THE EFFECT OF HEAD-DOWN TILT ON ARTERIAL BLOOD-PRESSURE AFTER SPINAL-ANESTHESIA

We examined the usefulness of 100 head-down tilt for hypotension after spinal block. Two different investigations were performed, one employ ing head-down tilt after arterial blood pressure had decreased (n = 40 ), and the other using a prophylactic tilt (n = 50). When the head-dow n tilt was applied to treat hypotension after spinal block (n = 40), a rterial blood pressure increased only in patients whose systemic blood pressure decreased more than 30% from the control (severe hypotension group, n = 11). However, even in the severe hypotension group, systol ic blood pressure did not increase in two patients after 10-degrees he ad-down tilt. When the head-down tilt was performed immediately after spinal block (n = 24), the changes in systolic blood pressure were the same as in the horizontal group (n = 26). The cephalad spread of anal gesia at 20 min after spinal block was higher, however, in the head-do wn tilt group (T3.8 +/- 1.6) than the horizontal group (T5.2 +/- 1.9). From these results we conclude that head-down tilt for hypotension af ter spinal block increases arterial blood pressure only for severe hyp otension, and that prophylactic bead-down tilt has no effect in mainta ining blood pressure.