Venoarterial Extracorporeal Membranous Oxygenation: Treatment Option for Sepsis-Induced Cardiogenic Shock? A Systematic Review

New Insights into Hepatic and Intestinal Microcirculation and Pulmonary Inflammation in a Model of Septic Shock and Veno-Arterial Extracorporeal Membrane Oxygenation in the Rat

Despite significant efforts toward improving therapy for septic shock, mortality remains high. Applying veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) in this context remains controversial. Since the cannulation of the femoral artery for V-A ECMO return leads to lower body hyperoxia, this study investigated the impact of V-A ECMO therapy on the intestinal and hepatic microcirculation during septic shock in a rodent model. Thirty male Lewis rats were randomly assigned to receive V-A ECMO therapy with low (60 mL/kg/min) or high (90 mL/kg/min) blood flow or a sham procedure. Hemodynamic data were collected through a pressure-volume catheter in the left ventricle and a catheter in the lateral tail artery. Septic shock was induced by intravenous administration of lipopolysaccharide (1 mg/kg). The rats received lung-protective ventilation during V-A ECMO therapy. The hepatic and intestinal microcirculation was measured by micro-lightguide spectrophotometry after median laparotomy for two hours. Systemic and pulmonary inflammation was detected via enzyme-linked immunosorbent assays (ELISA) of the plasma and bronchoalveolar lavage (BAL), respectively, measuring tumor necrosis factor-alpha (TNF-α), interleukins 6 (IL-6) and 10 (IL-10), and C-X-C motif ligands 2 (CXCL2) and 5 (CXCL5). Oxygen saturation and relative hemoglobin concentration were reduced in the hepatic and intestinal microcirculation during V-A ECMO therapy, independent of the blood flow rate. Further, rats treated with V-A ECMO therapy also presented elevated systolic, diastolic, and mean arterial blood pressure and increased stroke volume, cardiac output, and left ventricular end-diastolic volume. However, left ventricular end-diastolic pressure was only elevated during high-flow V-A ECMO therapy. Blood gas analysis revealed a dilutional anemia during V-A ECMO therapy. ELISA analysis showed an elevated plasma CXCL2 concentration only during high-flow V-A ECMO therapy and elevated BAL CXCL2 and CXCL5 concentrations only during low-flow V-A ECMO therapy. Rats undergoing V-A ECMO therapy exhibited impaired microcirculation of the intestine and liver during septic shock despite increased blood pressure and cardiac output. Increased pulmonary inflammation was detected only during low-flow V-A ECMO therapy in septic shock.

INVASIVE HEMODYNAMIC MONITORING WITH PULMONARY ARTERY CATHETER IN SEPSIS-ASSOCIATED CARDIOGENIC SHOCK

ABSTRACT

Background: Both sepsis-induced cardiomyopathy and worsening of preexisting cardiac disease can contribute to circulatory shock in septic patients. The early use of pulmonary artery catheter (PAC) could play a pivotal role in the management of sepsis-associated cardiogenic shock. In this study, we aimed to evaluate the impact of early invasive hemodynamic monitoring with PAC in patients with sepsis-associated cardiogenic shock. Method: We performed a retrospective study using the National Inpatient Sample data from January 2017 to December 2019. The early use of PAC was defined as the use of PAC within 2 days from the admission. We performed the multivariable logistic regression analysis to investigate the association between the early use of PAC and in-hospital mortality in patients with sepsis-associated cardiogenic shock and sepsis without cardiogenic shock, respectively. Results: There was no difference in in-hospital mortality between PAC and no PAC groups in sepsis without cardiogenic shock (adjusted odds ratio [aOR] = 1.05, 95% confidence interval [CI] = 0.82-1.35, P = 691). On the other hand, the early use of PAC was independently associated with lower in-hospital mortality in patients with sepsis-associated cardiogenic shock (aOR = 0.58, 95% confidence interval [CI] = 0.46-0.72, P < 0.001). The use of PAC was also associated with increased use of mechanical circulatory support in those with sepsis-associated cardiogenic shock (aOR = 12.26, 95% CI = 9.37-16.03, P < 0.001). For patients with sepsis-associated cardiogenic shock, the use of PAC after 2 days of admission was associated with significantly higher in-hospital mortality and decreased use of mechanical circulatory support. Conclusion: The use of pulmonary artery catheters in sepsis-associated cardiogenic shock was associated with significantly lower in-hospital mortality and increased use of mechanical circulatory supports in patients with sepsis-associated cardiogenic shock.

Temporary Mechanical Circulatory Support in Sepsis-Associated Cardiogenic Shock With and Without Acute Myocardial Infarction

OBJECTIVES

To describe the current use and outcomes of temporary mechanical circulatory support (MCS) in patients with sepsis-associated cardiogenic shocks with and without acute myocardial infarction (AMI) in the United States.

DESIGN

Retrospective cohort study.

SETTING

The National Inpatient Sample database from 2017 to 2019.

PARTICIPANTS

Adult patients with sepsis-associated cardiogenic shock with and without AMI.

INTERVENTIONS

Temporary MCSs, including intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD), and extracorporeal membrane oxygenation (ECMO).

MEASUREMENTS AND MAIN RESULTS

Multivariate logistic regression analyses adjusting for patient characteristics, organ failures, and socioeconomic status. Although the uses of IABP and pLVAD were associated with significantly lower odds of in-hospital mortality in patients with sepsis-associated cardiogenic shock (IABP: adjusted odds ratio [aOR] 0.57, 95% CI 0.44-0.73, p < .001; pLVAD: aOR 0.66, 95% CI 0.45-0.98, p = .037), ECMO was not (aOR 1.51, 95% CI 0.93-2.45, p = 0.096). In the subgroup with AMI, temporary MCSs were not associated with significantly lower or higher odds of in-hospital mortality. In the subgroup without AMI, IABP was associated with significantly lower odds of in-hospital mortality (aOR 0.43, 95% CI 0.28-0.65, p < 0.001).

CONCLUSIONS

Although temporary MCS is deemed to be a feasible option in sepsis-associated cardiogenic shock, the selection of the right patients whose shock is driven mainly by cardiogenic shock rather than septic shock, as represented by low cardiac output and high systemic vascular resistance, plays a critical role in the feasibility of this approach in the absence of clinical trials.

Extracorporeal membrane oxygenation in adult patients with sepsis and septic shock: Why, how, when, and for whom

Sepsis and septic shock remain the leading causes of death in intensive care units. Some patients with sepsis fail to respond to routine treatment and rapidly progress to refractory respiratory and circulatory failure, necessitating extracorporeal membrane oxygenation (ECMO). However, the role of ECMO in adult patients with sepsis has not been fully established. According to existing studies, ECMO may be a viable salvage therapy in carefully selected adult patients with sepsis. The choice of venovenous, venoarterial, or hybrid ECMO modes is primarily determined by the patient's oxygenation and hemodynamics (distributive shock with preserved cardiac output, septic cardiomyopathy (left, right, or biventricular heart failure), or right ventricular failure caused by acute respiratory distress syndrome). Veno-venous ECMO can be used in patients with sepsis and severe acute respiratory distress syndrome when conventional mechanical ventilation fails, and early application of veno-arterial ECMO in patients with sepsis-induced refractory cardiogenic shock may be critical in improving their chances of survival. When ECMO is indicated, the choice of an appropriate mode and determination of the optimal timing of initiation and weaning are critical, particularly in an experienced ECMO center. Furthermore, some special issues, such as ECMO flow, anticoagulation, and antibiotic therapy, should be noted during the management of ECMO support.

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2

The right ventricle (RV) is intricately linked in the clinical presentation of critical illness; however, the basis of this is not well-understood and has not been studied as extensively as the left ventricle. There has been an increased awareness of the need to understand how the RV is affected in different critical illness states. In addition, the increased use of point-of-care echocardiography in the critical care setting has allowed for earlier identification and monitoring of the RV in a patient who is critically ill. The first part of this review describes and characterizes the RV in different perioperative states. This second part of the review discusses and analyzes the complex pathophysiologic relationships between the RV and different critical care states. There is a lack of a universal RV injury definition because it represents a range of abnormal RV biomechanics and phenotypes. The term "RV injury" (RVI) has been used to describe a spectrum of presentations, which includes diastolic dysfunction (early injury), when the RV retains the ability to compensate, to RV failure (late or advanced injury). Understanding the mechanisms leading to functional 'uncoupling' between the RV and the pulmonary circulation may enable perioperative physicians, intensivists, and researchers to identify clinical phenotypes of RVI. This, consequently, may provide the opportunity to test RV-centric hypotheses and potentially individualize therapies.

Chemotherapy-induced leukopenic septic shock treated with veno-arterial extracorporeal membrane oxygenation: A case report

We present a case of chemotherapy-induced leukopenic septic shock treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Although the indication for VA-ECMO for septic shock in immunosuppressed states remains controversial, her relatively young age and a slightly increasing leukocyte count led to VA-ECMO induction and resulted in recovery.