Related Experiment Video
Updated: Sep 10, 2026

Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression
Published on: December 10, 2014
Continuous positive airway pressure breathing increases cerebral blood flow velocity in humans
H P Haring1, C Hörmann, S Schalow
1Department of Neurology, University Hospital, Innsbruck, Austria.
Abstract:
The effect of a continuous positive airway pressure (CPAP) of 12 cm H2O on mean middle cerebral artery flow velocity (CBFV) was studied in nine human volunteers by means of transcranial Doppler sonography (TCD). During CPAP breathing, CBFV increased (45 +/- 9 vs 59 +/- 11 cm/s; P < 0.001; mean +/- SD), and pulsatility index (PI) decreased (0.87 +/- 0.1 vs 0.74 +/- 0.2; P < 0.05), indicating an increase in cerebral blood flow due to cerebral vasodilation. This phenomenon should be taken into account when CPAP is applied to patients with intracranial disease or when assessing CBFV patterns of patients during CPAP respiration.
Related Concept Videos
Other Factors Affecting Respiration Centers
However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,...
Hyperpnea and Hyperventilation
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
Cardiopulmonary Resuscitation II: ACLS Airway Management
Increased Intracranial Pressure l: Introduction
Increased Intracranial Pressure ll: Pathophysiology

