Norepinephrine vs Vasopressin: Which Vasopressor Should Be Discontinued First in Septic Shock? A Meta-Analysis

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.

Effect Evaluation of Norepinephrine on Cardiac Function in Patients with Sepsis by Cardiac Ultrasound Imaging

In order to investigate the therapeutic effect of norepinephrine on patients with sepsis and the effect of echocardiography on the diagnosis of cardiac function in patients with sepsis, 86 patients with sepsis were selected as research objects and randomly divided into two groups. Patients in the control group (N = 43 cases) received conventional treatment (1~15 μg/kg∗min dopamine), and those in the experimental group (N = 43 cases) received conventional treatment+norepinephrine therapy (0.05~0.5 μg∗kg⁻¹/min). The clinical efficacy, cardiac ultrasonography results, and hemodynamic indexes of patients between the two groups were analyzed and compared. The results showed that the total effective rate of treatment in the experimental group (97.7%) was significantly higher than that in the control group (81.4%) (P < 0.05). The maximum, minimum, and average values of mitral valve E peak flow velocity (VEpeak) and left ventricular outflow tract peak flow velocity (Vpeak), respiratory variability of mitral valve E peak flow velocity (ΔVEpeak), and respiratory variability of peak flow velocity (ΔVpeak) were all significantly greater than those of the control group (P < 0.05). The area under the receiver operating characteristic curve (AUC) of ΔVEpeak and ΔVpeak for predicting positive volume response in patients with sepsis was 0.934 and 0.913, respectively; the sensitivity was 0.828 and 0.827; the specificity was 0.936 and 0.893; and the Youden indices were 0.765 and 0.712, respectively. In short, norepinephrine had a high total response rate in patients with sepsis, and echocardiography can well evaluate the effect of norepinephrine on cardiac function in patients with sepsis, which is worthy of further promotion.

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.

Incidence of Hypotension Associated With Two Different Vasopressin Discontinuation Strategies in the Recovery Phase of Septic Shock

INTRODUCTION

Safe and effective vasopressor withdrawal strategies during the recovery phase of septic shock lack consensus and are not addressed in clinical practice guidelines. The purpose of this study was to compare the incidence of clinically relevant hypotension associated with different vasopressin (AVP) discontinuation strategies.

METHODS

This was a single-center, retrospective, cohort study, conducted at a university medical center over a three-year period. Adult patients ≥18 years with septic shock were included in the study. Patients were stratified into two groups; patients incrementally weaned from AVP and patients in which AVP was abruptly discontinued. The primary endpoint was to compare the incidence of clinically relevant hypotension between study groups up to 24 hours following discontinuation. Secondary analyses included the incidence of any hypotensive event up to 24 hours after AVP cessation, intensive care unit and hospital length of stay, and in-hospital mortality.

RESULTS

A total of 74 patients (n = 46 AVP wean and n = 28 AVP no-wean) met inclusion criteria and were included in the study. The primary outcome was not statistically different between groups. Clinically relevant hypotension occurred in 24 patients (52.3%) and 16 patients (57.1%) in the AVP wean and AVP no-wean groups, respectively (P = .68). There were no significant differences in any secondary clinical outcome between the two study groups.

CONCLUSION

No differences were found in the incidence of clinically relevant hypotension, length of stay, or mortality between AVP weaning and no-weaning discontinuation strategies. These findings suggest incremental weaning and abrupt withdrawal of AVP are both acceptable discontinuation strategies.

Comparative efficacy of Chinese herbal injections for septic shock: A protocol for systematic review and network meta-analysis

BACKGROUND

Septic shock is a life-threatening syndrome. Despite Western medicine guidelines being continually updated on septic shock, the disease still has a high mortality rate. Chinese herbal injections (CHIs) are injections made from effective components of traditional Chinese medicine, which have a potential therapeutic effect on septic shock and are recommended as the adjunctive treatment for septic shock in China. Although pairwise meta-analysis has been published for category-single CHIs about treatment effects of septic shock, there is no meta-analysis comparing more than 3 various types of CHIs used for septic shock.

METHODS

Chinese and English databases will be retrieved for randomized controlled trials from the establishment of the databases to September 30, 2021. Two reviewers will perform literature searches and data extractions while another 2 reviewers for risk assessments. RevMan V.5.4 software, Stata V.14.0 software, and R V. 4.1.1 software will be applied to perform pairwise meta-analysis and network meta-analysis. We will apply the Cochrane risk of bias tool to assess the risk of bias while the Grades of Recommendation, Assessment, Development, and Evaluation approach will be used to summarize the results of the study. The PRISMA-P guideline was followed for this protocol.

RESULTS

The current study will explore the therapeutic effect of CHIs in the treatment of septic shock through pairwise meta-analysis and network meta-analysis.

CONCLUSION

This study will seek out the best-performed CHIs under various indicators for septic shock, providing supporting evidence for clinical selection of CHIs for septic shock.

Evaluation of Evidence, Pharmacology, and Interplay of Fluid Resuscitation and Vasoactive Therapy in Sepsis and Septic Shock

ABSTRACT

We sought to review the pharmacology of vasoactive therapy and fluid administration in sepsis and septic shock, with specific insight into the physiologic interplay of these agents. A PubMed/MEDLINE search was conducted using the following terms (vasopressor OR vasoactive OR inotrope) AND (crystalloid OR colloid OR fluid) AND (sepsis) AND (shock OR septic shock) from 1965 to October 2020. A total of 1,022 citations were reviewed with only relevant clinical data extracted. While physiologic rationale provides a hypothetical foundation for interaction between fluid and vasopressor administration, few studies have sought to evaluate the clinical impact of this synergy. Current guidelines are not in alignment with the data available, which suggests a potential benefit from low-dose fluid administration and early vasopressor exposure. Future data must account for the impact of both of these pharmacotherapies when assessing clinical outcomes and should assess personalization of therapy based on the possible interaction.

Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.

Non-catecholamine vasopressors in the treatment of adult patients with septic shock-evidence from meta-analysis and trial sequential analysis of randomized clinical trials

BACKGROUND

Norepinephrine (NE) has currently been the first-choice vasopressor in treating septic shock despite generally insufficient for patients with refractory septic shock. The aim of this update meta-analysis was to assess the safety and efficacy of a combination of non-catecholamine vasopressors (vasopressin/pituitrin/terlipressin/selepressin/angiotensin II) and NE versus NE in managing adult septic shock patients.

METHODS

We conducted this study of literatures published from the inception to April 30, 2020, using PubMed, Embase, and the Cochrane Library databases without language restriction. Randomized controlled trials comparing NE with non-catecholamine vasopressors among adult septic shock patients were included in this meta-analysis. Pooled effects of relative risk (RR) or standard mean difference (SMD) and corresponding 95% confidence interval (CI) were calculated using a random-effects model.

RESULTS

Twenty-three studies covering 4380 participants were finally enrolled. The combined analysis of non-catecholamine vasopressors resulted in a nonsignificant reduction in 90-day/ICU/hospital mortality except for a decreased in 28-day mortality (n = 4217; RR, 0.92; 95% CI 0.86-0.99; P = 0.02). This favorable result was subsequently verified by the subgroup analyses of low risk of bias studies (RR = 0.91, 95% CI = 0.84 to 0.98; P = 0.02) and catecholamine-resistant refractory shock patients group (RR, 0.84; 95% CI = 0.70-1.00; P = 0.048). The pooled analysis of non-catecholamine vasopressors showed a 14% higher success rate of shock reversal at 6 h, a 29% decreased risk of continuous renal replacement therapy, but a 51% increased risk of hyponatremia and a 2.43 times higher risk of digital ischemia. Besides, the pooled data showed that non-catecholamine vasopressors decreased heart rate (HR) (SMD, - 0.43; 95% CI - 0.66 - - 0.19; P < 0.001), serum creatinine (- 0.15; 95% CI - 0.29 - - 0.01; P = 0.04), and the length of mechanical ventilation (MV) (- 0.19; 95% CI - 0.31 - - 0.07; P < 0.01, but there was no significant difference in other parameters.

CONCLUSIONS

Current pooled results suggest that the addition of NE to non-catecholamine vasopressors was associated with a marginally significant reduction in 28-day mortality. Moreover, they were able to shorten the length of MV, improved renal function, decreased HR, and increased the 6-h shock reversal success rate at the expense of increased the risk of hyponatremia and digital ischemia.