Septic Shock

Septic Shock
Definition

Septic shock occurs in a subset of patients with sepsis and comprises of an underlying circulatory and cellular/metabolic abnormality that is associated with increased mortality

Patients with septic shock can be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia.

Symptoms

Patients in septic shock may experience the symptoms of sepsis, such as:

  • fast heart rate
  • high respiratory rate
  • low urine output
  • compromised mental status.

Additionally, septic shock patients have a very low mean arterial pressure (MAP) and don’t respond to fluid replacement.

Causes

Any pathogen infection can cause sepsis and subsequently septic shock.

Septic Shock Therapy/Treatment

Aside from antibiotic administration to treat the infection, vasopressor drugs are used to increase mean arterial pressure by increasing cardiac output or by increasing systemic vascular resistance (SVR). Currently, first-line vasoactive medication is norepinephrine, a catecholamine, which is causing vasoconstriction by inducing the α1 receptors located on the blood vessel walls and an increase in heart rate by inducing the β1 receptors.

Treatment of Catecholamine Refractory/Resistant Hypotension in Septic Shock

A catecholamine refractory hypotension in septic shock is present if the mean arterial blood pressure cannot be stabilised to target despite adequate volume substitution and application of catecholamines, as the α1 receptors become hyporesponsive. In these cases, argipressin (also known as arginine vasopressin, vasopressin or antidiuretic hormone) is providing a new solution, as it is activating the V1 receptors, located on the blood vessel walls, instead.
When administered in combination with norepinephrine within the first 6 hours of refractory septic shock, the body is replenished with its own physiological tool to deal with septic shock. Furthermore, adding argipressin instead of increasing norepinephrine dose helps reducing norepinephrine associated side effects.

Surviving Sepsis Campaign Guidelines

Current guidelines on the treatment of septic shock (surviving sepsis campaign) recommend norepinephrine as first-line vasopressor. Adding Vasopressin is recommended to raise MAP to target (≥65 mm Hg) or to decrease norepinephrine dosage.

Drugs

Argipressin (also known as vasopressin, arginine vasopressin or antidiuretic hormone)

Norepinephrine (also known as noradrenaline)