Comparison of Different Local Anesthetic Volumes for Saddle Block Anesthesia in Ambulatory Surgery: A Prospective Randomized Trial

Introduction: Saddle block anesthesia (SBA) is a frequently preferred method for ambulatory anorectal surgery. This study aimed to observe the effects of two different dose SBAs on discharge times and perioperative block characteristics in patients undergoing ambulatory anorectal surgery. Methods: The study was conducted as a prospective, randomized controlled study. Patients over the age of 18 who were scheduled for ambulatory anorectal surgery and had American Society of Anaesthesiologists (ASA) physical status I and II were included in the research. Patients were divided into two groups: 5 mg hyperbaric bupivacaine 0.5% (Group I; n=34) and 3 mg hyperbaric bupivacaine 0.5% (Group II; n=34). The primary outcome was discharge time. Characteristics of the spinal block like time to reach S4 blockade, maximum blocked dermatome, regression time of sensorial, first analgesic need time, voiding time, mobilization time, and side effects were the secondary outcomes. Results: Sixty-eight patients were included in the study. The groups were similar in terms of demographic and surgical characteristics (p > 0.05). In Group II, S4 sensory dermatome blockade time was statistically longer (p: 0.007) and the time to the disappearance of the sensory block was statistically shorter (p < 0.001). Also, voiding time and discharge times were statistically shorter in Group II (p: 0.049, p < 0.001, respectively). Conclusion: SBA provided adequate anesthesia, and the complication rates were limited. Saddle block can be considered an advantageous technique because of conditions that adversely affect recoveries, such as postoperative cognitive problems, nausea, and vomiting due to general anesthesia. In addition, better recovery results and optimal surgical condition with 3 mg hyperbaric bupivacaine in our study suggest that this dose may be a good alternative.