Diagnosis and Management of Vasoplegia in Temporary Mechanical Circulatory Support: A Narrative Review.

Refractory vasodilatory shock, or vasoplegia, is a pathophysiologic state observed in the intensive care unit and operating room in patients with a variety of primary diagnoses. Definitions of vasoplegia vary by source but are qualitatively defined clinically as a normal or high cardiac index and low systemic vascular resistance causing hypotension despite high-dose vasopressors in the setting of euvolemia. This definition can be difficult to apply to patients undergoing mechanical circulatory support (MCS). A large body of mostly retrospective literature exists on vasoplegia in the non-MCS population, but the increased use of temporary MCS justifies an examination of vasoplegia in this population. MCS, particularly extracorporeal membrane oxygenation, adds complexity to the diagnosis and management of vasoplegia due to challenges in determining cardiac output (or total blood flow), lack of clarity on appropriate dosing of noncatecholamine interventions, increased thrombosis risk, the difficulty in determining the endpoints of adequate volume resuscitation, and the unclear effects of rescue agents (methylene blue, hydroxocobalamin, and angiotensin II) on MCS device monitoring and function. Care teams must combine data from invasive and noninvasive sources to diagnose vasoplegia in this population. In this narrative review, the available literature is surveyed to provide guidance on the diagnosis and management of vasoplegia in the temporary MCS population, with a focus on noncatecholamine treatments and special considerations for patients supported by extracorporeal membrane oxygenation, transvalvular heart pumps, and other ventricular assist devices.

Vasoplegic syndrome during heart transplantation: A systematic review and meta-analysis.

BACKGROUND: Vasoplegic syndrome (VS) is a common occurrence during heart transplantation (HT). It currently lacks a uniform definition between transplant centers, and its pathophysiology and treatment remain enigmatic. This systematic review summarizes the available published clinical data regarding VS during HT. METHODS: We searched databases for all published reports on VS during HT. Data collected included the incidence of VS in the HT population, patient and intraoperative characteristics, and postoperative outcomes. RESULTS: Twenty-two publications were included in this review. The prevalence of VS during HT was 28.72% (95% confidence interval: 27.37%, 30.10%). Factors associated with VS included male sex, higher body mass index, hypothyroidism, pre-HT left ventricular assist device or venoarterial extracorporeal membrane oxygenation (VA-ECMO), pre-HT calcium channel blocker or amiodarone usage, longer cardiopulmonary bypass time, and higher blood product transfusion requirement. Patients who developed VS were more likely to require postoperative VA-ECMO support, renal replacement therapy, reoperation for bleeding, longer mechanical ventilation, and a greater 30-day and 1-year mortality. CONCLUSIONS: The results of our systematic review are an initial step for providing clinicians with data that can help identify high-risk patients and avenues for potential risk mitigation. Establishing guidelines that officially define VS will aid in the precise diagnosis of these patients during HT and guide treatment. Future studies of treatment strategies for refractory VS are needed in this high-risk patient population.

Red blood cell distribution width predicts mortality of adult patients receiving veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Red blood cell distribution width (RDW) is a numerical measure of the variation in the size of circulating red blood cells. Recently, there is increasing interest in the role of RDW as a biomarker for inflammatory states and as a prognostication tool for a wide range of clinical manifestations. The predictive power of RDW on mortality among patients receiving mechanical circulatory support remains largely unknown. METHODS: A retrospective analysis of 281 VA-ECMO patients at a tertiary referral academic hospital from 2009 to 2019 was performed. RDW was dichotomized with RDW-Low <14.5% and RDW-High ≥14.5%. The primary outcome was all-cause mortality at 30 days and 1 year. Cox proportional hazards models were used to examine the association between RDW and the clinical outcomes after adjusting for additional confounders. RESULTS: 281 patients were included in the analysis. There were 121 patients (43%) in the RDW-Low group and 160 patients (57%) in the RDW-High group. Survival to ECMO decannulation [RDW-H: 58% versus RDW-L: 67%, p = 0.07] were similar between the two groups. Patients in RDW-H group had higher 30-days mortality (RDW-H: 67.5% vs RDW-L: 39.7%, p < 0.001) and 1 year mortality (RDW-H: 79.4% vs RDW-L: 52.9%, p < 0.001) compared to patients in the RDW-L group. After adjusting for confounders, Cox proportional hazards model demonstrated that patients with high RDW had increased odds of mortality at 30 days (hazard ratio 1.9, 95% CI 1.2-3.0, p < 0.01) and 1 year (hazard ratio 1.9, 95% CI 1.3-2.8, p < 0.01) compared to patients with low RDW. CONCLUSIONS: Among patients receiving mechanical circulatory support with VA-ECMO, a higher RDW was independently associated with increased 30-days and 1-year mortality. RDW may serve as a simple biomarker that can be quickly obtained to help provide risk stratification and predict survival for patients receiving VA-ECMO.

ABO Blood Group and Bleeding and Survival in VA-ECMO Patients.

ABO blood group has been shown to be a major determinant of plasma von Willebrand factor (vWF) levels. O blood group is associated with the lowest vWF levels and confers an increased risk of hemorrhagic events, while AB blood group has the highest levels and is associated with thromboembolic events. We hypothesized in extracorporeal membrane oxygenation (ECMO) patients that O blood type would have the highest and AB blood type would have the lowest transfusions, with an inverse relationship to survival. A retrospective analysis of 307 VA-ECMO patients at a major quaternary referral hospital was performed. The distribution of blood groups included 124 group O (40%), 122 group A (40%), 44 group B (14%), and 17 group AB (6%) patients. Regarding usage of packed red blood cells, fresh frozen plasma, and platelets, there was a non-statistically significant difference in transfusions, with group O having the least and group AB having the most requirements. However, there was a statistically significant difference in cryoprecipitate usage when comparing to group O: group A (1.77, 95% CI: 1.05-2.97, P < .05), group B (2.05, 95% CI: 1.16-3.63, P < .05), and group AB (3.43, 95% CI: 1.71-6.90, P < .001). Furthermore, a 20% increase in length of days on ECMO was associated with a 2-12% increase in blood product usage. The cumulative 30-day mortality rate for groups O and A was 60%, group B was 50%, and group AB was 40%; the 1-year mortality rate for groups O and A was 65%, group B was 57%, and group AB was 41%; however, the mortality differences were not statistically significant.

Intracardiac thrombosis and pulmonary thromboembolism during liver transplantation: A systematic review and meta-analysis.

Intracardiac thrombosis and/or pulmonary thromboembolism (ICT/PE) is a rare but devastating complication during liver transplantation. Its pathophysiology remains poorly understood, and successful treatment remains a challenge. This systematic review summarizes the available published clinical data regarding ICT/PE during liver transplantation. Databases were searched for all publications reporting on ICT/PE during liver transplantation. Data collected included its incidence, patient characteristics, the timing of diagnosis, treatment strategies, and patient outcomes. This review included 59 full-text citations. The point prevalence of ICT/PE was 1.42%. Thrombi were most often diagnosed during the neohepatic phase, particularly at allograft reperfusion. Intravenous heparin was effective in preventing early-stage thrombus from progressing further and restoring hemodynamics in 76.32% of patients it was utilized for; however, the addition of tissue plasminogen activator or sole use of tissue plasminogen activator offered diminishing returns. Despite all resuscitation efforts, the in-hospital mortality rate of an intraoperative ICT/PE was 40.42%, with nearly half of these patients dying intraoperatively. The results of our systematic review are an initial step for providing clinicians with data that can help identify higher-risk patients. The clinical implications of our results warrant the development of identification and management strategies for the timely and effective treatment of these tragic occurrences during liver transplantation.

Trends in Cardiac Anesthesiologist Compensation, Work Patterns, and Training From 2010 to 2020: A Longitudinal Analysis of the Society of Cardiovascular Anesthesiologists Salary Survey.

Increasing cardiac procedural volume, a shortage of practicing cardiac anesthesiologists, and growth in specialist physician compensation would be expected to increase cardiac anesthesiologist compensation and work load. Additionally, more cardiac anesthesiologists are graduating from accredited fellowships and completing echocardiography certification. The Society of Cardiovascular Anesthesiologists (SCA) biannual salary survey longitudinally measures these data; we analyzed these data from 2010 to 2020 and hypothesized survey respondent inflation-adjusted total compensation, work load, and training would increase. For the primary outcome, we adjusted the median reported annual gross taxable income for inflation using the Consumer Price Index and then used linear regression to assess changes in inflation-adjusted median compensation. For the secondary outcomes, we analyzed the number of cardiac anesthetics managed annually and the most common care delivery staffing ratios. For the tertiary outcomes, we assessed changes in the proportion of respondents reporting transesophageal echocardiography (TEE) certification and completion of a 12-month cardiac anesthesia fellowship. We performed sensitivity analyses adjusting for yearly proportions of academic and private practice respondents. Annual survey response rates ranged from 8% to 17%. From 2010 to 2020, respondents reported a continuously compounded inflation-adjusted compensation decrease of 1.1% (95% confidence interval [CI], -1.6% to -0.6%; P = .003), equivalent to a total inflation-adjusted salary reduction of 10%. In sensitivity analysis, private practice respondents reported a continuously compounded compensation loss of -0.8% (95% CI, -1.4% to -0.2%; P = .022), while academic respondents reported no significant change (continuously compounded change, 0.4%; 95% CI, -0.4% to 1.1%; P = .23). The percentage of respondents managing more than 150 cardiac anesthetics per year increased from 26% in 2010 to 43% in 2020 (adjusted odds ratio [aOR], 1.03 per year; 95% CI, 1.03-1.04; P < .001). The proportion of respondents reporting high-ratio care models increased from 31% to 41% (aOR, 1.01 per year; 95% CI, 1.01-1.02; P < .001). Reported TEE certification increased from 69% to 90% (aOR, 1.10 per year; 95% CI, 1.10-1.11; P < .001); reported fellowship training increased from 63% to 82% (aOR, 1.15 per year; 95% CI, 1.14-1.16; P < .001). After adjusting for the proportion of academic or private practice survey respondents, SCA salary survey respondents reported decreasing inflation-adjusted compensation, rising volumes of cardiac anesthetics, and increasing levels of formal training in the 2010 to 2020 period. Future surveys measuring burnout and job satisfaction are needed to assess the association of increasing work and lower compensation with attrition in cardiac anesthesiologists.

Pulmonary artery pulsatility index as a predictor of right ventricular failure in left ventricular assist device recipients: A systematic review.

BACKGROUND: It is critical to identify patients at increased risk of right ventricular failure (RVF) before left ventricular assist device (LVAD) implantation. Pulmonary artery pulsatility index (PAPi) is a hemodynamic parameter that is a specific measure of right ventricular function and may better identify LVAD recipients at risk for RVF. This systematic review analyzes the predictive value of preoperative PAPi to RVF in the setting of LVAD implantation. METHODS: Databases were searched for all studies reporting on PAPi and RVF after LVAD implantation. Data collected included: number of patients, patient characteristics, incidences of RVF, PAPi, central venous pressure (CVP), CVP/pulmonary capillary wedge pressure, tricuspid annular plane systolic excursion, and right ventricular stroke work index. RESULTS: Thirty-two studies (4,756 patients) were included in this review. The incidence of RVF was found to be 27.48% (1,307 patients). The weighted mean (standard deviation) of preoperative PAPi associated with RVF vs No RVF was 2.17 (2.36) and 2.87 (3.21), respectively. When comparing LVAD recipients with RVF and No RVF, patients who developed RVF had a significantly lower preoperative PAPi by a WMD (95% CI) of -0.74 [-1.00, -0.49] (p < .001). The remaining variables (CVP; CVP/pulmonary capillary wedge pressure; tricuspid annular plane systolic excursion; and right ventricular stroke work index) were also confirmed as predictors of RVF after LVAD implantation. CONCLUSIONS: This systematic review demonstrates the utility of PAPi as a clinical predictor of RVF after LVAD implantation. Based on our findings, we recommend that PAPi be used in conjunction with traditional hemodynamic parameters when risk stratifying LVAD recipients for RVF.

The role of extracorporeal membrane oxygenation in COVID-19.

An extracorporeal membrane oxygenation (ECMO) program is an important component in the management of patients with COVID-19, but it is imperative to implement a system that is well-supported by the institution and staffed with well-trained clinicians to both optimize patient outcomes and to keep providers safe. There are many unknowns related to COVID-19, and one of the most challenging aspects for clinicians is the lack of predictive knowledge as to why some patients fail medical therapy and require advanced support such as ECMO. These factors can create challenges during a time of resource scarcity and interruptions in the supply chain. In the current environment, in which resources are limited and an ongoing pandemic, healthcare practitioners need to focus on evidence-based best practice for supportive care of patients with COVID-19 in refractory respiratory or cardiac failure. with As experience is gained, a greater understanding will develop in this cohort of patients regarding need and timing of ECMO. As this pandemic continues, it will be important to compile and analyze multicentered data pertaining to patient-specific outcomes to help guide clinicians caring for patients with COVID-19 undergoing ECMO support. In this paper, the authors demonstrate the strategies utilized by a major quaternary care center in the utilization and management of ECMO for patients with COVID-19.

Methylene blue for vasodilatory shock in the intensive care unit: a retrospective, observational study.

BACKGROUND: Refractory vasodilatory shock is a state of uncontrolled vasodilation associated with underlying inflammation and endothelial dysregulation. Rescue therapy for vasoplegia refractory to catecholamines includes methylene blue (MB) which restores vascular tone. We hypothesized that (1) at least 40% of critically ill patients would respond positively to MB administration and (2) that those who responded to MB would have a survival benefit. METHODS: This study was a retrospective review that included all adult patients admitted to an intensive care unit treated with MB for the indication of refractory vasodilatory shock. Responders to MB were identified as those with a ≥ 10% increase in mean arterial pressure (MAP) within the first 1-2 hours after administration. We examined the association of mortality to the groups of responders versus non-responders to MB. A subgroup analysis in patients undergoing continuous renal replacement therapy (CRRT) was also performed. Statistical calculations were performed in Microsoft Excel® (Redmond, WA, USA). Where appropriate, the comparison of averages and standard deviations of demographics, dosing, MAP, and reductions in vasopressor dosing were performed via Chi squared, Fisher's exact test, or two-tailed t-test with a p-value < 0.05 being considered as statistically significant. After using the F-test to assess for differences in variance, the proper two tailed t-test was used to compare SOFA scores among responders versus non-responders. RESULTS: A total of 223 patients were included in the responder analysis; 88 (39.5%) had a ≥ 10% increase in MAP post-MB administration that was not associated with a significant change in norepinephrine requirements between responders versus non-responders (p=0.41). There was a non-statistically significant trend (21.6% vs 14.8%, p=0.19) toward improved survival to hospital discharge in the MB responder group compared to the non-responder group. In 70 patients undergoing CRRT, there were 33 responders who were more likely to survive than those who were not (p = 0.0111). CONCLUSIONS: In patients with refractory shock receiving MB, there is a non-statistically significant trend toward improved outcomes in responders based on a MAP increase >10%. Patients supported with CRRT who were identified as responders had decreased ICU mortality compared to non-responders.

Mechanical Circulatory Support Options in Patients With Aortic Valve Pathology.

Mechanical circulatory support (MCS) is used in cardiogenic shock for periprocedural hemodynamic stability in high-risk patients and to support patients with symptomatic coronary artery disease. Depending on the MCS type, oxygenation and ventilation, in addition to increasing blood pressure by augmenting blood flow, can be achieved. MCS typically follows a failure of less invasive maneuvers or intolerance to them, such as significant ventricular arrhythmia burden from inotropic support. MCS options include intra-aortic balloon pump, transvalvular percutaneous left ventricular assist devices, venoarterial extracorporeal membrane oxygenation, and surgically implanted left ventricular assist devices. The number of MCS options has increased, and this has made the decision-making process complicated. MCS decision-making is complex, even in patients without valvular pathology. The presence of aortic valve (AV) abnormalities, such as aortic stenosis, aortic insufficiency, replaced AVs, or AV masses, adds even further to the challenge of selecting the appropriate support strategy. In this narrative review, a concise review of MCS options and the special considerations for various AV pathologies are presented.

One-Year Survival for Adult Venoarterial Extracorporeal Membrane Oxygenation Patients Requiring Renal-Replacement Therapy.

OBJECTIVES: Acute kidney injury (AKI) and chronic kidney disease (CKD) previously have been associated with in-hospital and long-term mortality of patients undergoing support with venoarterial extracorporeal membrane oxygenation (VA-ECMO). Patient selection criteria and survival prediction scores for VA-ECMO often include AKI or CKD, but exclude patients requiring renal replacement therapy (RRT). The need for RRT in ECMO patients is associated with increased intensive unit care and in-hospital mortality. The effect RRT has on mortality beyond hospital survival is not well-reported. The authors hypothesized that the timing of initiation (pre-ECMO v during ECMO) of RRT can have a significant impact on short- and long-term mortality. DESIGN: The authors categorized patients into 3 groups: those receiving RRT before initiation of ECMO, those initiated on RRT while on ECMO, and those who did not need RRT while on ECMO. The authors compared survival to decannulation, 30 days and 1 year between the 3 groups. A multivariate survival analysis also was conducted. SETTING: This was a single center retrospective review of all patients receiving VA-ECMO. PARTICIPANTS: A total of 347 adult VA-ECMO extracorporeal membrane oxygenation patients. INTERVENTIONS: None, retrospective. MEASUREMENTS AND MAIN RESULTS: The authors' cohort included 347 total patients, 39 required RRT before ECMO, 139 while on ECMO, and 169 did not require RRT while on ECMO. If RRT was initiated before ECMO, survival to decannulation was 48.72%, 46.6% if RRT was initiated on ECMO, and 73.96% for patients who did not need RRT while on ECMO. One-year survival was 25.64%, 23.74%, and 46.75%, respectively. There was no significant difference in survival between patients initiated on RRT before ECMO and those who required RRT while on ECMO. CONCLUSIONS: The authors demonstrated that the need for RRT before or while on ECMO has reduced short- and long-term survival when compared with those who did not need RRT while on ECMO. The authors believe that RRT is a marker for severe multiorgan failure and that, despite the benefits of RRT, high mortality will occur. This lack of mortality difference between patients previously on RRT and those newly requiring RRT may help clinicians in deciding to initiate ECMO for patients previously on RRT. Further investigation into complication rates between the groups is required.

Perioperative Implications of the 2020 American Heart Association Scientific Statement on Drug-Induced Arrhythmias-A Focused Review.

The recently released American Heart Association (AHA) scientific statement on drug-induced arrhythmias discussed medications commonly associated with bradycardia, supraventricular tachycardias, and ventricular arrhythmias. The foundational data for this statement were collected from general outpatient and inpatient populations. Patients undergoing surgical and minimally invasive treatments are a unique subgroup, because they may experience hemodynamic changes associated with anesthesia and their procedure, receive multiple drug combinations not given in either inpatient or outpatient settings, or experience postprocedural inflammatory syndromes. Accordingly, the generalizability of the AHA scientific statement to this perioperative population is unclear. This focused review highlights important aspects of the new AHA scientific statement and their application to the perioperative setting. The authors review medications frequently encountered and given by anesthesiologists and their risk of drug-induced arrhythmias and discuss common anesthetic and adjunctive medications and their associated risks of bradycardia, atrial fibrillation, torsades de pointes, and drug-induced Brugada syndrome. In many instances, the risk of arrhythmia reported by the AHA scientific statement in the general population appeared to be higher than found in perioperative arenas. Furthermore, the authors discuss the arrhythmia risk of additional medications commonly ordered or administered by anesthesiologists that are not included in the AHA scientific statement. As patient and procedural complexity increases and novel anesthetic combinations propagate, further research and observational studies will be required to delineate further perioperative risks for drug-induced arrhythmia.