Dose finding study of 0.75% hyperbaric ropivacaine for unilateral subarachnoid block in lower limb orthopedic surgeries

Subarachnoid block is one of the important techniques of anesthesia for performing orthopedic lower limb surgeries as it can produce adequate sensory, motor and sympathetic block in a rapid manner. This can become more cost effective with unilateral block as hemodynamic effects, post operative urinary retention can be minimized leading to better patient satisfaction and faster discharge. Ropivacaine is an alternative to bupivacaine for subarachnoid block as it has less chance of cardiotoxicity as well as neurotoxicity. Although 0.5% Ropivacaine in isobaric or hyperbaric form has been used in lower limb surgeries , very less information is available regarding 0.75% Ropivacaine for unilateral block for orthopedic lower limb surgeries. The ideal dose of 0.75% ropivacaine for unilateral subarachnoid block for this type of orthopedic surgeries can be ascertained by assessing the maximum and minimum sensory and motor block on the operative and nonoperative sides and its effect on hemodynamics.