Spinal anaesthesia with ropivacaine 5 mg ml(-1) in glucose 10 mg ml(-1) or 50 mg ml(-1)

Forty patients undergoing spinal anaesthesia for a variety ofsurgical procedures were randomly allocated to receive 3 mlof ropivacaine 5 mg ml^–1 in glucose 10 mg ml^–1 or50 mg ml^–1. Onset of sensory block to T10 was significantlyfaster (P=0.03) with the glucose 50 mg ml^–1 solution (median5 min, range 2–20 min) than with the 10 mg ml^–1solution (median 10 min, range 2–25 min). Maximum extentof cephalad spread was virtually the same in both groups (10mg ml^–1 median T6/7, range T3–T10; 50 mg ml^–1median T6, range T3–T10) with similar times to regressionbeyond S2 (10 mg ml^–1 median 210 min, range 150–330min; 50 mg ml^–1 median 210 min, range 150–330 min).Complete motor block was produced in the majority of patients(10 mg ml^–1 90%; 50 mg ml^–1 85%) and the time tocomplete regression was the same in both groups (median 120min, range 90–210 min). A block adequate for the projectedsurgery was achieved in all patients. Br J Anaesth 2001; 86: 241–4