Accuracy of Non-Invasive Blood Pressure Monitoring During Laparoscopic Surgery in the Trendelenburg Position: A Prospective Error Grid Analysis
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Proportion of Paired Systolic Blood Pressure Measurements Within Zone A of the Error Grid
研究概览
简要总结
This study will test how accurate a blood pressure cuff is during certain types of surgery.
During some abdominal surgeries done with small tools and a camera (called laparoscopic surgery), doctors place patients in a head-down position called the Trendelenburg position. In this position, it may be harder for the blood pressure cuff on the arm to give correct readings. This study will compare the cuff's readings (non-invasive) with readings from a thin tube placed inside an artery (invasive), which is more accurate but also more risky and uncomfortable.
The researchers will use a method called error grid analysis to check how closely the cuff readings match the invasive ones. They hope to learn if the blood pressure cuff is accurate enough to be used safely in this kind of surgery. If it is, doctors may not need to use the invasive method as often.
People 18 years or older who are already going to have invasive blood pressure monitoring as part of their planned surgery can join the study. The study will collect blood pressure measurements about every 20 minutes during surgery, as well as basic information like age, weight, and what medicines are given.
详细描述
This is a prospective observational study designed to evaluate the clinical accuracy and reliability of non-invasive blood pressure (NIBP) monitoring in adult patients undergoing laparoscopic surgery in the Trendelenburg position. The accuracy of NIBP will be assessed by comparing it to invasive arterial blood pressure (IABP), which is considered the reference standard. The comparison will be performed using error grid analysis, a method that not only quantifies measurement differences but also categorizes the clinical risk of those discrepancies.
The Trendelenburg position, characterized by a head-down tilt of the patient, is frequently employed during gynecological and urological laparoscopic procedures to enhance surgical exposure. However, this positioning alters hemodynamic physiology and may influence peripheral blood pressure measurements. Previous evaluations of NIBP in this context have primarily relied on Bland-Altman analysis, which measures statistical agreement but does not assess the potential clinical consequences of disagreement between methods.
Error grid analysis overcomes this limitation by mapping paired NIBP and IABP values into predefined risk zones (A-E), based on their potential to affect clinical decision-making. Zone A reflects acceptable agreement with no risk of incorrect treatment, whereas Zones B through E indicate increasing levels of clinical risk.
In this study, NIBP and IABP will be measured simultaneously every 20 minutes throughout the procedure. The proportion of measurements falling within each error grid zone will be calculated. If fewer than 90% of the paired measurements fall within Zone A, NIBP will be considered insufficiently reliable for use in this surgical context without concurrent invasive monitoring.
A pilot study of five patients was conducted to estimate the intracluster correlation coefficient and design effect, which informed the final sample size calculation. Based on these preliminary data, a total of 100 patients is estimated to provide adequate statistical power to evaluate the primary outcome with 95% confidence and a 5% margin of error.
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 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age 18 years or older
- •Scheduled to undergo laparoscopic surgery in the Trendelenburg position
- •Will receive invasive arterial blood pressure monitoring as part of routine clinical care
排除标准
- •Has peripheral artery disease
- •Has congestive heart failure
结局指标
主要结局
Proportion of Paired Systolic Blood Pressure Measurements Within Zone A of the Error Grid
时间窗: Intraoperative period (measurements taken every 20 minutes during surgery)
The percentage of systolic non-invasive blood pressure (NIBP) measurements that fall within Zone A of the consensus error grid with calibrated risk zones, as described by Saugel et al.\[1\]. Zone A represents measurement pairs with no risk of leading to inappropriate clinical decisions, based on comparison with simultaneously recorded systolic invasive arterial blood pressure values. Systolic NIBP measurements will be considered acuurate if 90% or more of the paired values fall within Zone A. 1. Saugel B, Grothe O, Nicklas JY. Error Grid Analysis for Arterial Pressure Method Comparison Studies. Anesth Analg. 2018 Apr;126(4):1177-1185
Proportion of Paired Mean Arterial Pressure (MAP) Measurements Within Zone A of the Error Grid
时间窗: Intraoperative period (measurements taken every 20 minutes during surgery)
The percentage of non-invasive mean arterial pressure (MAP) measurements that fall within Zone A of the consensus error grid with calibrated risk zones, as described by Saugel et al.\[1\]. Zone A represents measurement pairs with no risk of leading to inappropriate clinical decisions, based on comparison with simultaneously recorded invasive MAP values. Non-invasive MAP measurements will be considered accurate if 90% or more of the paired values fall within Zone A. 1. Saugel B, Grothe O, Nicklas JY. Error Grid Analysis for Arterial Pressure Method Comparison Studies. Anesth Analg. 2018 Apr;126(4):1177-1185
次要结局
- Distribution of Paired Mean Arterial Pressure (MAP) Measurements Across All Error Grid Zones (A-E)(Intraoperative period (measurements taken every 20 minutes during surgery))
- Effect of Antihypertensive Medication Use on the Accuracy of Systolic NIBP Measurements(Intraoperative period (measurements taken every 20 minutes during surgery))
- Distribution of Paired Systolic Blood Pressure Measurements Across All Error Grid Zones (A-E)(Intraoperative period (measurements taken every 20 minutes during surgery))
- Effect of Antihypertensive Medication Use on the Accuracy of Mean Arterial Pressure (MAP) NIBP Measurements(Intraoperative period (measurements taken every 20 minutes during surgery))
研究者
Kamil Darcin
Associate professor
Koç University