Complete regression of spinal anesthesia required 71 + / - 20 minutes in Group 4 ( range : 40 to 110 min ) , 82 + / - 25 minutes in Group 6 ( range : 30 to 160 min ) , and 97 + / - 37 minutes in Group 8 ( range : 50 to 120 min ) ( p = 0.003 ) .
