Minimal-flow Anesthesia, Surgical Duration, and Postoperative Cognitive Dysfunction in Older Patients
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 90
- 试验地点
- 1
- 主要终点
- Change in Mini-Mental State Examination score
研究概览
简要总结
Purpose:
Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following major surgery and is associated with impaired attention, memory, and executive functions. Advanced age and prolonged surgical duration are among the most important risk factors. Minimal flow anesthesia has been suggested to reduce postoperative cognitive impairment by providing more stable anesthetic depth and reducing physiological stress.
The aim of this study is to investigate the relationship between surgical duration and postoperative cognitive dysfunction in elderly patients undergoing surgery under minimal flow anesthesia.
详细描述
Detailed Description:
Postoperative cognitive dysfunction (POCD) is a syndrome characterized by deterioration in cognitive domains such as attention, memory, executive function, and psychomotor speed, particularly in elderly patients after major surgical procedures. POCD may become evident in the early postoperative hours or may present days to weeks after surgery. Its incidence increases with age, prolonged surgical duration, anesthetic technique, comorbid conditions, and perioperative physiological disturbances.
Diagnosis of POCD requires comparison of preoperative baseline cognitive status with postoperative neurocognitive assessments. The Mini-Mental State Examination (MMSE) and the Richmond Agitation-Sedation Scale (RASS) are validated and reliable tools for evaluating cognitive status in the perioperative period.
Minimal flow anesthesia is defined as the use of fresh gas flow rates between 0.25 and 0.5 L/min, allowing partial rebreathing of anesthetic agents. This technique reduces anesthetic consumption, maintains stable anesthetic depth, and preserves temperature and humidity, potentially minimizing physiological stress. Previous studies suggest that minimal flow anesthesia with sevoflurane may be associated with a lower incidence of early postoperative cognitive impairment compared to higher flow techniques.
In this prospective interventional study, patients aged 65-85 years undergoing surgery under minimal flow inhalational anesthesia will be enrolled. Patients will be divided into two groups based on surgical duration: surgeries lasting less than 2 hours and surgeries lasting 2 hours or longer, with 45 patients in each group.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- Single (Outcomes Assessor)
盲法说明
Outcome assessors performing the cognitive evaluations will be blinded to surgical duration and intraoperative management.
入排标准
- 年龄范围
- 65 Years 至 85 Years（Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Inclusion Criteria:
- •Patients aged between 65 and 85 years
- •ASA physical status I-III
- •Scheduled for elective surgery under general anesthesia in general surgery or otorhinolaryngology operating rooms
- •Planned to receive minimal flow general anesthesia
- •Preoperative Mini-Mental State Examination performed
- •Able to provide informed consent
排除标准
- •Age outside the specified range
- •ASA physical status IV or higher
- •Severe comorbid disease affecting perioperative stability
- •Surgery performed under regional anesthesia
- •History of alcohol, drug, or substance abuse
- •Significant visual or hearing impairment interfering with cognitive testing
- •Refusal to participate
- •Known neurological or psychiatric disorders
- •Preoperative MMSE score below 24
- •Perioperative hemodynamic instability
- •Illiteracy preventing completion of cognitive tests
- •Postoperative admission to intensive care unit
- •Exclusion Criteria:
研究组 & 干预措施
Arm 1: Surgery duration <2 hours
Elderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of less than 2 hours. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination.
干预措施: Mini-Mental State Examination (Other)
Arm 2: Surgery duration ≥2 hours
Elderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of 2 hours or longer. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination.
干预措施: Mini-Mental State Examination (Other)
结局指标
主要结局
Change in Mini-Mental State Examination score
时间窗: Preoperative baseline, postoperative 24 hours, and postoperative day 7
Cognitive function will be assessed using the Mini-Mental State Examination (MMSE), a 30-point scale ranging from 0 to 30, where higher scores indicate better cognitive function. The primary outcome is the change in MMSE score between the preoperative assessment and postoperative assessments. Change in cognitive function assessed by the difference between preoperative and postoperative Mini-Mental State Examination scores.
次要结局
- Incidence of postoperative cognitive dysfunction(Postoperative 24 hours and postoperative day 7)
研究者
oya Çimen
Specialist Physician
Ankara Etlik City Hospital