Anesthetic effect of epidural anesthesia with cephalad or caudad catheterization for ankle surgery or hemorrhoidectomy

Background: The larger size of the first sacral nerve root has been reported to be an unfavorable factor leading to sacral sparing in epidural anesthesia. Previous studies have shown that an adequate analgesic effect of the epidural block was achieved with the catheter placement in the caudal direction. In this study, the anesthetic effect of epidural anesthesia with catheter placement of a cephalic or caudad direction was compared in ankle and hemorrhoid surgery. Methods: Twenty-one ASA physical status I or II patients undergoing surgery for ankle fractures with epidural anesthesia were enrolled and randomized into two groups. The epidural catheter was placed either to a cephalad (AU group) or caudal (AD group) direction. Another 21 patients undergoing hemorrhoidectomy were also randomized into two groups to receive epidural anesthesia in a similar way (HU and HD groups). The onset for, duration of, and recovery time from epidural anesthesia and the incidence of analgesic request were recorded. Results: No significant differences were demonstrated when age, height, weight or sex were compared between the four study groups. The onset time of the block and the incidence of intrasurgical analgesic request were lower in the caudal subgroup when the ankle surgery patients were compared. Otherwise, there were no significant differences in the duration of anesthesia and time to recovery or level of anesthesia. Conclusion: Injection of local anesthetic solution through a caudally oriented epidural catheter produces faster onset and superior quality of anesthesia in comparison with the injection through the cephaladly oriented catheter in ankle surgery, but not hemorrhoidectomy.