Early Warning for Desaturation by Oxygen Reserve Index

Early Warning for Desaturation by Oxygen Reserve Index During Induction of General Anesthesia

During the induction of general anesthesia, the anesthesiologist needs to provide the oxygen supply to meet the patient's needs continuously. In the clinical scenario, the pulse oximeter is used as a standard to monitor hemoglobin oxygen saturation (SpO2) but is limited to assess the oxygenation status beyond the measurement of 100%. The Oxygen Reserve Index (ORi) is a dimensionless parameter between 0 and 1 that is related to real-time oxygenation reserve status. This study was designed to evaluate the duration of warning time for desaturation provided by different ORi alarm triggers during prolonged apnea in surgical patients. The primary endpoint was the duration of additional warning time provided by the ORi trigger. The secondary endpoint was the correlation of ORi and PaO2.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

This is an observational study of the routine clinical practice with no specific additional interventions required.

The investigators enrolled the American Society of Anesthesiologists (ASA) physical status I to III patients scheduled for elective surgery with planned arterial catheter placement before induction. Patients were positioned supine on the operating room table. Standard monitors and the ORi sensor were placed. The patients were preoxygenated with a facemask (flow rate of 8 to 10 liters/minute) for 3 minutes with spontaneous ventilation. Propofol (2-2.5 mg/kg), fentanyl (2-3 mcg/kg) and rocuronium (0.6-0.9 mg/kg) were administrated to achieve anesthesia induction during following 3 minutes. The patient was keeping ventilated manually by the anesthesiologist during the induction phase and intubated under direct visualization with a video-assisted laryngoscope at 6 minutes. The endotracheal tube was not connected to the breathing circuit to avoid apneic oxygenation. The patients remained apneic. Ventilation was resumed when SpO2 fell to 90%. ORi and SpO2 were recorded every ten seconds. Arterial blood is sampled every minute, from preoxygenation to resumed ventilation, to observe blood oxygen concentration changes.

Study Type

Observational

Enrollment (Actual)

25

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Taipei, Taiwan, 112
        • Department of Anesthesiology, Taipei Veterans General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Male and female patients aged 18 to 80 years with ASA physical status I to III scheduled for elective surgery with planned arterial catheter placement before induction of general anesthesia and did not match the exclusion criteria.

Description

Inclusion Criteria:

  • Male and female patients aged 18 to 80 years with ASA physical status I to III scheduled for elective surgery with planned arterial catheter placement before induction of general anesthesia.

Exclusion Criteria:

  • Age <18 years
  • Inability to give primary consent
  • Pregnancy
  • History of chronic obstructive pulmonary disease (COPD)
  • History of asthma
  • Suspected difficult intubation
  • Preoperative hemoglobin less than 10 mg/dl.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Oxygen reserve index
Male and female patients aged 18 to 80 years with ASA physical status I to III scheduled for elective surgery with planned arterial catheter placement before induction of general anesthesia and did not match the exclusion criteria.
This is an observational study of the routine clinical practice with no specific additional interventions required. The investigators enrolled the ASA physical status I to III patients scheduled for elective surgery with planned arterial catheter placement before induction. ORi and standard monitors were placed. The patients were preoxygenated and received anesthesia induction as routine clinical practice. Intubation was done by video-laryngoscope. The endotracheal tube was not connected to the breathing circuit to avoid apneic oxygenation. Ventilation was resumed when SpO2 fell to 90%. ORi and SpO2 were recorded every ten seconds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Additional warning time provided by ORi trigger
Time Frame: From time of starting preoxygenation until the time of SpO2 90%, assessed up to 20 minutes
The ORi peak warning time was defined as the duration from ORi decreased by 0.05 from the plateau or peak values until SpO2 decreased to 90%. The ORi 0.55 warning time was defined as the duration from the ORi value was 0.55 to SpO2 90%. The SpO2 waring time was defined as the duration from SpO2 98% to 90%. The added warning time provided by ORi peak or ORi 0.55 was defined as the difference between ORi peak warning time, ORi 0.55 warning time, and SpO2 warning time. The investigators will check the duration of the additional warning time provided by the ORi trigger.
From time of starting preoxygenation until the time of SpO2 90%, assessed up to 20 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation between ORi and PaO2
Time Frame: From time of starting preoxygenation until the time of SpO2 90%, assessed up to 20 minutes
The Oxygen Reserve Index is a dimensionless parameter between 0 and 1 that is related to real-time oxygenation reserve status in the moderate hyperoxic range (PaO2 of about 100 to 200 mmHg). The investigators will check the correlation between ORi and PaO2 in our study.
From time of starting preoxygenation until the time of SpO2 90%, assessed up to 20 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2019

Primary Completion (Actual)

October 30, 2019

Study Completion (Actual)

October 30, 2019

Study Registration Dates

First Submitted

July 7, 2021

First Submitted That Met QC Criteria

July 21, 2021

First Posted (Actual)

July 26, 2021

Study Record Updates

Last Update Posted (Actual)

July 26, 2021

Last Update Submitted That Met QC Criteria

July 21, 2021

Last Verified

July 1, 2021

More Information

Terms related to this study

Other Study ID Numbers

  • 2019-06-1-018CC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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