Continuous Versus 1-min Oscillometric Arterial BP Monitoring

Study Overview
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Brief Summary
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Hypotension is common during surgery and about one-third of hypotension occur during the period from anesthesia induction to skin incision. Therefore, monitoring blood pressure during this period is crucial. Two methods are used for measuring blood pressure during surgery: the intermittent measurement method (oscillometric method) and the continuous measurement method (arterial catheterization method). The latter is frequently used in surgical patients who require meticulous hemodynamic management, although there is no clearly defined indication for its use. Despite the benefits of arterial catheterization, it is often delayed after induction of general anesthesia, and blood pressure is monitored intermittently using the oscillometric method. A recent study showed that continuous arterial pressure monitoring using arterial catheterization method during the induction of general anesthesia reduced hypotension significantly compared to 2.5-min interval intermittent arterial pressure monitoring using oscillometric method. The study was conducted on patients scheduled for continuous arterial pressure monitoring during surgery and the group with continuous arterial pressure monitoring showed significantly lower incidence of hypotension during the first 15 minutes of anesthesia induction. However, measuring blood pressure using the oscillometric method at 1-min interval, rather than 2.5-min interval, may not be significantly inferior to continuous monitoring via arterial catheterization in terms of hypotension occurrence. This study aims to compare hypotension incidence between arterial catheterization method and oscillometric method with 1-min interval during induction of anesthesia in non-cardiac surgery patients.

Official Title
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Continuous Invasive Versus 1-min Interval Oscillometric Arterial Pressure Monitoring and Hypotension During Induction of Anesthesia: a Bicenter, Randomized, Noninferiority Trial

Conditions
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Anesthesia, General

Intervention / Treatment
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* Device: 1-min interval oscillometric method
* Device: arterial catheterization method


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients aged 19 or older undergoing scheduled non-cardiac surgery with general anesthesia and continuous invasive arterial blood pressure monitoring via the radial artery Exclusion Criteria: Arterial access is clinically necessary before induction of anesthesia (e.g., moderate or higher degree of aortic stenosis, moderate or higher degree of heart failure, coronary artery disease requiring revascularization, intracranial aneurysm with a significant risk of rupture, etc.) Emergency surgery American Society of Anesthesiologists (ASA) physical status 5 or 6 Arterial access is required in a different artery other than the radial artery (e.g., the femoral artery) Electrocardiogram other than sinus rhythm Refusal to participate in the study

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1-min interval oscillometric method<br>1-min interval blood pressure monitoring using oscillometric method during induction of anesthesia | Device: 1-min interval oscillometric method<br>* Before induction of anesthesia, 20-gauge catheter is inserted to radial artery after local anesthesia with lidocaine, and continuous blood pressure monitoring is started. Anesthesia is induced using propofol, opioids (fentanyl or remifentanil), and neuromuscular relaxants (rocuronium, cisatracurium, or vecuronium). For maintenance of anesthesia, propofol infusion or inhalation anesthetics (sevoflurane or desflurane) are used. From the start of anesthesia induction to 15 minutes after, arterial blood pressure is monitored at 1-min interval using oscillometric method. The display of continuous arterial pressure on the anesthesia monitor is turned off during the 15-min study period.<br>|
| Active Comparator: arterial catheterization method<br>Continuous blood pressure monitoring through arterial catheter during induction of anesthesia | Device: arterial catheterization method<br>* During the same time window for 1-min interval oscillometric method, arterial blood pressure is monitored using continuous blood pressure monitoring.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MAP integral | The area under the mean arterial pressure (MAP) of 65 mmHg calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under MAP of 60, 50, 40 mmHg (mmHg∙min) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| Duration of MAP <65, <60, <50, <40 mmHg (min) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| Exposure to MAP <65, <60, <50, and <40 mmHg (binary) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| Exposure to continuous MAP <65, <60, <50, <40 mmHg for 1 minute or longer (binary) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| Area above MBP of 100, 110, 120, 140 mmHg (mmHg∙min) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| MAP standard deviation (mmHg) | calculated using the MAP recorded every second | From the start of anesthesia induction to 15 minutes after | 
| Use of vasopressor (binary) | ephedrine, phenylephrine, norepinephrine (binary) | From the start of anesthesia induction to 15 minutes after | 
| Use of vasopressor (dose) | ephedrine (mg), phenylephrine (μg/kg), norepinephrine (μg/kg) | From the start of anesthesia induction to 15 minutes after | 
| Crystalloid (ml) | Total amount of crystalloid administered | From the start of anesthesia induction to 15 minutes after | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intraoperative hypotention, Induction of anesthesia, Arterial blood pressure monitoring