Comparison of haemodynamic parameters between the high and low spinal block in young healthy patients

Background. For some surgical proce-dures a higher sensory block is needed. However, it is complicated by a higher in-cidence of hypotension, more bradycardia and nausea and a higher use of vasoactive drugs. In elderly and obstetric population complications have been attributed to the decrease in cardiac output and systemic vascular resistance, especially in a high block (above Th6). The aim of our study was to find the incidence of hypotension and bradycardia after a spinal anaesthesia in young, healthy patients. As young pa-tients compensate more, we aimed to find the difference in haemodynamic variables between the group with a high and the group with a low spinal block and the un-derlying mechanisms of hypotension. Methods. In a prospective, randomized study 44 American Society of Anaesthe-siologists (ASA) 1 patients scheduled for knee arthroscopy under spinal anaesthe-sia were randomly distributed to a high (group H) and a low (group L) spinal block group. In a group H patients were placed into horizontal, whereas in a group L in 15-degree anti-Trendelenburg posi-tion immediately after the spinal block. Haemodynamic parameters were meas-ured continuously noninvasively from 10 min before to 25 min after the spinal block using the CNAPTM device with the LiD-CORapid monitor.Results. The differences in haemodynamic parameters between the groups were not statistically significant at all measured times despite a significant difference in the spinal block level (18.5 vs 13.3 dermato-mes above S5, p