Blood Pressure Monitoring Accuracy in Patients Undergoing Lung Surgery With One-Lung Ventilation Using an Arm Cuff and Arterial Line
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Non-Invasive Blood Pressure Monitoring During Thoracoscopic Surgery With One-Lung Ventilation. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Accuracy of Non-Invasive Blood Pressure Monitoring During Video-Assisted Thoracoscopic Surgery With One-Lung Ventilation: A Prospective Error Grid Analysis
Overview
This study will test how accurate a blood pressure cuff is during a specific type of chest surgery. In some lung surgeries, doctors use a method called video-assisted thoracoscopic surgery (VATS), where small tools and a camera are inserted through the chest wall. During these procedures, patients often have only one lung ventilated to give the surgeon more space to work. This setup can affect how well a blood pressure cuff on the arm reflects the true blood pressure inside the body. This study will compare readings from the arm cuff (non-invasive) with those from a thin tube placed inside an artery (invasive), which is more accurate but also more uncomfortable and carries some risks. Researchers will use a method called error grid analysis to see how closely the cuff readings match the invasive ones. They want to find out if the cuff is accurate enough to be used safely in these surgeries. If it is, patients might not need an invasive line as often in the future. People 18 years or older who are already going to have invasive blood pressure monitoring during planned thoracic surgery with one-lung ventilation may be able to join the study. The research team will collect blood pressure measurements about every 20 minutes during surgery, as well as basic information like age, weight, and what medications are given.
Detailed description
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 video-assisted thoracoscopic surgery (VATS) with one-lung ventilation (OLV). 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.
During VATS procedures, one lung is intentionally deflated to improve surgical access, which alters thoracic pressures, ventilation dynamics, and cardiovascular physiology. These changes may affect the accuracy of peripheral blood pressure measurements obtained using an arm cuff. Previous evaluations of NIBP in surgical patients have primarily relied on Bland-Altman analysis, which measures statistical agreement but does not assess the clinical consequences of disagreement between methods.
Error grid analysis overcomes this limitation by mapping paired NIBP and IABP values into predefined clinical risk zones (A-E), based on their potential to affect treatment decisions. Zone A represents measurements with no risk of causing inappropriate treatment, while Zones B through E indicate increasing levels of clinical risk due to measurement error.
In this study, NIBP and IABP measurements will be recorded simultaneously approximately every 20 minutes throughout surgery. The percentage of measurements that fall 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 without concurrent invasive monitoring in this clinical context.
A pilot study of five patients was used to estimate the intracluster correlation coefficient and design effect, which informed the final sample size calculation. Based on these preliminary data, a total sample size of 90 patients is estimated to provide adequate statistical power to evaluate the primary outcome with 95% confidence and a 5% margin of error.
The study will also collect intraoperative data that may influence blood pressure measurement accuracy, such as the use of vasoactive infusions. These data may help identify subgroups in which NIBP is more or less reliable during one-lung ventilation.
The results of this study may help refine intraoperative monitoring strategies and potentially reduce unnecessary use of invasive blood pressure lines in selected thoracic surgical patients, improving both safety and comfort while maintaining clinical reliability.
Primary outcome measures
- Proportion of Paired Systolic Blood Pressure Measurements Within Zone A of the Error Grid [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
- Proportion of Paired Mean Arterial Pressure (MAP) Measurements Within Zone A of the Error Grid [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
Secondary outcome measures (4)
- Distribution of Paired Systolic Blood Pressure Measurements Across All Error Grid Zones (A-E) [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
- Distribution of Paired Mean Arterial Pressure (MAP) Measurements Across All Error Grid Zones (A-E) [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
- Effect of Antihypertensive Medication Use on the Accuracy of Systolic NIBP Measurements [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
- Effect of Antihypertensive Medication Use on the Accuracy of Mean Arterial Pressure (MAP) NIBP Measurements [Time frame: Intraoperative period (measurements taken every 20 minutes during surgery)]
Eligibility criteria
Inclusion criteria
- Age 18 years or older
- Scheduled to undergo video-assisted thoracoscopic surgery with one-lung ventilation
- Will receive invasive arterial blood pressure monitoring as part of routine clinical care
Exclusion criteria
- Has peripheral artery disease
- Has congestive heart failure
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Center list to be confirmed — check the primary protocol.
Publications
- Saugel B, Grothe O, Nicklas JY. Error Grid Analysis for Arterial Pressure Method Comparison Studies. Anesth Analg. 2018 Apr;126(4):1177-1185. doi: 10.1213/ANE.0000000000002585. PMID 29239945
Identifiers
NCT: NCT07107698 · 2025.244.IRB2.110