The Relationship Between Needle Position and Injection Pressure During Femoral Nerve Block
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Incidence of high opening injection pressure (15 psi or greater) when needle tip in contact with nerve
研究概览
简要总结
Recent evidence suggests that injection pressure monitoring may be able to predict needle nerve contact in the brachial plexus nerve block model, but little is known about multifascicular nerves. The investigators hypothesize that injection pressure monitoring can reliably predict needle-nerve contact during femoral nerve block.
详细描述
Single center, observational study. Patients scheduled for elective lower limb surgery with femoral nerve block will be recruited. Femoral nerve will be identified using a linear ultrasound transducer. A 22 GA 5 cm nerve block needle will be inserted with bevel downward and advanced to the following conditions:
- Needle tip slightly indenting the fascia iliaca lateral to the femoral nerve
- Needle tip advanced through fascia iliaca
- Needle tip slightly indenting the anterior surface of the femoral nerve
- Needle tip withdrawn 1 mm from nerve.
At each of these conditions, 1 ml of dextrose solution will be injected via an automated pump at 10 ml/min and the spread of injectate observed sonographically. Simultaneously, a blinded observer will measure opening injection pressure using both an electronic and a mechanical transducer. If opening pressure reaches 15 psi, this investigator will halt the injection. In addition, minimum threshold current required to elicit a motor response will be recorded for conditions 3 and 4. Patients will be contacted at 7 days and asked about any adverse effects.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age 18-65
- •ASA physical status I-III
- •scheduled for lower limb surgery where femoral block is part of intended analgesic plan
排除标准
- •Contraindication to femoral nerve block (e.g. infection)
- •BMI > 35 kg/m2
- •inability to communicate postoperative symptoms
- •pre-existing neurologic deficits in the operative extremity
- •allergy to local anesthetics
- •history of opioid dependence
结局指标
主要结局
Incidence of high opening injection pressure (15 psi or greater) when needle tip in contact with nerve
时间窗: 1 minute
次要结局
- Incidence of paresthesias(1 week)
- Incidence of high opening injection pressure (15 psi or greater) at other needle locations(1 minute)
- Minimum threshold current to elicit a motor response with needle-nerve contact and needle disengagement(1 minute)