Early adjunctive methylene blue in patients with septic shock: a randomized controlled trial

Methylene blue therapy in addition to standard treatment for acute-phase septic shock: a pilot randomized controlled trial

Purpose

Methylene blue (MB) has been used to increase blood pressure in patients with septic shock by acting on guanylate cyclase and nitric oxide synthase.

Objective

To determine whether the administration of MB to patients in the initial phase of septic shock leads to a reduction in the use of vasopressors compared to the Control group.

Methods

This was a 1:1 randomized clinical trial of two groups (MB and Control). Forty-two patients were included in the present study; 23 patients were allocated to the Control group, and 19 were randomized to the MB group. Both groups had access to standard treatment, consisting of fluid replacement, vasopressors, and antibiotic therapy. Patients received a loading dose of MB (3 mg/kg) and maintenance (0.5 mg/kg/h) for 48 h. Vasopressor doses, laboratory test results, inflammatory and anti-inflammatory cytokine levels, and hemodynamic monitoring were recorded before the infusion of MB (T1) and after 20 min (T2), 2 h (T3), 24 h (T4), 48 h after the infusion started (T5) and 24 h after weaning (T6).

Results

MB therapy was started together with the indication of vasopressin (VAS) as a second vasopressor. The MB group showed an immediate reduction in NOR dosage, an earlier reduction in VAS dosage, and higher IL-10 levels compared to the Control group.

Conclusion

Early administration of MB in combination with standard treatment for septic shock might be reduce vasopressors dose. Continuous infusion of MB for 48 h was considered safe and there was no adverse events. These results highlight the potential of MB as a safe adjuvant therapeutic option in the treatment of septic shock.

Clinical trial registration

https://clinicaltrials.gov/, identifier RBR-96584w4.

Major Publications in the Critical Care Pharmacotherapy Literature: 2023

OBJECTIVES

We aimed to summarize the most significant and impactful publications describing the pharmacotherapeutic care of critically ill patients in 2023.

DATA SOURCES

PubMed/MEDLINE and the Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update.

STUDY SELECTION

Randomized controlled trials and prospective studies of adult critically ill patients assessing a pharmacotherapeutic intervention and reporting clinical endpoints published between January 1, 2023, and December 31, 2023, were eligible for inclusion in this article.

DATA EXTRACTION

Articles from a systematic search and the Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update were included. An a priori defined three-round modified Delphi process was employed to achieve consensus on the most impactful publications based on the following considerations: 1) overall contribution to scientific knowledge and 2) novelty to the literature.

DATA SYNTHESIS

The systematic search and Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update returned a total of 1202 articles, of which 1164 were excluded. The remaining 38 articles underwent a three-round modified Delphi process. In each round, articles were independently scored based on overall contribution to scientific knowledge and novelty to the literature. Included articles are summarized and their impact discussed. Article topics included hydrocortisone for severe community-acquired pneumonia, inhaled amikacin for prevention of ventilator-associated pneumonia, methylene blue for septic shock, restrictive vs. liberal fluid management for sepsis-induced hypotension, andexanet alfa for major bleeding associated with factor Xa inhibitors, and early administration of four-factor prothrombin complex concentrate in patients with trauma at risk for massive transfusion.

CONCLUSIONS

This review provides a summary and perspective on the potential impact of the most relevant articles in 2023 describing advances in the pharmacotherapeutic care of critically ill patients.

Efficacy of methylene blue in refractory septic shock: study protocol for a multicenter, randomized, placebo-controlled trial

BACKGROUND

Septic shock is now the leading cause of mortality in intensive care units (ICUs). Refractory septic shock requires high doses of vasopressors. Some previous studies have revealed that methylene blue could improve hypotension status and help reduce the dosage of catecholamines. This study aims to investigate the clinical effect of methylene blue in septic shock and explore whether it can increase arterial pressure and reduce the usage of vasopressors.

METHODS

This study is a multicenter, randomized, placebo-controlled trial planning to include 100 refractory septic shock patients. The protocol is to administer a bolus of 2 mg/kg methylene blue intravenously followed by a continuous infusion of 0.5 mg/kg/h for 48 h. The primary outcome is the total dose of vasopressor required in refractory septic shock in the first 48 h. Secondary outcomes include other hemodynamic parameters, oxygen metabolism indexes, tissue perfusion indexes, major organ function indexes, and certain plasma cytokines and other factors.

DISCUSSION

This protocol aims to evaluate the safety and efficacy of methylene blue as adjuvant therapy for refractory septic shock. The main outcome measure will be vasopressor requirements and hemodynamic parameters. Additionally, bedside ultrasonography, blood gases, and cytokines will be assessed to evaluate perfusion, respiratory, and metabolic effects. The results are intended to provide evidence on the safety and efficacy of methylene blue in refractory septic shock, guiding clinical decision-making.

TRIAL REGISTRATION

This clinical trial has been registered at ChiCTR ( https://www.chictr.org.cn/ ) on March 16, 2023. ChiCTR registration number: ChiCTR2300069430.

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.

Haemophagocytic lymphohistiocytosis (HLH) secondary to disseminated histoplasmosis infection in a patient with HIV

A male in his 30s who was recently diagnosed with HIV arrived at the emergency department exhibiting an altered mental state and acute respiratory distress. Initial laboratory tests revealed a high anion gap metabolic acidosis, elevated liver enzyme levels and bicytopenia. A CT scan identified a miliary pattern. Bronchoscopy with bronchoalveolar lavage displayed epithelial and inflammatory cells. However, subsequent tests ruled out the presence of fungi, Pneumocystis organisms, malignancies, granulomas and viral inclusions. Broad-spectrum antibiotics with emphasis on Mycobacterium tuberculosis and antifungal treatments were administered. The regimen was adjusted after a positive urine test for the Histoplasma antigen.The patient later manifested signs and symptoms, including increased ferritin level, fever, splenomegaly, diminished natural killer cell function and heightened interleukin-2 receptor levels, confirming haemophagocytic lymphohistiocytosis. Given the patient's gravely decompensated state, the treatment incorporated dexamethasone, and the patient's vasopressor-resistant septic shock was addressed with methylene blue.

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.

Efficacy and safety of dynamic arterial elastance for weaning vasopressor support in septic shock patients: a randomised controlled trial protocol

INTRODUCTION

The dynamic arterial elastance (EaDyn), calculated as pulse pressure variation divided by stroke volume variation, has been studied as a predictor of vasopressor weaning. However, its potential as a haemodynamic tool for tapering off vasopressors in patients with sepsis remains unexplored. Therefore, our study aimed to assess whether using EaDyn for weaning vasopressor support could reduce the duration of vasopressor support in patients with sepsis.

METHODS AND ANALYSIS

This pragmatic single-centre controlled clinical trial will take place at Fundación Santa Fe de Bogotá, Colombia. Adult patients diagnosed with septic shock according to the sepsis-3 criteria and a Sequential Organ Failure Assessment score ≥4 will be included. A total of 114 patients (57 per group) will undergo conventional critical care monitoring, and the weaning of vasopressor support will be initiated based on the EaDyn or mean arterial pressure (MAP), depending on the assigned group. EaDyn will be estimated based on the measurements obtained from a PiCCO device connected to a PulsioFlex Monitoring Platform (PULSION Medical Systems SE, Feldkirchen, Germany). Our primary outcome is the difference in vasopressor support duration between the EaDyn and MAP groups.Participants and statisticians performing the statistical analysis will be blinded to the group allocation. Dependent and independent variables will be analysed through univariate and multivariate statistical tests. Since we will perform three repeated measurements for analysis, we will implement a Bonferroni post hoc correction. Additionally, Cox regression and Kaplan-Meier analyses will be conducted to address objectives related to time.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee at Fundación Santa Fe de Bogotá (CCEI-16026-2024). Written informed consent will be obtained from all participants. The results will be disseminated through publication in peer-reviewed journals and presentations at national and international events.

TRIAL REGISTRATION NUMBER

NCT06118775.

Methylene Blue in Septic Shock: A Systematic Review and Meta-Analysis

OBJECTIVES

Although clinicians may use methylene blue (MB) in refractory septic shock, the effect of MB on patient-important outcomes remains uncertain. We conducted a systematic review and meta-analysis to investigate the benefits and harms of MB administration in patients with septic shock.

DATA SOURCES

We searched six databases (including PubMed, Embase, and Medline) from inception to January 10, 2024.

STUDY SELECTION

We included randomized clinical trials (RCTs) of critically ill adults comparing MB with placebo or usual care without MB administration.

DATA EXTRACTION

Two reviewers performed screening, full-text review, and data extraction. We pooled data using a random-effects model, assessed the risk of bias using the modified Cochrane tool, and used Grading of Recommendations Assessment, Development, and Evaluation to rate certainty of effect estimates.

DATA SYNTHESIS

We included six RCTs (302 patients). Compared with placebo or no MB administration, MB may reduce short-term mortality (RR [risk ratio] 0.66 [95% CI, 0.47-0.94], low certainty) and hospital length of stay (mean difference [MD] -2.1 d [95% CI, -1.4 to -2.8], low certainty). MB may also reduce duration of vasopressors (MD -31.1 hr [95% CI, -16.5 to -45.6], low certainty), and increase mean arterial pressure at 6 hours (MD 10.2 mm Hg [95% CI, 6.1-14.2], low certainty) compared with no MB administration. The effect of MB on serum methemoglobin concentration was uncertain (MD 0.9% [95% CI, -0.2% to 2.0%], very low certainty). We did not find any differences in adverse events.

CONCLUSIONS

Among critically ill adults with septic shock, based on low-certainty evidence, MB may reduce short-term mortality, duration of vasopressors, and hospital length of stay, with no evidence of increased adverse events. Rigorous randomized trials evaluating the efficacy of MB in septic shock are needed.

REGISTRATION

Center for Open Science (https://osf.io/hpy4j).

Methylene blue in sepsis and septic shock: a systematic review and meta-analysis

Background

Methylene blue is an interesting approach in reducing fluid overload and vasoactive drug administration in vasodilatory shock. The inhibition of guanylate cyclase induced by methylene blue infusion reduces nitric oxide production and improves vasoconstriction. This systematic review and meta-analysis aimed to assess the effects of methylene blue administration compared to placebo on the hemodynamic status and clinical outcomes in patients with sepsis and septic shock.

Methods

The authors specifically included randomized controlled trials that compared the use of methylene blue with placebo in adult patients with sepsis and septic shock. The outcomes were length of intensive care unit stay, hemodynamic parameters [vasopressor use], and days on mechanical ventilation. We also evaluated the abnormal levels of methemoglobinemia. This systematic review and meta-analysis were recorded in PROSPERO with the ID CRD42023423470.

Results

During the initial search, a total of 1,014 records were identified, out of which 393 were duplicates. Fourteen citations were selected for detailed reading, and three were selected for inclusion. The studies enrolled 141 patients, with 70 of them in the methylene blue group and 71 of them in the control group. Methylene blue treatment was associated with a lower length of intensive care unit stay (MD -1.58; 95%CI -2.97, -0.20; I2 = 25%; p = 0.03), decreased days on mechanical ventilation (MD -0.72; 95%CI -1.26, -0.17; I2 = 0%; p = 0.010), and a shorter time to vasopressor discontinuation (MD -31.49; 95%CI -46.02, -16.96; I2 = 0%; p < 0.0001). No association was found with methemoglobinemia.

Conclusion

Administering methylene blue to patients with sepsis and septic shock leads to reduced time to vasopressor discontinuation, length of intensive care unit stay, and days on mechanical ventilation.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023423470, CRD42023423470.

Refractory circulatory failure in COVID-19 patients treated with veno-arterial ECMO a retrospective single-center experience

OBJECTIVE

In this retrospective case series, survival rates in different indications for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and differential diagnoses of COVID-19 associated refractory circulatory failure are investigated.

METHODS

Retrospective analysis of 28 consecutive COVID-19 patients requiring VA-ECMO. All VA-ECMO's were cannulated peripherally, using a femoro-femoral cannulation.

RESULTS

At VA-ECMO initiation, median age was 57 years (IQR: 51-62), SOFA score 16 (IQR: 13-17) and norepinephrine dosing 0.53μg/kg/min (IQR: 0.35-0.87). Virus-variants were: 61% wild-type, 14% Alpha, 18% Delta and 7% Omicron. Indications for VA-ECMO support were pulmonary embolism (PE) (n = 5, survival 80%), right heart failure due to secondary pulmonary hypertension (n = 5, survival 20%), cardiac arrest (n = 4, survival 25%), acute heart failure (AHF) (n = 10, survival 40%) and refractory vasoplegia (n = 4, survival 0%). Among the patients with AHF, 4 patients suffered from COVID-19 associated heart failure (CovHF) (survival 100%) and 6 patients from sepsis associated heart failure (SHF) (survival 0%). Main Complications were acute kidney injury (AKI) 93%, renal replacement therapy was needed in 79%, intracranial hemorrhage occurred in 18%. Overall survival to hospital discharge was 39%.

CONCLUSION

Survival on VA-ECMO in COVID-19 depends on VA-ECMO indication, which should be considered in further studies and clinical decision making. A subgroup of patients suffers from acute heart failure due to inflammation, which has to be differentiated into septic or COVID-19 associated. Novel biomarkers are required to ensure reliable differentiation between these entities; a candidate might be soluble interleukin 2 receptor.

Treatment of refractory shock with vitamin B12 : A narrative review

High-dose vitamin B12 is a potential treatment for patients with vasodilatory shock that is refractory to other therapies. Vasodilatory shock is characterized by low blood pressure and low systemic vascular resistance. Nitric oxide and hydrogen sulfide, two potential targets of high-dose vitamin B12 given as hydroxocobalamin, facilitate this syndrome. This review explores the relationship between high-dose vitamin B12 and hemodynamic outcomes in adults with vasodilatory shock and provides an update on the literature since a 2019 review on this topic. A literature search of studies published in the past 5 years was conducted in the CINAHL, PubMed, Cochrane, and EMBASE databases in May 2023. After assessing for eligibility, eight studies met this review's inclusion criteria. Seven of the eight studies reported decreased vasopressor requirements for part or all of the study samples after receiving a hydroxocobalamin infusion. However, not all patients responded to hydroxocobalamin. These findings are limited by patient selection and differences in the timing of vasopressor requirement and blood pressure outcome assessments. The current evidence is promising as to whether vitamin B12 , given as a hydroxocobalamin infusion, may improve hemodynamic outcomes in vasodilatory shock, but the evidence is of low quality. The use of hydroxocobalamin to treat refractory, vasodilatory shock remains investigative. Larger randomized controlled trials are required to elucidate the role of vitamin B12 in treating refractory, vasodilatory shock, including in conjunction with other alternative therapies such as methylene blue and corticosteroids.

Spectrophotometric analysis of purple urine secondary to methylene blue and hydroxocobalamin co-administration

BACKGROUND

The development of purple urine after methylene blue (methylthioninium chloride) and hydroxocobalamin co-administration is a rare clinical entity that has not been fully elucidated. A 47-year-old male presented to the emergency department with hypotension, cyanosis, and depressed mental status. The patient was noted to have profound peripheral and central cyanosis, as well as chocolate-colored arterial blood. He was treated with both methylene blue and hydroxocobalamin and developed purple urine for approximately 1 week.

METHODS

Color chromatography was performed by placing the patient's urine directly onto absorbent filter paper. Urine spectrophotometry was performed utilizing the NanoDrop One/One C UV-Vis Spectrophotometer.

RESULTS

Color chromatography of the urine was demonstrated clear separation of distinct red and blue phases. Urine spectrophotometry demonstrated near perfect overlap between the methylene blue + hydroxocobalamin absorbance spectrum and the patient's purple urine absorbance spectrum.

CONCLUSION

Purple urine secondary to methylene blue and hydroxocobalamin co-administration is due to combined urinary excretion of methylene blue (blue) and hydroxocobalamin (red), and not a novel purple metabolite. We anticipate that this is going to be an increasingly common clinical entity as the roles of both hydroxocobalamin and methylene blue expand from toxicologic antidotes to adjunct therapies for vasoplegia, poor cardiac output, and sepsis.

Administration of methylene blue in septic shock: pros and cons

Septic shock typically requires the administration of vasopressors. Adrenergic agents remain the first choice, namely norepinephrine. However, their use to counteract life-threatening hypotension comes with potential adverse effects, so that non-adrenergic vasopressors may also be considered. The use of agents that act through different mechanisms may also provide an advantage. Nitric oxide (NO) is the main driver of the vasodilation that leads to hypotension in septic shock, so several agents have been tested to counteract its effects. The use of non-selective NO synthase inhibitors has been of questionable benefit. Methylene blue, an inhibitor of soluble guanylate cyclase, an important enzyme involved in the NO signaling pathway in the vascular smooth muscle cell, has also been proposed. However, more than 25 years since the first clinical evaluation of MB administration in septic shock, the safety and benefits of its use are still not fully established, and it should not be used routinely in clinical practice until further evidence of its efficacy is available.

Effect of methylene blue on outcomes in patients with distributive shock: a meta-analysis of randomised controlled trials

OBJECTIVE

This meta-analysis aimed to demonstrate the effect of methylene blue (MB) in patients with distributive shock.

DESIGN

Meta-analysis.

METHODS

According to the Prospective International Register of Systematic Reviews (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the relevant randomised controlled trials (RCTs) via PubMed, Embase and Cochrane Library from the date of database inception to 19 April 2023. The primary outcome was mortality during follow-up, and secondary outcomes included mean arterial pressure (mm Hg), mechanical ventilation time (hours), intensive care unit (ICU) length of stay (LOS) (days), hospital LOS (days) and heart rate (times/min).

RESULTS

This study included six RCTs with 265 participants. The study showed no significant difference in mortality between the MB and placebo groups (ORs: 0.59; 95% CI 0.32 to -1.06). However, MB reduced the duration of mechanical ventilation (mean difference (MD): -0.68; 95% CI -1.23 to -0.14), ICU LOS (MD: -1.54; 95% CI -2.61 to -0.48) and hospital LOS (MD: -1.97; 95% CI -3.92 to -0.11).

CONCLUSIONS

The use of MB may not reduce mortality in patients with distributive shock, but may shorten the duration of mechanical ventilation, ICU LOS and hospital LOS. More clinical studies are needed to confirm these findings in the future.

TRIAL REGISTRATION NUMBER

CRD42023415938.

Author Response

How to cite this article: Rajbanshi LK, Arjyal B. Author Response. Indian J Crit Care Med 2024;28(1):90-91.

Methylene Blue Reduces Mortality in Critically Ill and Perioperative Patients: A Meta-Analysis of Randomized Trials

Vasodilatory hypotension is common in critically ill and perioperative patients, and is associated with adverse outcomes. As a nitric oxide production inhibitor, methylene blue (MB) exerts its vasoconstrictor property and is an adjuvant for catecholamine-refractory vasodilatory shock. However, the effects of MB on clinically relevant outcomes remain unclear. Therefore, the authors performed a meta-analysis of randomized trials on MB in critically ill and perioperative patients. The authors searched through databases for randomized trials on MB in critically ill and perioperative patients, which yielded 11 studies consisting of 556 patients. The primary outcome was mortality at the longest follow-up. Secondary outcomes included hemodynamic parameters and organ dysfunction (PROSPERO: CRD42023409243). Nine out of the 11 included randomized trials reported mortality, which was significantly lower in the MB group (risk ratio, 0.60 [95% CI 0.43-0.84] p = 0.003), with findings confirmed in septic shock and cardiac surgery subgroups. The authors found reduced lengths of stay in the intensive care unit (mean difference [MD], -0.9 days [95% CI -1.06 to -0.77] p < 0.001) and in the hospital (MD, -2.2 days [95% CI, -2.68 to -1.70] p < 0.001) in the MB group. MB was associated with increased mean arterial pressure (MD, 8.4 mmHg [95% CI 5.01-11.75] p < 0.001) and systemic vascular resistance (MD, 94.5 dyn/s/cm5 [95% CI 17.73-171.15] p = 0.02), with no difference in cardiac output (standardized MD, 0.16 [95% CI, -0.25 to 0.57] p = 0.45). This meta-analysis showed that MB reverses vasodilation in critically ill and perioperative patients and might improve survival. Further adequately powered randomized trials are needed to confirm these findings.

The effects of methylene blue during and after cardiac arrest in a porcine model; a randomized, blinded, placebo-controlled study

PURPOSE

To evaluate the effect of methylene blue administered as a bolus on return of spontaneous circulation (ROSC), lactate levels, vasopressor requirements, and markers of neurological injury in a clinically relevant pig model of cardiac arrest.

MATERIALS AND METHODS

40 anesthetized pigs were subjected to acute myocardial infarction and 7 min of untreated cardiac arrest. Animals were randomized into three groups: one group received saline only (controls), one group received 2 mg/kg methylene blue and saline (MB + saline), and one group received two doses of 2 mg/kg methylene blue (MB + MB). The first intervention was given after the 3rd rhythm analysis, while the second dose was administered one hour after achieving ROSC. Animals underwent intensive care and observation for six hours, followed by cerebral magnetic resonance imaging (MRI). The primary outcome for this study was development in lactate levels after cardiac arrest. Categorical data were compared using Fisher's exact test and pointwise data were analyzed using one-way analysis of variance (ANOVA) or equivalent non-parametric test. Continuous data collected over time were analyzed using a linear mixed effects model. A value of p < .05 was considered statistically significant.

RESULTS

Lactate levels increased in all groups after cardiac arrest and resuscitation, however lactate levels in the MB + MB group decreased significantly faster compared with the control group (p = .007) and the MB + saline group (p = .02). The proportion of animals achieving initial ROSC was similar across groups: 11/13 (85%) in the control group, 10/13 (77%) in the MB + saline group, and 12/14 (86%) in the MB + MB group (p = .81). Time to ROSC did not differ between groups (p = .67). There was no significant difference in accumulated norepinephrine dose between groups (p = .15). Cerebral glycerol levels were significantly lower in the MB + MB group after resuscitation compared with control group (p = .03). However, MRI data revealed no difference in apparent diffusion coefficient, cerebral blood flow, or dynamic contrast enhanced MR perfusion between groups.

CONCLUSION

Treatment with a bolus of methylene blue during cardiac arrest and after resuscitation did not significantly improve hemodynamic function. A bolus of methylene blue did not yield the neuroprotective effects that have previously been described in animals receiving methylene blue as an infusion.

The Eight Unanswered and Answered Questions about the Use of Vasopressors in Septic Shock

Septic shock is mainly characterized-in addition to hypovolemia-by vasoplegia as a consequence of a release of inflammatory mediators. Systemic vasodilatation due to depressed vascular tone results in arterial hypotension, which induces or worsens organ hypoperfusion. Accordingly, vasopressor therapy is mandatory to correct hypotension and to reverse organ perfusion due to hypotension. Currently, two vasopressors are recommended to be used, norepinephrine and vasopressin. Norepinephrine, an α₁-agonist agent, is the first-line vasopressor. Vasopressin is suggested to be added to norepinephrine in cases of inadequate mean arterial pressure instead of escalating the doses of norepinephrine. However, some questions about the bedside use of these vasopressors remain. Some of these questions have been well answered, some of them not clearly addressed, and some others not yet answered. Regarding norepinephrine, we firstly reviewed the arguments in favor of the choice of norepinephrine as a first-line vasopressor. Secondly, we detailed the arguments found in the recent literature in favor of an early introduction of norepinephrine. Thirdly, we reviewed the literature referring to the issue of titrating the doses of norepinephrine using an individualized resuscitation target, and finally, we addressed the issue of escalation of doses in case of refractory shock, a remaining unanswered question. For vasopressin, we reviewed the rationale for adding vasopressin to norepinephrine. Then, we discussed the optimal time for vasopressin administration. Subsequently, we addressed the issue of the optimal vasopressin dose, and finally we discussed the best strategy to wean these two vasopressors when combined.

Successful Use of Methylene Blue in Catecholamine-Resistant Septic Shock: A Case Report and Short Literature Review

Despite efforts to improve treatment outcomes, mortality in septic shock remains high. In some patients, despite the use of several adrenergic drugs, features of refractory vasoplegic shock with progressive multiorgan failure are observed. We present a case report of the successful reversal of vasoplegic shock following the use of methylene blue, a selective inhibitor of the inducible form of nitric oxide synthase, which prevents vasodilation in response to inflammatory cytokines. We also briefly review the literature.