Advancing Vasoplegic Shock Management : Innovative Strategies in Critical Care

This article aims to provide a comprehensive guide to vasoplegic shock, its causes, and its symptoms. This article will further explore the various type of treatment options that are present today for its management and give an outlook on the preoperative measure that helps in preventing the occurrence of vasoplegic shock following cardiopulmonary bypass or CPB.

Vasoplegic shock (VS) is defined as a critical condition that is characterized by severe hypotension (decreased blood pressure) and usually occurs following cardiovascular surgery or cardiopulmonary bypass (CPB). Its incidence rate may vary from 5% to 44%. It is very often associated with vasodilation which may result in decreased systemic vascular resistance and if this condition is not treated in a certain period, then it may lead to life-threatening conditions.

There are a variety of causes known so far that cause the VS condition or can potentiate this condition. Cardiopulmonary bypass, genetic predispositions, excessive production of nitric oxide and endothelial dysfunction are some factors which can lead to vasoplegic syndrome.

• Genetic factors: It is crucial to recognize that genetic factors can significantly increase the risk of developing vasoplegic shock, either independently or in conjunction with non-genetic or environmental factors. Mainly mutations in genes that regulate the nitric oxide signalling pathway, contribute to the development of vasoplegic shock
• Cardiopulmonary bypass surgery: Vasoplegic syndrome is known to be strongly associated with certain surgical procedures. One of the significant causes of this syndrome is when blood comes into contact with foreign surfaces during surgery. This contact triggers the release of anti-inflammatory factors, which, through various mechanisms, can precipitate the occurrence of vasoplegic syndrome.^[6]

Symptoms associated with Vasoplegic shock are vasodilation (blood vessel dilatation), tachycardia (increased heartbeat), hypotension (decreased blood pressure), warm skin, organ dysfunctioning due to the poor blood supply, and also delayed wound healing observed in many cases.

The management of vasoplegic shock requires a highly individualized approach. Effective coordination among the patient, physicians, and medical staff is crucial for providing optimal care. The primary goal of managing vasoplegic shock is to restore organ perfusion pressure (OPP) and ensure adequate oxygen delivery to the tissues.

There are several treatment and management techniques present that can be together utilised for the better management of vasoplegic shock. They are-

• Perioperative Prevention: Perioperative care refers to the health care provided before a surgical operation. The main aim of providing perioperative care is to do whatever is necessary to increase the success of the surgery. In the case of vasoplegic syndrome, it is very important if we want to prevent vasoplegic shock after a cardiopulmonary bypass. To enhance perioperative care, Van Vessem et al. proposed a risk scorecard by incorporating the age, sex, type of surgery, and value of creatinine clearance. Using these parameters, he formulated a theory that suggests the chances of vasoplegic shock after cardiopulmonary bypass into three different categories such as low, intermediate, and high risk with an observed incidence of about 13, 39, and 65% respectively.^[1] This risk stratification enables the implementation of targeted preoperative measures, such as hemodynamic optimization and renal function improvement, to prevent vasoplegic shock in the postoperative period
• Haemodynamic Optimization And Supportive Measures: In the management of vasoplegic shock, closely monitoring the patient’s hemodynamic functions, including blood pressure, heart rate, and systemic vascular resistance, is of utmost importance.^[1] By continuously monitoring these vital signs and optimizing them, healthcare professionals can effectively address the challenges posed by vasoplegic shock
• Volume Resuscitation: Fluid resuscitation plays a crucial role in managing vasoplegic shock by ensuring sufficient preload and maintaining cardiac output in affected individuals.^[2] It is important to note that the additional administration of fluids can have a positive impact on cardiac output. However, caution must be exercised to avoid overloading or excessive perfusion, as this can lead to potential complications. Striking the right balance is essential to prevent any serious adverse effects
• Vasoactive Drugs: In the management of vasoplegic shock, physicians employ two main categories of drugs: catecholamines and non-catecholamines. Each category has its own set of advantages and disadvantages, and their usage is determined based on the patient’s condition and individual responsiveness to specific drugs.^[5]

Firstly, it was considered that vasopressors should be started following adequate volume resuscitation, but now this approach has changed and in today’s modern world it is recommended that start vasoactive drugs with volume resuscitation because this therapy has shown promising results in reducing short term mortality in sepsis-associated vasoplegia.^[4] So that’s why the modern approach is used by most physicians.

• Catecholamines: In this category mainly noradrenaline and adrenaline are used for the treatment and management of vasoplegic shock. Two drugs share a quite similar mode of action, they act by primarily targeting the vascular alpha 1 receptors located in the vascular smooth muscle. Due to binding with these receptors, calcium influx is increased inside the cell, leading to the contraction of smooth muscle and thereby helping in maintaining vascular tone.^[2] However, among these two drugs, noradrenaline is mostly preferred as it offers fewer side effects and has a high safety profile. The decision regarding which drug to use is based on the individual patient’s condition and specific considerations, to achieve the most optimal therapeutic outcome
• Non-catecholamines: In this category various types of drugs are used such as vasopressin, corticosteroids, and ascorbic acid which act by a different type of mechanism
• Vasopressin: It is the first-line drug used for the management of vasoplegic shock. It acts by various mechanisms, firstly, it binds to the vascular V1 receptors, leading to increased calcium entry inside the smooth muscle. This calcium influx induces smooth muscle contraction and thereby helps in maintaining vascular tone.

It can also interfere with the nitric oxide signalling pathway. It controls the nitric oxide signalling and produces vasodilation. Due to vasodilation properties, it is used in the management of vasoplegic shock.

Moreover, it may also increase catecholamine sensitivity. By improving catecholamine sensitivity, vasopressin can enhance the effectiveness of endogenous vasoconstrictors, further making it helpful in the treatment of vasoplegic shock.

• Role of Corticosteroids and Other Adjuvants: Corticosteroids are mainly used in the management of vasoplegic shock when it is associated with sepsis. They mainly act by improving the vascular tone and by enhancing the response to vasopressor therapy.^[3]
• Ascorbic Acid (Vitamin C): Ascorbic acid, also known as vitamin C, is particularly useful in cases of vasoplegic shock associated with sepsis. This versatile drug exhibits multiple mechanisms of action, making it beneficial in the management of the condition. One of the ways of its producing action is due to its antioxidant activity. It acts as a scavenger of free radicals, which are highly reactive molecules that can contribute to tissue injury during oxidative stress. By neutralizing free radicals, ascorbic acid helps protect tissues from oxidant-mediated damage, which can occur in vasoplegic shock.^[1] Other than this, it is helpful in the synthesis of catecholamine. These combined mechanisms of action, including its antioxidant properties and role in catecholamine biosynthesis, make ascorbic acid a valuable drug in the management of vasoplegic shock.

• Methylene Blue (MB): It is a dye having several pharmacological actions, among them increasing vascular tone is evaluated for the treatment of the vasoplegic shock associated with sepsis or following cardiopulmonary bypass. It acts by inhibiting the nitric oxide, dependent vasodilation which results in enhancement of the vascular tone.^[1] It is contraindicated in patients with a deficiency of the enzyme glucose-6phosphate dehydrogenase which is responsible for its metabolism and may result in hemolytic anemia
• Hydroxycobalamin (vitamin B12): Due to its potent vasoconstricting action, it enhances the vascular tone and is used in the management of vasoplegic syndrome

There is no clinical data or any study present which shows that only one therapy or use of any one drug is sufficient in the treatment and management of the Vasoplegic shock. ^[2] To ensure optimal patient care most physicians used the perioperative manner so that it is avoided in most of the patients. If it has occurred, then the use of low doses of both categories drugs catecholamines and non-catecholamines are preferred to overcome the side effects possessed by both of the drugs.

Vasoplegic shock mainly occurs following cardiopulmonary bypass surgery. It produces a variety of symptoms such as hypotension, tachycardia etc. If it is not treated well it may prove fatal to the patients. So it is very necessary to provide proper clinical care to the patient for the management of this Vasoplegic shock. From the above-given treatment strategies we concluded that, for the treatment of the VS, a multifaceted approach can be useful which includes the use of both catecholamines as well as non-catecholamines and also include the target-based drug in the treatment regimen. Scientists must continue researching and developing appropriate treatment approaches to effectively address vasoplegic shock and prevent its potentially devastating consequences.

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