Related Experiment Video
Updated: Mar 28, 2026
Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography
Published on: March 26, 2020
Safety of the CO-Rebreathing Method in Patients with Coronary Artery Disease
Trine Karlsen1, Ingeborg Megård Leinan, Inger-Lise Aamot
11K.G. Jebsen Center of Exercise in Medicine, Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, NORWAY; 2Department of Cardiology, St. Olav's University Hospital, NORWAY; 3Clinical Services, St. Olav's University Hospital, NORWAY; 4Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Norway; and 5Levanger Hospital, Nord-Trøndelag Health Trust, Levanger, NORWAY.
Insights
The carbon monoxide rebreathing test is safe for measuring total blood volume in coronary artery disease patients. Cardiovascular function remained stable, with no significant changes observed during or after the test.
Area of Science:
- Cardiovascular Physiology
- Diagnostic Methodologies
Background:
- Accurate measurement of total blood volume is crucial for managing patients with coronary artery disease.
- The carbon monoxide (CO) rebreathing method offers a potential approach for assessing total blood volume.
Purpose of the Study:
- To evaluate the safety and cardiovascular impact of an improved CO rebreathing test for total blood volume measurement.
- To determine the feasibility of using this method in patients with stable coronary artery disease.
Main Methods:
- A crossover study involving 18 patients with stable coronary artery disease.
- Monitoring of ECG, blood pressure, oxygen saturation, cardiac function, hemoglobin bound to carbon monoxide (HbCO%), and troponin-T before, during, and after the CO rebreathing test.
Main Results:
- Hemoglobin bound to carbon monoxide (HbCO%) peaked at 6.0% ± 0.6% post-test and returned to baseline within 24 hours.
- No significant changes were observed in heart rate, stroke volume, cardiac output, or ejection fraction.
- No adverse cardiovascular events, ST-T wave changes, or elevated troponin-T levels were detected.
Conclusions:
- The improved CO rebreathing test is safe for patients with stable coronary artery disease.
- The method does not adversely affect cardiovascular function or safety indices at approximately 6% HbCO exposure.
Purpose:
To address and study the safety concerns with the improved carbon monoxide (CO) rebreathing method for measuring total blood volume in patients with coronary artery disease to implement the use of the methodology in this patient group.
Methods:
Eighteen patients with stable coronary artery disease (age 62 ± 7 yr, 24 ± 5 months since diagnosis) were investigated using the improved CO-rebreathing test. Before, during, and up to 2 h after the test, ECG, blood pressure, arterial oxygen saturation, carbon monoxide bound to hemoglobin (HbCO%), and cardiac function were measured. At 24 h, HbCO% and troponin-T were measured.
Design:
Cross-over.
Results:
Six minutes after the CO-rebreathing test, HbCO increased from 1.5% ± 0.4% to 6.0% ± 0.6%, with a subsequent decrease to 4.5% ± 0.4% and 1.4% ± 0.4% at 2 h and 24 h after the test, respectively. Resting heart rate, stroke volume, cardiac output, and ejection fraction were 64 ± 11 bpm, 93.9 ± 16.5 mL per beat, 5.84 ± 0.99 L, and 48.5% ± 5.7% and remained unchanged during and 10 min after the rebreathing. All patients were in sinus rhythm during the 2-h observation period, without ST- or T-wave changes, with low numbers of premature beats and normal rate variability. Systolic and diastolic blood pressure gradually decreased during the observation period. Troponin-T was below the 99th percentile for all the participants 24 h after the test.
Conclusion:
Cardiovascular function and safety indices remained unchanged after exposure to approximately 6% HbCO, indicating that the method is safe to perform in patients with stable coronary artery disease.
More Related Videos
07:52Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
08:35Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
Related Concept Videos
01:17Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this...
01:22Cardiopulmonary Resuscitation II: ACLS Airway Management
01:26Acute Coronary Syndrome V: Nursing Management
01:27Coronary Artery Disease V: Interprofessional Care
01:30Acute Respiratory Failure-III
01:31Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated....