Best practice & research. Clinical anaesthesiology
-
Best Pract Res Clin Anaesthesiol · Jun 2008
ReviewRole of vasopressinergic V1 receptor agonists in the treatment of perioperative catecholamine-refractory arterial hypotension.
Three pathways are critically involved in blood pressure regulation during anaesthesia, i.e. the sympathetic nervous system, the renin angiotensin system (RAS), and the vasopressinergic system. The fact that anaesthetic agents typically blunt the regulatory role of the adrenergic system emphasises the importance of the remaining compensatory mechanisms. In patients chronically treated with RAS antagonists, such as angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists, however, this mechanism is also blunted, possibly resulting in absolute dependency of blood pressure regulation on the vasopressinergic system. ⋯ In the absence of catecholamine resistance and RAS blockade, administration of V1 agonists may contribute to a dose-dependent reduction in regional splanchnic vasoconstriction. Likewise, bolus infusion may result in coronary vasospasm and is thus not recommended for routine clinical use. Future large-scale randomized, controlled clinical trials are warranted to evaluate the role of V1 agonists in the treatment of perioperative hypotension in more detail.
-
Best Pract Res Clin Anaesthesiol · Jun 2008
ReviewPhysiology and pathophysiology of the vasopressinergic system.
Arginine vasopressin, a hypothalamic peptide hormone, has multiple physiological functions, including body water regulation, control of blood pressure and effects on body temperature, insulin release, corticotropin release, memory and social behaviour. These functions are achieved via at least three specific G-protein-coupled vasopressin receptors. ⋯ The complex signalling and messenger processes which take place after receptor stimulation are now more clearly understood. Vasopressin dysregulation can occur in various disease processes, and a better understanding of the mechanisms underlying physiological synthesis, release and regulation of vasopressin will help in the development of therapies to treat these conditions.
-
Best Pract Res Clin Anaesthesiol · Jun 2008
ReviewArginine vasopressin as a rescue vasopressor to treat epidural anaesthesia-induced arterial hypotension.
Epidural anaesthesia is a well-established and recognized technique in anaesthetic practice. Its benefits are multiple and range from positive effects on the respiratory and cardiocirculatory system, a reduced need for analgesics and decreased costs to earlier hospital discharge. Disadvantages like sympathetic blockade followed by hypotension, bradycardia, and cardiac arrest, however, must be taken into consideration. ⋯ In case reports and a small clinical study, administration of AVP or one of its analogues could rapidly reverse hypotension and restore cardiovascular stability. Because no major controlled clinical trial has yet evaluated the effects of AVP on morbidity, AVP can so far not be recommended as a first-line drug to treat cardiovascular instability during epidural anaesthesia. In refractory cases, however, the use of AVP as a rescue vasopressor may be beneficial.
-
This review article summarizes the structure, signalling pathways, and tissue distribution of the vasopressin receptors, V1 vascular, V2 renal, V3 pituitary, and oxytocin receptors, as well as the P2 class of purinoceptors. The physiological effects of vasopressin on its receptors are described. The future direction with regard to the role of the V1a receptor in circulatory shock states is discussed; further studies with V1a receptor agonists are warranted to further develop treatment strategies to reduce mortality in life threatening diseases like septic shock.