THE EFFECT OF HEAD-DOWN TILT POSITION ON ARTERIAL BLOOD-PRESSURE AFTER SPINAL-ANESTHESIA FOR CESAREAN DELIVERY

Background and Objectives. The effect of the head-down tilt position a fter induction of spinal anesthesia for cesarean delivery on blood pre ssure and level of sensory block was examined. Methods. Patients were allocated randomly into two groups, the head-down tilt group (n = 17) and the horizontal group (n = 17). In the head-down tilt group, patien ts were positioned with a 10 degrees head-down tilt immediately after supine positioning, while those in the horizontal group were maintaine d in a horizontal position. All patients received 500 mL, of lactated Ringer's solution intravenously over 10 minutes prior to spinal inject ion, a wedge was placed under the patient's right hip, and the operati ng table was rotated 5 degrees in a counterclockwise direction to prov ide left uterine displacement. Hypotension (defined as systolic blood pressure below 100 mm Hg) was treated with 5 mg ephedrine intravenousl y and an increase in the infusion rate of lactated Ringer's solution. The change in systolic blood pressure was expressed as percent change from the baseline value. Results. Systolic blood pressure decreased 20 % at 3 minutes after spinal block in both groups but recovered to half of this decrease. The incidence of postspinal hypotension was not dif ferent between the two groups. The total amount of ephedrine and lacta ted Ringer's solution administered during the first 20 minutes of spin al block did not differ between the two groups nor did the extent of t he cephalad spread of analgesia 20 minutes after spinal block (T4 +/- 2 vs T4 +/- 1 for the head-down and horizontal groups, respectively). Conclusions. The head-down position is concluded to have no effect on the incidence of hypotension during spinal anesthesia for cesarean del ivery.