Shock is a syndrome characterized by acute circulatory failure resulting in impaired peripheral tissue perfusion. Distributive shock is the most common type of shock and is usually caused by severe sepsis. Distributive shock is characterized by profound vasodilatation leading to decreased arterial blood pressure and impaired organ perfusion despite high cardiac output.~The use of vasopressors is an essential management line for distributive sock. Two groups of vasopressors are usually used for management of shock: catecholamines and vasopressin-like peptides. There is a continuous need for other vasopressors because:~1- Available vasopressors have narrow therapeutic window. 2- Patients with severe hypotension refractory to the currently available classes usually die.~A third system is usually engaged in the physiology of shock which is Renin-Angiotensin-aldosterone system. Angiotensin II is a natural hormone which is a potent vasopressor; moreover, angiotensin II stimulates the production of both antidiuretic hormone and adrenocorticotropin hormone.~In a pilot study, angiotensin II was reported as an effective rescue vasopressor in septic shock patients on multiple vasopressors. Angiotensin II improved mean arterial pressure and helped in reduction of the doses of catecholamines. In a recent large randomized controlled trial, angiotensin II improved blood pressure in catecholamine-resistant distributive shock patients.~Microcirculation is the primary site of oxygen and nutrient exchange. Maintenance of microcirculatory perfusion is a prerequisite for preservation of organ function. Multiple organ failure is common in patients with distributive shock despite maintenance of parameters of global perfusion due to disrupted microcirculatory perfusion. Furthermore, restoration of microcirculatory perfusion was correlated with improvement in survival. This study aims to investigate the effect of angiotensin II on peripheral microcirculation in patients with septic shock.
This study aims to investigate the effect of angiotensin II on microcirculation and peripheral perfusion in patients with septic shock.