Angiotensin II in Vasodilatory Shock

The pharmacotherapeutic options in patients with catecholamine-resistant vasodilatory shock

INTRODUCTION

Septic and vasoplegic shock are common types of vasodilatory shock (VS) with high mortality. After fluid resuscitation and the use of catecholamine-mediated vasopressors (CMV), vasopressin, angiotensin II, methylene blue (MB) and hydroxocobalamin can be added to maintain blood pressure.

AREAS COVERED

VS treatment utilizes a phased approach with secondary vasopressors added to vasopressor agents to maintain an acceptable mean arterial pressure (MAP). This review covers additional vasopressors and adjunctive therapies used when fluid and catecholamine-mediated vasopressors fail to maintain target MAP.

EXPERT OPINION

Evidence supporting additional vasopressor agents in catecholamine resistant VS is limited to case reports, series, and a few randomized control trials (RCTs) to guide recommendations. Vasopressin is the most common agent added next when MAPs are not adequately supported with CMV. VS patients failing fluids and vasopressors with cardiomyopathy may have cardiotonic agents such as dobutamine or milrinone added before or after vasopressin. Angiotensin II, another class of vasopressor is used in VS to maintain adequate MAP. MB and/or hydoxocobalamin, vitamin C, thiamine and corticosteroids are adjunctive therapies used in refractory VS. More RCTs are needed to confirm the utility of these drugs, at what doses, which combinations and in what order they should be given.

Protocol Compliance Guiding Angiotensin II Use in Post Cardiovascular Surgery Vasoplegia

Catecholamines and vasopressin are commonly used in patients with post cardiovascular surgery vasoplegia (PCSV). Multimodal therapy, including methylene blue (MB), hydroxocobalamin, and angiotensin II (Ang II), may improve outcomes in patients who remain hypotensive despite catecholamine and vasopressin therapy. However, a standardized approach has not been established. We created a protocol at Emory Healthcare (Emory Protocol), which provides guidance on norepinephrine equivalent dose (NED) and the use of noncatecholamines in the setting of PCSV and sought to determine the clinical significance of adherence to the protocol.

The Role of Angiotensin II in Poisoning-Induced Shock-a Review

Background

Shock in drug poisoning is a life-threatening condition and current management involves fluid resuscitation and vasopressor therapy. Management is limited by the toxicity of high-dose vasopressors such as catecholamines. Clinical trials have shown the efficacy of angiotensin II as an adjunct vasopressor in septic shock. The aim of this review is to assess the use of angiotensin II in patients with shock secondary to drug overdose.

Methods

Medline (from 1946), Embase (from 1947) and PubMed (from 1946) databases were searched until July 2021 via OVID. Included studies were those with shock due to drug poisoning and received angiotensin II as part of their treatment regimen. Of the 481 articles identified, 13 studies (case reports and scientific abstracts) were included in the final analysis with a total of 14 patients. Extracted data included demographics, overdose drug and dosage, angiotensin II dosage, time of angiotensin II administration, haemodynamic changes, length of hospital stay, mortality, complications, cardiac function and other treatment agents used.

Results

Thirteen studies were included consisting of 6 case reports, 6 scientific abstracts and 1 case series. Overdose drugs included antihypertensives (n = 8), psychotropics (n = 4), isopropanol (n = 1) and tamsulosin (n = 1). Out of a total of 14 patients, 3 patients died. Ten patients had their haemodynamic changes reported. In terms of MAP or SBP changes, three patients (30%) had an immediate response to angiotensin II, four patients (40%) had responses within 30 min, one patient (10%) within two hours and two patients (20%) did not have their time reported. Two patients were shown to have direct chronotropic effects within 30 min of angiotensin II administration. The median hospital stay for patients was 5 days (IQR = 4). The time from overdose until angiotensin II administration ranged from 5 to 56 h. Other vasopressors used included phenylephrine, noradrenaline, adrenaline, vasopressin, dobutamine, dopamine, methylene blue and ephedrine. A median of 3 vasopressors were used before initiation of angiotensin II. Twelve patients received angiotensin II as their final treatment.

Conclusions

Angiotensin II may be useful as an adjunct vasopressor in treating shock secondary to drug poisoning. However, the current literature consisted of only very low-quality studies. To truly assess the utility of angiotensin II use in drug-induced poisoned patients, further well-designed prospective studies are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13181-022-00885-4.

Angiotensin II: A Review of Current Literature

Up to one-third of all patients admitted to intensive care units carry a diagnosis of shock. The use of angiotensin II is becoming widespread in all forms of shock, including cardiogenic, after the U.S. Food and Drug Administration's (FDA's) initial approval for vasoplegic shock in 2017. Here, the authors review the literature on angiotensin II's mechanism of action, benefits, and future therapeutic opportunities.

Angiotensin II-mediated improvement of renal mitochondrial function via the AMPK/PGC-1α/NRF-2 pathway is superior to norepinephrine in a rat model of septic shock associated with acute renal injury

Background

This study sought to compare the therapeutic effects of angiotensin II (ANG II) and norepinephrine (NE) on cecal ligation and puncture (CLP)-induced septic acute kidney injury (AKI) in rats.

Methods

Sepsis shock was induced in anesthesia Sprague-Dawley male rats by CLP model for 24 hours. A total of 40 rats were divided into five groups, including control group, sham group, CLP group, CLP + ANG II group, and CLP + NE group. CLP + ANG II and CLP + NE group were administration of ANG II or NE after sepsis shock respectively, maintaining the MAP at 75–85 mmHg. CLP group was administration of saline for contrast. At 0, 18, 24 hours measured the renal blood grades and resistant index (RI) by ultrasound equipment. At 6, 12, 18 and 24 hours collected 0.5 mL blood sample for creatinine and lactic acid examination. Rats were observed for 24 hours after CLP procedure and then sacrificed for subsequent examination, rat serum were used to determine the levels of inflammatory response factors, kidney tissues were used to examine the oxidative stress factors and mitochondrial related proteins.” We added the sentence as following: “The AMPK, PGC-1α and NRF-2 expression in renal cortex was significantly increased in the CLP + ANG II group.

Results

Compared to the vehicle treatment, both ANG II and NE administration restored the decrease in the mean arterial pressure (MAP) and alleviated mitochondrial impairments in CLP rats. However, only ANG II alleviated CLP-induced abnormalities in serum creatinine and lactic acid concentrations, renal blood flow, the renal resistant index, renal histopathology, the production of proinflammatory cytokines, and oxidative stress markers in rats. ANG II was also found to be superior to NE in reversing the CLP-induced suppression of mitochondrial biogenesis-related protein expression in the kidneys of rats.

Conclusions

ANG II was better than NE in alleviating CLP-induced septic AKI in rats.

Angiotensin II for the treatment of septic shock in a neutropenic patient with T-cell acute lymphoblastic leukaemia

Mortality remains high in septic shock with few new treatment options. Angiotensin II has been recently approved for use in septic shock due to promising results in the ATHOS-3 trial. However, patients with neutropenia were excluded in the trial. This patient population is becoming increasingly common in the intensive care unit as there is an increase in novel biologic therapies and stem cell transplantations for haematological and solid organ malignancies. We present a case of a patient with T-cell acute lymphoblastic leukaemia who received chemotherapy, resulting in neutropenia and septic shock. There was persistent hypotension despite initiating multiple conventional vasopressors. Angiotensin II was attempted with immediate improvement in the blood pressure which resulted in weaning of other vasopressors. This positive haemodynamic response suggests that angiotensin II can successfully be used in neutropenic patients without increasing the overall catecholamine burden of septic shock.

Vasoplegia after cardiopulmonary bypass: A narrative review of pathophysiology and emerging targeted therapies

Cardiovascular disease remains the leading cause of death in the United States, and cardiopulmonary bypass is a cornerstone in the surgical management of many related disease states. Pathophysiologic changes associated both with extracorporeal circulation and shock can beget a syndrome of low systemic vascular resistance paired with relatively preserved cardiac output, termed vasoplegia. While increased vasopressor requirements accompany vasoplegia, related pathophysiologic mechanisms may also lead to true catecholamine resistance, which is associated with further heightened mortality. The introduction of a second non-catecholamine vasopressor, angiotensin II, and non-specific nitric oxide scavengers offers potential means by which to manage this challenging phenomenon. This narrative review addresses both the definition, risk factors, and pathophysiology of vasoplegia and potential therapeutic interventions.

Elucidation of the pathophysiology of intradialytic muscle cramps: pharmacokinetics applied to translational research

In the conventional concept of translational research, investigations flow from the laboratory bench to the bedside. However, clinical research can also serve as the starting point for subsequent laboratory investigations that then lead back to the bedside. This article chronicles the evolution of a series of studies in which a detailed analysis of pharmacokinetics in hemodialysis patients revealed new physiological insight that, through a systems approach incorporating kinetic, physicochemical, physiologic, and clinical trial results, led to an elucidation of the pathophysiology of intradialytic skeletal muscle cramps. Based on this understanding, a therapeutic path forward is proposed.

Angiotensin II in Decompensated Cirrhosis Complicated by Septic Shock

This case describes the first reported use of human-derived synthetic angiotensin II (Ang-2) in a patient with decompensated cirrhosis and septic shock. The patient presented in vasodilatory shock from Enterobacter cloacae bacteremia with a Sequential Organ Failure Assessment Score of 14 and a Model for End-Stage Liver Disease score of 36. This case is significant because liver failure was an exclusion criterion in the Angiotensin II for the Treatment of Vasodilatory Shock (ATHOS-3) trial, but the liver produces angiotensinogen, which is key precursor to Ang-2 in the renin-angiotensin-aldosterone system. Resuscitation with Ang-2 is a potentially beneficial medication when conventional vasopressors have failed to control mean arterial pressure in this population.

Synthetic Human Angiotensin II in Pediatric Patients With Vasodilatory Shock: A Report on Two Patients

Severe sepsis and septic shock continue to be an important problem in children, with hospital mortality rates for pediatric severe sepsis as high as 25%.