Reversal of Prilocaine Epidural Anesthesia Using Epidural Saline or Ringer’s Lactate Washout

Abstract

Several investigators have described the phenomena of epidural saline washout using bolus injections. This study was designed to determine whether epidural block could be reversed more effectively by infusion of crystalloid solutions via the epidural catheter. One hundred male patients scheduled for outpatient surgery were enrolled in this study. After 30 min of 2% prilocaine epidural anesthesia, patients were randomly assigned to receive 45 mL of study solution as follows: (1) normal saline bolus (group NSB); (2) Ringer's lactate bolus (group RLB); (3) normal saline infusion (group NSI); (4) Ringer's lactate infusion (group RLI). Patients in the control group received no washout fluid. Motor, sensory blockade and side effects were compared among 5 groups. Ambulation time is defined as the recovery time. In the control group, ambulation time (139 +/- 15 min) was significantly longer than in the washout groups (NSB 90 +/- 10, RLB 88 +/- 10, NSI 85 +/- 8, RLI 91 +/- 6 minutes) (P < .001). Two-segment sensory regression time in the control group (86 +/- 15 min) was significantly longer than in groups NSB, RLB, NSI and RLI (55 +/- 8, 51 +/- 4, 58 +/- 8, and 53 +/- 10 minutes, respectively) (P < .001). We concluded that a more rapid recovery of motor and sensory blockade in patients undergoing epidural anesthesia may be achieved by the use of an epidural washout with either bolus or infusion of 45 mL normal saline or Ringer's lactate.