Preventing the Obturator Nerve Reflex: A Comparison of Ultrasound Guided Obturator Nerve Block and Classic Anatomic Block Technique.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 40
- 试验地点
- 1
- 主要终点
- Nerve conduction velocity
研究概览
简要总结
The key objective of this study is to compare success rates of ultrasound guided obturator nerve block and anatomic landmark guided obturator nerve block as determined by neuromonitoring endpoints and surgeon observations.
详细描述
Transurethral resection of bladder tumor (TURBT) is a urologic surgery used in the treatment of non-muscle invasive bladder cancer. A potential complication of this procedure is bladder rupture or injury secondary to adductor muscle contraction from obturator nerve stimulation. This risk is increased in resection of lateral wall tumors, as electrosurgical resection of these lesions is more likely to inadvertently stimulate the obturator nerve.
There are several mechanisms for preventing the obturator reflex. Pharmacologic paralysis can reliably inhibit thigh adduction. However, TURBT is often a short procedure that is not amendable to intermediate duration neuromuscular blocking medications. The use of succinylcholine is another option but is limited by its short duration of action which may not be adequate for the time needed to resect the tumor. Additionally, many patients have contraindications to the use of succinylcholine. Spinal anesthesia does not reliably prevent the obturator reflex.
Regional anesthesia is another potential treatment modality to prevent the obturator reflex during TURBT. Motor blockade of the obturator nerve will prevent this adduction in the event of inadvertent nerve stimulation. Peripheral blockade of the obturator nerve can be combined with either general or spinal anesthesia. Historically, obturator nerve block (ONB) has been considered a technically challenging procedure. Recently, however, successful ultrasound guided ONB techniques have been reported. To the best of our knowledge there has been no study to date comparing the effectiveness of ONB achieved by anatomic landmarks (with nerve stimulation) versus ultrasound guided ONB (with nerve stimulation) at preventing the obturator reflex during TURBT surgery.
The key objective of this study is to compare success rates of ultrasound guided obturator nerve block and anatomic guided obturator nerve block as determined by neuromonitoring endpoints and surgeon observations.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 35 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients undergoing TURBT for lateral wall bladder tumors at risk for electrical stimulation as determined by the attending surgeon.
排除标准
- •Pre-existing obturator nerve injury
- •Thigh adductor muscle weakness
- •Neuropathy
- •Local anesthetic allergy
- •Infection at the site of injection
- •Abnormal coagulation studies
- •use of neuromuscular blocking medications (if deemed necessary by attending anesthesiologist caring for the patient).
研究组 & 干预措施
Ultrasound Guided
Ultrasound guided obturator nerve block will be performed after induction of general anesthesia. The anterior and posterior divisions of the obturator nerve will be identified with ultrasound. A stimulating needle will be inserted under direct ultrasound visualization. The anterior division will be blocked first. When adductor twitches are present at less than or equal to 0.5 mA, 10 ml of 2% lidocaine will be injected. Next, the needle will be re-directed under direct ultrasound visualization towards the posterior branch of the obturator nerve. After twitches < 0.5 mA are achieved then 10 mL of 2% lidocaine will be injected when the needle tip is visualized in proximity of the posterior branch.
干预措施: Obturator nerve block (Procedure)
Anatomic landmark
Obturator nerve block will be performed after induction of general anesthesia. The adductor magnus tendon approach will be used. A 4 cm insulated stimulating needle will be used to verify location of the obturator nerve by contraction of the thigh adductor group. The needle will be advanced until nerve stimulation is still present at less than or equal to 0.5 mA. When the appropriate nerve stimulation is achieved 10 ml of 2% lidocaine will be injected in divided doses with frequent aspiration. Nerve conduction studies will be repeated once a minute for the first 10 minutes after block completion.
干预措施: Obturator nerve block (Procedure)
结局指标
主要结局
Nerve conduction velocity
时间窗: 1 day
Neuromonitoring technician will measure and record obturator nerve conduction velocity in pre-defined time intervals after performance of obturator nerve block.
次要结局
未报告次要终点
研究者
Jonathan Anson
Assitant professor of Anesthesiology
Milton S. Hershey Medical Center