Comparison of hyperbaric and plain ropivacaine 15 mg in spinal anaesthesia for lower limb surgery

Abstract

Background. Previously, plain ropivacaine 15 mg given intrathecally has been shown to be feasible for ambulatory surgery of lower-extremities. Hypothetically, hyperbaric solution could improve and shorten the block. Methods. This prospective, randomized, double-blind study included 56 patients undergoing surgery of lower extremities. They received intrathecally either 1.5 ml of ropivacaine 10 mg ml-1 0.5 ml of glucose 300 mg ml-1 (HYP) or 2 ml of ropivacaine 7.5 mg ml-1 (PL). Results. All patients in Group HYP achieved T10 dermatome analgesia but only 64% (18/28) of Group PL. T10 analgesia was reached in 5 min (median, range 5-20 min) in the HYP group vs 10 min (5-45 min) in the PL group (P=0.022), and full motor block in 10 min (5-45 min) vs 20 min (5-60 min) (P=0.003), respectively. Group HYP had a longer duration of analgesia at T10; 83 min (5-145 min) vs 33 min (0-140 min) (P=0.004). Duration of sensory block from injection of the anesthetic to complete recovery was shorter in Group HYP than in Group PL, 210 min (120-270 min vs 270 min (210-360 min) (P<0.001), as was duration of motor block, 120 min (5-150 min) vs 210 min (120-330 min) (P<0.001). Patients of Group HYP attained discharge criteria earlier than those of Group PL (P=0.009). Conclusion. In comparison with the plain solution, 15 mg of intrathecal hyperbaric ropivacaine produced a faster onset, greater success rate of analgesia atthe level of T10 dermatome, and faster recovery of the block. © The Board of Management and Trustees of the British Journal of Anaesthesia 2004.