Effect of Patient Position on Bupivacaine Dose Requirement and Hemodynamic Stability in Spinal Anesthesia
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 100
- 主要终点
- Maximum Sensory Block Level
研究概览
简要总结
This study compares different combinations of local anesthetic doses and patient positions during spinal anesthesia for urogenital surgery. Spinal anesthesia is a common and safe technique where medication is injected into the lower back to numb the body during surgery.
The study will test two different doses of bupivacaine (a numbing medication): a lower dose (8 mg) and a standard dose (12 mg). It will also test two different patient positions after the spinal injection: lying flat (neutral position) and lying with the head slightly lower than the feet (Trendelenburg position).
Participants will be randomly assigned to one of four groups:
- Group 1: Lower dose + lying flat
- Group 2: Lower dose + head-down position
- Group 3: Standard dose + lying flat
- Group 4: Standard dose + head-down position
The study will measure how well the anesthesia works, how high the numbness spreads in the body, and how it affects blood pressure and heart rate. The goal is to find the best combination of dose and position that provides good anesthesia while keeping blood pressure stable.
This research may help doctors choose the safest and most effective anesthesia approach for each patient based on their individual needs.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Factorial
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
盲法说明
The outcomes assessor evaluating sensory block levels, motor block, and recording data will be blinded to group allocation. The anesthesiologist performing the spinal anesthesia and positioning cannot be blinded due to the nature of the intervention.
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age 18-70 years
- •American Society of Anesthesiologists (ASA) physical status classification I-II
- •Scheduled for elective urogenital surgery
- •Suitable candidate for spinal anesthesia
- •Able to read, understand, and provide written informed consent
- •Body Mass Index (BMI) less than 35 kg/m²
- •Willing to participate in the study
排除标准
- •Contraindications to spinal anesthesia (coagulopathy, infection at injection site, patient refusal)
- •History of neurological disease
- •Spinal deformity or previous spinal surgery
- •History of allergic reaction to local anesthetics (amide-type)
- •ASA physical status classification III or higher
- •Emergency surgery
- •Pregnancy
- •Psychiatric illness preventing effective communication
- •Refusal to participate in the study
- •Unable to understand or provide informed consent
研究组 & 干预措施
8 mg Bupivacaine + Neutral Position
Participants will receive 8 mg of 0.5% hyperbaric bupivacaine via spinal anesthesia at L3-4 or L4-5 interspace in sitting position. Immediately after injection, participants will be positioned supine in neutral (horizontal, 0°) position and maintained in this position throughout the procedure. Standard hemodynamic monitoring and management protocols will be applied.
干预措施: Bupivacaine %0.5 (hyperbaric) (Drug)
8 mg Bupivacaine + 10° Trendelenburg
Participants will receive 8 mg of 0.5% hyperbaric bupivacaine via spinal anesthesia at L3-4 or L4-5 interspace in sitting position. Immediately after injection, participants will be positioned in 10° Trendelenburg position (head-down tilt) and maintained in this position throughout the procedure. Standard hemodynamic monitoring and management protocols will be applied.
干预措施: Bupivacaine %0.5 (hyperbaric) (Drug)
12 mg Bupivacaine + Neutral Position
Participants will receive 12 mg of 0.5% hyperbaric bupivacaine via spinal anesthesia at L3-4 or L4-5 interspace in sitting position. Immediately after injection, participants will be positioned supine in neutral (horizontal, 0°) position and maintained in this position throughout the procedure. Standard hemodynamic monitoring and management protocols will be applied.
干预措施: Bupivacaine %0.5 (hyperbaric) (Drug)
12 mg Bupivacaine + 10° Trendelenburg
Participants will receive 12 mg of 0.5% hyperbaric bupivacaine via spinal anesthesia at L3-4 or L4-5 interspace in sitting position. Immediately after injection, participants will be positioned in 10° Trendelenburg position (head-down tilt) and maintained in this position throughout the procedure. Standard hemodynamic monitoring and management protocols will be applied.
干预措施: Bupivacaine %0.5 (hyperbaric) (Drug)
结局指标
主要结局
Maximum Sensory Block Level
时间窗: From injection to 30 minutes post-spinal anesthesia
The highest dermatomal level of sensory blockade achieved, assessed using pin-prick test (sharp/dull discrimination). Measured as the specific dermatome level (e.g., T4, T6, T8).
Incidence of Hypotension
时间窗: From spinal injection through end of surgery
Proportion of participants experiencing hypotension, defined as mean arterial pressure (MAP) decrease ≥20% from baseline
Sensory Block Onset Time
时间窗: From spinal injection through end of surgery
Time required to achieve T10 dermatomal sensory block level, measured from completion of intrathecal injection to confirmation of T10 level by pin-prick test.
次要结局
- Motor Block Degree(From spinal injection through end of surgery)
- Surgical Adequacy(Throughout surgery)
- Incidence of Bradycardia(From spinal injection through end of surgery)
- Incidence of Nausea and Vomiting(From spinal injection through end of surgery)