[Elimination of the obturator reflex with prilocaine in transurethral resection of bladder tumors in combination with spinal and general anesthesia].

During transurethral resection of bladder tumors under either spinal or general anesthesia without muscular relaxation, direct stimulation of the obturator nerve by the electroresectoscope is possible. The resulting obturator reflex may lead to severe complications, at the worst to a perforation of the bladder. Therefore, if resection in lateral bladder regions is necessary, blockade of the obturator nerve is often required to provide optimal conditions for transurethral resection of bladder tumors. To interrupt the obturator reflex are, we blocked the inguinal lumbar plexus using the "3-in-1-block" as described by Winnie because of its advantages compared to isolated blockade of the obturator nerve. Prilocaine 1% was the chosen local anesthetic because of its low tendency towards cardiac and cerebral side effects. Spinal anesthesia was induced with 3-4 ml hyperbaric bupivacaine 0.5%. After the onset of analgesia, making use of a nerve stimulator, a "3-in-1-block" was completed with 30-35 ml prilocaine 1%. The study included over 90 patients. Firstly we observed the efficiency of the obturator motor block by the "3-in-1-block"; secondly clinical side effects of prilocaine were evaluated; and finally in 20 cases methemoglobin levels were measured before and 90 min after injection of prilocaine. A "3-in-1-block" with prilocaine 1% provided a good motor block of the obturator nerve. Neither clinical side effects nor relevant methemoglobinemia occurred. In 3 cases methemoglobin levels were elevated by 1%, whereas in the remaining 17 cases methemoglobin values were normal.(ABSTRACT TRUNCATED AT 250 WORDS)