Related Experiment Video
Updated: Jun 9, 2026
Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure
Published on: October 1, 2019
Changes in cerebral oxygen saturation and blood flow during hypoxic gas ventilation therapy in HLHS and CoA/IAA
Kentaro Toiyama1, Kenji Hamaoka, Tatsujiro Oka
1Department of Pediatric Cardiology and Nephrology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan. toy-ken@koto.kpu-m.ac.jp
Background:
Hypoxic gas ventilation therapy has recently been performed to prevent post-birth increased pulmonary blood flow in cases of congenital heart diseases with increased pulmonary blood flow. However, how the oxygen supply to the tissues changes during breathing a hypoxic gas mixture, remains unknown. The changes in cerebral oxygen saturation and blood supply during hypoxic gas ventilation therapy using a nitrogen gas mixture were studied.
Methods And Results:
Cerebral regional oxygen saturation (cerebral rSO(2)) was measured by near-infrared spectroscopy, and changes in middle cerebral artery (MCA) blood flow and an index of vascular resistance (RI) were assessed in 8 consecutive patients having congenital heart diseases with increased pulmonary blood flow. In all patients, urinary volume increased significantly, and the respiratory rate showed a clear decrease. Percutaneous oxygen saturation showed no significant change. The average of cerebral rSO(2) was 67.3% before hypoxic gas ventilation, but increased to 69.4%, 69.1%, and 70.7% within 1, 12, and 24 h after initiation of treatment, respectively. MCA blood flow significantly increased in the diastolic phase, and RI significantly improved from 0.80 to 0.68 within 12 h after initiation of therapy.
Conclusions:
These results indicate that hypoxic gas ventilation therapy does not decrease cerebral oxygen saturation, but safely improves the cerebral blood supply in cases of congenital heart diseases with increased pulmonary blood flow.
Related Concept Videos
01:16Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue, improving...
01:21Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
01:27Oxygen Transport in the Blood
01:23Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
01:30Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
01:31Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...