Regional anaesthesia and blood loss.

Epidural and spinal anaesthesia for various types of surgery offer advantages over general anaesthesia by decreasing blood loss and transfusion requirements. This paper focuses on the importance of the choice of anaesthesia on surgical blood loss in total hip arthroplasty. Haemodynamic differences, with lower arterial blood pressure, lower central venous blood pressure, and most importantly lower peripheral venous blood pressure in the surgical wound seem to explain the lower blood loss intra- and post-operatively in patients given regional anaesthesia. These differences in haemodynamics give rise to less arterial, and notably less venous oozing of blood from the surgical area. The latter observation is strengthened by the significant correlations between the intraoperative peripheral venous blood pressure and the intraoperative blood loss. The reduction in blood loss and consequently the reduced transfusion requirements in regional anaesthesia are beneficial in decreasing the hazards and costs of homologous blood transfusion. Although impossible to quantify, reduced bleeding also greatly facilitates the surgeon's work.