Veno-arterial extracorporeal membrane oxygenation for adult cardiovascular failure

Serum Total Bilirubin With Hospital Survival in Adults During Extracorporeal Membrane Oxygenation

Background

Extracorporeal membrane oxygenation (ECMO) is widely used for refractory cardiopulmonary failure treatment. The disadvantage of ECMO is its higher risk profile and clinical resource consumption. This observation examines the role of serum total bilirubin (TBIL) as a predictor of adult patient outcomes on ECMO support.

Methods

This retrospective observation reports a single-center experience with adults on ECMO support between 2018 and 2021. Data were collected regarding demographics, ECMO details, laboratory parameters, and outcomes. We examined the elevation of TBIL to predict survival and variables associated with hyperbilirubinemia.

Results

The patients who died within 28 days had a twofold higher peak level of TBIL than those who survived [73.10 (38.60, 98.64) vs. 34.50 (24.03, 54.85); P = 0.003]. Univariate logistic regression analyses demonstrated that high TBIL was remarkably associated with an elevated risk of 28-day mortality (OR: 7.25; 95% CI: 2.31–25.49; P = 0.001) and total mortality (OR: 5.71; 95% CI: 1.82–20.66; P = 0.001). The TBIL value was 65 μmol/L as the best cut-off value, and the observation group was divided into a high TBIL subgroup (n = 21) or a low TBIL subgroup (n = 39). The demographic and clinical features did not show a difference, whereas Sequential Organ Failure Assessment (SOFA) and APACHE II scores and ALT, AST, and LAC before ECMO initiation correlated with high or low TBIL (P < 0.05). For coagulation function at the time of TBIL peak, the levels of prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin time activity (PTA), and fibrinogen (FIB) were different between the two subgroups (P < 0.05). The SOFA score was potentially associated with hyperbilirubinemia after ECMO initiation, and the prediction accuracy was 0.800.

Conclusion

Serum total bilirubin elevation appears after ECMO initiation and correlates with survival, while other markers of liver injury do not. Serum total bilirubin is an easy-to-measure biomarker to be a predictor of survival after ECMO initiation.

Liver Dysfunction Associated With In-Hospital Mortality in Adult Extracorporeal Membrane Oxygenation Support

OBJECTIVES:

Extracorporeal membrane oxygenator support is a powerful clinical tool that is currently enjoying a resurgence in popularity. Wider use of extracorporeal membrane oxygenator support is limited by its significant risk profile and extreme consumption of resources. This study examines the role of markers of liver dysfunction in predicting outcomes of adult patients requiring extracorporeal membrane oxygenator support.

DESIGN:

Retrospective review.

SETTING:

Large extracorporeal membrane oxygenator center, Chicago, IL.

PATIENTS:

This study reports a single institution experience examining all adult patients for whom extracorporeal membrane oxygenator support was used over an 8-year period. Data were collected regarding patient demographics, details of extracorporeal membrane oxygenator support provided, laboratory data, and outcomes. Trends in liver function were examined for their ability to predict survival.

INTERVENTION:

Extracorporeal membrane oxygenator support, critical care.

MEASUREMENTS AND MAIN RESULTS:

Mean age was 50 years (range, 19–82 yr). There were 86 male patients (56.6%) and 66 female patients (43.4%). Indications for initiation of extracorporeal membrane oxygenator support included cardiac 76 patients (50.0%), respiratory 48 patients (31.6%), extracorporeal cardiopulmonary resuscitation 21 patients (13.3%), and combined cardiac/respiratory seven patients (4.6%). Mean duration of extracorporeal membrane oxygenator support was 17 days (range 1–223 d) or median 8 days (interquartile range, 4–17 d). Overall, in-hospital mortality was 56% (86/152). Forty-five percent of adult patients (68/152) surpassed at least one of the following established liver dysfunction thresholds: total bilirubin greater than 15 mg/dL, aspartate aminotransferase greater than 20× upper limit of normal, and alanine aminotransferase greater than 20× upper limit of normal. The multivariable logistic analysis yielded three significant findings associated with in-hospital mortality: highest total bilirubin greater than 15 (adjusted odds ratio = 4.40; 95% CI, 1.19–21.87; p = 0.04), age (adjusted odds ratio = 1.03; 95% CI, 1.00–1.05; p = 0.04), and highest lactate (adjusted odds ratio = 1.15; 95% CI, 1.06–1.26; p = 0.002).

CONCLUSIONS:

Increases in age, highest total bilirubin, and lactate all correlated with in-hospital mortality in multivariable analysis of patients requiring extracorporeal membrane oxygenator support.

Predicting Survival After VA-ECMO for Refractory Cardiogenic Shock: Validating the SAVE Score

Background

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used increasingly to support patients who are in cardiogenic shock. Due to the risk of complications, prediction models may aid in identifying patients who would benefit most from VA-ECMO. One such model is the Survival After Veno-Arterial Extracorporeal Membrane Oxygenation (SAVE) score. Therefore, we wanted to validate the utility of the SAVE score in a contemporary cohort of adult patients.

Methods

Retrospective data were extracted from electronic health records of 120 patients with cardiogenic shock supported with VA-ECMO between 2011 and 2018. The SAVE score was calculated for each patient to predict survival to hospital discharge. We assessed the SAVE score calibration by comparing predicted vs observed survival at discharge. We assessed discrimination with the area under the receiver operating curve using logistic regression.

Results

A total of 45% of patients survived to hospital discharge. Survivors had a significantly higher mean SAVE score (–9.3 ± 4.1 in survivors vs –13.1 ± 4.4, respectively; P = 0.001). SAVE score discrimination was adequate (c = 0.77; 95% confidence interval 0.69-0.86; P < 0.001). SAVE score calibration was limited, as observed survival rates for risk classes II-V were higher in our cohort (II: 67% vs 58%; III: 78% vs 42%; IV: 61% vs 30%; and V: 29% vs 18%).

Conclusions

The SAVE score underestimates survival in a contemporary North American cohort of adult patients with cardiogenic shock. Its inaccurate performance could lead to denying ECMO support to patients deemed to be too high risk. Further studies are needed to validate additional predictive models for patients requiring VA-ECMO.

In-hospital cardiac arrest: are we overlooking a key distinction?

PURPOSE OF REVIEW

To review the epidemiology, peri-arrest management, and research priorities related to in-hospital cardiac arrest (IHCA) and explore key distinctions between IHCA and out-of-hospital cardiac arrest (OHCA) as they pertain to the clinician and resuscitation scientist.

RECENT FINDINGS

IHCA is a common and highly morbid event amongst hospitalized patients in the United States. As compared with patients who experience an OHCA, patients who experience an IHCA tend to have more medical comorbidities, have a witnessed arrest, and be attended to by professional first responders. Further, providers resuscitating patients from IHCA commonly have access to tools and information not readily available to the OHCA responders. Despite these differences, society guidelines for the peri-arrest management of patients with IHCA are often based on data extrapolated from the OHCA population. To advance the care of patients with IHCA, clinicians and investigators should recognize the many important distinctions between OHCA and IHCA.

SUMMARY

IHCA is a unique disease entity with an epidemiology and natural history that are distinct from OHCA. In both research and clinical practice, physicians should recognize these distinctions so as to advance the care of IHCA victims.

Postoperative Extracorporeal Membrane Oxygenation Support for Acute Type A Aortic Dissection

BACKGROUND

Few studies have investigated the use of postoperative extracorporeal membrane oxygenation (ECMO) in acute type A aortic dissection (aTAAD). We identified aTAAD surgical patients at risk of ECMO implantation postoperatively and analyzed the prognosis of these patients.

METHODS

We retrospectively reviewed 162 consecutive aTAAD patients undergoing operations from January 2008 to December 2015. Patient data were analyzed for risk factors leading to an ECMO requirement. Short-term and long-term outcomes in patients who did and did not require ECMO were compared.

RESULTS

Postoperative ECMO was required in 20 patients (12.3%), and in-hospital mortality was higher in the ECMO group (65.0% vs 8.5%, p < 0.001). Factors predicting postoperative ECMO were preoperative hemodynamic instability (p = 0.049), aortic cross-clamp time (p = 0.036), and postoperative peak creatinine kinase-MB (p = 0.002). ECMO survivors presented at a younger age (p = 0.036) and had a less postoperative blood transfusion (p = 0.034) than ECMO nonsurvivors. The postdischarge survival rate was equivalent in patients with or without ECMO support.

CONCLUSIONS

Although postoperative ECMO is an important predictor of in-hospital death, this pilot study showed that aTAAD patients supported with postoperative ECMO who survive to hospital discharge have a long-term survival comparable to patients who did not receive ECMO.

The Right Ventricle in ARDS

ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator-induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population.

Veno-arterial extracorporeal membrane oxygenation: an overview of different cannulation techniques

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has known a widespread application over the last decade and is now an effective and valuable therapeutic option in refractory cardiogenic shock of various etiologies. In this subgroup of critically ill and unstable patients in cardiogenic shock, VA-ECMO allows, on the one hand, temporary hemodynamic stabilization with improvement of end-organ function and, on the other hand, gives the time to perform complementary diagnostic exams and to decide the therapeutic strategy in these high-risk candidates for immediate long-term mechanical circulatory support (MCS) implantation. VA-ECMO could also be suggested as a rescue therapeutic option for refractory cardiac arrest. It showed promising results in the specific setting of in-hospital cardiac arrest and survival rates with good neurological outcome are reported between 20% and 40%. Conversely, there are contrasting data in the literature about survival after VA-ECMO for out-of-hospital cardiac arrest, as results are highly dependent on low-flow time. The aim of the present report is to offer an overview of different cannulation techniques of VA-ECMO.

Cardiopulmonary responses during the cooling and the extracorporeal life support rewarming phases in a porcine model of accidental deep hypothermic cardiac arrest

Background

This study aimed to assess cardiac and pulmonary pathophysiological responses during cooling and extracorporeal life support (ECLS) rewarming in a porcine model of deep hypothermic cardiac arrest (DHCA). In addition, we evaluated whether providing a lower flow rate of ECLS during the rewarming phase might attenuate cardiopulmonary injuries.

Methods

Twenty pigs were cannulated for ECLS, cooled until DHCA occurred and subjected to 30 min of cardiac arrest. In order to assess the physiological impact of ECLS on cardiac output we measured flow in the pulmonary artery using Doppler echocardiography as well as a modified thermodilution technique using the Swan-Ganz catheter (injection site in the right ventricle). The animals were randomized into two groups during rewarming: a group with a low blood flow rate of 1.5 L/min (LF group) and a group with a normal flow rate of 3.0 L/min (NF group). The ECLS temperature was adjusted to 5 °C above the central core. Cardiac output, hemodynamics and pulmonary function parameters were evaluated.

Results

During the cooling phase, cardiac output, heart rhythm and blood pressure decreased continuously. Pulmonary artery pressure tended to increase at 32 °C compared to the initial value (20.2 ± 1.7 mmHg vs. 29.1 ± 5.6 mmHg, p = 0.09). During rewarming, arterial blood pressure was higher in the NF than in the LF group at 20° and 25 °C (p = 0.003 and 0.05, respectively). After rewarming to 35 °C, cardiac output was 3.9 ± 0.5 L/min in the NF group vs. 2.7 ± 0.5 L/min in LF group (p = 0.06). At the end of rewarming under ECLS cardiac output was inversely proportional to the ECLS flow rate. Moreover, the ECLS flow rate did not significantly change pulmonary vascular resistance.

Discussion

Using a newly developed experimental model of DHCA treated by ECLS, we assessed the cardiac and pulmonary pathophysiological response during the cooling phase and the ECLS rewarming phase. Despite lower metabolic need during hypothermia, a low ECLS blood flow rate during rewarming did not improved cardiopulmonary injuries after rewarming.

Conclusion

A low ECLS flow rate during the rewarming phase did not attenuate pulmonary lesions, increased blood lactate level and tended to decrease cardiac output after rewarming. A normal ECLS flow rate did not increase pulmonary vascular resistance compared to a low flow rate. This experimental model on pigs contributes a number of pathophysiological findings relevant to the rewarming strategy for patients who have undergone accidental DHCA.

Extracorporeal membrane oxygenation 2016: an update

The use of extracorporeal membrane oxygenation (ECMO) is an important issue for intensivists, critical care nurses, surgeons, cardiologists, and many others. There has been a continued increase in the number of centres performing ECMO. This review examines novel applications and recent trends in the use of ECMO over the last 2 years. These include ECMO to facilitate the safe use of other treatments, changing the timing of initiation, newer equipment and better biocompatibility, and the ability of ECMO programs to essentially choose which cluster of potential complications they are prepared to accept. ECMO continues to evolve, diversify in its applications, and improve in safety.

Experts' opinion on management of hemodynamics in ARDS patients: focus on the effects of mechanical ventilation

RATIONALE

Acute respiratory distress syndrome (ARDS) is frequently associated with hemodynamic instability which appears as the main factor associated with mortality. Shock is driven by pulmonary hypertension, deleterious effects of mechanical ventilation (MV) on right ventricular (RV) function, and associated-sepsis. Hemodynamic effects of ventilation are due to changes in pleural pressure (Ppl) and changes in transpulmonary pressure (TP). TP affects RV afterload, whereas changes in Ppl affect venous return. Tidal forces and positive end-expiratory pressure (PEEP) increase pulmonary vascular resistance (PVR) in direct proportion to their effects on mean airway pressure (mPaw). The acutely injured lung has a reduced capacity to accommodate flowing blood and increases of blood flow accentuate fluid filtration. The dynamics of vascular pressure may contribute to ventilator-induced injury (VILI). In order to optimize perfusion, improve gas exchange, and minimize VILI risk, monitoring hemodynamics is important.

RESULTS

During passive ventilation pulse pressure variations are a predictor of fluid responsiveness when conditions to ensure its validity are observed, but may also reflect afterload effects of MV. Central venous pressure can be helpful to monitor the response of RV function to treatment. Echocardiography is suitable to visualize the RV and to detect acute cor pulmonale (ACP), which occurs in 20-25 % of cases. Inserting a pulmonary artery catheter may be useful to measure/calculate pulmonary artery pressure, pulmonary and systemic vascular resistance, and cardiac output. These last two indexes may be misleading, however, in cases of West zones 2 or 1 and tricuspid regurgitation associated with RV dilatation. Transpulmonary thermodilution may be useful to evaluate extravascular lung water and the pulmonary vascular permeability index. To ensure adequate intravascular volume is the first goal of hemodynamic support in patients with shock. The benefit and risk balance of fluid expansion has to be carefully evaluated since it may improve systemic perfusion but also may decrease ventilator-free days, increase pulmonary edema, and promote RV failure. ACP can be prevented or treated by applying RV protective MV (low driving pressure, limited hypercapnia, PEEP adapted to lung recruitability) and by prone positioning. In cases of shock that do not respond to intravascular fluid administration, norepinephrine infusion and vasodilators inhalation may improve RV function. Extracorporeal membrane oxygenation (ECMO) has the potential to be the cause of, as well as a remedy for, hemodynamic problems. Continuous thermodilution-based and pulse contour analysis-based cardiac output monitoring are not recommended in patients treated with ECMO, since the results are frequently inaccurate. Extracorporeal CO2 removal, which could have the capability to reduce hypercapnia/acidosis-induced ACP, cannot currently be recommended because of the lack of sufficient data.

Concepts from paediatric extracorporeal membrane oxygenation for adult intensivists

Over the last 5 years, there has been a dramatic increase in the use of extracorporeal membrane oxygenation (ECMO) in adult patients with severe respiratory or cardiac failure. This contrasts to the use of the technology in neonatal and paediatric intensive care units, where it has been regarded as a standard of care for a number of conditions for over 25 years. Many innovations in ECMO circuitry or clinical management evolve first in one particular discipline and it may be helpful for individual clinicians to keep abreast of developments in ECMO across the entire age range, from neonatology to older adults. This review addresses nine concepts in ECMO that are better studied or established in paediatric medicine and considers their application in adult patients.

Percutaneous cannulation for extracorporeal membrane oxygenation by intensivists: a retrospective single-institution case series

OBJECTIVE

Extracorporeal membrane oxygenation provides support for patients with severe acute cardiopulmonary failure, allowing the application of lung or myocardial rest in anticipation of organ recovery, or as a bridge to long-term support. Advances in technology have improved the safety and ease of application of extracorporeal membrane oxygenation. Percutaneous cannulation is one of these advances and is now preferred over surgical cannulation in most cases. Percutaneous cannulation is increasingly performed by intensivists, cardiologists, interventional radiologists, and related specialties. The objective of this study is to review the experience of percutaneous cannulation by intensivists at a single institution.

DESIGN

A retrospective review of 100 subjects undergoing percutaneous cannulation for extracorporeal membrane oxygenation.

SETTING

Adult ICUs and PICUs at a tertiary academic medical institution.

PATIENTS

Critically ill neonatal, pediatric, and adult subjects with severe respiratory and/or cardiac failure undergoing percutaneous cannulation for extracorporeal membrane oxygenation. Modes of support included venoarterial, venovenous, venovenoarterial, and arteriovenous.

INTERVENTIONS

Percutaneous extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Case reports submitted to the Extracorporeal Life Support Organization and hospital records of the subjects were retrospectively reviewed. Subject demographics, type of support, cannulation configuration, types of cannulas, use of imaging modalities, and complications were recorded and summarized. One hundred ninety cannulations with cannula sizes from size 12 to 31F were performed by four intensivists in 100 subjects. Twenty-three were arterial (12-16F) and 167 were venous (12-31F). Preinsertion ultrasound was performed in 93 subjects (93%), fluoroscopic guidance in 79 subjects (85% of nonarteriovenous subjects), and ultrasound-guided insertion was performed in 65 subjects (65%). Two major complications occurred, each associated with mortality. Cannulation was successful in all other subjects (98% of subjects and 99% of cannulations). There were no cases of cannula-related bloodstream infection.

CONCLUSIONS

Percutaneous cannulation for extracorporeal membrane oxygenation by intensivists can be performed with a high rate of success and a low rate of complications when accompanied by imaging support.

Percutaneous Ventricular Assist Devices and ECMO in the Management of Acute Decompensated Heart Failure

The successful treatment of acute decompensated heart failure continues to evolve with an increasing utilization of nondurable mechanical support devices. Indications for acute support have broadened to include their use as a bridge to recovery or decision (for durable ventricular assist devices [VADs] or heart transplant). Available devices have improved in terms of effectiveness, ease of insertion, and reduction in complications. The commonly used devices (intra-aortic balloon pump, TandemHeart, Impella, and extracorporeal membrane oxygenation circuit), together with their mechanisms of action, are reviewed. Current considerations for support, specific to each device, are examined and future directions and indications for percutaneous VADs are explored.