The Utility of Oxygen Reserve Index Guidance in Inspiratory Oxygen Titration for Patients Undergoing Surgery in the Beach Chair Position: A Prospective Comparative Study
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 80
- 试验地点
- 1
- 主要终点
- Incidence of Intraoperative Severe Hyperoxemia
研究概览
简要总结
This study aims to evaluate whether guidance by the Oxygen Reserve Index (ORi) improves inspiratory oxygen fraction (FiO₂) titration compared with conventional pulse oximetry (SpO₂)-guided oxygen administration in adult patients undergoing surgery in the beach chair position.
Oxygen therapy is routinely used during general anesthesia to prevent hypoxemia; however, excessive oxygen administration may result in hyperoxia, which has been associated with adverse cardiovascular and pulmonary effects. Standard pulse oximetry may not adequately detect hyperoxia when oxygen saturation values are high.
In this prospective comparative study, patients will receive oxygen titration guided either by SpO₂ alone or by combined ORi and SpO₂ monitoring. The primary outcome is the incidence of intraoperative hyperoxemia, assessed by arterial blood gas analysis. Secondary outcomes include intraoperative oxygenation parameters and hemodynamic variables.
详细描述
This prospective study will be conducted in adult patients (ASA physical status I-III) undergoing elective orthopedic surgery in the beach chair position under general anesthesia. Following approval by the institutional ethics committee and acquisition of written informed consent, eligible patients will be included in the study.
Standard monitoring will include electrocardiography, noninvasive blood pressure, peripheral oxygen saturation (SpO₂), bispectral index (BIS), perfusion index (PI), pleth variability index (PVI), near-infrared spectroscopy (NIRS), and multiwavelength pulse co-oximetry for Oxygen Reserve Index (ORi) monitoring. Invasive arterial blood pressure monitoring will be established via radial arterial cannulation to allow continuous hemodynamic monitoring and arterial blood gas sampling.
General anesthesia will be induced with intravenous propofol, fentanyl, and rocuronium, followed by orotracheal intubation. Mechanical ventilation will be applied in volume-controlled mode with lung-protective settings. Anesthesia will be maintained using sevoflurane and remifentanil infusion, targeting bispectral index values between 40 and 60.
From anesthesia induction onward, inspiratory oxygen fraction (FiO₂) will be titrated either according to SpO₂ values alone or using combined ORi and SpO₂ guidance. In the ORi-guided group, FiO₂ adjustments will aim to maintain ORi values between 0.2 and 0.5, with reassessment at regular intervals. In the SpO₂-guided group, FiO₂ will be adjusted to maintain SpO₂ values at or above 98%, in accordance with routine clinical practice.
Hemodynamic parameters, oxygenation variables, ORi values, and cerebral oxygenation assessed by NIRS will be recorded at predefined time points during surgery and recovery. Arterial blood gas analysis will be performed to determine PaO₂ and arterial oxygen saturation.
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
- 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
- 是
入选标准
- •Adult patients aged 18 to 65 years
- •American Society of Anesthesiologists (ASA) physical status I-III
- •Scheduled for elective orthopedic surgery in the beach chair position
- •Body mass index (BMI) <35 kg/m²
- •Ability to provide written informed consent
排除标准
- •Age <18 or ≥65 years
- •Finger deformities preventing the use of Oxygen Reserve Index (ORi) monitoring
- •Severe anemia (hemoglobin <8 g/dL)
- •Pregnancy
- •Refusal or inability to provide informed consent
- •History of stroke or significant vascular pathology
- •Severe cardiac or respiratory disease
研究组 & 干预措施
ORi-Guided FiO₂ Titration
Inspiratory oxygen fraction (FiO₂) will be titrated using combined Oxygen Reserve Index (ORi) and peripheral oxygen saturation (SpO₂) monitoring throughout surgery.
干预措施: ORi-Guided FiO₂ Titration (Other)
SpO₂-Guided Oxygen Titration
Inspiratory oxygen fraction (FiO₂) will be titrated based on peripheral oxygen saturation (SpO₂) values according to routine clinical practice.
干预措施: SpO₂-Guided FiO₂ Titration (Other)
结局指标
主要结局
Incidence of Intraoperative Severe Hyperoxemia
时间窗: Perioperative/Periprocedural
Severe hyperoxemia will be defined as an arterial partial pressure of oxygen (PaO2) ≥200 mmHg, measured by arterial blood gas analysis at predefined intraoperative time points.
次要结局
- Mean Peripheral Oxygen Saturation (SpO2) During Surgery(Perioperative/Periprocedural)
- Mean Oxygen Reserve Index (ORi) During Surgery(Perioperative/Periprocedural)
- Mean Fraction of Inspired Oxygen (FiO₂) During Surgery(Perioperative/Periprocedural)
- Mean Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy During Surgery(Intraoperative period (from induction of anesthesia to end of surgery))
研究者
Çağla Sancak
Resident in Anesthesiology
Fatih Sultan Mehmet Training and Research Hospital