Modulation of β-adrenergic receptor subtype activities in perioperative medicine: Mechanisms and sites of action

Abstract

This review focuses on the mechanisms and sites of action underlying β-adrenergic antagonism in perioperative medicine. A large body of knowledge has recently emerged from basic and clinical research concerning the mechanisms of the life-saving effects of β-adrenergic antagonists (β-AAs) in high-risk cardiac patients. This article re-emphasizes the mechanisms underlying β-adrenergic antagonism and also illuminates novel rationales behind the use of perioperative β-AAs from a biological point of view. Particularly, it delineates new concepts of β-adrenergic signal transduction emerging from transgenic animal models. The role of the different characteristics of various β-AAs is discussed, and evidence will be presented for the selection of one specific agent over another on the basis of individual drug profiles in defined clinical situations. The salutary effects of β-AAs on the cardiovascular system will be described at the cellular and molecular levels. β-AAs exhibit many effects beyond a reduction in heart rate, which are less known by perioperative physicians but equally desirable in the perioperative care of high-risk cardiac patients. These include effects on core components of an anaesthetic regimen, such as analgesia, hypnosis, and memory function. Despite overwhelming evidence of benefit, β-AAs are currently under-utilized in the perioperative period because of concerns of potential adverse effects and toxicity. The effects of acute administration of β-AAs on cardiac function in the compromised patient and strategies to counteract potential adverse effects will be discussed in detail. This may help to overcome barriers to the initiation of perioperative treatment with β-AAs in a larger number of high-risk cardiac patients undergoing surgery.