RESUMEN
The aim of the present study was to compare spinal 0.25% hyperbaric ropivacaine [6 mg] to 0.25% hyperbaric bupivacaine [4 mg] to produce selective spinal anesthesia for ambulatory diabetic foot debridment in critically ill patients. Thirty patients aged >/= 70 years with ASA score of III-IV, type I diabetes mellitus, secondary hypertension and ischemic heart disease undergoing unilateral diabetic foot debridment [30 minutes duration] were included in the study. They were divided into two groups, 15 patients each. The peak sensory level in the operative side was nearly equal in both groups [T[10]]. Time to peak sensory block was significantly longer, however the duration of sensory block was significantly shorter in ropivacaine group compared to bupivacaine group [18 +/- 2 min and 90 +/- 10 min versus 15 +/- 2 min and 115 +/- 10 min respectively]. Time to maximum motor block was equal in both groups [17 min]. However duration of motor block, time to walk and time to void were significantly shorter in ropivacaine group [100 +/- 8 min, 130 +/- 10 min and 160 +/- 15 min] respectively, in comparison to bupivacaine group [119 +/- 10 min. 142 +/- 12 min and 180 +/- 10 min]. These data suggest that the 6 mg dose of 0.25% hyperbaric ropivacaine is as effective as the 4mg dose of 0.25% hyperbaric bupivacaine in ambulatory diabetic foot debridment, however superior to produce more selective spinal anaesthesia with shorter duration of sensory and motor block