Cardiovascular and pulmonary effects of epidural anaesthesia.

The cardiovascular effects observed with epidural anaesthesia are complex and are predominantly related to the extent of sympathetic denervation, autonomous balance, baseline blood volume and cardiovascular function of the patient. With epidural anaesthesia the pharmacological effect of systemically absorbed local anaesthetic agents and inclusion of adrenaline to the local anaesthetic solution may play a role. Individual cardiovascular response to different levels of sympathetic blockade varies widely, depending on the degree of sympathetic tone prior to the block. Epidural anaesthesia per se has little effect on respiration in patients with pre-existing lung disease. Thoracic epidural anaesthesia appears to reverse the diaphragmatic dysfunction which is a major determinant of the decrease in lung volumes observed after upper abdominal surgery. This article summarizes cardiovascular and pulmonary responses to epidural anaesthesia.