Regional Blockade versus Analgesic Therapy

Abstract

The early postoperative period is characterized by pain, high plasma catecholamine concentrations, increased energy expenditure, decreased arterial oxygen tension as well as increased glycogenolysis, lipolysis, proteolysis and low turn-over rate of glucose. Per- and postoperative local anaesthesia has often been supposed to counteract some of these phenomena without causing ventilatory depression or mental confusion. During the past few years a number of studies have been carried out in our department in order to elucidate possible differences between systemic analgesics and different local anaesthetic blockades. We have found that adequately performed local anaesthesia as well as systemic analgesic therapy relieve postoperative pain and decrease the increased total energy expenditure towards the normal range. An important difference is perhaps that local anaesthetic techniques during surgery results in a better maintenance of the body core temperature, resulting in less postoperative increase of the systemic oxygen uptake and less strain on the cardiovascular system. It also seems that less interference with ventilatory function is accomplished if local anaesthetic techniques are used. Thus, after orthopaedic surgery of the hip continuous epidural block results in a better oxygen delivery compared to systemic analgesics. It has, however, been difficult to demonstrate any reduction in the rate of respiratory complications. Only recently a large prospective clinical trial on postoperative intercostal blocks has shown a 50 % reduction in pulmonary complications after upper abdominal surgery. It has also been possible to show that local postoperative anaesthesia causes less mental confusion, less bowel problems and less thromboembolic disease.