Effect of vasopressin on hemodynamics in patients with refractory cardiogenic shock complicating acute myocardial infarction

ICU management of cardiogenic shock before mechanical support

PURPOSE OF REVIEW

Treatment of cardiogenic shock remains largely driven by expert consensus due to limited evidence from randomized controlled trials. In this review, we aim to summarize the approach to the management of patients with cardiogenic shock in the ICU prior to mechanical circulatory support (MCS).

RECENT FINDINGS

Main topics covered in this article include diagnosis, monitoring, initial management and key aspects of pharmacological therapy in the ICU for patients with cardiogenic shock.

SUMMARY

Despite efforts to improve therapy, short-term mortality in patients with cardiogenic shock is still reaching 40-50%. Early recognition and treatment of cardiogenic shock are crucial, including early revascularization of the culprit lesion with possible staged revascularization in acute myocardial infarction (AMI)-CS. Optimal volume management and vasoactive drugs titrated to restore arterial pressure and perfusion are the cornerstone of cardiogenic shock therapy. The choice of vasoactive drugs depends on the underlying cause and phenotype of cardiogenic shock. Their use should be limited to the shortest duration and lowest possible dose. According to recent observational evidence, assessment of the complete hemodynamic profile with a pulmonary artery catheter (PAC) was associated with improved outcomes and should be considered early in patients not responding to initial therapy or with unclear shock. A multidisciplinary shock team should be involved early in order to identify potential candidates for temporary and/or durable MCS.

Medical therapy of cardiogenic shock: Contemporary use of inotropes and vasopressors

Cardiogenic shock is a primary cardiac disorder that results in both clinical and biochemical evidence of tissue hypoperfusion and can lead to multi-organ failure and death depending on its severity. Inadequate cardiac contractility or cardiac power secondary to acute myocardial infarction remains the most frequent cause of cardiogenic shock, although its contribution has declined over the past two decades, compared with other causes. Despite some advances in cardiogenic shock management, this clinical syndrome is still burdened by an extremely high mortality. Its management is based on immediate stabilization of haemodynamic parameters so that further treatment, including mechanical circulatory support and transfer to specialized tertiary care centres, can be accomplished. With these aims, medical therapy, consisting mainly of inotropic drugs and vasopressors, still has a major role. The purpose of this article is to review current evidence on the use of these medications in patients with cardiogenic shock and discuss specific clinical settings with indications to their use.

Advances in the Management of Cardiogenic Shock

OBJECTIVES

To review a contemporary approach to the management of patients with cardiogenic shock (CS).

DATA SOURCES

We reviewed salient medical literature regarding CS.

STUDY SELECTION

We included professional society scientific statements and clinical studies examining outcomes in patients with CS, with a focus on randomized clinical trials.

DATA EXTRACTION

We extracted salient study results and scientific statement recommendations regarding the management of CS.

DATA SYNTHESIS

Professional society recommendations were integrated with evaluated studies.

CONCLUSIONS

CS results in short-term mortality exceeding 30% despite standard therapy. While acute myocardial infarction (AMI) has been the focus of most CS research, heart failure-related CS now predominates at many centers. CS can present with a wide spectrum of shock severity, including patients who are normotensive despite ongoing hypoperfusion. The Society for Cardiovascular Angiography and Intervention Shock Classification categorizes patients with or at risk of CS according to shock severity, which predicts mortality. The CS population includes a heterogeneous mix of phenotypes defined by ventricular function, hemodynamic profile, biomarkers, and other clinical variables. Integrating the shock severity and CS phenotype with nonmodifiable risk factors for mortality can guide clinical decision-making and prognostication. Identifying and treating the cause of CS is crucial for success, including early culprit vessel revascularization for AMI. Vasopressors and inotropes titrated to restore arterial pressure and perfusion are the cornerstone of initial medical therapy for CS. Temporary mechanical circulatory support (MCS) is indicated for appropriately selected patients as a bridge to recovery, decision, durable MCS, or heart transplant. Randomized controlled trials have not demonstrated better survival with the routine use of temporary MCS in patients with CS. Accordingly, a multidisciplinary team-based approach should be used to tailor the type of hemodynamic support to each individual CS patient's needs based on shock severity, phenotype, and exit strategy.

State of Shock: Contemporary Vasopressor and Inotrope Use in Cardiogenic Shock

Cardiogenic shock is characterized by tissue hypoxia caused by circulatory failure arising from inadequate cardiac output. In addition to treating the pathologic process causing impaired cardiac function, prompt hemodynamic support is essential to reduce the risk of developing multiorgan dysfunction and to preserve cellular metabolism. Pharmacologic therapy with the use of vasopressors and inotropes is a key component of this treatment strategy, improving perfusion by increasing cardiac output, altering systemic vascular resistance, or both, while allowing time and hemodynamic stability to treat the underlying disease process implicated in the development of cardiogenic shock. Despite the use of mechanical circulatory support recently garnering significant interest, pharmacologic hemodynamic support remains a cornerstone of cardiogenic shock management, with over 90% of patients receiving at least 1 vasoactive agent. This review aims to describe the pharmacology and hemodynamic effects of current pharmacotherapies and provide a practical approach to their use, while highlighting important future research directions.

The medical treatment of cardiogenic shock

Cardiogenic shock (CS) is a leading cause of mortality worldwide. CS presentation and management in the current era have been widely depicted in epidemiological studies. Its treatment is codified and relies on medical care and extracorporeal life support (ECLS) in the bridge to recovery, chronic mechanical device therapy, or transplantation. Recent improvements have changed the landscape of CS. The present analysis aims to review current medical treatments of CS in light of recent literature, including addressing excitation-contraction coupling and specific physiology on applied hemodynamics. Inotropism, vasopressor use, and immunomodulation are discussed as pre-clinical and clinical studies have focused on new therapeutic options to improve patient outcomes. Certain underlying conditions of CS, such as hypertrophic or Takotsubo cardiomyopathy, warrant specifically tailored management that will be overviewed in this review.

Early Recognition and Risk Stratification in Cardiogenic Shock: Well Begun Is Half Done

Cardiogenic shock is a complex syndrome manifesting with distinct phenotypes depending on the severity of the primary cardiac insult and the underlying status. As long as therapeutic interventions fail to divert its unopposed rapid evolution, poor outcomes will continue challenging health care systems. Thus, early recognition in the emergency setting is a priority, in order to avoid delays in appropriate management and to ensure immediate initial stabilization. Since advanced therapeutic strategies and specialized shock centers may provide beneficial support, it seems that directing patients towards the recently described shock network may improve survival rates. A multidisciplinary approach strategy commands the interconnections between the strategic role of the ED in affiliation with cardiac shock centers. This review outlines critical features of early recognition and initial therapeutic management, as well as the utility of diagnostic tools and risk stratification models regarding the facilitation of patient trajectories through the shock network. Further, it proposes the implementation of precise criteria for shock team activation and the establishment of definite exclusion criteria for streaming the right patient to the right place at the right time.

Involvement of Vasopressin in Tissue Hypoperfusion during Cardiogenic Shock Complicating Acute Myocardial Infarction in Rats

Acute heart failure (AHF) due to acute myocardial infarction (AMI) is likely to involve cardiogenic shock (CS), with neuro-hormonal activation. A relationship between AHF, CS and vasopressin response is suspected. This study aimed to investigate the implication of vasopressin on hemodynamic parameters and tissue perfusion at the early phase of CS complicating AMI. Experiments were performed on male Wistar rats submitted or not to left coronary artery ligation (AMI and Sham). Six groups were studied Sham and AMI treated or not with either a vasopressin antagonist SR-49059 (Sham-SR, AMI-SR) or agonist terlipressin (Sham-TLP, AMI-TLP). Animals were sacrificed one day after surgery (D₁) and after hemodynamic parameters determination. Vascular responses to vasopressin were evaluated, ex vivo, on aorta. AHF was defined by a left ventricular ejection fraction below 40%. CS was defined by AHF plus tissue hypoperfusion evidenced by elevated serum lactate level or low mesenteric oxygen saturation (SmO₂) at D₁. Mortality rates were 40% in AMI, 0% in AMI-SR and 33% in AMI-TLP. Immediately after surgery, a sharp decrease in SmO₂ was observed in all groups. At D₁, SmO₂ recovered in Sham and in SR-treated animals while it remained low in AMI and further decreased in TLP-treated groups. The incidence of CS among AHF animals was 72% in AMI or AMI-TLP while it was reduced to 25% in AMI-SR. Plasma copeptin level was increased by AMI. Maximal contractile response to vasopressin was decreased in AMI (32%) as in TLP- and SR- treated groups regardless of ligation. Increased vasopressin secretion occurring in the early phase of AMI may be responsible of mesenteric hypoperfusion resulting in tissue hypoxia. Treatment with a vasopressin antagonist enhanced mesenteric perfusion and improve survival. This could be an interesting therapeutic strategy to prevent progression to cardiogenic shock.

Pharmacological treatment of cardiogenic shock - A state of the art review

Cardiogenic shock is a clinical syndrome of impaired tissue perfusion caused by primary cardiac dysfunction and inadequate cardiac output. It represents one of the most lethal clinical conditions in intensive care medicine with mortality >40%. Management of different clinical presentations of cardiogenic shock includes guidance of cardiac preload, afterload, heart rate and contractility by differential pharmacological modulation of volume, systemic and pulmonary vascular resistance and cardiac output besides reversing the triggering cause. Data from large registries and randomized controlled trials on optimal diagnostic guidance as well as choice of pharmacological agents has accrued significantly in recent years. This state-of-the-art review summarizes the basic concepts of cardiogenic shock, the diagnostic work-up and currently available evidence and guideline recommendations on pharmacological treatment of cardiogenic shock.

A Clinical Update on Vasoactive Medication in the Management of Cardiogenic Shock

This is a focused review looking at the pharmacological support in cardiogenic shock. There are a plethora of data evaluating vasopressors and inotropes in septic shock, but the data are limited for cardiogenic shock. This review article describes in detail the pathophysiology of cardiogenic shock, the mechanism of action of different vasopressors and inotropes emphasizing their indications and potential side effects. This review article incorporates the currently used specific risk-prediction models in cardiogenic shock as well as integrates data from many trials on the use of vasopressors and inotropes. Lastly, this review seeks to discuss the future direction for vasoactive medications in cardiogenic shock.

Beyond the bundle: Clinical controversies in the management of sepsis in emergency medicine patients

Sepsis is a condition characterized by life-threatening organ dysfunction caused by a dysregulated host response to infection. The emergency department (ED) serves as a crucial entry point for patients presenting with sepsis. Given the heterogeneous presentation and high mortality rate associated with sepsis and septic shock, several clinical controversies have emerged in the management of sepsis. These include the use of novel therapeutic agents like angiotensin II, hydrocortisone, ascorbic acid, thiamine ("HAT") therapy, and levosimendan, Additionally, controversies with current treatments in vasopressor dosing, and the use of and balanced or unbalanced crystalloid are crucial to consider. The purpose of this review is to discuss clinical controversies in the management of septic patients, including the use of novel medications and dosing strategies, to assist providers in appropriately determining what treatment strategy is best suited for patients.

Joint EAPCI/ACVC expert consensus document on percutaneous ventricular assist devices

There has been a significant increase in the use of short-term percutaneous ventricular assist devices (pVADs) as acute circulatory support in cardiogenic shock and to provide haemodynamic support during interventional procedures, including high-risk percutaneous coronary interventions. Although frequently considered together, pVADs differ in their haemodynamic effects, management, indications, insertion techniques, and monitoring requirements. This consensus document summarizes the views of an expert panel by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) and the Association for Acute Cardiovascular Care (ACVC) and appraises the value of short-term pVAD. It reviews the pathophysiological context and possible indications for pVAD in different clinical settings and provides guidance regarding the management of pVAD based on existing evidence and best current practice.

Vasoactive pharmacologic therapy in cardiogenic shock: a critical review

BACKGROUND

Cardiogenic shock (CS) is an acute complex condition leading to morbidity and mortality. Vasoactive medications, such as vasopressors and inotropes are considered the cornerstone of pharmacological treatment of CS to improve end-organ perfusion by increasing cardiac output (CO) and blood pressure (BP), thus preventing multiorgan failure.

OBJECTIVE

A critical review was conducted to analyze the currently available randomized studies of vasoactive agents in CS to determine the indications of each agent and to critically appraise the methodological quality of the studies.

METHODS

PubMed database search was conducted to identify randomized controlled trials (RCTs) on vasoactive therapy in CS. After study selection, the internal validity of the selected studies was critically appraised using the three-item Jadad scale.

RESULTS

Nine studies randomized 2388 patients with a mean age ranged between 62 and 69 years, were identified. Seven of studies investigated CS in the setting of acute myocardial infarction (AMI). The studies evaluated the comparisons of norepinephrine (NE) vs. dopamine, epinephrine vs. NE, levosimendan vs. dobutamine, enoximone or placebo, and nitric oxide synthase inhibitors (NOSi) vs. placebo. The mean Jadad score of the nine studies was 3.33, with only three studies of a score of 5.

CONCLUSIONS

The evidence from the studies of vasoactive agents in CS carries uncertainties. The methodological quality between the studies is variable due to the inherent difficulties to conduct a study in CS. Vasopressors and inotropes continue to have a fundamental role given the lack of pharmacological alternatives.

Joint EAPCI/ACVC expert consensus document on percutaneous ventricular assist devices

There has been a significant increase in the use of short-term percutaneous ventricular assist devices (pVADs) as acute circulatory support in cardiogenic shock and to provide haemodynamic support during interventional procedures, including high-risk percutaneous coronary interventions. Although frequently considered together, pVADs differ in their haemodynamic effects, management, indications, insertion techniques, and monitoring requirements. This consensus document summarizes the views of an expert panel by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) and the Association for Acute Cardiovascular Care (ACVC) and appraises the value of short-term pVAD. It reviews the pathophysiological context and possible indications for pVAD in different clinical settings and provides guidance regarding the management of pVAD based on existing evidence and best current practice.

Vasopressors and Inotropes as Predictors of Mortality in Acute Severe Cardiogenic Shock Treated With the Impella Device

BACKGROUND

Vasopressors and inotropes are the primary pharmacologic agents in the management of cardiogenic shock. Increased use of these agents in the setting of cardiogenic shock treated with the Impella is associated with increased mortality. This study evaluates the use of vasopressors and inotropes as predictors of mortality in patients treated with the Impella for acute cardiogenic shock.

METHODS

This retrospective study included 276 patients treated with the Impella 2.5, Impella CP, or Impella 5.0 from March 2011 to January 2020 at a single, tertiary referral center for acute cardiogenic shock.

RESULTS

All-cause in-hospital mortality was 44.6%. Mortality significantly increased with escalating use of vasopressors and inotropes, with the most significant increase in mortality from use of 2 agents to the use of 3 agents (8.1% vs 39.7%, p < 0.001). There was no difference in mortality whether dobutamine or milrinone was used (44.4% vs 35.7%, p = 0.41); there was increased mortality with use of multiple inotropes. Patients treated with only vasopressors had increased mortality compared to those treated with a combination of agents that included 1 inotrope.

CONCLUSIONS

The escalating need for vasopressors and inotropes and particular combinations of these agents are significant predictors of mortality that may help determine whether the Impella or higher level of support is more appropriate to treat acute cardiogenic shock.

Time-sensitive approach in the management of acute heart failure

Acute heart failure (AHF) has become a global public health burden largely because of the associated high morbidity, mortality, and cost. The treatment options for AHF have remained relatively unchanged over the past decades. Historically, clinical congestion alone has been considered the main target for treatment of acute decompensation in patients with AHF; however, this is an oversimplification of the complex pathophysiology. Within the similar clinical presentation of congestion, significant differences in pathophysiological mechanisms exist between the fluid accumulation and redistribution. Tissue hypoperfusion is another vital characteristic of AHF and should be promptly treated with appropriate interventions. In addition, recent clinical trials of novel therapeutic strategies have shown that heart failure management is ‘time sensitive’ and suggested that treatment selection based on individual aetiologies, triggers, and risk factor profiles could lead to better outcomes. In this review, we aim to describe the specifics of the ‘time‐sensitive’ approach by the clinical phenotypes, for example, pulmonary/systemic congestion and tissue hypoperfusion, wherein patients are classified based on pathophysiological conditions. This mechanistic classification, in parallel with the comprehensive risk assessment, has become a cornerstone in the management of patients with AHF and thus supports effective decision making by clinicians. We will also highlight how therapeutic modalities should be individualized according to each clinical phenotype.

Acute myocardial infarction and cardiogenic shock: Should we unload the ventricle before percutaneous coronary intervention?

Despite early reperfusion and coordinated systems of care, cardiogenic shock (CS) remains the number one cause of morbidity and in-hospital mortality following acute myocardial infarction (AMI). CS is a complex clinical syndrome that begins with hemodynamic instability and can progress to multi-organ failure and profound hemo-metabolic compromise. To improve outcomes, a clear understanding of the treatment objectives in CS and developing time-sensitive management strategies aimed at stabilizing hemodynamics and restoring myocardial perfusion are critical. Left ventricular (LV) load has been identified as an independent predictor of heart failure and mortality following AMI. Decades of preclinical and clinical research have identified several effective LV unloading strategies. Recent initiatives from single and multi-center registries and more recently the Door to Unload (DTU)-STEMI pilot study have provided valuable insight to developing a standardized treatment approach to AMI, based on early invasive hemodynamics and tailored circulatory support to unload the LV. To follow is a review of the pathophysiology and prevalence of shock, limitations of current therapies, and the pre-clinical and translational basis for incorporating LV unloading into contemporary AMI and shock care.

Vasopressor and Inotrope Therapy in Cardiac Critical Care

Patients admitted to the cardiac intensive care unit (CICU) are often in shock and require hemodynamic support. Identifying and addressing the pathophysiology mechanisms operating in an individual patient is crucial to achieving a successful outcome, while initiating circulatory support therapy to restore adequate tissue perfusion. Vasopressors and inotropes are the cornerstone of supportive medical therapy for shock, in addition to fluid resuscitation when indicated. Timely initiation of optimal vasopressor and inotrope therapy is essential for patients with shock, with the ultimate goals of restoring effective tissue perfusion in order to normalize cellular metabolism. Use of vasoactive agents for hemodynamic support of patients with shock should take both arterial pressure and tissue perfusion into account when choosing therapeutic interventions. For most patients with shock, including cardiogenic or septic shock, norepinephrine (NE) is an appropriate choice as a first-line vasopressor titrated to achieve an adequate arterial pressure due to a lower risk of adverse events than other catecholamine vasopressors. If tissue and organ perfusion remain inadequate, an inotrope such as dobutamine may be added to increase cardiac output to a sufficient level that meets tissue demand. Low doses of epinephrine or dopamine may be used for inotropic support, but high doses of these drugs carry an excessive risk of adverse events when used for vasopressor support and should be avoided. When NE alone is inadequate to achieve an adequate arterial pressure, addition of a noncatecholamine vasopressor such as vasopressin or angiotensin-II is reasonable, in addition to rescue therapies that may improve vasopressor responsiveness. In this review, we discuss the pharmacology and evidence-based use of vasopressor and inotrope drugs in critically ill patients, with a focus on the CICU population.

Inotropes and vasopressors use in cardiogenic shock: when, which and how much?

PURPOSE OF REVIEW

Data and interventional trials regarding vasopressor and inotrope use during cardiogenic shock are scarce. Their use is limited by their side-effects and the lack of solid evidence regarding their effectiveness in improving outcomes. In this article, we review the current use of vasopressor and inotrope agents during cardiogenic shock.

RECENT FINDINGS

Two recent Cochrane analyses concluded that there was not sufficient evidence to prove that any one vasopressor or inotrope was superior to another in terms of mortality. A recent RCT and a meta-analysis on individual data suggested that norepinephrine may be preferred over epinephrine in patients with cardiogenic shock . For inotrope agents, when norepinephrine fails to restore perfusion, dobutamine represents the first-line agent. Levosimendan is a calcium sensitizer agent, which improves acute hemodynamics, albeit with uncertain effects on mortality.

SUMMARY

When blood pressure needs to be restored, norepinephrine is a reasonable first-line agent. Dobutamine is the first-line inotrope agent wheraes levosimendan can be used as a second-line agent or preferentially in patients previously treated with beta-blockers. Current information regarding comparative effective outcomes is nonetheless sparse and their use should be limited as a temporary bridge to recovery, mechanical circulatory support or heart transplantation.

Nonischemic Causes of Cardiogenic Shock

Although cardiogenic shock is uncommon in the emergency department, it is associated with high mortality. Most cardiogenic shock is caused by ischemia, but nonischemic etiologies are essential to recognize. Clinicians should optimize preload, contractility, and afterload. Volume-responsive patients should be resuscitated in small aliquots, although some patients may require diuresis to improve cardiac output. Vasopressors are important to restore end-organ perfusion, and inotropes improve contractility. Intubation and positive pressure ventilation impact hemodynamics, which, depending on volume status, may be beneficial or deleterious. Knowing indications for mechanical circulatory support is important for timely consultation or transfer as indicated.

Management of cardiogenic shock complicating acute myocardial infarction: A review

Despite advances in percutaneous coronary interventions and their widespread use, mortality in patients presenting with acute myocardial infarction (MI) complicated by cardiogenic shock (CS) has remained very high, and treatment options are limited. Limited evidences exist, supporting many of the routinely used therapies in treating these patients. In the present article, we discuss CS complicating MI in general and an update on the currently available treatment options, including inotropes and vasopressor, coronary revascularization, mechanical circulatory support devices, mechanical complications, and long‐term outcomes.

Predictors of Vasopressin Responsiveness in Critically Ill Adults

BACKGROUND

Vasopressin is commonly used as an adjunct vasopressor in shock. However, response to vasopressin varies among critically ill patients.

OBJECTIVE

To identify patient-specific factors that are associated with vasopressin responsiveness in critically ill adults.

METHODS

This retrospective, multicenter study included adult patients who were admitted to an intensive care unit (ICU) and received vasopressin for shock. Patients were excluded if they received vasopressin for less than 30 minutes, if vasopressin was initiated prior to ICU arrival, or if an additional vasopressor was initiated within 30 minutes of starting vasopressin. Responsiveness was defined as an increase in mean arterial pressure of ≥10 mm Hg or the ability to taper a concurrent catecholamine vasopressor. Patient-specific factors evaluated in a multivariate analysis included age, gender, ethnicity, body mass index, type of shock, serum pH, Sequential Organ Failure Assessment (SOFA) score, and use of stress-dose steroids. These variables were also evaluated in a subgroup analysis of patients with septic shock.

RESULTS

Of 1619 patients screened, 400 patients were included, with 231 identified as vasopressin responsive and 169 as nonresponsive. Vasopressin used as an adjunct vasopressor, as opposed to first line, during shock was the only variable associated with vasopressin responsiveness (odds ratio [OR] = 1.71; 95% CI = 1.10 to 2.65). Among the subgroup of patients with septic shock, female patients had a higher odds of responding than male patients (OR = 2.10; 95% CI = 1.12 to 3.95).

CONCLUSIONS

Vasopressin initiated as an adjunct vasopressor, as opposed to first-line therapy, was associated with response.

Effect of Early Initiation of Mechanical Circulatory Support on Survival in Cardiogenic Shock

The role and timing of percutaneous mechanical circulatory support (MCS) devices in the treatment of acute myocardial infarction complicated by cardiogenic shock (AMICS) are not well understood. We sought to evaluate patient characteristics and predictors of outcomes in patients presenting with AMICS supported with an axial flow percutaneous MCS device; 287 consecutive unselected patients enrolled in the catheter-based ventricular assist device registry presenting with AMICS who underwent percutaneous coronary intervention (PCI) were included in this analysis. All patients were supported with either the Impella 2.5 or Impella CP. Mean patient age was 66 ± 12.5 years, 76% were men, and mean left ventricular ejection fraction was 25 ± 12%. Before receiving MCS, 80% of patients required inotropes or vasopressors and 40% were supported with intra-aortic balloon pump; 9% of patients were under active cardiopulmonary resuscitation at the time of MCS implantation. Survival to discharge was 44%. In a multivariate analysis, early implantation of a MCS device before PCI (p = 0.04) and before requiring inotropes and vasopressors (p = 0.05) was associated with increased survival. Survival was 66% when MCS was initiated <1.25 hours from shock onset, 37% when initiated within 1.25 to 4.25 hours, and 26% when initiated after 4.25 hours (p = 0.017). Survival was 68%, 46%, 35%, 35%, and 26% for patients requiring 0, 1, 2, 3, and ≥4 inotropes before MCS support, respectively (p <0.001). In conclusion, MCS implantation early after shock onset, before initiation of inotropes or vasopressors and before PCI, is independently associated with improved survival in patients presenting with AMICS.

Thromboembolic Events During Continuous Vasopressin Infusions: A Retrospective Evaluation

Background:

Published guidelines suggest that vasopressin has a role in shock treatment, although its safety has not been adequately evaluated in a clinical setting. Vasopressin causes platelet aggregation and has been associated with the release of factor VIII coagulant and von Willebrand factor.

Objective:

To compare the incidence of venous thromboembolism (VTE) in patients with a diagnosis of shock who received vasopressin with those who did not receive vasopressin for hemodynamic support.

Methods:

A retrospective, single-center, cohort study was conducted at an academic, tertiary care center with 350 patients with a diagnosis of shock. Patients from the intensive care unit were randomly selected and separated into 2 groups for comparison of those receiving only catecholamines with those receiving vasopressin with or without catecholamines for hypotension. Patients with diabetes insipidus or variceal hemorrhage and those with any documented history of VTE were excluded. The primary outcome, VTE occurrence, was defined as a positive Doppler ultrasound, spiral computed tomography, or documented diagnosis in the discharge records. Frequency and type of risk factors for VTE were compared between the 2 study arms. A risk factor modeling approach was performed, using logistic regression to identify potential confounders and effect modifiers in the relationship between vasopressin and VTE.

Results:

There were 175 patients in each arm of the study. The crude incidence of VTE was 7.4% and 8% in the vasopressin and catecholamine groups, respectively (p = 0.84). No significant difference in the incidence of deep venous thrombosis (vasopressin 5.1%, control 7.4%; p = 0.51) or pulmonary embolism (vasopressin 2.3%, control 0.6%; p = 0.37) was found between groups. After adjusting for covariates, there was no statistically significant difference in the incidence of VTE between the 2 arms (p = 0.72).

Conclusions:

This investigation provides initial evidence that vasopressin infusions do not increase the risk of VTE in patients with shock.

Pharmacologic agents for acute hemodynamic instability: recent advances in the management of perioperative shock- a systematic review

Despite the growing body of evidence evaluating the efficacy of vasoactive agents in the management of hemodynamic instability and circulatory shock, it appears no agent is superior. This is becoming increasingly accepted as current guidelines are moving away from detailed algorithms for the management of shock, and instead succinctly state that vasoactive agents should be individualized and guided by invasive hemodynamic monitoring. This extends to the perioperative period, where vasoactive agent selection and use may still be left to the discretion of the treating physician with a goal-directed approach, consisting of close hemodynamic monitoring and administration of the lowest effective dose to achieve the hemodynamic goals. Successful therapy depends on the ability to rapidly diagnose the etiology of circulatory shock and thoroughly understand its pathophysiology as well as the pharmacology of vasoactive agents. This review focuses on the physiology and resuscitation goals in perioperative shock, as well as the pharmacology and recent advances in vasoactive agent use in its management.

[Modern drug therapy in cardiovascular intensive care medicine]

Vasoactive drugs and inotropes are important in the hemodynamic management of patients with cardiogenic shock despite modest volume administration. Currently, the concept of cardiac relief is pursued in the treatment of acute heart failure. In this article we present the use of different drugs in the intensive care unit for acute heart failure and cardiogenic shock. In acute heart failure catecholamines are only used during the transition from heart failure to cardiogenic shock. Here, the therapeutic concept of ventricular unloading is more sought after. This can be achieved by the use of diuretics, nitrates, levosimendan (inodilatator), or in the future serelaxin. The hemodynamic management in cardiogenic shock occurs after moderate volume administration with dobutamine to increase inotropy. If no adequate perfusion pressures are achieved, norepinephrine can be administered as a vasopressor. If there is still no sufficient increase in cardiac output, the inodilatator levosimendan can be used. Levosimendan instead of phosphodiesterase inhibitors in this case is preferable. The maxim of hemodynamic management in cardiogenic shock is the transient use of inotropes and vasopressors in the lowest dose possible and only for as long as necessary. This means that one should continuously check whether the dose can be reduced. There are no mortality data demonstrating the utility of hemodynamic monitoring based on objective criteria—but it makes sense to use inotropes and vasopressors sparingly.

Use of Inotropic Agents in Treatment of Systolic Heart Failure

The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.). Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

Prolonged observation time reveals temporal fluctuations in the sublingual microcirculation in pigs given arginine vasopressin

Intravital videomicroscopy of sublingual microcirculation is used to monitor critically ill patients. Existing guidelines suggest averaging handheld video recordings of ∼20 s in duration from five areas. We assessed whether an extended observation time may provide additional information on the microcirculation. Pigs (n = 8) under general anesthesia were divided between two groups, one with manually held camera, in which microcirculation was assessed continuously for 1 min in five areas, and one with a fixed camera, in which the observation time was extended to 10 min in a single area. The microcirculation was challenged by infusing arginine vasopressin (AVP). In the fixed group, ischemic acute heart failure was induced by left coronary microembolization, and the AVP infusion was repeated. All recordings were divided into 20-s sequences, and the small-vessel microvascular flow index (MFI) was scored and averaged for each measurement point. When administering 0.003, 0.006, and 0.012 IU·kg(-1)·min(-1) of AVP, we observed that the small-vessel MFI in the fixed 10-min group was significantly reduced (2.03 ± 0.38, 0.98 ± 0.18, and 0.48 ± 0.11) compared with both the initial 20 s (2.77 ± 0.04, 2.06 ± 0.04, and 1.74 ± 0.06; P < 0.05) and the 1-min total (2.63 ± 0.09, 1.70 ± 0.07, and 1.33 ± 0.16; P < 0.05) in the handheld group. In acute heart failure, the cardiac output decreased to half of the preischemic values. Interestingly, the small-vessel MFI was more affected by the administration of 0.001 and 0.003 IU·kg(-1)·min(-1) of AVP in acute heart failure (1.62 ± 0.60 and 1.16 ± 0.38) compared with preischemic values (2.86 ± 0.09 and 2.03 ± 0.38; P < 0.05). In conclusion, a prolonged recording time reveals temporal heterogeneity that may impact the assessment of microcirculatory function.

Conventional hemodynamic resuscitation may fail to optimize tissue perfusion: an observational study on the effects of dobutamine, enoximone, and norepinephrine in patients with acute myocardial infarction complicated by cardiogenic shock

AIM

To investigate the effects of inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock.

METHODS AND RESULTS

Thirty patients with cardiogenic shock were included. Patients received dobutamine, enoximone, or norepinephrine. We performed hemodynamic measurements at baseline and after titration of the inotropic agent until cardiac index (CI) ≥ 2.5 L.min-1.m(-2) or mixed-venous oxygen saturation (SvO2) ≥ 70% (dobutamine or enoximone), and mean arterial pressure (MAP) ≥ 70 mmHg (norepinephrine). As parameters of tissue perfusion, we measured central-peripheral temperature gradient (delta-T) and sublingual perfused capillary density (PCD). All patients reached predefined therapeutic targets. The inotropes did not significantly change delta-T. Dobutamine did not change PCD. Enoximone increased PCD (9.1 [8.9-10.2] vs. 11.4 [8.4-13.9] mm.mm(-2); p<0.05), and norepinephrine tended to decrease PCD (9.8 [8.5-11.9] vs. 8.8 [8.2-9.6] mm.mm-2, p = 0.08). Fifteen patients (50%) died within 30 days after admission. Patients who had low final PCD (≤ 10.3 mm.mm-2; 64%) were more likely to die than patients who had preserved PCD (>10.3 mm.mm(-2); mortality 72% vs. 17%, p = 0.003).

CONCLUSION

This study demonstrates the effects of commonly used inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock. Despite hemodynamic optimization, tissue perfusion was not sufficiently restored in most patients. In these patients, mortality was high. Interventions directed at improving microcirculation may eventually help bridging the gap between improved hemodynamics and dismal patient outcome in cardiogenic shock.

Inotropes

Inotropes have been fundamental to resuscitation of acute cardiogenic shock for decades. Heart failure and cardiogenic shock, in severe cases, are syndromes characterized in many patients by a reduction in myocardial contractile force. While inotropes successfully increase cardiac output, their use has been plagued by excessive mortality due to increased tachycardia and myocardial oxygen consumption leading to arrhythmia and myocardial ischemia. There is a pressing need for new inotropic agents that avoid these harmful effects. This review describes the mechanism of action and the clinical utility of some of the older inotropic agents, which are still commonly used, and provides an update for physicians on the development of newer inotropic drugs. The field is rapidly changing, and it is likely that new agents will be designed that improve systolic performance without necessarily increasing the myocardial oxygen consumption.

Hemorrhagic shock: The "physiology approach"

A shift of approach from ‘clinics trying to fit physiology’ to the one of ‘physiology to clinics’, with interpretation of the clinical phenomena from their physiological bases to the tip of the clinical iceberg, and a management exclusively based on modulation of physiology, is finally surging as the safest and most efficacious philosophy in hemorrhagic shock. ATLS^® classification and recommendations on hemorrhagic shock are not helpful because antiphysiological and potentially misleading. Hemorrhagic shock needs to be reclassified in the direction of usefulness and timing of intervention: in particular its assessment and management need to be tailored to physiology.

[Cardiogenic shock]

Cardiogenic shock is most commonly a complication of acute myocardial infarction. The ischemic loss of functional myocardium triggers distinct cardiovascular responses which can deteriorate to global pump failure with a mortality rate of more than 50%. Causes of cardiogenic shock beyond myocardial ischemia are very diverse. Decisive management with rapid evaluation, identification of the underlying disease and urgent initiation of supportive measures as well as definitive therapy is of prognostic value. Causal treatment of the cardiac disease is crucial but has to be weighed against the specific surgical circumstances of perioperative patients, particularly concerning anticoagulation, platelet inhibition and bleeding risks. Hemodynamic stabilization is achieved by pharmacological support of myocardial function, control of arrhythmia and volume load. Prevention and intensive care of shock-related multiorgan failure is of pivotal importance in the successful management of cardiogenic shock.

Vasoactive support in the optimization of post-cardiac arrest hemodynamic status: from pharmacology to clinical practice

As a critical component of post-resuscitation care, prompt optimization of hemodynamic status by means of targeted interventions is vital in order to maximize the likelihood of good outcome. Vasoactive agents play an essential role in the supportive care of post cardiac arrest patients. The administration of these agents is associated with serious side-effects and therefore they should be used in the minimal dose necessary to achieve low-normal mean arterial pressure and adequate systematic perfusion. Careful and frequent serial evaluation of the patient is important primarily to assess volume status and adequacy of circulatory support. Continuous monitoring of blood pressure and laboratory parameters is essential both to accurately titrate therapy and because inotropes and vasopressors have the potential to induce life-threatening side-effects. The clinical efficacy of inotropes and vasopressors has been largely investigated through examination of their impact on hemodynamic end points, and clinical practice has been driven in part by expert opinion, extrapolation from animal studies, and physician preference. Clearly these agents should all be considered as supportive measures to stabilize the patient prior to some form of definitive therapy.

Inotropes in cardiac patients: update 2011

PURPOSE OF REVIEW

ICU patients frequently develop low output syndromes due to cardiac dysfunction, myocardial injury, and inflammatory activation. Conventional inotropic agents seem to be useful in restoring hemodynamic parameters and improving peripheral organ perfusion, but can increase short-term and long-term mortality in these patients. Novel inotropes may be promising in the management of ICU patients, having no serious adverse effects. This review summarizes all the current knowledge about the use of conventional and new inotropic agents in various clinical entities of critically ill patients.

RECENT FINDINGS

In recent European Society of Cardiology guidelines, inotropic agents are administered in patients with low output syndrome due to impaired cardiac contractility, and signs and symptoms of congestion. The most recommended inotropes in this condition are levosimendan and dobutamine (both class of recommendation: IIa, level of evidence: B). Recent data indicate that levosimendan may be useful in postmyocardial infarction cardiac dysfunction and septic shock through increasing coronary flow and attenuating inflammatory activation, respectively. Furthermore, calcium sensitizing by levosimendan can be effectively used for weaning of mechanical ventilation in postcardiac surgery patients and has also cardioprotective effect as expressed by the absence of troponin release in this patient population. Finally, new agents, such as istaroxime and cardiac myosin activators may be safe and improve central hemodynamics in experimental models of heart failure and heart failure patients in phase II clinical trials; however, large-scale randomized clinical trials are required.

SUMMARY

In an acute cardiac care setting, short-term use of inotropic agents is crucial for the restoration of arterial blood pressure and peripheral tissue perfusion, as well as weaning of cardiosurgery. New promising agents should be tested in randomized clinical trials.

Dobutamine-norepinephrine, but not vasopressin, restores the ventriculoarterial matching in experimental cardiogenic shock

We assessed the hemodynamic effects of guideline therapy in experimental cardiogenic shock and compared this treatment with a combination containing an alternative vasopressor (arginine vasopressin, AVP). Our hypothesis was that combined dobutamine-norepinephrine still is the superior inopressor therapy assessed by ventriculoarterial matching in both systole and diastole. Cardiogenic shock (CS) was induced by coronary microembolization in 16 pigs. Dobutamine (Dobu, 2ug/kg/min) alone and combined with either norepinephrine (NE, 100 ng/kg/min) or the pure vasopressor AVP (0.001 u/kg/min) were infused. In CS, Dobu increased cardiac output (CO) and central venous oxygen saturation (SVO₂) from 74 ± 3 mL/kg and 37 ± 2% to 103 ± 8 mL/kg and 49 ± 3%. Adding NE resulted in a further improvement of CO (125 ± 9 mL/kg) and SVO₂ (59 ± 4%) because of an increased heart rate and contractility with minimal change in systemic vascular resistance. Also, energy transfer from the ventricle to the arterial system was restored partly by Dobu and was normalized by supplementing NE. In contrast, supplemental AVP further worsened the shock state by decreasing CO (70 ± 6 mL/kg) and SVO₂ (45 ± 5%) compared with Dobu alone. Combined Dobu-NE has an efficient hemodynamic profile in CS. A pure afterload increasing substance used in acute ischemic CS aggravates the shock state by causing a ventriculoarterial mismatch despite its use in combination with an inotropic compound.

Vasopressin and ischaemic heart disease: more than coronary vasoconstriction?

During advanced vasodilatory shock, arginine vasopressin (AVP) is increasingly used to restore blood pressure and thus to reduce catecholamine requirements. The AVP-related rise in mean arterial pressure is due to systemic vasoconstriction, which, depending on the infusion rate, may also reduce coronary blood flow despite an increased coronary perfusion pressure. In a murine model of myocardial ischaemia, Indrambarya and colleagues now report that a 3-day infusion of AVP decreased the left ventricular ejection fraction, ultimately resulting in increased mortality, and thus compared unfavourably with a standard treatment using dobutamine. The AVP-related impairment myocardial dysfunction did not result from the increased left ventricular afterload but from a direct effect on cardiac contractility. Consequently, the authors conclude that the use of AVP should be cautioned in patients with underlying cardiac disease.

Low-dose vasopressin infusion results in increased mortality and cardiac dysfunction following ischemia-reperfusion injury in mice

Introduction

Arginine vasopressin is a vasoactive drug commonly used in distributive shock states including mixed shock with a cardiac component. However, the direct effect of arginine vasopressin on the function of the ischemia/reperfusion injured heart has not been clearly elucidated.

Methods

We measured left ventricular ejection fraction using trans-thoracic echocardiography in C57B6 mice, both in normal controls and following ischemia/reperfusion injury induced by a one hour ligation of the left anterior descending coronary artery. Mice were treated with one of normal saline, dobutamine (8.33 μg/kg/min), or arginine vasopressin (0.00057 Units/kg/min, equivalent to 0.04 Units/min in a 70 kg human) delivered by an intraperitoneal micro-osmotic pump. Arterial blood pressure was measured using a micromanometer catheter. In addition, mortality was recorded and cardiac tissues processed for RNA and protein.

Results

Baseline left ventricular ejection fraction was 65.6% (60 to 72). In normal control mice, there was no difference in left ventricular ejection fraction according to infusion group. Following ischemia/reperfusion injury, AVP treatment significantly reduced day 1 left ventricular ejection fraction 46.2% (34.4 to 52.0), both in comparison with baseline and day 1 saline treated controls 56.9% (42.4 to 60.2). There were no significant differences in preload (left ventricular end diastolic volume), afterload (blood pressure) or heart rate to account for the effect of AVP on left ventricular ejection fraction. The seven-day mortality rate was highest in the arginine vasopressin group. Following ischemia/reperfusion injury, we found no change in cardiac V1 Receptor expression but a 40% decrease in Oxytocin Receptor expression.

Conclusions

Arginine vasopressin infusion significantly depressed the myocardial function in an ischemia/reperfusion model and increased mortality in comparison with both saline and dobutamine treated animals. The use of vasopressin may be contraindicated in non-vasodilatory shock states associated with significant cardiac injury.