Prolonged methylene blue infusion in refractory septic shock: a case report

Effect of methylene blue on hemodynamic response in the early phase of septic shock: A case series

RATIONALE

Methylene blue (MB) has been used to increase blood pressure in septic shock, acting on the activity of guanylate cyclase and nitric oxide synthase.

PATIENCE CONCERNS

The aim of this study is to demonstrate the benefit of MB in early phase of septic shock.Diagnoses: We report 6 cases of patients with septic shock with up to 72 hours of evolution.

INTERVENTIONS

We used MB after fluid replacement, use of norepinephrine and vasopressin. Patients received a loading dose of MB and maintenance for 48 hours.

OUTCOMES

All patients presented a reduction in the dose of vasopressors and lactate levels soon after the administration of the loading dose of MB, an effect that was maintained with the maintenance dose for 48 hours. Interleukin 6 and interleukin 8 were elevated at the beginning of the septic condition, with a progressive and marked reduction after the beginning of MB infusion, demonstrating a role of MB in reducing the inflammatory activity.

LESSONS

This case series suggests that MB used early in the treatment of septic shock may be useful in reducing vasopressor dose and lactate levels. Further studies are still required to further validate these findings.

Efficacy and safety of methylene blue in patients with vasodilatory shock: A systematic review and meta-analysis

Background

The role of methylene blue (MB) in patients with vasodilatory shock is unclear. The purpose of this systematic review and meta-analysis was to evaluate the efficacy and safety of MB in patients with vasodilatory shock.

Methods

We searched MEDLINE at PubMed, Embase, Web of Science, Cochrane, CNKI, CBM and Wanfang Medical databases for all observational and intervention studies comparing the effect of MB vs. control in vasodilatory shock patients. This study was performed in accordance with the PRISMA statement. There were no language restrictions for inclusion.

Results

A total of 15 studies with 832 patients were included. Pooled data demonstrated that administration of MB along with vasopressors significantly reduced mortality [odds ratio (OR) 0.54, 95% confidence interval (CI) 0.34 to 0.85, P = 0.008; I 2 = 7%]. This benefit in mortality rate was also seen in a subgroup analysis including randomized controlled trials and quasi-randomized controlled trials. In addition, the vasopressor requirement was reduced in the MB group [mean difference (MD) -0.77, 95%CI -1.26 to -0.28, P = 0.002; I 2 = 80%]. Regarding hemodynamics, MB increased the mean arterial pressure, heart rate and peripheral vascular resistance. In respect to organ function, MB was associated with a lower incidence of renal failure, while in regards to oxygen metabolism, it was linked to reduced lactate levels. MB had no effect on the other outcomes and no serious side effects.

Conclusions

Concomitant administration of MB and vasopressors improved hemodynamics, decreased vasopressor requirements, reduced lactate levels, and improved survival in patients with vasodilatory shock. However, further studies are required to confirm these findings.

Systematic review registration

Identifier: CRD42021281847.

Effect of methylene blue on hemodynamic and metabolic response in septic shock patients

INTRODUCTION

Septic shock is a lethal disease responsible for a large proportion of deaths in the Intensive Care Unit (ICU), even with therapy centered on fluid resuscitation, use of vasopressors and empirical antibiotic therapy applied within the first hour of diagnosis. Considering the multifactorial pathophysiology of septic shock and the mechanism of action of vasopressors, some patients may not respond adequately, which can lead to the maintenance of vasodilatation, hypotension and increased morbidity, and mortality. This protocol aims to verify whether the use of methylene blue in septic patients with an early diagnosis can contribute to an earlier resolution of a shock compared to standard treatment.

METHODS AND ANALYSIS

This is a study protocol for a single-center randomized clinical trial design in an ICU of a tertiary university hospital. In this study, we intend to include 64 patients aged between 18 and 80 years with a diagnosis of septic shock, of any etiology, with up to 72 hours of evolution after volume restoration, using norepinephrine at a dose ≥0.2 μg/kg/min and vasopressin at a dose of 0.04 IU/min. After the initial approach, we will randomize patients into two groups, standard care, and standard care plus methylene blue. The sample size was calculated in order to show 30% differences in septic shock resolution between groups. The Research Ethics Committee approved the study, and all patients included will sign an informed consent form (Clinical registration: RBR-96584w4).

Vasopressor-Sparing Action of Methylene Blue in Severe Sepsis and Shock: A Narrative Review

Shock is a serious acute circulatory failure leading to inadequate oxygen delivery to the cells. Its treatment is mainly based on circulating fluid optimization, and vasopressors to provide an adequate mean arterial pressure and microcirculatory flow. Norepinephrine is the drug of choice, but high dosages may be responsible for several side effects, including increased myocardial oxygen consumption, dysrhythmias, and peripheral and organ ischemia. Moreover, some patients are “non-responders” to first-line norepinephrine treatment. Hence, other drugs have been proposed to reach and maintain the hemodynamic target. In general, they are described as catecholamine-sparing agents. Among others, the most used are vasopressin, corticosteroids, and angiotensin II. Methylene blue (MB) represents a further option, even though its use is still a topic of controversy. This review article tries to summarize what is known and unknown about the actions of MB in patients in shock. It reduces excessive production of nitric oxide via blockade of guanylate cyclase in shock states. At present, it appears the MB provides positive results in septic shock, if administered early. Further randomized controlled trials are warranted regarding its use to provide more precise indications to physicians involved in the treatment of such patients.

The Story of Nitric Oxide, Sepsis and Methylene Blue: A Comprehensive Pathophysiologic Review

Methylene blue (MB) is considered to be the first synthetic medication ever used in humans. There are many indications for MB, including vasoplegic shock. Nitric oxide (NO), the central mediator of sepsis, promotes vasoplegia by enhancing the guanylate cyclase cyclic guanosine monophosphate second messenger system, the effect of which is attenuated by MB. Therefore, the use of MB represents a unique pharmacologic approach towards treating the underlying pathophysiology of vasoplegia in sepsis. There are numerous reports of the successful use of MB in refractory shock in the literature. This manuscript describes the historical aspects of the identification of NO as the endothelial derived relaxation factor and its role in the pathogenesis of vasoplegia in septic shock. An analysis of the existing evidence for the use of MB as an inhibitor of NO in vasodilatory shock is provided. The adverse effects associated with the use of MB and an approach to optimal dosing in septic shock are also addressed.

Clinical utility of midodrine and methylene blue as catecholamine-sparing agents in intensive care unit patients with shock

Shock is common in the intensive care unit, affecting up to one third of patients. Treatment of shock is centered upon managing hypotension and ensuring adequate perfusion via administration of fluids and catecholamine vasopressors. Due to the risks associated with catecholamine vasopressors, interest has grown in using catecholamine-sparing agents such as midodrine and methylene blue. Midodrine is an orally administered alpha-1 adrenergic agonist while methylene blue is an intravenously administered blue dye used to restore vascular tone and increase blood pressure. Separate MEDLINE, Scopus, and Embase database searches were conducted to assess literature revolving around these agents. Examples of search terms included "midodrine", "methylene blue", "critically ill", "shock", and "catecholamine-sparing." Several studies have evaluated their use in patients with shock and found potential benefits in terms of causing significant elevations in blood pressure and hastening catecholamine vasopressor discontinuation with few adverse effects; however, robust evidence is lacking for these off-label indications. Because of the variety of dosing strategies used and the incongruences between patient populations, it is also challenging to define finite recommendations. This review aims to summarize current evidence for the use of midodrine and methylene blue as catecholamine-sparing agents in critically ill patients with resolving or refractory shock.

Methylene blue, midodrine, and pseudoephedrine: a review of alternative agents for refractory hypotension in the intensive care unit

Hypotensive episodes are common among patients in the intensive care unit and can lead to multiorgan failure if uncontrolled. Fluid administration and continuous infusion of vasoactive agents are frequently used for management of hypotension; however, both therapies may be associated with adverse effects including pulmonary edema and tissue necrosis. In addition, availability of these first-line agents has been impacted by the increasing occurrence of drug shortages. Methylene blue, pseudoephedrine, and midodrine have been considered potential alternatives to standard therapy. These agents may not only be used when first-line agents are unavailable due to shortages, but they may also aid in reducing the cumulative dose of other vasoactive agents used. The purpose of this review was to discuss strategies for the safe and effective use of methylene blue, pseudoephedrine, and midodrine for the treatment of hypotension in the critically ill.

A Novel Use of Methylene Blue in the Pediatric ICU

Methylene blue (MB) is a medication commonly used to treat methemoglobinemia, reducing methemoglobin to hemoglobin. A novel use of MB, as detailed here, is in the treatment of refractory hypotension. A number of reports have detailed use of MB for this purpose in adults, but few data in pediatrics. A 22-month-old girl with Noonan syndrome, biventricular hypertrophic cardiomyopathy, and chronic positive pressure ventilation developed shock with tachycardia, hypotension, and fever after 3 days of diarrhea. She was critically ill, with warm extremities, bounding pulses, and brisk capillary refill. Laboratory tests revealed metabolic acidosis, low mixed venous oxygen saturation, and leukocytosis with bandemia. Treatment of severe septic shock was initiated with fluid resuscitation, inotropic support, sedation, and paralysis. She remained hypotensive despite norepinephrine at 0.7 μg/kg per minute, dopamine at 20 μg/kg per minute, and vasopressin at 0.04 U/kg per hour. Her vasoplegic shock worsened, despite aggressive conventional therapy. Intravenous MB was initiated, with a loading dose of 1 mg/kg followed by a continuous infusion at 0.25 mg/kg per hour. Upon initiation of MB, her systolic blood pressure increased by 33 points (40% increase), and diastolic blood pressure increased by 20 points (46% increase). She was able to wean off all inotropes quickly after initiation of MB. MB should be considered in the setting of refractory vasoplegic shock in the PICU.

A severe case of vasoplegic shock following metformin overdose successfully treated with methylene blue as a last line therapy

A 44-year-old man presented to hospital 24 h after an intentional overdose of metformin and gliclazide. He had a critical metabolic acidosis on presentation with a pH of 6.88, and very rapidly deteriorated into distributive shock refractory to large volume fluid resuscitation and massive doses of vasopressors. We introduced a methylene blue infusion as a rescue therapy in an attempt to improve the patient's haemodynamics, which was successful. The patient made a full recovery with no long-term sequelae.

New directions for sepsis and septic shock research

BACKGROUND

Septic shock is a frequent complication in intensive care unit that can result in multiple organ failure and death. In addition, recent data suggested that severe sepsis and septic shock represent an economic burden. Therefore, septic shock is an important public health problem.

METHOD

In this review, we will focus on the recent evidences concerning the stages of septic shock, the complex macrocirculation and microcirculation relationship, and the importance of those evidences for future resuscitation goals and therapeutic strategies during late septic shock.

RESULT

Recently, two stages of septic shock are suggested. In early stage, hypovolemia is the main contributing factor. During this stage, macrocirculatory and microcirculatory changes run parallel, and fluid resuscitation seems to be effective in restoring the hemodynamic parameters. Late stage of septic shock is characterized by complex microcirculation and macrocirculation relationship.

CONCLUSIONS

Although early goal-directed therapy is a stepwise approach in the treatment of septic shock, tissue perfusion remains an important factor that contributes to septic shock outcome. Because appropriate monitoring of tissue perfusion is a matter of debt, the ideal therapeutic strategy remains a controversial issue that needs further investigations.

Methylene blue for distributive shock: a potential new use of an old antidote

Methylene blue is used primarily in the treatment of patients with methemoglobinemia. Most recently, methylene blue has been used as a treatment for refractory distributive shock from a variety of causes such as sepsis and anaphylaxis. Many studies suggest that the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway plays a significant role in the pathophysiology of distributive shock. There are some experimental and clinical experiences with the use of methylene blue as a selective inhibitor of the NO-cGMP pathway. Methylene blue may play a role in the treatment of distributive shock when standard treatment fails.

A review of methylene blue treatment for cardiovascular collapse

BACKGROUND

Historically, methylene blue (MB) has been used for multiple purposes, including as an antidote for toxin-induced and hereditary methemoglobinemia, ifosfamide-induced encephalopathy, and ackee fruit and cyanide poisoning; as an aniline dye derivative, antimalarial agent, and antidepressant.

DISCUSSION

Most recently, the use of MB has been advocated as a potential adjunct in the treatment of shock states. Our article reviews the role of MB in septic shock, anaphylactic shock, and toxin-induced shock. MB is proposed to increase blood pressure in these shock states by interfering with guanylate cyclase activity, and preventing cyclic guanosine monophosphate production and vasodilatation.

SUMMARY

MB may be an adjunct in the treatment of septic shock, anaphylactic shock, and toxin-induced shock.

Vasoplegia in septic shock: do we really fight the right enemy?

Vasoplegia is a key factor for the death of patients with septic shock in intensive care unit owing to persistent and irreversible hypotension. Impairment of vascular reactivity has been attributed to a combination of endothelial injury, arginine-vasopressin system dysfunction, release of other vasodilatory inflammatory mediators, and muscle hyperpolarizaton. Nitric oxide induced by a Ca(+2) independent isoform of nitric oxide synthase has been suggested to play an important role in sepsis-induced vasoplegia. However, inhibition of nitric oxide synthase only partially restores the endotoxin-induced vascular hyporeactivity. The aim of this review is to discuss in detail the recent suggested alternative mechanisms of vasoplegia and to briefly outline the current therapeutic strategies and the novel therapeutic options based on those mechanisms.