A comparison of epinephrine and norepinephrine in critically ill patients

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

Angiotensin II as a Vasopressor for Perioperative Hypotension in Solid Organ Transplant

During the perioperative period of transplantation, patients experience hypotension secondary to the side effects of anesthesia, surgical stress, inflammatory triggering, and intraoperative fluid shifts, among others causes. Vasopressor support, in this context, must reverse systemic hypotension, but ideally, the agents used should benefit allograft function and avoid the adverse events commonly seen after transplantation. Traditional therapies to reverse hypotension include catecholamine vasopressors (norepinephrine, epinephrine, dopamine, and phenylephrine), but their utility is limited when considering allograft complications and adverse events such as arrhythmias with agents with beta-adrenergic properties. Synthetic angiotensin II (AT2S-[Giapreza]) is a novel vasopressor indicated for distributive shock with a unique mechanism of action as an angiotensin receptor agonist restoring balance to an often-disrupted renin angiotensin aldosterone system. Additionally, AT2S provides a balanced afferent and efferent arteriole vasoconstriction at the level of the kidney and could avoid the arrhythmic complications of a beta-adrenergic agonist. While the data, to date, are limited, AT2S has demonstrated safety in case reports, pilot studies, and small series in the kidney, liver, heart, and lung transplant populations. There are physiologic and hemodynamic reasons why AT2S could be a more utilized agent in these populations, but further investigation is warranted.

A Clinical Review of Vasopressors in Emergency Medicine

BACKGROUND

Vasopressor medications raise blood pressure through vasoconstriction and are essential in reversing the hypotension seen in many critically ill patients. Previously, vasopressor administration was largely limited to continuous infusions through central venous access.

OBJECTIVES OF THE REVIEW

This review addresses the clinical use of vasopressors in various shock states, including practical considerations and innovations in vasopressor administration. The focus is on the clinical administration of vasopressors across a range of shock states, including hypovolemic, distributive, cardiogenic, and obstructive shock.

DISCUSSION

Criteria for starting vasopressors are not clearly defined, though early use may be beneficial. A number of physiologic factors affect the body's response to vasopressors, such as acidosis and adrenal insufficiency. Peripheral and push-dose administration of vasopressors are becoming more common. Distributive shock is characterized by inappropriate vasodilation and vasopressors play a crucial role in maintaining adequate blood pressure. The use of vasopressors is more controversial in hypovolemic shock, as the preferred treatment is correction of the volume deficit. Evidence for vasopressors is limited in cardiogenic shock. For obstructive shock, vasopressors can temporize a patient's blood pressure until definitive therapy can reverse the underlying cause.

CONCLUSION

Across the categories of shock states, norepinephrine has wide applicability and is a reasonable first-line agent for shock of uncertain etiology. Keeping a broad differential when hypotension is refractory to vasopressors may help to identify adjunctive treatments in physiologic states that impair vasopressor effectiveness. Peripheral administration of vasopressors is safe and facilitates early administration, which may help to improve outcomes in some shock states.

Acute Kidney Injury in Sepsis

Sepsis-associated kidney injury is common in critically ill patients and significantly increases morbidity and mortality rates. Several complex pathophysiological factors contribute to its presentation and perpetuation, including macrocirculatory and microcirculatory changes, mitochondrial dysfunction, and metabolic reprogramming. Recovery from acute kidney injury (AKI) relies on the evolution towards adaptive mechanisms such as endothelial repair and tubular cell regeneration, while maladaptive repair increases the risk of progression to chronic kidney disease. Fundamental management strategies include early sepsis recognition and prompt treatment, through the administration of adequate antimicrobial agents, fluid resuscitation, and vasoactive agents as needed. In septic patients, organ-specific support is often required, particularly renal replacement therapy (RRT) in the setting of severe AKI, although ongoing debates persist regarding the ideal timing of initiation and dosing of RRT. A comprehensive approach integrating early recognition, targeted interventions, and close monitoring is essential to mitigate the burden of SA-AKI and improve patient outcomes in critical care settings.

Limb Necrosis in the Setting of Vasopressor Use

BACKGROUND

It remains poorly understood why only some hemodynamically unstable patients who receive aggressive treatment with vasopressor medications develop limb necrosis.

OBJECTIVE

To determine the incidence of limb necrosis and the factors associated with it following high-dose vasopressor therapy.

METHODS

A retrospective case-control medical records review was performed of patients aged 18 to 89 years who received vasopressor therapy between 2012 and 2021 in a single academic medical center. The study population was stratified by the development of limb necrosis following vasopressor use. Patients who experienced necrosis were compared with age- and sex-matched controls who did not experience necrosis. Demographic information, comorbidities, and medication details were recorded.

RESULTS

The incidence of limb necrosis following vasopressor administration was 0.25%. Neither baseline demographics nor medical comorbidities differed significantly between groups. Necrosis was present in the same limb as the arterial catheter most often for femoral catheters. The vasopressor dose administered was significantly higher in the necrosis group than in the control group for ephedrine (P = .02) but not for the other agents. The duration of therapy was significantly longer in the necrosis group than in the control group for norepinephrine (P = .001), epinephrine (P = .04), and ephedrine (P = .01). The duration of vasopressin administration did not differ significantly between groups.

CONCLUSION

The findings of this study suggest that medication-specific factors, rather than patient and disease characteristics, should guide clinical management of necrosis in the setting of vasopressor administration.

Early post-resuscitation outcomes in patients receiving norepinephrine versus epinephrine for post-resuscitation shock in a non-trauma emergency department: A parallel-group, open-label, feasibility randomized controlled trial

Background

Post-resuscitation shock is the main cause of early death in post-cardiac arrest patients. To date, no randomized trial compares the efficacy between norepinephrine and epinephrine in post-resuscitation shock patients.

Objectives

This study aimed to assess the feasibility of the study protocol, and explore potential differences in efficacy and adverse events between norepinephrine and epinephrine in post-resuscitation shock patients.

Methods

This single-center, parallel-group, open-label, feasibility randomized controlled trial included adult non-traumatic cardiac arrest patients who had post-resuscitation shock within one hour after successful resuscitation. Patients were randomized to receive norepinephrine or epinephrine in a 1:1 ratio. Feasibility outcomes were reported descriptively and narratively. Exploratory analyses were performed to compare the efficacy and adverse events.

Results

A total of 40 patients were equally allocated. Most feasibility goals were achieved. All patients received the allocated intervention with no withdrawals. Ten (50%) patients in the norepinephrine group and 15 (75%) patients in the epinephrine group achieved the target blood pressure by the protocol with a median time of 42 and 39 min, respectively. However, the protocol deviated in 10 (25%) patients and the recruitment rate did not reach the acceptable threshold. The vasopressor dose to achieve the target blood pressure was significantly lower in the norepinephrine group. No significant differences in mortality rates and adverse outcomes were observed in the exploratory analyses.

Conclusion

It is feasible to conduct the definitive trial comparing early post-resuscitation outcomes in patients receiving NE versus EPI for post-resuscitation shock. Some protocol modifications are necessary.

Norepinephrine versus epinephrine for hemodynamic support in post-cardiac arrest shock: A systematic review

PURPOSE

The preferred vasopressor in post-cardiac arrest shock has not been established with robust clinical outcomes data. Our goal was to perform a systematic review and meta-analysis comparing rates of in-hospital mortality, refractory shock, and hemodynamic parameters in post-cardiac arrest patients who received either norepinephrine or epinephrine as primary vasopressor support.

METHODS

We conducted a search of PubMed, Cochrane Library, and CINAHL from 2000 to 2022. Included studies were prospective, retrospective, or published abstracts comparing norepinephrine and epinephrine in adults with post-cardiac arrest shock or with cardiogenic shock and extractable post-cardiac arrest data. The primary outcome of interest was in-hospital mortality. Other outcomes included incidence of arrhythmias or refractory shock.

RESULTS

The database search returned 2646 studies. Two studies involving 853 participants were included in the systematic review. The proposed meta-analysis was deferred due to low yield. Crude incidence of in-hospital mortality was numerically higher in the epinephrine group compared with norepinephrine in both studies, but only statistically significant in one. Risk of bias was moderate to severe for in-hospital mortality. Additional outcomes were reported differently between studies, minimizing direct comparison.

CONCLUSION

The vasopressor with the best mortality and hemodynamic outcomes in post-cardiac arrest shock remains unclear. Randomized studies are crucial to remedy this.

Angiotensin ii therapy in refractory septic shock: which patient can benefit most? A narrative review

Patients with septic shock who experience refractory hypotension despite adequate fluid resuscitation and high-dose noradrenaline have high mortality rates. To improve outcomes, evidence-based guidelines recommend starting a second vasopressor, such as vasopressin, if noradrenaline doses exceed 0.5 µg/kg/min. Recently, promising results have been observed in treating refractory hypotension with angiotensin II, which has been shown to increase mean arterial pressure and has been associated with improved outcomes. This narrative review aims to provide an overview of the pathophysiology of the renin-angiotensin system and the role of endogenous angiotensin II in vasodilatory shock with a focus on how angiotensin II treatment impacts clinical outcomes and on identifying the population that may benefit most from its use.

Surviving Sepsis Campaign Research Priorities 2023

OBJECTIVES

To identify research priorities in the management, epidemiology, outcome, and pathophysiology of sepsis and septic shock.

DESIGN

Shortly after publication of the most recent Surviving Sepsis Campaign Guidelines, the Surviving Sepsis Research Committee, a multiprofessional group of 16 international experts representing the European Society of Intensive Care Medicine and the Society of Critical Care Medicine, convened virtually and iteratively developed the article and recommendations, which represents an update from the 2018 Surviving Sepsis Campaign Research Priorities.

METHODS

Each task force member submitted five research questions on any sepsis-related subject. Committee members then independently ranked their top three priorities from the list generated. The highest rated clinical and basic science questions were developed into the current article.

RESULTS

A total of 81 questions were submitted. After merging similar questions, there were 34 clinical and ten basic science research questions submitted for voting. The five top clinical priorities were as follows: 1) what is the best strategy for screening and identification of patients with sepsis, and can predictive modeling assist in real-time recognition of sepsis? 2) what causes organ injury and dysfunction in sepsis, how should it be defined, and how can it be detected? 3) how should fluid resuscitation be individualized initially and beyond? 4) what is the best vasopressor approach for treating the different phases of septic shock? and 5) can a personalized/precision medicine approach identify optimal therapies to improve patient outcomes? The five top basic science priorities were as follows: 1) How can we improve animal models so that they more closely resemble sepsis in humans? 2) What outcome variables maximize correlations between human sepsis and animal models and are therefore most appropriate to use in both? 3) How does sepsis affect the brain, and how do sepsis-induced brain alterations contribute to organ dysfunction? How does sepsis affect interactions between neural, endocrine, and immune systems? 4) How does the microbiome affect sepsis pathobiology? 5) How do genetics and epigenetics influence the development of sepsis, the course of sepsis and the response to treatments for sepsis?

CONCLUSIONS

Knowledge advances in multiple clinical domains have been incorporated in progressive iterations of the Surviving Sepsis Campaign guidelines, allowing for evidence-based recommendations for short- and long-term management of sepsis. However, the strength of existing evidence is modest with significant knowledge gaps and mortality from sepsis remains high. The priorities identified represent a roadmap for research in sepsis and septic shock.

Resuscitation and Preparation of the Emergency General Surgery Patient

Traditionally, the workflow surrounding a general surgery patient allows for a period of evaluation and optimization of underlying medical issues to allow for risk modification; however, in the emergency, this optimization period is largely condensed because of its time-dependent nature. Because the lack of optimization can lead to complications, the ability to rapidly resuscitate the patient, proceed to procedural intervention to control the situation, and manage common medical comorbidities is paramount. This article provides an overview on these subjects.

THE EFFICACY AND SAFETY OF VASOPRESSORS FOR SEPTIC SHOCK PATIENTS: A SYSTEMIC REVIEW AND NETWORK META-ANALYSIS

ABSTRACT

Background: Septic shock is a distributive shock with decreased systemic vascular resistance and MAP. Septic shock contributes to the most common causes of death in the intensive care unit (ICU). Current guidelines recommend the use of norepinephrine as the first-line vasopressor, whereas adrenergic agonists and vasopressin analogs are also commonly used by physicians. To date, very few studies have synthetically compared the effects of multiple types of vasoactive medications. The aim of this study was to systemically evaluate the efficacy of vasoactive agents both individually and in combination to treat septic shock. Methods: The PubMed, MEDLINE, Embase, Web of Science, and Cochrane Central Register for Controlled Trials (CENTRAL) were searched up to May 12, 2022, to identify relevant randomized controlled trials. A network meta-analysis was performed to evaluate the effect of different types of vasopressors. The primary outcome was 28-day all-cause mortality. The secondary outcome was the ICU length of stay. Adverse events are defined as any undesirable outcomes, including myocardial infarction, cardiac arrhythmia, peripheral ischemia, or stroke and cerebrovascular events. Findings: Thirty-three randomized controlled trials comprising 4,966 patients and assessing 8 types of vasoactive treatments were included in the network meta-analysis. The surface under the cumulative ranking curve provided a ranking of vasoactive medications in terms of 28-day all-cause mortality from most effective to least effective: norepinephrine plus dobutamine, epinephrine, vasopressin, terlipressin, norepinephrine, norepinephrine plus vasopressin, dopamine, and dobutamine. Dopamine was associated with a significantly shorter ICU stay than norepinephrine, terlipressin, and vasopressin, whereas other vasoactive medications showed no definite difference in ICU length of stay. Regarding adverse events, norepinephrine was associated with the highest incidences of myocardial infarction and peripheral ischemia. Dopamine was associated with the highest incidence of cardiac arrhythmia. Epinephrine and terlipressin were associated with the highest incidences of myocardial infarction and peripheral ischemia. Interpretation: The results of this network meta-analysis suggest that norepinephrine plus dobutamine is associated with a lower risk of 28-day mortality in septic shock patients than other vasoactive medications, and the use of dopamine is associated with a higher risk of 28-day mortality due to septic shock than norepinephrine, terlipressin, and vasopressin.

Vasopressin in Sepsis and Other Shock States: State of the Art

This review of the use of vasopressin aims to be comprehensive and highly practical, based on the available scientific evidence and our extensive clinical experience with the drug. It summarizes controversies about vasopressin use in septic shock and other vasodilatory states. Vasopressin is a natural hormone with powerful vasoconstrictive effects and is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Septic shock is defined by the need for vasopressors to correct hypotension and lactic acidosis secondary to infection, with a high mortality rate. The Surviving Sepsis Campaign guidelines recommend vasopressin as a second-line vasopressor, added to norepinephrine. However, these guidelines do not address specific debates surrounding the use of vasopressin in real-world clinical practice.

Management of Sepsis and Septic Shock: What Have We Learned in the Last Two Decades?

Sepsis is a clinical syndrome encompassing physiologic and biological abnormalities caused by a dysregulated host response to infection. Sepsis progression into septic shock is associated with a dramatic increase in mortality, hence the importance of early identification and treatment. Over the last two decades, the definition of sepsis has evolved to improve early sepsis recognition and screening, standardize the terms used to describe sepsis and highlight its association with organ dysfunction and higher mortality. The early 2000s witnessed the birth of early goal-directed therapy (EGDT), which showed a dramatic reduction in mortality leading to its wide adoption, and the surviving sepsis campaign (SSC), which has been instrumental in developing and updating sepsis guidelines over the last 20 years. Outside of early fluid resuscitation and antibiotic therapy, sepsis management has transitioned to a less aggressive approach over the last few years, shying away from routine mixed venous oxygen saturation and central venous pressure monitoring and excessive fluids resuscitation, inotropes use, and red blood cell transfusions. Peripheral vasopressor use was deemed safe and is rising, and resuscitation with balanced crystalloids and a restrictive fluid strategy was explored. This review will address some of sepsis management's most important yet controversial components and summarize the available evidence from the last two decades.

Society for Maternal-Fetal Medicine Consult Series #67: Maternal sepsis

Maternal sepsis is a significant cause of maternal morbidity and mortality, and is a potentially preventable cause of maternal death. This Consult aims to summarize what is known about sepsis and provide guidance for the management of sepsis during pregnancy and the postpartum period. Most studies cited are from the nonpregnant population, but where available, pregnancy data are included. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend that clinicians consider the diagnosis of sepsis in pregnant or postpartum patients with otherwise unexplained end-organ damage in the presence of a suspected or confirmed infectious process, regardless of the presence of fever (GRADE 1C); (2) we recommend that sepsis and septic shock in pregnancy be considered medical emergencies and that treatment and resuscitation begin immediately (Best Practice); (3) we recommend that hospitals and health systems use a performance improvement program for sepsis in pregnancy with sepsis screening tools and metrics (GRADE 1B); (4) we recommend that institutions develop their own procedures and protocols for the detection of maternal sepsis, avoiding the use of a single screening tool alone (GRADE 1B); (5) we recommend obtaining tests to evaluate for infectious and noninfectious causes of life-threatening organ dysfunction in pregnant and postpartum patients with possible sepsis (Best Practice); (6) we recommend that an evaluation for infectious causes in pregnant or postpartum patients in whom sepsis is suspected or identified includes appropriate microbiologic cultures, including blood, before starting antimicrobial therapy, as long as there are no substantial delays in timely administration of antibiotics (Best Practice); (7) we recommend obtaining a serum lactate level in pregnant or postpartum patients in whom sepsis is suspected or identified (GRADE 1B); (8) in pregnant or postpartum patients with septic shock or a high likelihood of sepsis, we recommend administration of empiric broad-spectrum antimicrobial therapy, ideally within 1 hour of recognition (GRADE 1C); (9) after a diagnosis of sepsis in pregnancy is made, we recommend rapid identification or exclusion of an anatomic source of infection and emergency source control when indicated (Best Practice); (10) we recommend early intravenous administration (within the first 3 hours) of 1 to 2 L of balanced crystalloid solutions in sepsis complicated by hypotension or suspected organ hypoperfusion (GRADE 1C); (11) we recommend the use of a balanced crystalloid solution as a first-line fluid for resuscitation in pregnant and postpartum patients with sepsis or septic shock (GRADE 1B); (12) we recommend against the use of starches or gelatin for resuscitation in pregnant and postpartum patients with sepsis or septic shock (GRADE 1A); (13) we recommend ongoing, detailed evaluation of the patient's response to fluid resuscitation guided by dynamic measures of preload (GRADE 1B); (14) we recommend the use of norepinephrine as the first-line vasopressor during pregnancy and the postpartum period with septic shock (GRADE 1C); (15) we suggest using intravenous corticosteroids in pregnant or postpartum patients with septic shock who continue to require vasopressor therapy (GRADE 2B); (16) because of an increased risk of venous thromboembolism in sepsis and septic shock, we recommend the use of pharmacologic venous thromboembolism prophylaxis in pregnant and postpartum patients in septic shock (GRADE 1B); (17) we suggest initiating insulin therapy at a glucose level >180 mg/dL in critically ill pregnant patients with sepsis (GRADE 2C); (18) if a uterine source for sepsis is suspected or confirmed, we recommend prompt delivery or evacuation of uterine contents to achieve source control, regardless of gestational age (GRADE 1C); and (19) because of an increased risk of physical, cognitive, and emotional problems in survivors of sepsis and septic shock, we recommend ongoing comprehensive support for pregnant and postpartum sepsis survivors and their families (Best Practice).

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.

Comparison of metaraminol versus no metaraminol on time to resolution of shock in critically ill patients

OBJECTIVE

There is limited evidence to support metaraminol use in critically ill patients. Metaraminol is not included as a vasopressor choice in international guidelines for the management of shock. Nevertheless, metaraminol is used in rates up to 42% in this patient population. The objective of this study was to investigate the effectiveness of metaraminol for the treatment of critically ill patients with shock.

METHODS

A single-centre retrospective matched observational study was conducted in a 54-bed intensive care unit of a tertiary hospital. Patients aged 16 years or older who were admitted from 2017 to 2019 with shock were included. Patients treated with metaraminol and norepinephrine (MET-NOR) were compared with those treated with norepinephrine without metaraminol (NOR). The primary outcome was the time to resolution of shock defined as the time to cessation of vasopressors. The secondary outcome was vasopressor-free days until 28 days.

RESULTS

There were 286 patients included in this study, including 143 patients in each group. The median time to resolution of shock was 44 hours (IQR 28-66 hours) in the MET-NOR group compared with 27 hours (IQR 14-63 hours) in the NOR group (95% CI of median difference 7 to 19 hours; p<0.01). The Cox regression analysis for the time to resolution of shock showed no significant difference between groups (HR 1.24, 95% CI 0.96 to 1.60; p=0.10). However, the proportional hazards assumption was not met (p<0.01). The median number of vasopressor-free days until 28 days was 26 days (IQR 24-27 days) in the MET-NOR group compared with 27 days (IQR 25-27 days) in the NOR group (95% CI of median difference -0.8 to -0.1 day; p<0.01).

CONCLUSION

In critically ill patients, metaraminol may be associated with a longer time to resolution of shock compared with those who do not receive metaraminol.

Running from a Bear: How We Teach Vasopressors, Adrenoreceptors, and Shock

Vasopressors are widely used in the management of shock among critically ill patients. The physiology of vasopressors and adrenoreceptors and their effects on end organs therefore represent important, high-yield topics for learners in the critical care environment. In this report, we describe our approach to teaching this core concept using the stereotypical human physiologic response when running from a bear, in the context of the relevant supporting literature. We use escaping from a threatening predator as a lens to describe the end-organ effects of activating adrenoreceptors together with the effects of endogenous and exogenous catecholamines and vasopressors. After reviewing this foundational physiology, we transition to the clinical environment, reviewing the pathophysiology of various shock states. We then consolidate our teaching by integrating the physiology of adrenoreceptors with the pathophysiology of shock to understand the appropriateness of each therapy to various shock phenotypes. We emphasize to learners the importance of generating a hypothesis about a patient's physiology, testing that hypothesis with an intervention, and then revising the hypothesis as needed, a critical component in the management of critically ill patients.

Infection as an under-recognized precipitant of acute heart failure: prognostic and therapeutic implications

As the prevalence of heart failure (HF) continues to rise, prompt diagnosis and management of various medical conditions, which may lead to HF exacerbation and result in poor patient outcomes, are of paramount importance. Infection has been identified as a common, though under-recognized, precipitating factor of acute heart failure (AHF), which can cause rapid development or deterioration of HF signs and symptoms. Available evidence indicates that infection-related hospitalizations of patients with AHF are associated with higher mortality, protracted length of stay, and increased readmission rates. Understanding the intricate interaction of both clinical entities may provide further therapeutic strategies to prevent the occurrence of cardiac complications and improve prognosis of patients with AHF triggered by infection. The purpose of this review is to investigate the incidence of infection as a causative factor in AHF, explore its prognostic implications, elucidate the underlying pathophysiological mechanisms, and highlight the basic principles of the initial diagnostic and therapeutic interventions in the emergency department.

[Fluid and vasopressor therapy in sepsis]

Sepsis is one of the most common and lethal conditions in intensive care medicine. Besides adequate treatment of the infection, timely hemodynamic management is essential to treat tissue hypoperfusion due to sepsis. Adequate fluid resuscitation plays a central role, and this should be carried out with dynamic monitoring of the hemodynamic response. However, a positive fluid balance is associated with poor outcome. Vasopressor therapy is required in case of inadequate response to fluid resuscitation, with norepinephrine considered the first choice. With increasing norepinephrine dose, addition of hydrocortisone or vasopressin may contribute to maintaining the hemodynamic state, although the prognostic advantage of these drugs has not been demonstrated. While dobutamine may be considered in patients with septic cardiomyopathy, the evidence for inotropic therapy in sepsis is limited.

An updated "norepinephrine equivalent" score in intensive care as a marker of shock severity

Vasopressors and fluids are the cornerstones for the treatment of shock. The current international guidelines on shock recommend norepinephrine as the first-line vasopressor and vasopressin as the second-line vasopressor. In clinical practice, due to drug availability, local practice variations, special settings, and ongoing research, several alternative vasoconstrictors and adjuncts are used in the absence of precise equivalent doses. Norepinephrine equivalence (NEE) is frequently used in clinical trials to overcome this heterogeneity and describe vasopressor support in a standardized manner. NEE quantifies the total amount of vasopressors, considering the potency of each such agent, which typically includes catecholamines, derivatives, and vasopressin. Intensive care studies use NEE as an eligibility criterion and also an outcome measure. On the other hand, NEE has several pitfalls which clinicians should know, important the lack of conversion of novel vasopressors such as angiotensin II and also adjuncts such as methylene blue, including a lack of high-quality data to support the equation and validate its predictive performance in all types of critical care practice. This review describes the history of NEE and suggests an updated formula incorporating novel vasopressors and adjuncts.

Multimodal strategy to counteract vasodilation in septic shock

Early initiation of a multimodal treatment strategy in the management of vasopressors during septic shock has been advocated to reduce delays in restoring adequate organ perfusion and to mitigate side effects associated with the administration of high-dose catecholamines. We provide a review that summarises the pathophysiology of vasodilation, the physiologic response to the vascular response, and the different drugs used in this situation, focusing on the need to combine early different vasopressors. Fluid loading being insufficient for counteracting vasoplegia, norepinephrine is usually the first-line vasopressor used to restore hemodynamics. Norepinephrine sparing is discussed in further detail through the concomitant use of adrenergic, vasopressinergic, and renin-angiotensin systems and the optimisation of endothelial reactivity with methylene blue. A blueprint for the construction of new studies is outlined to address the question of vasopressor selection and timing in septic shock.

Therapeutic Dilemmas in Mixed Septic-Cardiogenic Shock

Sepsis is an increasing cause of decompensation in patients with chronic heart failure with reduced or preserved ejection fraction. Sepsis and decompensated heart failure results in a mixed septic-cardiogenic shock that poses several therapeutic dilemmas: Rapid fluid resuscitation is the cornerstone of sepsis management, while loop diuretics are the main stay of decompensated heart failure treatment. Whether inotropic therapy with dobutamine or inodilators improves microvascular alterations remains unsettled in sepsis. When to resume loop diuretic therapy in patients with sepsis and decompensated heart failure is unclear. In the absence of relevant guidelines, we review vasopressor therapy, the timing and volume of fluid resuscitation, and the need for inotropic therapy in patients who, with sepsis and decompensated heart failure, present with a mixed septic-cardiogenic shock.

Circulatory shock in adults in emergency department

Circulatory shock is a common condition that carries high morbidity and mortality. This review aims to update the critical steps in managing common types of shock in adult patients admitted to medical emergency and intensive care units. A literature review was performed by searching PubMed, EMBASE Ovid, and Cochrane Library, using the following search items: ("shock" OR "circulatory shock" OR "septic shock" OR "cardiogenic shock") AND ("management" OR "treatment" OR "resuscitation"). The review emphasizes prompt shock identification with tissue hypoperfusion, knowledge of the underlying pathophysiological mechanism, initial fluid resuscitation with balanced crystalloids, norepinephrine as the preferred vasopressor in septic and profound cardiogenic shock, and tailored intervention addressing specific etiologies. Point-of-care ultrasound may help evaluate an undifferentiated shock and determine fluid responsiveness. The approach to septic shock is improving; however, confirmatory studies are required for many existing (e.g., amount of initial fluids and steroids) and emerging (e.g., angiotensin II) therapies. Knowledge gaps and wide variations persist in managing cardiogenic shock that needs urgent addressing to improve outcomes.

Updates in the Management of Perioperative Vasoplegic Syndrome

Vasoplegic syndrome occurs relatively frequently in cardiac surgery, liver transplant, major noncardiac surgery, in post-return of spontaneous circulation situations, and in pateints with sepsis. It is paramount for the anesthesiologist to understand both the pathophysiology of vasoplegia and the different treatment strategies available for rescuing a patient from life-threatening hypotension.

Is there an association between 30-day mortality and adrenaline infusion rates in post-ROSC patients? A retrospective observational analysis

Introduction

Revised guidelines for the management of cardiac arrest have placed greater emphasis on early defibrillation and closed chest compressions; subsequently there has been a significant rise in the number of patients gaining a return of spontaneous circulation (ROSC). As a consequence, emergency medical services have realised the importance of therapies delivered during this phase of care. In some Trusts this includes the use of inotropic agents to augment the cardiovascular system and maintain adequate cerebral and coronary perfusion pressures to mitigate the effects of post-cardiac arrest syndrome. Currently, limited evidence exists with regards to the efficacy of such treatments in the pre-hospital phase.

Methods

Retrospective observational analysis of out-of-hospital cardiac arrest patients who received an adrenaline infusion by critical care paramedics. Infusion rates, time of call (ToC) to ROSC and 30-day mortality were compared.

Results

Over a 2-year period, 202 patients were recorded as having an adrenaline infusion commenced. Of these, 25 were excluded as they did not meet criteria or had incomplete data and 22 were excluded as the infusion was stopped at scene; 155 patients were admitted to hospital. There were no survivors in the non-shockable group and three survivors in the shockable group at 30 days. A rare events analysis found no relationship between infusion rate, ToC to ROSC and 30-day mortality (Wald chi2, 1.37).

Conclusion

Commencement of adrenaline infusions in post-ROSC was associated with significant 30-day mortality, especially in non-shockable rhythms. Further research is needed to elucidate whether this intervention has any benefit in the post-ROSC patient.

Methylene blue dosing strategies in critically ill adults with shock-A retrospective cohort study

Background

Shock increases mortality in the critically ill and the mainstay of therapy is the administration of vasopressor agents to achieve hemodynamic targets. In the past, studies have found that the NO-pathway antagonist methylene blue improves hemodynamics. However, the optimal dosing strategy remains elusive. Therefore, we investigated the hemodynamic and ICU outcome parameters of three different dosing strategies for methylene blue.

Methods

We performed a retrospective cohort study of patients in shock treated with methylene blue. Shock was defined as norepinephrine dose >0.1 μg/kg/min and serum lactate level >2 mmol/l at the start of methylene blue administration. Different demographic variables, ICU treatment, and outcome parameters were evaluated. To compare the differences in the administration of vasopressors or inotropes, the vasoactive inotropic score (VIS) was calculated at different time points after starting the administration of methylene blue. Response to methylene blue or mortality at 28 days were assessed.

Results

262 patients from July 2014 to October 2019 received methylene blue. 209 patients met the inclusion criteria. Three different dosing strategies were identified: bolus injection followed by continuous infusion (n = 111), bolus injection only (no continuous infusion; n = 59) or continuous infusion only (no bolus prior; n = 39). The groups did not differ in demographics, ICU scoring system, or comorbidities. In all groups, VIS decreased over time, indicating improved hemodynamics. Cardiogenic shock and higher doses of norepinephrine increased the chance of responding to methylene blue, while bolus only decreased the chance of responding to methylene blue treatment. 28-day mortality increased with higher SAPSII scores and higher serum lactate levels, while bolus injection followed by continuous infusion decreased 28-day mortality. No severe side effects were noted.

Conclusion

In this cohort, methylene blue as a bolus injection followed by continuous infusion was associated with a reduced 28-day mortality in patients with shock. Prospective studies are needed to systematically evaluate the role of methylene blue in the treatment of shock.

Applicability of Vasopressor Trials in Adult Critical Care: A Prospective Multicentre Meta-Epidemiologic Cohort Study

Objective

To assess the applicability of evidence from landmark randomized controlled trials (RCTs) of vasopressor treatment in critically ill adults.

Study Design and Setting

This prospective, multi-center cohort study was conducted at five medical and surgical intensive care units at three tertiary care centers. Consecutive cases of newly initiated vasopressor treatment were included. The primary end point was the proportion of patients (≥18 years) who met the eligibility criteria of 25 RCTs of vasopressor therapy in critically ill adults included in the most recent Cochrane review. Multilevel Poisson regression was used to estimate the eligibility proportions with 95% confidence intervals for each trial. Secondary end points included the eligibility criteria that contributed most to trial ineligibility, and the relationship between eligibility proportions and (i) the Pragmatic-Explanatory Continuum Indicator Summary-2 (PRECIS-2) score, and (ii) the recruitment-to-screening ratio of each RCT. The PRECIS-2 score was used to assess the degree of pragmatism of each trial.

Results

Between January 1, 2017, and January 1, 2019, a total of 1189 cases of newly initiated vasopressor therapy were included. The median proportion of cases meeting eligibility criteria for all 25 RCTs ranged from 1.3% to 6.0%. The eligibility criteria contributing most to trial ineligibility were the exceedance of a specific norepinephrine dose, the presence of a particular shock type, and the drop below a particular blood pressure value. Eligibility proportions increased with the PRECIS-2 score but not with the recruitment-to-screening ratio of the trials.

Conclusion

The applicability of evidence from available trials on vasopressor treatment in critically ill adults to patients receiving vasopressors in daily practice is limited. Applicability increases with the degree of study pragmatism but is not reflected in a high recruitment-to-screening ratio. Our findings may help researchers design vasopressor trials and promote standardized assessment and reporting of the degree of pragmatism achieved.

Vasoactive pharmacological management according to SCAI class in patients with acute myocardial infarction and cardiogenic shock

Background

Vasoactive treatment is a cornerstone in treating hypoperfusion in cardiogenic shock following acute myocardial infarction (AMICS). The purpose was to compare the achievement of treatment targets and outcome in relation to vasoactive strategy in AMICS patients stratified according to the Society of Cardiovascular Angiography and Interventions (SCAI) shock classification.

Methods

Retrospective analysis of patients with AMICS admitted to cardiac intensive care unit at two tertiary cardiac centers during 2010–2017 with retrieval of real-time hemodynamic data and dosages of vasoactive drugs from intensive care unit databases.

Results

Out of 1,249 AMICS patients classified into SCAI class C, D, and E, mortality increased for each shock stage from 34% to 60%, and 82% (p<0.001). Treatment targets of mean arterial blood pressure > 65mmHg and venous oxygen saturation > 55% were reached in the majority of patients; however, more patients in SCAI class D and E had values below treatment targets within 24 hours (p<0.001) despite higher vasoactive load and increased use of epinephrine for each severity stage (p<0.001). In univariate analysis no significant difference in mortality within SCAI class D and E regarding vasoactive strategy was observed, however in SCAI class C, epinephrine was associated with higher mortality and a significantly higher vasoactive load to reach treatment targets. In multivariate analysis there was no statistically association between individually vasoactive choice within each SCAI class and 30-day mortality.

Conclusion

Hemodynamic treatment targets were achieved in most patients at the expense of increased vasoactive load and more frequent use of epinephrine for each shock severity stage. Mortality was high regardless of vasoactive strategy; only in SCAI class C, epinephrine was associated with a significantly higher mortality, but the signal was not significant in adjusted analysis.

First-line Vasopressor Use in Septic Shock and Route of Administration: An Epidemiologic Study

RATIONALE

Norepinephrine is a first-line agent for treatment of hypotension in septic shock. However, its frequency of use, and potential barriers to its use are unclear.

OBJECTIVES

To evaluate the frequency of use of norepinephrine in septic shock, to identify potential barriers to its use, and to evaluate trends in use of vasopressors over time.

METHODS

Retrospective population-based cohort study of patients with septic shock in Alberta, Canada between July 1, 2012 and December 31, 2018. The primary outcome was receipt of a first-line vasopressor other than norepinephrine ("non-norepinephrine vasopressor"). Predictors of receiving a non-norepinephrine vasopressor were assessed using a multivariable-adjusted, multilevel logistic regression model with intensive care unit (ICU) as a random effect.

RESULTS

Among 6343 patients with septic shock, the proportion of patients receiving non-norepinephrine vasopressors as first-line treatment decreased steadily from 11.5% in 2012 to 3.0% in 2018. Two factors most strongly associated with their receipt were having peripheral intravenous access only (adjusted odds ratio (aOR) 6.15, 95% confidence interval (CI) 4.58-8.26, p<0.001) and year of admission (aOR 0.74 per year after 2012, 95% CI 0.69-0.80, p<0.001). Other factors that had associations after adjustment included admission to a non-teaching hospital (aOR 2.19, 95% CI 1.23-3.89, p=0.007), admission to a coronary care unit (aOR 2.56, 95% CI 1.001-6.54, p=0.05), SOFA score (aOR 0.92 per unit increase, 95% CI 0.88-0.96, p<0.001) and heart rate (aOR 0.92 per 10 beat per minute increase, 95% CI 0.87-0.97, p=0.002).

CONCLUSIONS

In a large cohort of patients in Alberta, Canada, we found a steady decrease in use of first-line vasopressors other than norepinephrine in septic shock. The strongest factor associated with their use was the presence of only peripheral venous access, suggesting this may still be considered a barrier to administration of norepinephrine.

Alternatives to norepinephrine in septic shock: Which agents and when?

Vasopressors are the cornerstone of hemodynamic management in patients with septic shock. Norepinephrine is currently recommended as the first-line vasopressor in these patients. In addition to norepinephrine, there are many other potent vasopressors with specific properties and/or advantages that act on vessels through different pathways after activation of specific receptors; these could be of interest in patients with septic shock. Dopamine is no longer recommended in patients with septic shock because its use is associated with a higher rate of cardiac arrhythmias without any benefit in terms of mortality or organ dysfunction. Epinephrine is currently considered as a second-line vasopressor therapy, because of the higher rate of associated metabolic and cardiac adverse effects compared with norepinephrine; however, it may be considered in settings where norepinephrine is unavailable or in patients with refractory septic shock and myocardial dysfunction. Owing to its potential effects on mortality and renal function and its norepinephrine-sparing effect, vasopressin is recommended as second-line vasopressor therapy instead of norepinephrine dose escalation in patients with septic shock and persistent arterial hypotension. However, two synthetic analogs of vasopressin, namely, terlipressin and selepressin, have not yet been employed in the management of patients with septic shock, as their use is associated with a higher rate of digital ischemia. Finally, angiotensin Ⅱ also appears to be a promising vasopressor in patients with septic shock, especially in the most severe cases and/or in patients with acute kidney injury requiring renal replacement therapy. Nevertheless, due to limited evidence and concerns regarding safety (which remains unclear because of potential adverse effects related to its marked vasopressor activity), angiotensin Ⅱ is currently not recommended in patients with septic shock. Further studies are needed to better define the role of these vasopressors in the management of these patients.

Selepressin in Septic Shock

ABSTRACT

Sepsis and septic shock usually show a high mortality rate and frequently need of intensive care unit admissions. After fluid resuscitation, norepinephrine (NE) is the first-choice vasopressor in septic shock patients. However, high-NE doses are associated with increased rates of adverse effects and mortality. In this perspective, many authors have proposed the administration of non-adrenergic vasopressors (NAV). Selepressin is a selective vasopressin type 1A (V1A) receptor agonist and may be a valid option in this field, because it can decrease NE requirements and also limit the deleterious effects induced by high doses of catecholamines. Only few clinical data actually support selepressin administration in this setting. Here, we review the current literature on this topic analyzing some pathophysiological aspects, the rationale about the use of NAV, the possible use of selepressin differentiating animal, and human studies. Various issues remain unresolved and future trials should be focused on early interventions based on a multimodal activation of the vasopressive pathways using both alpha and V1A receptors pathways.

Vasopressors and Risk of Acute Mesenteric Ischemia: A Worldwide Pharmacovigilance Analysis and Comprehensive Literature Review

Vasodilatory shock, such as septic shock, requires personalized management which include adequate fluid therapy and vasopressor treatments. While these potent drugs are numerous, they all aim to counterbalance the vasodilatory effects of a systemic inflammatory response syndrome. Their specific receptors include α- and β-adrenergic receptors, arginine-vasopressin receptors, angiotensin II receptors and dopamine receptors. Consequently, these may be associated with severe adverse effects, including acute mesenteric ischemia (AMI). As the risk of AMI depends on drug class, we aimed to review the evidence of plausible associations by performing a worldwide pharmacovigilance analysis based on the World Health Organization database, VigiBase®. Among 24 million reports, 104 AMI events were reported, and disproportionality analyses yielded significant association with all vasopressors, to the exception of selepressin. Furthermore, in a comprehensive literature review, we detailed mechanistic phenomena which may enhance vasopressor selection, in the course of treating vasodilatory shock.

Colorectal Surgery in Critically Unwell Patients: A Multidisciplinary Approach

A proportion of patients require critical care support following elective or urgent colorectal procedures. Similarly, critically ill patients in intensive care units may also need colorectal surgery on occasions. This patient population is increasing in some jurisdictions given an aging population and increasing societal expectations. As such, this population often includes elderly, frail patients or patients with significant comorbidities. Careful stratification of operative risks including the need for prolonged intensive care support should be part of the consenting process. In high-risk patients, especially in setting of unplanned surgery, treatment goals should be clearly defined, and appropriate ceiling of care should be established to minimize care that is not in the best interest of the patient. In this article we describe approaches to critically unwell patients requiring colorectal surgery and how a multidisciplinary approach with proactive intensive care involvement can help achieve the best outcomes for these patients.

A Comprehensive Appraisal of Risk Prediction Models for Cardiogenic Shock

ABSTRACT

Despite advances in early revascularization, percutaneous hemodynamic support platforms, and systems of care, cardiogenic shock (CS) remains associated with a mortality rate higher than 50%. Several risk stratification models have been derived since the 1990 s to identify patients at high risk of adverse outcomes. Still, limited information is available on the differences between scoring systems and their relative applicability to both acute myocardial infarction and advanced decompensated heart failure CS. Thus, we reviewed the similarities, differences, and limitations of published CS risk prediction models and herein discuss their suitability to the contemporary management of CS care.

[Resuscitation strategy for patients with sepsis and septic shock]

Fluid and vasopressor resuscitation is, along with antimicrobial therapy and control of the focus of infection, a basic issue of the treatment of sepsis and septic shock. There is currently no accepted protocol that we can follow for the resuscitation of these patients and the Surviving Sepsis Campaign proposes controversial measures and without sufficient evidence support to establish firm recommendations. We propose a resuscitation strategy adapted to the situation of each patient: in the patient in whom community sepsis is suspected, we consider that the early administration of 30mL/kg of crystalloids is effective and safe; in the patient with nosocomial sepsis, we must carry out a more in-depth evaluation before initiating aggressive resuscitation. In patients who do not respond to initial resuscitation, it is necessary to increase monitoring level and, depending on the hemodynamic profile, administer more fluids, a second vasopressor or inotropes.

[Vasoactive drugs in the treatment of septic shock]

Septic shock is a high mortality complication frequently associated with sepsis. Early initiation of vasopressor treatment, even before completion of initial fluid resuscitation, is a determining factor in prognosis. In this sense, norepinephrine continues to be the drug of first choice, although there is increasing evidence of benefit combining it with other non-adrenergic drugs, such as vasopressin, instead of escalating norepinephrine doses. The pathophysiology of septic shock is multifactorial, and sometimes is associated with a situation of myocardial dysfunction that contributes to hemodynamic instability. It is essential to identify this situation since it worsens the prognosis and may benefit from combined treatment with inotropic drugs. There are novel vasoactive agents under study, more selective than the classic ones that in a next future could help to design more individualized and precise treatments. In the present work, the current knowledge about vasoactive drugs and their use in the management of septic shock is summarized according to the most recent scientific evidence.

Surgical stress quickly affects the numbers of circulating B-cells and neutrophils in murine septic and aseptic models through a β2 adrenergic receptor

Sepsis is a pathology accompanied by increases in myeloid cells and decreases in lymphoid cells in circulation. In a murine sepsis model induced by cecum ligation and puncture (CLP), increasing numbers of neutrophils and decreasing levels of B-cells in circulation are among the earliest changes in the immune system. However, to date, the mechanisms for these changes remain to be elucidated. The study here sought to elucidate mechanisms underlying the changes in the leukocyte levels after CLP and also to determine what, if any, role for an involvement of the sympathetic nervous system (SNS). Here, male C57/BL6 mice were subjected to CLP or sham-CLP (abdominal wall incised, but cecum was not punctured). The changes in the number of circulating leukocytes over time were then investigated using flow cytometry. The results showed that a sham-CLP led to increased polymorphonuclear cells (PMN; most of which are neutrophils) and decreased B-cells in the circulation to an extent similar to that induced by CLP. Effects of adrenergic agonists and antagonists, as well as of adrenalectomy, were also examined in mice that underwent CLP or sham-CLP. Administering adrenaline or a β₂ adrenergic receptor agonist (clenbuterol) to mice 3 h before sacrifice produced almost identical changes to as what was seen 2 h after performing a sham-CLP. In contrast, giving a β₂ adrenergic receptor antagonist ICI118,551 1 h before a CLP or sham-CLP suppressed the expected changes 2 h after the operations. Noradrenaline and an α1 adrenergic receptor agonist phenylephrine did not exert significant effects. Adrenalectomy 24 h before a sham-CLP significantly abolished the expected sham-CLP-induced changes seen earlier. Clenbuterol increased splenocyte expression of Cxcr4 (a chemokine receptor gene); adrenalectomy abolished sham-CLP-induced Cxcr4 expression. A CXCR4 antagonist AMD3100 repressed the sham-CLP-induced changes. From these results, it may be concluded that sepsis-induced activation of the SNS may be one cause for immune dysfunction in sepsis - regardless of the pathogenetic processes.

Epinephrine versus norepinephrine in cardiac arrest patients with post-resuscitation shock

PURPOSE

Whether epinephrine or norepinephrine is preferable as the continuous intravenous vasopressor used to treat post-resuscitation shock is unclear. We assessed outcomes of patients with post-resuscitation shock after out-of-hospital cardiac arrest according to whether the continuous intravenous vasopressor used was epinephrine or norepinephrine.

METHODS

We conducted an observational multicenter study of consecutive patients managed in 2011-2018 for post-resuscitation shock. The primary outcome was all-cause hospital mortality, and secondary outcomes were cardiovascular hospital mortality and unfavorable neurological outcome (Cerebral Performance Category 3-5). A multivariate regression analysis and a propensity score analysis were performed, as well as several sensitivity analyses.

RESULTS

Of the 766 patients included in five hospitals, 285 (37%) received epinephrine and 481 (63%) norepinephrine. All-cause hospital mortality was significantly higher in the epinephrine group (OR 2.6; 95%CI 1.4-4.7; P = 0.002). Cardiovascular hospital mortality was also higher with epinephrine (aOR 5.5; 95%CI 3.0-10.3; P < 0.001), as was the proportion of patients with CPC of 3-5 at hospital discharge. Sensitivity analyses produced consistent results. The analysis involving adjustment on a propensity score to control for confounders showed similar findings (aOR 2.1; 95%CI 1.1-4.0; P = 0.02).

CONCLUSION

Among patients with post-resuscitation shock after out-of-hospital cardiac arrest, use of epinephrine was associated with higher all-cause and cardiovascular-specific mortality, compared with norepinephrine infusion. Until additional data become available, intensivists may want to choose norepinephrine rather than epinephrine for the treatment of post-resuscitation shock after OHCA.

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.

Medication based machine learning to identify subpopulations of pediatric hemodialysis patients in an electronic health record database

Electronic health records (EHRs) have given rise to large and complex databases of medical information that have the potential to become powerful tools for clinical research. However, differences in coding systems and the detail and accuracy of the information within EHRs can vary across institutions. This makes it challenging to identify subpopulations of patients and limits the widespread use of multi-institutional databases. In this study, we leveraged machine learning to identify patterns in medication usage among hospitalized pediatric patients receiving renal replacement therapy and created a predictive model that successfully differentiated between intermittent (iHD) and continuous renal replacement therapy (CRRT) hemodialysis patients. We trained six machine learning algorithms (logistical regression, Naïve Bayes, k-nearest neighbor, support vector machine, random forest, and gradient boosted trees) using patient records from a multi-center database (n = 533) and prescribed medication ingredients (n = 228) as features to discriminate between the two hemodialysis types. Predictive skill was assessed using a 5-fold cross-validation, and the algorithms showed a range of performance from 0.7 balanced accuracy (logistical regression) to 0.86 (random forest). The two best performing models were further tested using an independent single-center dataset and achieved 84–87% balanced accuracy. This model overcomes issues inherent within large databases and will allow us to utilize and combine historical records, significantly increasing population size and diversity within both iHD and CRRT populations for future clinical studies. Our work demonstrates the utility of using medications alone to accurately differentiate subpopulations of patients in large datasets, allowing codes to be transferred between different coding systems. This framework has the potential to be used to distinguish other subpopulations of patients where discriminatory ICD codes are not available, permitting more detailed insights and new lines of research.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Recent advances in the pharmacological management of sepsis-associated acute kidney injury

INTRODUCTION

Acute kidney injury is a common occurrence in patients with sepsis and portends a high mortality as well as increased morbidity with numerous sequelae including the development of chronic kidney disease. Currently, there are no specific therapies that either prevent AKI or hasten its recovery. Thus, clinicians typically rely on management of the underlying infection, optimization of hemodynamic parameters as well as avoidance of nephrotoxins to maximize outcomes.

AREAS COVERED

Recent advances in understanding the mechanisms of sepsis as well as how these pathways may interact to lead to acute kidney injury have opened the door to the development of new, targeted therapies. This review focuses on the operative pathways in sepsis that have been identified as critical in leading to acute kidney injury and associated therapeutic agents that target these pathways.

EXPERT OPINION

Despite increased understanding of the pathogenesis of sepsis, development of effective therapeutics to decrease the incidence of AKI have lagged. This is likely due to the complex pathophysiology with overlapping pathways and need for multiple therapies guided by specific biomarkers. Biomarkers that detail operative pathways may be able to guide the institution of more specific therapies with the hope for improved outcomes.

Intensive care patients receiving vasoactive medications: A retrospective cohort study

BACKGROUND

Vasoactive medications are high-risk drugs commonly used in intensive care units (ICUs), which have wide variations in clinical management.

OBJECTIVES

The aim of this study was to describe the patient population, treatment, and clinical characteristics of patients who did and did not receive vasoactive medications while in the ICU and to develop a predictive tool to identify patients needing vasoactive medications.

METHODS

A retrospective cohort study of patients admitted to a level three tertiary referral ICU over a 12-month period from October 2018 to September 2019 was undertaken. Data from electronic medical records were analysed to describe patient characteristics in an adult ICU. Chi square and Mann-Whitney U tests were used to analyse data relating to patients who did and did not receive vasoactive medications. Univariate analysis and Pearson's r² were used to determine inclusion in multivariable logistic regression.

RESULTS

Of 1276 patients in the cohort, 40% (512/1276) received a vasoactive medication for haemodynamic support, with 84% (428/512) receiving noradrenaline. Older patients (odds ratio [OR] = 1.02; 95% confidence interval [CI] = 1.01-1.02; p < 0.001) with higher Acute Physiology and Chronic Health Evaluation (APACHE) III scores (OR = 1.04; 95% CI = 1.03-1.04; p < 0.001) were more likely to receive vasoactive medications than those not treated with vasoactive medications during an intensive care admission. A model developed using multivariable analysis predicted that patients admitted with sepsis (OR = 2.43; 95% CI = 1.43-4.12; p = 0.001) or shock (OR = 4.05; 95% CI = 2.68-6.10; p < 0.001) and managed on mechanical ventilation (OR = 3.76; 95% CI = 2.81-5.02; p < 0.001) were more likely to receive vasoactive medications.

CONCLUSIONS

Mechanically ventilated patients admitted to intensive care for sepsis and shock with higher APACHE III scores were more likely to receive vasoactive medications. Predictors identified in the multivariable model can be used to direct resources to patients most at risk of receiving vasoactive medications.

Catecholaminergic Vasopressors Reduce Toll-Like Receptor Agonist-Induced Microvascular Endothelial Cell Permeability But Not Cytokine Production

Supplemental Digital Content is available in the text.

OBJECTIVES:

Catecholaminergic vasopressors are the cornerstone of circulatory shock management. Nevertheless, catecholamines have problematic side effects, arousing a growing interest in noncatecholaminergic agents such as vasopressin or angiotensin-II. However, their respective effects on sepsis-associated microvascular endothelial dysfunction such as permeability or inflammation remain elusive. We investigated the role of catecholamines and other vasopressors on Toll-like receptor agonists-induced microvascular endothelial permeability and inflammation.

SETTING:

University research laboratory/cell research.

SUBJECTS:

Human pulmonary microvascular endothelial cells from multiple donors.

INTERVENTION:

Confluent monolayers of human pulmonary microvascular endothelial cells were treated with Toll-like receptor agonists (lipopolysaccharide, Poly[I:C], or tripalmitoyl-S-glyceryl cysteine) in the presence or absence of epinephrine, norepinephrine, vasopressin, and angiotensin-II. Permeability was inferred from transendothelial resistance, measured using electrical cell impedance sensing, where decreased transendothelial resistance is consistent with increased permeability. Cell-cell junction molecule expression was assessed via immunofluorescence microscopy and flow cytometry. We quantified cytokines in supernatants of Toll-like receptor agonist-treated human pulmonary microvascular endothelial cells.

MEASUREMENTS AND MAIN RESULTS:

Epinephrine and norepinephrine both ameliorate lipopolysaccharide, polyinosinic:polycytidylic acid, or tripalmitoyl-S-glyceryl cysteine–induced reductions in transendothelial resistance, a surrogate for endothelial permeability. In contrast, the noncatecholaminergic agents, vasopressin, and angiotensin-II did not affect Toll-like receptor agonists-induced reductions in transendothelial resistance. β1- and β2-adrenergic receptor antagonists reduced the effects of the catecholamines on transendothelial resistance, whereas α-adrenergic receptor antagonists did not. We observed that epinephrine and norepinephrine induced actin cytoskeletal rearrangement and normalized the membrane expression of proteins involved with adherens-junctions (vascular endothelial-cadherin) and tight-junctions (zona occludens-1). Despite having a substantial effect on endothelial permeability, epinephrine and norepinephrine did not affect human pulmonary microvascular endothelial cell survival or production of interleukin-8, interleukin-6, or monocyte chemoattractant protein-1 (CCL-2) induced by Toll-like receptor agonists, suggesting that these functions are regulated separately from permeability.

CONCLUSIONS:

Our findings demonstrate that treatment with epinephrine or norepinephrine strongly reduces endothelial permeability induced by agonists of multiple Toll-like receptors (Toll-like receptor-2, Toll-like receptor-3, Toll-like receptor-4) in vitro. Our studies suggest that both β1- and β2-adrenergic receptors mediate the stabilizing effects of epinephrine and norepinephrine on the endothelial barrier.