Is Obturator Nerve Block Effective as Spinal Anesthesia in Preventing Adductor Spasms in General Anesthesia Without Muscle Relaxants?

Aim: During transurethral resection of bladder tumor (TUR-BT), adductor muscle spasms in varying degrees can be seen due to stimulation of obturator nerve if the tumor is in the inferolateral localization. This can cause some serious complications such as bladder perforation. We aim to show the effectiveness of obturator nerve block (ONB) to avoid the adductor muscle spasm in general anesthesia applied with laryngeal mask (LMA) without using muscle relaxant according to the spinal anesthesia method. Methods: The study has been designed prospectively and observationally. A total of 64 patients who underwent TUR-BT were divided into two groups. Group I consisted of 30 patients in whom TUR-BT was performed under general anesthesia without muscle relaxant + ONB. Group II consisted of 31 patients in whom TUR-BT was performed under spinal anesthesia + ONB. Intraoperative adductor spasm, the severity of adductor response, and surgeon satisfaction were recorded. Results: Median values of adductor muscle strengths were found to be higher in Group I (p < 0.05). There was no statistically significant relationship between the anesthetic method and adductor spasm (p = 0.110). Of patients in Group I, 13.4% showed moderate or severe adductor response, whereas the ratio was 0% in Group II (p = 0.015). Surgeon satisfaction was similar in both groups (p = 0.363). Conclusions: Obturator spasm was not different in both anesthesia techniques. General anesthesia without muscle relaxant combined with ONB was found effective to prevent adductor muscle spasms as the spinal anesthesia in TUR-BT operations. It has been concluded that surgical complications can be reduced via general anesthesia without the muscle relaxant method, although surgeons' satisfaction did not alter. General anesthesia and obturator block applications with the help of LMA without muscle relaxants can be preferred in short-term TUR-B operations where spinal anesthesia is not desired.