Effect of Lidocaine Injected on Lower Rectal Submucosa During Hemorrhoidectomy under Caudal Anesthesia

ABSTRACT

BACKGROUND/AIMS: The caudal anesthesia for anal surgery is simple and effective. Also, it is relatively safe because there is no headache or other neurologic complications. But, during the operation under caudal anesthesia, the unwanted symptoms such as lower abdominal pain or hypotensive symptoms were experienced in some patients. These unwanted symptoms may occur due to anal and lower rectal dilatation. The precise mechanism is unknown. But we speculated that some sensory nerve endings in rectal submucosa may be involved in this mechanism. So, we think that it is possible to prevent or reduce these symptoms if we block these sensory nerve endings effectively with local anesthetics. Therefore, the aim of this study is to see whether the locally injected lidocaine can reduce or prevent the unwanted symptoms during anal surgery under caudal anesthesia. METHODS: There were 100 consecutive patients in this study who had hemorrhoidectomy with Jack-knife position under caudal anesthesia at our clinic. We divided evenly these 100 patients into two groups, injection and control groups(in each group, 50 patients were included.). In injection-group, We injected 10 cc(100 mg) of 1% lidocaine solution cir cumferentially into the lower rectal submucosa at the beginning of the operation. In control-group, we did not inject lidocaine solution initially, but the lidocaine injection was done during the operation in the same manner in the injection-group if the severe unwanted symptoms occurred. We used Parks-type retractor to dilate the anus and recorded the patient,s complaints. RESULTS: In injection-group, male to female ratio was 33:17, mean age was 42.1 years(20~69) and mean operation time was 38.3 minutes(15~80). In control-group, male to female ratio was 25:25, mean age was 43.7 years(17~65) and mean oeration time was 38.5 minutes(15~80). Lower abdominal pain was present in 11 patients(22%) among injection-group and in 37 patients(74%) among control-group(p=0.000). Hypotensive symptoms such as nausea, vomiting, sweating and dizziness were present in 1 patient(2%) among injection-group and in 8 patients(16%) among control-group(p=0.014). We injected lidocaine solution into lower rectal submucosa during the operation in 18 patients with severe symptoms among control-group. The effect of the injected lidocaine solution in 18 control patients was good in 13(72%) and fair in 5(28%). With regard to factors influencing the occurrence of symptoms, there was a tendency of higher occurrence in male, the younger-aged and the longer-operation groups. CONCLUSION: The lower rectal submucosal lidocaine injection reduced the unwanted symptoms such as lower abdominal pain and hypotensive symptoms during the anal surgery under the caudal anesthesia.