Distributive Shock Management

Definition and Pathophysiology

Distributive shock is characterized by an insufficient intravascular volume of blood secondary to pathological vasodilation, resulting in abnormal distribution of microvascular blood flow and metabolic distress despite potentially normal or elevated cardiac output, as described by the European Heart Journal 1
The pathophysiological hallmark is peripheral vasodilation leading to decreased systemic vascular resistance, resulting in relative hypovolemia despite potentially normal or even elevated cardiac output, according to the European Heart Journal 1, 2
Myocardial depression is common, particularly in septic shock, with up to one-third of patients developing right ventricular systolic dysfunction, as reported by the European Heart Journal 1

Pancreatitis is a cause of distributive shock, as mentioned in Intensive Care Medicine 3
Burns are a cause of distributive shock, as reported in Circulation 4

Hypotension refractory to fluid administration is the cardinal feature of distributive shock, as described by Intensive Care Medicine 3, 5
Tachycardia is a compensatory mechanism to maintain cardiac output in distributive shock, according to Circulation 6
Altered mental status is a sign of cerebral hypoperfusion in distributive shock, as reported by Intensive Care Medicine 5
Decreased urine output is a reflection of renal hypoperfusion in distributive shock, as mentioned in Intensive Care Medicine 5
Elevated serum lactate levels indicate tissue hypoxia and anaerobic metabolism in distributive shock, according to Intensive Care Medicine 5

Clinical diagnosis of distributive shock is based on hemodynamic parameters, including hypotension, tachycardia, and normal or elevated cardiac output, as described by Intensive Care Medicine 3 and European Heart Journal 1
Serum lactate levels are used to assess tissue hypoperfusion in distributive shock, as reported by Intensive Care Medicine 5
Echocardiography is used to assess cardiac function and rule out other shock types in distributive shock, according to European Heart Journal 1

Fluid resuscitation with balanced crystalloids is the first step in managing distributive shock, as recommended by Circulation 8 and Intensive Care Medicine 5
Norepinephrine is the first-line vasopressor after adequate fluid resuscitation in distributive shock, as described by Intensive Care Medicine 3, 5
Vasopressin can be added to reduce norepinephrine requirements in distributive shock, according to Intensive Care Medicine 3, 5
Dobutamine can be added to norepinephrine to manage myocardial dysfunction in distributive shock, as reported by Intensive Care Medicine 3, 5

Acute respiratory distress syndrome is a potential complication of distributive shock, as reported by Circulation 9
Acute kidney injury requiring renal replacement therapy is a potential complication of distributive shock, according to Circulation 9

Failure to improve with appropriate fluid resuscitation and vasopressors should prompt reassessment for alternative or additional shock types, as described by Intensive Care Medicine 3 and European Heart Journal 1
Myocardial depression in septic shock may require addition of inotropic support, according to Intensive Care Medicine 3 and European Heart Journal 1
Target a MAP of 65 mmHg as the standard goal in managing distributive shock, but individualize based on patient's baseline blood pressure and comorbidities, as recommended by Intensive Care Medicine 5