Comparative Analysis of Sevoflurane-Based Minimal and Metabolic Flow Anaesthesia: A Prospective Randomized Study in a Gynecological Surgery Patient Cohort
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 97
- 试验地点
- 1
- 主要终点
- Core body temperature (°C)
研究概览
简要总结
The aim of this study is to observe the effects of minimal and metabolically required basal anesthetic gas flow rates delivered by the anesthesia workstation under general anesthesia on body temperature, blood pressure, and heart rate during surgery.
It also aims to evaluate the impact of reducing excessive delivery of anesthetic gases, air, and oxygen beyond the patient's physiological needs during general anesthesia on minimizing the harmful effects of anesthetic gases on the environment, climate, and global warming, as well as on contributing positively to hospital costs.
详细描述
This prospective randomized study will be conducted in adult female patients undergoing elective gynecological surgery under general anesthesia. Following standard intravenous induction and endotracheal intubation, anesthesia will be maintained with sevoflurane using an advanced anesthesia workstation capable of delivering minimal and metabolic fresh gas flow rates.
After achieving the target anesthetic depth guided by minimum alveolar concentration (MAC) and MAC Brain monitoring, patients will be randomized to receive either minimal-flow (0.5 L/min) or metabolic-flow (0.3 L/min) fresh gas anesthesia. Randomization will be performed using an internet-based randomization tool.
Standard intraoperative monitoring will be applied in all patients, including electrocardiography, non-invasive blood pressure monitoring, pulse oximetry, capnography, anesthetic gas analysis, and esophageal temperature monitoring. Hemodynamic and respiratory parameters will be recorded at predefined time intervals throughout surgery. Sevoflurane consumption will be automatically calculated by the anesthesia workstation.
At the end of surgery, fresh gas flow will be increased to eliminate residual anesthetic gases, and patients will be extubated according to standard clinical criteria. Postoperative monitoring will continue in the post-anesthesia care unit.
The total study duration for each participant includes the intraoperative period and approximately 30 minutes of postoperative monitoring.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 否
入选标准
- •Female patients aged 18-65 years
- •Undergoing elective gynecologic surgery under general anesthesia (including hysterectomy and/or oophorectomy)
排除标准
- •Pregnant patients
- •Patients with advanced cardiac disease
- •Patients with advanced renal disease
- •Patients with advanced hepatic disease
- •Patients with advanced respiratory disease
- •Severe obesity
- •Heavy smokers
- •Excessive alcohol consumption
- •Known allergic sensitivity to halogenated anesthetic gases
- •Use of medications that may interact with volatile anesthetics
- •History of or susceptibility to malignant hyperthermia or neuromuscular disorders
研究组 & 干预措施
Minimal Flow Group (0.5 L/min)
Participants will receive general anesthesia maintained with sevoflurane at a fresh gas flow rate of 0.5 L/min (minimal flow) after induction and achievement of target anesthetic concentration. Standard monitoring will be applied throughout surgery, including hemodynamic and respiratory parameters.
干预措施: Low Flow Anesthesia (Procedure)
Metabolic Flow Group (0.3 L/min)
Participants will receive general anesthesia maintained with sevoflurane at a fresh gas flow rate of 0.3 L/min (metabolic flow) after induction and achievement of target anesthetic concentration. Standard intraoperative monitoring will be applied as in the minimal flow group.
干预措施: Low Flow Anesthesia (Procedure)
结局指标
主要结局
Core body temperature (°C)
时间窗: From induction of anesthesia until the end of surgery (approximately 1-2 hours)
Mean intraoperative core body temperature (Degrees Celsius (°C)): Measured intraoperatively using an esophageal temperature probe.
Mean intraoperative heart rate (bpm)
时间窗: From induction of anesthesia until the end of surgery (approximately 1-2 hours)
Mean intraoperative heart rate (Beats per minute (bpm)): Measured intraoperatively via electrocardiographic monitoring.
Mean intraoperative mean arterial pressure (mmHg)
时间窗: From induction of anesthesia until the end of surgery (approximately 1-2 hours)
Mean intraoperative mean arterial pressure (Millimeters of mercury (mmHg)): Measured intraoperatively using non-invasive blood pressure monitoring.
Anesthetic gas consumption (mL)
时间窗: From induction of anesthesia until the end of surgery (approximately 1-2 hours)
Total sevoflurane consumption (Milliliters (mL)): As recorded by the anesthesia workstation.
Richmond Agitation-Sedation Scale (RASS) (-5 to 4)
时间窗: At the end of surgery / immediate postoperative period
Richmond Agitation-Sedation Scale (RASS) (-5 to 4): The RASS is a 10-point scale ranging from -5 to +4. Negative scores (-1 to -5) indicate increasing levels of sedation, with -5 indicating an unarousable patient. Positive scores (+1 to +4) indicate increasing levels of agitation, with +4 indicating combative behavior. Scores closer to 0 reflect better recovery quality.
次要结局
- Anesthetic gas cost (USD or local currency)(Intraoperative period - calculated at the end of surgery (1-2 hours).)