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Completed

NCT Number: NCT05792436

Continuous Versus 1-min Oscillometric Arterial BP Monitoring

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.

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Key information

Conditions

Age range

19 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Seoul National University Hospital, Seoul, South Korea

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

1-min interval oscillometric method

Device

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.

arterial catheterization method

Device

During the same time window for 1-min interval oscillometric method, arterial blood pressure is monitored using continuous blood pressure monitoring.

Primary outcomes

  1. MAP integral

    Time frame: From the start of anesthesia induction to 15 minutes after

    The area under the mean arterial pressure (MAP) of 65 mmHg calculated using the MAP recorded every second

Secondary outcomes

  1. Area under MAP of 60, 50, 40 mmHg (mmHg∙min)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  2. Duration of MAP <65, <60, <50, <40 mmHg (min)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  3. Exposure to MAP <65, <60, <50, and <40 mmHg (binary)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  4. Exposure to continuous MAP <65, <60, <50, <40 mmHg for 1 minute or longer (binary)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  5. Area above MBP of 100, 110, 120, 140 mmHg (mmHg∙min)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  6. MAP standard deviation (mmHg)

    Time frame: From the start of anesthesia induction to 15 minutes after

    calculated using the MAP recorded every second

  7. Use of vasopressor (binary)

    Time frame: From the start of anesthesia induction to 15 minutes after

    ephedrine, phenylephrine, norepinephrine (binary)

  8. Use of vasopressor (dose)

    Time frame: From the start of anesthesia induction to 15 minutes after

    ephedrine (mg), phenylephrine (μg/kg), norepinephrine (μg/kg)

  9. Crystalloid (ml)

    Time frame: From the start of anesthesia induction to 15 minutes after

    Total amount of crystalloid administered

Sponsors and collaborators

Lead sponsor

Seoul National University Hospital

Other

Registry information

Official study title

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

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Mar 31, 2023
Registry last updated
Jan 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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