Beta blocker therapy in the intensive care unit

Abstract

Critically ill patients in intensive care units often manifest tachycardia induced by hyperactivity of the sympathetic nervous system, which has been shown to have deleterious effects in patients. As tachycardia has been recognized as a predictor of a poor prognosis, it is very important to suppress hyperactivity of the sympathetic nervous system. Beta blockers have often been used to control tachycardia in high-risk patients undergoing non-cardiac surgery or cardiac surgery, and those with acute myocardial infarction or acute heart failure; previous studies have demonstrated many beneficial effects of beta blocker therapy under these conditions. However, in accordance with advances in medical care, some recent studies have raised concerns about the effects of beta blocker therapy in some cases. It has been pointed out that cardiac dysfunction progresses in the early phase of sepsis, which is characterized by a dysregulated immune system associated with organ dysfunction induced by infection. Some recent animal studies have demonstrated cardioprotective effects of beta blocker therapy in cases of sepsis-induced cardiac dysfunction. Furthermore, these beneficial effects of beta blocker therapy in cases of sepsis were also shown in recent clinical randomized control trials. In this review article, based on the findings of recent studies, both beneficial and deleterious effects of beta blocker therapy in patients with pathophysiologies wherein beta blocker therapy was shown in previous studies to confer beneficial effects are described. The author hopes that future large clinical trials will elucidate the clinical conditions under which beta blocker therapy can confer maximal beneficial effects in critically ill patients.