Effect Of Dexmedetomidine Infusion On Sublingual Microcirculation In Patients Undergoing On Pump Coronary Artery Bypass Graft Surgery
试验速览
- 阶段
- 4 期
- 入组人数
- 70
- 试验地点
- 1
- 主要终点
- Change in Microvascular flow index
研究概览
简要总结
This study is designed to explore the possible effects of dexmedetomidine infusion on sublingual microcirculation in patients undergoing on-pump coronary artery bypass graft surgery
详细描述
All patients will be premedicated the night before surgery with bromazepam 3 mg PO, and 0.1 mg/Kg morphine sulphate IM one hour preoperatively. Upon arrival to the pre-induction room, the patient will receive supplementary oxygen via a nasal cannula, and will be monitored with ECG, Non invasive blood pressure and pulse oximeter. Under local infiltration anesthesia (lidocaine 2%) a peripheral venous cannula (14 or 16 G) and a 20 G arterial cannula will be inserted. Induction of anesthesia will be accomplished with fentanyl (7-10 μg/Kg), propofol 0.5 - 1.0 mg/Kg and pancuronium (0.08 - 0.12 mg/Kg). After intubation a triple lumen central venous catheter will be inserted in a central vein. The temperature probe will be inserted in the nasopharynx; the TEE probe will be also inserted after decompression of the stomach with a nasogastric tube.
All patients will be mechanically ventilated with a tidal volume of 6-8 mL/kg and a respiratory rate of 12 - 14 to achieve end-tidal CO2 30 - 35 mmHg . A PEEP of 5 cm H2O is also added. FiO2 will be adjusted to achieve a PaO2 between 200 and 300 mmHg. Isoflurane will be adjusted to 1 - 1.5 expired MAC , as well as fentanyl increments of 2 μg/Kg will be used to control adequate level of anesthesia and to maintain hemodynamic stability. Incremental doses of pancuronium will be administered as needed.
Before starting CPB anticoagulation with 400IU/kg heparin iv will be administered and activated clotting time (ACT) will be used to check proper anticoagulation throughout CPB aiming at ACT >400s.
Cardiopulmonary bypass flow rate of 2.2 - 2.4 l/min/m2 is maintained aiming to keep MAP of 50-80 mmHg together with the use of vasopressors and vasodilators when needed. After Initiation of CPB mild hypothermia (34-35℃) will be performed . During weaning from CPB, volume and pharmacological therapy with inotropes and vasodilators will be used as needed to maintain hemodynamic stability. All blood on the CPB machine will be re-infused into the patient and protamine will be administered in a dose of 4 mg/kg to return ACT to baseline values.
Using a computer-generated random sequence of numbers, patients will be allocated to one of the following two study groups:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adult patients aged (>18), males and females, undergoing elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB).
排除标准
- •Patient refusal.
- •Emergency surgeries
- •Redo surgeries
- •Pregnancy
- •Vasculitis
- •Inflammation or infection at the study site
- •History of allergic reaction to study medications
研究组 & 干预措施
Control group (Group C)
During bypass, patients in this group will receive propofol infusion 50 - 70 mcg/kg/min plus normal saline infusion
干预措施: Propofol infusion (Drug)
Control group (Group C)
During bypass, patients in this group will receive propofol infusion 50 - 70 mcg/kg/min plus normal saline infusion
干预措施: Placebo for Dexmedetomidine normal saline infusion (Drug)
Group Dexmedetomidine (Group DEX)
During bypass, patients in this group will receive propofol infusion 50 - 70 mcg/kg/min plus dexmedetomidine infusion 0.5 mcg/kg/hr
干预措施: Dexmedetomidine (Drug)
Group Dexmedetomidine (Group DEX)
During bypass, patients in this group will receive propofol infusion 50 - 70 mcg/kg/min plus dexmedetomidine infusion 0.5 mcg/kg/hr
干预措施: Propofol infusion (Drug)
结局指标
主要结局
Change in Microvascular flow index
时间窗: Immediately before starting CBP (T0) , 30 min after initiation of bypass (T1), and 30 min after weaning from bypass
Microcirculation will be studied with side-stream dark field (SDF) imaging (Microscan; MicroVision Medical, Amsterdam, Netherlands) 5 steady images of at least 20 seconds each will be obtained and stored under a random number. Offline blind analysis of each video will be done by two investigators. A previously validated semiquantitative score will be used (15). It distinguishes between no flow (0), intermittent flow (1), sluggish flow (2), and continuous flow (3). A value is assigned to each individual vessel. The overall score, called the microvascular flow index (MFI), is the average of the individual values.
次要结局
- Change in perfused vessel density(Immediately before starting CBP (T0) , 30 min after initiation of bypass (T1), and 30 min after weaning from bypass)
- Change in Serum lactate(Immediately before starting CBP (T0) , 30 min after initiation of bypass (T1), and 30 min after weaning from bypass)
- Hemodynamic parameters(Every hour for six hours after induction)
- Vasopressor dose(Every hour for six hours after induction)
- Change in Total vascular density(Immediately before starting CBP (T0) , 30 min after initiation of bypass (T1), and 30 min after weaning from bypass)
- Change in proportion of perfused vessel(Immediately before starting CBP (T0) , 30 min after initiation of bypass (T1), and 30 min after weaning from bypass)