Role of levosimendan in sepsis and septic shock

Perioperative Management of Patients with Sepsis and Septic Shock, Part II: Ultrasound Support for Resuscitation

Point-of-care ultrasound is capable of identifying the precise causes of hemodynamic failure in patients with septic shock. Patients in shock demonstrate complex alterations in their circulation, including changes in loading conditions (preload and afterload), right and left ventricular function, and development of obstructive physiology, and some of them have a burden of underlying cardiac disease. Knowledge of underlying hemodynamic derangements in such situations allows targeted interventions, that is, fluids, vasoactive, and inotropic medications, to optimize patient's perfusion. One example of competing goals involves a patient with hypertrophic "thick" left ventricle (LV), which is easily identified using point-of-care ultrasound (POCUS). Such patients usually have diastolic dysfunction and commonly require higher filling pressures (mainly grade II and III diastolic dysfunction) to maintain adequate cardiac output. They are vulnerable to the effects of hypovolemia with the potential for dynamic LV outflow tract (LVOT) obstruction. The use of inotrope is harmful under these circumstances and could lead to worsening of the obstructive physiology because of systolic anterior motion of the mitral valve leaflet and mitral regurgitation with rapid progression toward a cardiac arrest. Recognizing the increasingly important role of POCUS in the perioperative arena, in this review, we highlight how POCUS allows anesthesiologists to recognize and manage hemodynamic derangements in patients with sepsis and septic shock. We provide a systematic approach to the evaluation of this patient population using qualitative assessment of myocardial performance, fluid responsiveness, and fluid tolerance. Our approach is based on a limited number of ultrasound views: subcostal, inferior vena cava (IVC), and lung views are obtained in rapid succession. A combination of findings in these views is grouped into distinct hemodynamic phenotypes, each of them requiring their own approach to management.

Levosimendan and Global Longitudinal Strain Assessment in Sepsis (GLASSES 1): a study protocol for an observational study

INTRODUCTION

Cardiogenic shock is a condition of low cardiac output that represents the end stage of a progressive deterioration of cardiac function. The main cause is ischaemic heart disease, but there are several non-ischaemic causes, including sepsis. The use of levosimendan in cardiogenic shock during sepsis is still under debate.

METHODS

We are conducting an observational, single-centre, not-for-profit study enrolling patients aged 18-80 years old admitted to the intensive care unit with a diagnosis of septic shock. Patients will be monitored with the EV1000/VolumeView device (Edwards Lifesciences, Irvine, USA). Patients with cardiac index (CI) values <2.5 L/min/m² and/or stroke volume index (SVI) <30 mL/beat/m² are considered eligible for the study. Enrolled participants will undergo an echocardiographic examination using the Vivid S6 ultrasound machine (General Electric, Northville, Michigan) and a 3.6 MHz cardiology probe through which the apical projections of chambers 2, 3 and 4 will be acquired; this is necessary to calculate the global longitudinal strain (GLS) using EchoPAC* Clinical Workstation Software (General Electric). A dobutamine infusion will be started in these patients; 24 hours later CI and SVI will be recalculated using EV1000/VolumeView and then a levosimendan infusion will begin for 24 hours. Once the infusion cycle of the calcium-sensitising drug has been carried out, the infusion of dobutamine will be reduced until it stops, and the CI, SVI, GLS and arterial elastance (Ea):Ventricular Elastance (Ees) will be re-evaluated. The primary endpoint is recovery of GLS ≥15% and the secondary endpoint is a relative reduction in mortality of 15%.

ETHICS AND DISSEMINATION

The investigators declare that the study will be conducted in full compliance with international regulations (EU Directive 2016/679/EC) and national implementation (DM 15 July 1997; 211/2003; 200/2007) regarding the clinical trial and the principles of the Declaration of Helsinki. Study results will be disseminated through peer-reviewed journals and conferences. Ethical approval for this study has been given by Comitato Etico Regione Toscana - Area Vasta Centro, Florence, Italy (ethical committee number: 13875_oss) on 25 May 2019 (Chairperson Professor Marco Marchi).

TRIAL REGISTRATION NUMBER

NCT04141410.

Preclinical septic shock research: why we need an animal ICU

Animal experiments are widely used in preclinical medical research with the goal of disease modeling and exploration of novel therapeutic approaches. In the context of sepsis and septic shock, the translation into clinical practice has been disappointing. Classical animal models of septic shock usually involve one-sex-one-age animal models, mostly in mice or rats, contrasting with the heterogeneous population of septic shock patients. Many other factors limit the reliability of preclinical models and may contribute to preclinical research failure in critical care, including the host specificity of several pathogens, the fact that laboratory animals are raised in pathogen-free facilities and that organ support techniques are either absent or minimal. Advanced animal models have been developed with the aim of improving the clinical translatability of experimental findings. So-called animal ICUs refer to the preclinical investigation of adult or even aged animals of either sex, using—in case of rats and mice—miniaturized equipment allowing for reproducing an ICU environment at a small animal scale and integrating chronic comorbidities to more closely reflect the clinical conditions studied. Strength and limitations of preclinical animal models designed to decipher the mechanisms involved in septic cardiomyopathy are discussed. This article reviews the current status and the challenges of setting up an animal ICU.

[Vasopressors and inotropes: use in paediatrics]

The cardiovascular system is a dynamic system, which is required to ensure adequate delivery of oxygen, nutrients, and hormones to the tissues that are necessary for cell metabolism. It also synthesises and modifies the vasoactive components that regulate vascular tone and myocardial function. These vasoactive components have demonstrated their beneficial effects in the management of paediatric patients in a critical condition with heart failure and shock. However, their use and abuse brings harmful effects, increases mortality, and is associated with arrhythmias. An increase in myocardial oxygen consumption favours the presence of ischaemia, therefore it is necessary to know the mechanism of action and indications of these drugs to minimise their harmful effects. The purpose of this review is to describe the pharmacology and clinical applications of inotropic and vasopressor agents in the paediatric patient in acritical condition.

Levosimendan reduces mortality in patients with severe sepsis and septic shock: A meta-analysis of randomized trials

PURPOSE

There is controversy about the use of inotropes in the treatment of severe sepsis and septic shock. The objective of this study was to evaluate if levosimendan, as compared with standard inotropic therapy (eg, dobutamine), reduces mortality in septic patients.

MATERIALS AND METHODS

BioMedCentral, PubMed, EMBASE, and the Cochrane Central Register were searched for pertinent studies, up to 1st May 2015. Randomized trials on the use of levosimendan in patients with severe sepsis and septic shock were included if reporting mortality data. The primary outcome was mortality, whereas secondary outcomes were blood lactate, cardiac index, total fluid infused, norepinephrine dosage, and mean arterial pressure.

RESULTS

Seven studies for a total of 246 patients were included in the analysis. Levosimendan was associated with significantly reduced mortality compared with standard inotropic therapy (59/125 [47%] in the levosimendan group and 74/121 [61%] in the control group; risk difference = -0.14, risk ratio = 0.79 [0.63-0.98], P for effect = .03, I(2) = 0%, numbers needed to treat = 7). Blood lactate was significantly reduced in the levosimendan group, whereas cardiac index and total fluid infused were significantly higher in the levosimendan group. No difference in mean arterial pressure and norepinephrine usage was noted.

CONCLUSIONS

In patients with severe sepsis and septic shock, levosimendan is associated with a significant reduction in mortality compared with standard inotropic therapy. A large ongoing multicenter randomized trial will have to confirm these findings.

Inotropes and inodilators for acute heart failure: sarcomere active drugs in focus

Acute heart failure (AHF) emerges as a major and growing epidemiological concern with high morbidity and mortality rates. Current therapies in patients with acute heart failure rely on different strategies. Patients with hypotension, hypoperfusion, or shock require inotropic support, whereas diuretics and vasodilators are recommended in patients with systemic or pulmonary congestion. Traditionally inotropic agents, referred to as Ca²⁺ mobilizers load the cardiomyocyte with Ca²⁺ and thereby increase oxygen consumption and risk for arrhythmias. These limitations of traditional inotropes may be avoided by sarcomere targeted agents. Direct activation of the cardiac sarcomere may be achieved by either sensitizing the cardiac myofilaments to Ca²⁺ or activating directly the cardiac myosin. In this review, we focus on sarcomere targeted inotropic agents, emphasizing their mechanisms of action and overview the most relevant clinical considerations.

An efficacy and mechanism evaluation study of Levosimendan for the Prevention of Acute oRgan Dysfunction in Sepsis (LeoPARDS): protocol for a randomized controlled trial

BACKGROUND

Organ dysfunction consequent to infection ('severe sepsis') is the leading cause of admission to an intensive care unit (ICU). In both animal models and early clinical studies the calcium channel sensitizer levosimendan has been demonstrated to have potentially beneficial effects on organ function. The aims of the Levosimendan for the Prevention of Acute oRgan Dysfunction in Sepsis (LeoPARDS) trial are to identify whether a 24-hour infusion of levosimendan will improve organ dysfunction in adults who have septic shock and to establish the safety profile of levosimendan in this group of patients.

METHODS/DESIGN

This is a multicenter, randomized, double-blind, parallel group, placebo-controlled trial. Adults fulfilling the criteria for systemic inflammatory response syndrome due to infection, and requiring vasopressor therapy, will be eligible for inclusion in the trial. Within 24 hours of meeting these inclusion criteria, patients will be randomized in a 1:1 ratio stratified by the ICU to receive either levosimendan (0.05 to 0.2 μg.kg⁻¹.min⁻¹ or placebo for 24 hours in addition to standard care. The primary outcome measure is the mean Sequential Organ Failure Assessment (SOFA) score while in the ICU. Secondary outcomes include: central venous oxygen saturations and cardiac output; incidence and severity of renal failure using the Acute Kidney Injury Network criteria; duration of renal replacement therapy; serum bilirubin; time to liberation from mechanical ventilation; 28-day, hospital, 3 and 6 month survival; ICU and hospital length-of-stay; and days free from catecholamine therapy. Blood and urine samples will be collected on the day of inclusion, at 24 hours, and on days 4 and 6 post-inclusion for investigation of the mechanisms by which levosimendan might improve organ function. Eighty patients will have additional blood samples taken to measure levels of levosimendan and its active metabolites OR-1896 and OR-1855. A total of 516 patients will be recruited from approximately 25 ICUs in the United Kingdom.

DISCUSSION

This trial will test the efficacy of levosimendan to reduce acute organ dysfunction in adult patients who have septic shock and evaluate its biological mechanisms of action.

TRIAL REGISTRATION

Current controlled trials ISRCTN12776039 (19 September 2013).

Inotropic Support in the Treatment of Septic Myocardial Dysfunction: Pathophysiological Implications Supporting the Use of Levosimendan

Myocardial dysfunction is a frequent organ manifestation during septic shock and the subsequent impairment in cardiac output may result in organ hypoperfusion, requiring prompt and adequate treatment to restore cardiovascular function and reverse shock [1]. Current sepsis guidelines recommend resuscitation with intravascular fluid administration in association with inotropes and vasopressors to maintain organ perfusion [2]. Dobutamine is recommended as first-line inotropic agent and should be administered when low cardiac output or signs of hypoperfusion persist after adequate fluid resuscitation and perfusion pressure have been achieved [2]. However, the efficacy of dobutamine in patients with heart failure has not been fully demonstrated and concerns on its use are still present [3]. Although dobutamine improves perfusion and increases oxygen delivery (DO₂), its impact on survival in septic shock patients is limited, with guideline recommendations based mainly on the landmark study by Rivers et al. [4]. Recently, Wilkman et al. [5] reported that the use of inotropes, particularly dobutamine, in septic shock was associated with increased 90-day mortality. In explaining the lack of outcome benefit [3, 5], several aspects need to be taken into account. First, the need of inotropic support may simply represent an expression of disease severity rather than the cause of a poor outcome. Second, whereas the treatment of impaired cardiac output should be tailored based on the etiological mechanism of the cardiovascular dysfunction, the current guidelines recommend the use of inotropes without differentiating the underlying causes of impaired left ventricular (LV) stroke volume [2, 6]. In addition, the majority of cardiovascular monitoring instruments provide data almost exclusively on cardiac output and pressures. This approach may potentially increase the number of patients who may be harmed by inotrope administration (Fig. 1). Finally, the beneficial short-term effect of enhanced contractility by cAMP-increasing drugs (e. g., dobutamine, milrinone) is, at least partly, abolished by the increased energy consumption, the worsening of ventricular relaxation and the direct cardiomyocyte toxicity [1, 7–10].

Possible interventional therapies in severe sepsis or septic shock

For many years, basic research with relatively straightforward pathophysiologic approaches has driven clinical trials using molecules that supposedly interfere positively with inflammatory processes. However, most of these trials have failed to demonstrate any outcome benefit. Indeed, we need to revisit current paradigms and to think about the possibility that outcome may be predetermined in severe sepsis or septic shock. In addition, an early diagnosis of sepsis prior to the onset of clinical decline is also of particular interest to health practitioners because this information increases the possibilities for early and specific treatment of this life threatening condition. Indeed, the time to initiate therapy is thought to be crucial and the major determent factor in surviving sepsis. Despite substantial progress in sepsis therapy, the gap between the discovery of new effective medical molecules and their implementation in the daily clinical practice of the intensive care unit remains a major hurdle. Fortunately, ongoing research continues to provide new information on the management of sepsis, in particular, severe sepsis or septic shock. High quality and effective management tools are necessary to bring evidence-based therapy to the bedside. On this basis, new therapies could be tested to reduce mortality rates with respect to recently published studies.

Inotrope and vasopressor therapy of septic shock

The ultimate goals of hemodynamic therapy in shock are to restore effective tissue perfusion and to normalize cellular metabolism. In sepsis, both global and regional perfusion must be considered. In addition, mediators of sepsis can perturb cellular metabolism, leading to inadequate use of oxygen and other nutrients despite adequate perfusion; one would not expect organ dysfunction mediated by such abnormalities to be corrected by hemodynamic therapy. Despite the complex pathophysiology of sepsis, an underlying approach to its hemodynamic support can be formulated that is particularly pertinent with respect to vasoactive agents. Both arterial pressure and tissue perfusion must be taken into account when choosing therapeutic interventions and the efficacy of hemodynamic therapy should be assessed by monitoring a combination of clinical and hemodynamic parameters. It is relatively easy to raise blood pressure, but somewhat harder to raise cardiac output in septic patients. How to optimize regional blood and microcirculatory blood flow remains uncertain. Specific end points for therapy are debatable and are likely to evolve. Nonetheless, the idea that clinicians should define specific goals and end points, titrate therapies to those end points, and evaluate the results of their interventions on an ongoing basis remains a fundamental principle. The practice parameters were intended to emphasize the importance of such an approach so as to provide a foundation for the rational choice of vasoactive agents in the context of evolving monitoring techniques and therapeutic approaches.

Levosimendan in the Treatment of Acute Heart Failure, Cardiogenic and Septic Shock: A Critical Review

Levosimendan is a drug which increases the sensitivity of the heart to calcium and which opens potassium channels, resulting in inodilation. Clinical trial data from patients suffering from heart failure have demonstrated that it improves haemodynamics without increasing intra-cellular calcium or oxygen consumption. However, there is no consistent evidence of mortality reduction. This narrative review summarises the key trials of its use in acute heart failure, acute coronary syndrome, cardiogenic shock and septic shock.

Levosimendan for resuscitating the microcirculation in patients with septic shock: a randomized controlled study

INTRODUCTION

The purpose of the present study was to investigate microcirculatory blood flow in patients with septic shock treated with levosimendan as compared to an active comparator drug (i.e. dobutamine). The primary end point was a difference of ≥ 20% in the microvascular flow index of small vessels (MFIs) among groups.

METHODS

The study was designed as a prospective, randomized, double-blind clinical trial and performed in a multidisciplinary intensive care unit. After achieving normovolemia and a mean arterial pressure of at least 65 mmHg, 40 septic shock patients were randomized to receive either levosimendan 0.2 μg·kg(-1)·min(-1) (n = 20) or an active comparator (dobutamine 5 μg·kg(-1)·min(-1); control; n = 20) for 24 hours. Sublingual microcirculatory blood flow of small and medium vessels was assessed by sidestream dark-field imaging. Microcirculatory variables and data from right heart catheterization were obtained at baseline and 24 hours after randomization. Baseline and demographic data were compared by means of Mann-Whitney rank sum test or chi-square test, as appropriate. Microvascular and hemodynamic variables were analyzed using the Mann-Whitney rank sum test.

RESULTS

Microcirculatory flow indices of small and medium vessels increased over time and were significantly higher in the levosimendan group as compared to the control group (24 hrs: MFIm 3.0 (3.0; 3.0) vs. 2.9 (2.8; 3.0); P = .02; MFIs 2.9 (2.9; 3.0) vs. 2.7 (2.3; 2.8); P < .001). The relative increase of perfused vessel density vs. baseline was significantly higher in the levosimendan group than in the control group (dMFIm 10 (3; 23)% vs. 0 (-1; 9)%; P = .007; dMFIs 47 (26; 83)% vs. 10 (-3; 27); P < .001). In addition, the heterogeneity index decreased only in the levosimendan group (dHI -93 (-100; -84)% vs. 0 (-78; 57)%; P < .001). There was no statistically significant correlation between systemic and microcirculatory flow variables within each group (each P > .05).

CONCLUSIONS

Compared to a standard dose of 5 μg·kg(-1)·min(-1) of dobutamine, levosimendan at 0.2 μg·kg(-1)·min(-1) improved sublingual microcirculatory blood flow in patients with septic shock, as reflected by changes in microcirculatory flow indices of small and medium vessels.

TRIAL REGISTRATION

NCT00800306.

Levosimendan neither improves nor worsens mortality in patients with cardiogenic shock due to ST-elevation myocardial infarction

Background:

The aim of this study was to evaluate the effect of levosimendan on mortality in cardiogenic shock (CS) after ST elevation myocardial infarction (STEMI).

Methods and results:

Data were obtained prospectively from the SCAAR (Swedish Coronary Angiography and Angioplasty Register) and the RIKS-HIA (Register of Information and Knowledge about Swedish Heart Intensive Care Admissions) about 94 consecutive patients with CS due to STEMI. Patients were classified into levosimendan-mandatory and levosimendan-contraindicated cohorts. Inotropic support with levosimendan was mandatory in all patients between January 2004 and December 2005 (n = 46). After the SURVIVE and REVIVE II studies were presented, levosimendan was considered contraindicated and was not used in consecutive patients between December 2005 and December 2006 (n = 48). The cohorts were similar with respect to pre-treatment characteristics and concomitant medications. There was no difference in the incidence of new-onset atrial fibrillation, in-hospital cardiac arrest and length of stay at the coronary care unit. There was no difference in adjusted mortality at 30 days and at one year.

Conclusion:

The use of levosimendan neither improves nor worsens mortality in patients with CS due to STEMI. Well-designed randomized clinical trials are needed to define the role of inotropic therapy in the treatment of CS.

Inotrope and vasopressor therapy of septic shock

When fluid administration fails to restore an adequate arterial pressure and organ perfusion in patients with septic shock, therapy with vasoactive agents should be initiated. The ultimate goals of such therapy in shock are to restore effective tissue perfusion and to normalize cellular metabolism. The efficacy of hemodynamic therapy in sepsis should be assessed by monitoring a combination of clinical and hemodynamic parameters. Although specific end points for therapy are debatable, and therapies will inevitably evolve as new information becomes available, the idea that clinicians should define specific goals and end points, titrate therapies to those end points, and evaluate the results of their interventions on an ongoing basis remains a fundamental principle.

Sepsis and the heart

Septic shock, the most severe complication of sepsis, accounts for approximately 10% of all admissions to intensive care. Our understanding of its complex pathophysiology remains incomplete but clearly involves stimulation of the immune system with subsequent inflammation and microvascular dysfunction. Cardiovascular dysfunction is pronounced and characterized by elements of hypovolaemic, cytotoxic, and distributive shock. In addition, significant myocardial depression is commonly observed. This septic cardiomyopathy is characterized by biventricular impairment of intrinsic myocardial contractility, with a subsequent reduction in left ventricular (LV) ejection fraction and LV stroke work index. This review details the myocardial dysfunction observed in adult septic shock, and discusses the underlying pathophysiology. The utility of using the regulatory protein troponin for the detection of myocardial dysfunction is also considered. Finally, options for the management of sepsis-induced LV hypokinesia are discussed, including the use of levosimendan.

Microcirculation and mitochondria in sepsis: getting out of breath

PURPOSE OF REVIEW

To present the recent findings obtained in clinical and experimental studies examining microcirculatory alterations in sepsis, their link to mitochondrial dysfunction, and current knowledge regarding the impact of these alterations on the outcome of septic patients.

RECENT FINDINGS

Interlinked by a mutual cascade effect and driven by the host-pathogen interaction, microcirculatory and mitochondrial functions are impaired during sepsis. Mitochondrial respiration seems to evolve during the course of sepsis, demonstrating a change from reversible to irreversible inhibition. The spatiotemporal heterogeneity of microcirculatory and mitochondrial dysfunction suggests that these processes may be compartmentalized. Although a causal relationship between mitochondrial and microcirculatory dysfunction and organ failure in sepsis is supported by an increasing number of studies, adaptive processes have also emerged as part of microcirculatory and mitochondrial alterations. Treatments for improving or preserving microcirculatory, mitochondrial function, or both seem to yield a better outcome in patients.

SUMMARY

Even though there is evidence that microcirculatory and mitochondrial dysfunction plays a role in the development of sepsis-induced organ failure, their interaction and respective contribution to the disease remains poorly understood. Future research is necessary to better define such relationships in order to identify therapeutic targets and refine treatment strategies.