

This is a retrospective analysis of the clinical data of elderly patients with cardiogenic shock (258 cases) who underwent ECMO in People's Hospital of Guangxi Zhuang Autonomous Region from January 2016 to January 2022. All patients were followed up for 6 months after ECMO treatment. The prognosis was evaluated, and the prognostic factors were analyzed. BP neural network, RF and decision tree were used to establish predictive models, and the predictive performance of the models was evaluated.

RESULTS

Among the 258 elderly patients with cardiogenic shock, 52 (20.16%) died 6 months after the ECMO treatment. Based on BP neural network, RF, and decision tree, predictive models for the prognosis and death of elderly patients with cardiogenic shock were constructed. A test set was used to predict the performance of the three models. The results showed that the predictive performances of the three models were all more than 80.00%. The accuracy, sensitivity, and specificity of the RF model were 0.987, 1.000, and 0.929 respectively, which were higher than those of the decision tree model. The area under the receiver operating characteristic curve (AUC) of the RF model was 1.000, which was higher than 0.916 for the decision tree model. DeLong test showed that there was a significant difference in the AUC of the RF model compared to the decision tree test set (D=-2.063, P=0.042 < 0.05).

CONCLUSION

The predictive performance is good in all the three models, which have a high application value for prognosis of ECMO in elderly patients with cardiogenic shock. In clinical practice, predictive models should be selected according to the actual situation, so clinicians and patients can make decisions.

The Use of Cardioprotective Devices and Strategies in Patients Undergoing Percutaneous Procedures and Cardiac Surgery

In the United States, about one million people are seen to visit the operating theater for cardiac surgery annually. However, nearly half of these visits result in complications such as renal, neurological, and cardiac injury of varying degrees. Historically, many mechanisms and approaches have been explored in attempts to reduce injuries associated with cardiac surgery and percutaneous procedures. Devices such as cardioplegia, mechanical circulatory support, and other methods have shown promising results in managing and preventing life-threatening cardiac-surgery-related outcomes such as heart failure and cardiogenic shock. Comparably, cardioprotective devices such as TandemHeart, Impella family devices, and venoarterial extracorporeal membrane oxygenation (VA-ECMO) have also been proven to show significant cardioprotection through mechanical support. However, their use as interventional agents in the prevention of hemodynamic changes due to cardiac surgery or percutaneous interventions has been correlated with adverse effects. This can lead to a rebound increased risk of mortality in high-risk patients who undergo cardiac surgery. Further research is necessary to delineate and stratify patients into appropriate cardioprotective device groups. Furthermore, the use of one device over another in terms of efficacy remains controversial and further research is necessary to assess device potential in different settings. Clinical research is also needed regarding novel strategies and targets, such as transcutaneous vagus stimulation and supersaturated oxygen therapy, aimed at reducing mortality among high-risk cardiac surgery patients. This review explores the recent advances regarding the use of cardioprotective devices in patients undergoing percutaneous procedures and cardiac surgery.

Levosimendan in patients undergoing extracorporeal membrane oxygenation after cardiac surgery: an emulated target trial using observational data

BACKGROUND

Retrospective cohorts have suggested that levosimendan may facilitate the weaning of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We therefore studied this clinical question by emulating a randomized trial with observational data.

METHODS

All patients with refractory postcardiotomy cardiogenic shock and assisted with VA-ECMO, admitted to a surgical intensive care unit at La Pitié-Salpêtrière Hospital between 2016 and 2019, were eligible. To avoid immortal-time bias, we emulated a target trial sequentially comparing levosimendan administration versus no levosimendan administration in patients treated with VA-ECMO. The primary outcome was time to successful ECMO weaning. The secondary outcomes were 30-day and 1-year mortality. We performed a multivariable analysis to adjust for confounding at baseline.

RESULTS

Two hundred and thirty-nine patients were included in the study allowing building a nested trials cohort of 1434 copies of patients. No association of levosimendan treatment and VA-ECMO weaning was found (HR = 0.91, [0.57; 1.45], p = 0.659 in multivariable analysis), or 30-day mortality (OR = 1.03, [0.52; 2.03], p = 0.940) and 1-year mortality (OR = 1.00, [0.53; 1.89], p = 0.999).

CONCLUSIONS

Using the emulated target trial framework, this study did not find any association of levosimendan treatment and ECMO weaning success after postcardiotomy cardiogenic shock. However, the population of interest remains heterogeneous and subgroups might benefit from levosimendan.

Integral assessment of gas exchange during veno-arterial ECMO: accuracy and precision of a modified Fick principle in a porcine model

Assessment of native cardiac output during extracorporeal circulation is challenging. We assessed a modified Fick principle under conditions such as dead space and shunt in 13 anesthetized swine undergoing centrally cannulated veno-arterial extracorporeal membrane oxygenation (V-A ECMO, 308 measurement periods) therapy. We assumed that the ratio of carbon dioxide elimination (V̇co₂) or oxygen uptake (V̇o₂) between the membrane and native lung corresponds to the ratio of respective blood flows. Unequal ventilation/perfusion (V̇/Q̇) ratios were corrected towards unity. Pulmonary blood flow was calculated and compared to an ultrasonic flow probe on the pulmonary artery with a bias of 99 mL/min (limits of agreement -542 to 741 mL/min) with blood content V̇o₂ and no-shunt, no-dead space conditions, which showed good trending ability (least significant change from 82 to 129 mL). Shunt conditions led to underestimation of native pulmonary blood flow (bias -395, limits of agreement -1,290 to 500 mL/min). Bias and trending further depended on the gas (O₂, CO₂) and measurement approach (blood content vs. gas phase). Measurements in the gas phase increased the bias (253 [LoA -1,357 to 1,863 mL/min] for expired V̇o₂ bias 482 [LoA -760 to 1,724 mL/min] for expired V̇co₂) and could be improved by correction of V̇/Q̇ inequalities. Our results show that common assumptions of the Fick principle in two competing circulations give results with adequate accuracy and may offer a clinically applicable tool. Precision depends on specific conditions. This highlights the complexity of gas exchange in membrane lungs and may further deepen the understanding of V-A ECMO.

Quantitative evaluation of hemodynamic parameters by echocardiography in patients with post-cardiotomy cardiac shock supported by extracorporeal membrane oxygenation

BACKGROUND

When drugs fail to reverse post-cardiotomy cardiac shock (PCS), extracorporeal membrane oxygenation (ECMO) is considered the most effective adjuvant strategy. Transthoracic echocardiography is a useful imaging modality for monitoring of cardiac hemodynamics. The aim of this study was to investigate the value of echocardiography for monitoring the left and right heart hemodynamics in PCS patients before, during, and after weaning from ECMO.

METHODS

Fifty-two patients were divided into successful weaning group (group A, n = 23) and non-successful weaning group (group B, n = 29). Hemodynamic parameters measured by echocardiography were collected before, during, and after ECMO. The intra-group changes and inter-group differences were retrospectively analyzed.

RESULTS

In group A, the central venous pressure (CVP), proximal right ventricular outflow tract (RVOT), tricuspid annular plane systolic excursion (TAPSE), velocity of tricuspid valve (TVDV), and systolic velocity of tricuspid annulus ([Formula: see text]) during ECMO were significantly lower than those before ECMO. After ECMO, left ventricular ejection fraction (LVEF), systolic velocity of mitral annulus ([Formula: see text]), and velocity-time integral of LV outflow tract (LVOT-VTI) were higher than pre-ECMO levels, and CVP, LVEF, [Formula: see text], LVOT-VTI, RVOT, TAPSE, TVDV and [Formula: see text] were higher than those during ECMO (all P < 0.05). In group B, compared to pre-ECMO, subjects exhibited decreased CVP, RVOT, TAPSE, TVDV and [Formula: see text] during ECMO. TAPSE, TVDV, and [Formula: see text] were continuously lower after ECMO, while CVP and RVOT increased after ECMO (all P < 0.05). After ECMO, LVEF, [Formula: see text], LVOT-VTI, TAPSE, TVDV and [Formula: see text] in group A were higher than those in group B (all P < 0.05). Inter-group comparison showed the LVEF and RV Tei indices of group A were significantly different than those of group B before, during, and after ECMO.

CONCLUSION

Quantitative assessment of both LV and RV by echocardiography is important for ECMO weaning. Patients with better LVEF and lower RV Tei index may have a better chance of successful weaning from ECMO.

Perioperative Management of the Patient at High-Risk for Cardiac Surgery-Associated Acute Kidney Injury

Acute kidney injury (AKI) is one of the most common major complications of cardiac surgery, and is associated with increased morbidity and mortality. Cardiac surgery-associated AKI has a complex, multifactorial etiology, including numerous factors such as primary cardiac dysfunction, hemodynamic derangements of cardiac surgery and cardiopulmonary bypass, and the possibility of a large volume of blood transfusion. There are no truly effective pharmacologic therapies for the management of AKI, and, therefore, anesthesiologists, intensivists, and cardiac surgeons must remain vigilant and attempt to minimize the risk of developing renal dysfunction. This narrative review describes the current state of the scientific literature concerning the specific aspects of cardiac surgery-associated AKI, and presents it in a chronological fashion to aid the perioperative clinician in their approach to this high-risk patient group. The evidence was considered for risk prediction models, preoperative optimization, and the intraoperative and postoperative management of cardiac surgery patients to improve renal outcomes.

Elevated lactate levels and impaired lactate clearance during extracorporeal life support (ECLS) are associated with poor outcome in cardiac surgery patients

The use of extracorporeal life support (ECLS) as part of cardio-circulatory support has increased rapidly in recent years. Severe hyperlactatemia is not uncommon in this group of patients. Lactate peak concentrations and lactate clearance have already been identified as independent marker for mortality in critical ill patients without mechanical device support. The aim of this study was to determine a supposed correlation between the variables lactate peak concentration and clearance in the blood and mortality in the ECLS context. Therefore, a total of 51 cardiac surgery ICU patients with ECLS therapy were included in this retrospective, clinical observational study (survivors n = 23; non-survivors n = 28). Lactate measurement was performed before, during and after ECLS therapy. Further, common ICU scores (SAPSII, SOFA, TISS28), the rates of transfusion and the different vasopressor therapies will be compared. Significant elevated peak lactate levels and poor lactate clearance were associated with higher mortality during ECLS therapy (p < 0.001). Deceased patients had higher SAPSII scores (p < 0.001), received more transfusions (p < 0.001) and presented with higher rates of epinephrine (p < 0.001). In conclusion, hyperlactatemia during ECLS therapy is a time sensitive emergency. Lactate cannot be cleared in all patients. Reversible causes should be explored and treated. In cases where the cause is irreversible, the prognosis of elevated lactate concentrations and reduced clearance is very poor.

Impact of Initial Operative Urgency on Short-Term Outcomes in Patients Treated with ECMO Due to Postcardiotomy Cardiogenic Shock

The outcomes of patients with PCS and following ECMO therapy are associated with several preoperative risk factors. Our aim was to compare clinical presentation, ECMO-related data and in-hospital outcomes of patients treated with ECMO due to PCS after cardiac surgery, in regard to elective or emergent cardiac surgery procedures. Between April 2006 and October 2016, 164 consecutive patients that received VA-ECMO therapy due to PCS were identified and included in this retrospective cohort study. The patients were divided into groups based on the urgency of the initial procedures performed: elective group (ELG; n = 95) and an emergency group (EMG; n = 69). To compare the unequal patient groups, a propensity score-based matching (PSM) was applied (ELG, n = 56 vs. EMG, n = 56). The EMG primarily received ECMO intraoperatively (p ≤ 0.001). In contrast, the ELG were needed ECMO support more frequently postoperatively (p < 0.001). In-hospital mortality accounted for 71% (n = 40) in the ELG and 76% (n = 43) in the EMG (p = 0.518). Outcome data showed no major differences in the (abdominal ischemia (p = 0.371); septic shock (p = 0.393): rhythm disturbances (p = 0.575); emergency re-thoracotomy (p = 0.418)) between the groups. The urgency of the initial procedures performed is secondary in patients suffering PCS and following ECMO. In this regard, PCS itself seems to trigger outcomes in cardiac surgery ECMO patients substantially.

Mechanical Circulatory Support in Cardiovascular Surgical Patients: Single Center Practice and Experience

Background

In view of the role of mechanical circulatory support in patients with severe cardiac insufficiency during perioperative period, we searched the relevant articles on mechanical circulatory support at Fuwai Hospital, and analyzed the indications and complications of different mechanical circulatory support methods.

Methods

Relevant studies were identified by computerized searches of PubMed, Ovid, Embase, Cochrane Library, Wanfang Data, VIP Data, Chinese BioMedical Literature & Retrieval System (SinoMed), and China National Knowledge Infrastructure (CNKI), using search words ("intra-aortic balloon counter pulsation" OR "IABP" OR "extracorporeal membrane oxygenation" OR "ECMO" OR "ventricular assist device" OR "VAD") AND ("Fuwai" OR "fuwai"). All studies concerning the application of IABP, ECMO, and VAD at Fuwai Hospital were included, exclusion criteria included: (1) studies published as review, case report or abstract; (2) animal or cell studies; (3) duplicate publications; (4) studies lacking information about outcomes of interest.

Results

A total of 36 literatures were selected for analysis. The specific mechanical circulatory support methods of ECMO and VAD retrieved from the studies were VA-ECMO and LVAD. The number of cases using IABP, ECMO, LVAD was 1968, 972, 67; and the survival rate was 80.4%, 54.9%, 56.7%, respectively. The major complications of IABP, ECMO and LVAD were hemorrhage (1.2%, 35.9% and 14.5%), infection (3.7%, 12.7% and 9.7%), acute kidney injury (9.1%, 29.6% and 6.5%), the secondary complications were limb ischemia, neurological events, cardiovascular events and thrombosis.

Conclusions

The present study suggested that, IABP, ECMO and VAD, either alone or in combination, were effective and safe mechanical circulation support when managing cardiovascular surgical patients with severe hemodynamic instability at Fuwai Hospital.

Trends and Outcomes of Myocardial Infarction in Patients With Previous Coronary Artery Bypass Surgery

Data on myocardial infarction (MI) treatment in patients with previous coronary artery bypass grafting (CABG) is limited. We queried the Nationwide Readmissions Database to identify hospitalizations of patients with MI from 2016 to 2019. Among hospitalized patients presenting with MI, 10.3% had previous CABG. Patients with MI who had previous CABG were less likely to be revascularized than those without previous CABG for both ST-segment elevation MI (STEMI) (46.4% vs 68.4%) and non-ST-segment elevation MI (NSTEMI) (30.8% vs 36.7%). CABG was associated with a lower risk of death in NSTEMI patients (odds ratio [OR] 0.84, 95% confidence interval [CI] 0.82 to 0.86), but a higher risk in STEMI patients (OR 1.06, 95% CI 1.01 to 1.13). Revascularization was associated with a lower risk of in-hospital death in patients with previous CABG presenting with STEMI (OR 0.30, 95% CI 0.26 to 0.35) and NSTEMI (OR 0.21, 95% CI 0.19 to 0.23).

A Narrative Review of Nutrition Therapy in Patients Receiving Extracorporeal Membrane Oxygenation

The use of extracorporeal membrane oxygenation (ECMO) in patients with severe cardiorespiratory failure has seen significant growth in the last decade. Despite this, there is paucity of data surrounding the optimum nutritional management for ECMO patients. This review aimed to describe current nutrition practices in patients receiving ECMO, critically appraise available studies and identify areas for future research. A literature search was conducted in PubMed, MEDLINE, and CINAHL Plus to identify all randomized trials and observational studies published between July 2000 and July 2020 investigating nutrition practices in critically ill adults receiving ECMO. The primary outcomes were nutritional adequacy, gastrointestinal complications, and physical function. Secondary outcomes included mortality, length of stay, and duration on ECMO support. From a total of 31 studies identified, 12 met the inclusion criteria. Nine observational studies were reviewed following eligibility assessment. Early enteral nutrition was deemed safe and feasible for ECMO patients; however, meeting nutritional targets was challenging. Utilizing alternative nutrition routes is an option, although risks and benefits should be taken into consideration. Data on gastrointestinal complications and other clinical outcomes were inconsistent, and no data were identified investigating the effects of nutrition on the physical and functional recovery of ECMO patients. Nutrition therapy in ECMO patients should be provided in line with current guidelines for nutrition in critical illness until further data are available. Further prospective, randomized studies investigating optimum nutrition practices and effects on clinical and functional outcomes are urgently required.

The Early Introduction of Extracorporeal Membrane Oxygenation for Postcardiotomy Cardiogenic Shock Does Not Improve 30-Day Mortality Rates in Low-Volume Centers

Background and objective

Postcardiotomy cardiogenic shock (PCS) is one of the most critical conditions observed in cardiac surgery. Recently, the early initiation of venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been recommended for PCS patients to ensure end-organ perfusion, especially in high-volume centers. In this study, we investigated the effectiveness of earlier initiation of VA-ECMO for PCS in low-volume centers.

Methods

We retrospectively assessed patients admitted in two of our related facilities from April 2014 to March 2019. The patients who underwent VA-ECMO during peri- or post-cardiac surgery (within 48 hours) were included. We divided the patients into two groups according to the timing of VA-ECMO initiation. In the early initiation of VA-ECMO group, the “early ECMO group,” VA-ECMO was initiated when patients needed high-dose inotropic support with high-dose catecholamines, such as epinephrine, without waiting for PCS recovery. In the late initiation of VA-ECMO group, the “late ECMO group,” VA-ECMO was delayed until PCS was not controlled with high-dose catecholamines, with the intent of avoiding severe bleeding complications.

Results

A total of 30 patients were included in the analysis (early ECMO group/late ECMO group: 19/11 patients). Thirty-day mortality in the entire cohort was 60% (n=18), and there was no significant difference between the two groups (early ECMO group/late ECMO group: 64%/55%, p=0.712). Thirteen and six patients died without being weaned off in the early ECMO (43%) and late ECMO groups (55%), respectively; there was no significant difference between the two groups (p=0.696). The median duration of ECMO support was five days (IQR: 1.5-6.5).

Conclusions

The early initiation of ECMO did not contribute to patients’ 30-day outcomes in low-volume centers. To improve outcomes of ECMO therapy in patients with PCS, centralization of low-volume centers may be required.

Similarities in extracorporeal membrane oxygenation management across intensive care unit types in the United States: An analysis of the Extracorporeal Life Support Organization Registry

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) use in the United States occurs often in cardiothoracic ICUs (CTICU). It is unknown how it varies across ICU types.

METHODS

We identified 10,893 ECMO runs from the Extracorporeal Life Support Organization (ELSO) Registry across 2018 and 2019. Primary outcome was ECMO case volume by ICU type (CTICU vs. non-CTICU). Adjusting for pre-ECMO characteristics and case mix, secondary outcomes were on-ECMO physiologic variables by ICU location stratified by support type.

RESULTS

CTICU ECMO occurred in 65.1% and 55.1% (2018 and 2019) of total runs. A minority of total runs related to cardiac surgery procedures (CTICU: 21.7% [2018], 18% [2019]; non-CTICU: 11.2% [2018], 13% [2019]). After multivariate adjustment, non-CTICU ECMO for cardiac support associated with lower 4- and 24-hour circuit flow (3.9 liters per minute [LPM] vs. 4.1 LPM, p<0.0001; 4.1 LPM vs. 4.3 LPM, p<0.0001); for respiratory support, lower on-ECMO mean fraction of inspired oxygen ([F_i O₂ ], 67% versus 69%, p=0.02) and lower respiratory rate (14 versus 15, p<0.0001); and, for extracorporeal cardiopulmonary resuscitation (ECPR), lower ECMO flow rates at 24 hours (3.5 liters per minute [LPM] versus 3.7 LPM, p=0.01).

CONCLUSIONS

ECMO mostly remains in CTICUs though a minority is associated with cardiac surgery. Statistically significant but clinically minor differences in on-ECMO metrics were observed across ICU types.

Levosimendan in intensive care and emergency medicine: literature update and expert recommendations for optimal efficacy and safety

The inodilator levosimendan, in clinical use for over two decades, has been the subject of extensive clinical and experimental evaluation in various clinical settings beyond its principal indication in the management of acutely decompensated chronic heart failure. Critical care and emergency medicine applications for levosimendan have included postoperative settings, septic shock, and cardiogenic shock. As the experience in these areas continues to expand, an international task force of experts from 15 countries (Austria, Belgium, China, Croatia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Spain, Sweden, Switzerland, and the USA) reviewed and appraised the latest additions to the database of levosimendan use in critical care, considering all the clinical studies, meta-analyses, and guidelines published from September 2019 to November 2021. Overall, the authors of this opinion paper give levosimendan a "should be considered" recommendation in critical care and emergency medicine settings, with different levels of evidence in postoperative settings, septic shock, weaning from mechanical ventilation, weaning from veno-arterial extracorporeal membrane oxygenation, cardiogenic shock, and Takotsubo syndrome, in all cases when an inodilator is needed to restore acute severely reduced left or right ventricular ejection fraction and overall haemodynamic balance, and also in the presence of renal dysfunction/failure.

A Meta-Analysis Comparing Venoarterial (VA) Extracorporeal Membrane Oxygenation (ECMO) to Impella for Acute Right Ventricle Failure

The right ventricular complication happens when the right ventricle (RV) fails to move sufficient blood through the pulmonary circle to enable enough left ventricular pumping. A significant pulmonary embolism/right-sided myocardial infarction may cause this to develop suddenly in a previously healthy heart, but many of the patients treated in the critical care unit have gradual, compensated RV failure as a result of chronic heart and lung disease. RV failure management aims to decrease afterload and improve right-side filling pressures. Vasoactive medications have a lower effect on lowering vascular obstruction in the pulmonary circulation than in the systemic circle because the vascular tone is lower in the pulmonary circulation. Any factors that induce an elevation in pulmonary vascular tone must be addressed, and selective pulmonary vasodilators must be administered in a prescription that does not result in systemic hypotension or compromise oxygenation. The system-based systolic arterial pressure should be kept near the RV systolic pressure to ensure RV perfusion. When these efforts prove futile, judicious application of inotropic medications for better RV contractility may help ensure cardiac output. After obtaining the finest medical treatment, certain individuals may need the implantation of a mechanical circulatory support device. This meta-analysis is intended to compare the Impella and venoarterial (VA) extracorporeal membrane oxygenation (ECMO) mechanical supports for patients with acute right ventricular failure. This comparison should demonstrate the best mechanical support between the two through thorough analysis. The analysis was begun by data collection from relevant sites; PUBMED and EMBASE were searched in collaboration with Google Scholar. Keywords were searched: Impella for acute right ventricle failure and VA ECMO for acute right ventricle failure. The results that were close to the search titles had their respective articles downloaded for further scrutiny. The search finally brought 1001 related articles that were exposed to further analysis to find more refined and closer articles within the needs of this meta-analysis. After extensive scrutiny, 23 articles were found to be the best for these analyses. The data showed that VA ECMO had better results than Impella for acute RV failure. However, the data were not statistically significant, as either the numbers of the studies were not enough or the null hypothesis was true and there was no true difference between them. More studies will be needed to confirm this.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: An Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part I, Technical Aspects of Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is used to support patients with refractory cardiopulmonary failure. Given ECMO's increased use in adults and the fact that many ECMO patients are cared for by anesthesiologists, the Society of Cardiovascular Anesthesiologists ECMO working group created an expert consensus statement that is intended to help anesthesiologists manage adult ECMO patients who are cared for in the operating room. In the first part of this 2-part series, technical aspects of ECMO are discussed, and related expert consensus statements are provided.

Access site complications of postcardiotomy extracorporeal life support

OBJECTIVE

To assess the influence of primary arterial access in patients receiving peripheral postcardiotomy extracorporeal life support on associated complications and outcome.

METHODS

Of 573 consecutive patients requiring PC-ECLS between 2000 and 2019 at a single center, 436 were included in a retrospective analysis and grouped according to primary arterial extracorporeal life support access site. Survival and rate of access-site-related complications with special emphasis on fatal/disabling stroke were compared.

RESULTS

The axillary artery was cannulated in 250 patients (57.3%), whereas the femoral artery was used as primary arterial access in 186 patients (42.6%). There was no significant difference in 30-day (axillary: 62%; femoral: 64.7%; P = .561) and 1-year survival (axillary: 42.5%; femoral: 44.8%; P = .657). Cerebral computed tomography-confirmed stroke with a modified ranking scale ≥4 was significantly more frequent in the axillary group (axillary: n = 28, 11.2%; femoral: n = 4, 2.2%; P = .0003). Stroke localization was right hemispheric (n = 20; 62.5%); left hemispheric (n = 5; 15.6%), bilateral (n = 5; 15.6%), or infratentorial (n = 2; 6.25%). Although no difference in major cannulation site bleeding was observed, cannulation site change for bleeding was more frequent in the axillary group (axillary: n = 13; 5.2%; femoral: n = 2; 1.1%; P = .03). Clinically apparent limb ischemia was significantly more frequent in the femoral group (axillary: n = 12, 4.8%; femoral: n = 31, 16.7%; P < .0001).

CONCLUSIONS

Although survival did not differ, surgeons should be aware of access-site-specific complications when choosing peripheral PC-ECLS access. Although lower rates of limb ischemia and the advantage of antegrade flow seem beneficial for axillary cannulation, the high incidence of right hemispheric strokes in axillary artery cannulation should be considered.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: an Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part I, Technical Aspects of Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is used to support patients with refractory cardiopulmonary failure. Given ECMO's increased use in adults and the fact that many ECMO patients are cared for by anesthesiologists, the Society of Cardiovascular Anesthesiologists ECMO working group created an expert consensus statement that is intended to help anesthesiologists manage adult ECMO patients who are cared for in the operating room. In the first part of this 2-part series, technical aspects of ECMO are discussed, and related expert consensus statements are provided.