Cerebral circulation is profoundly affected by changes in PaCO2. CO2 manipulation plays a basic role in the management of intracranial hypertension; CO2 reactivity (CO2R) defines the changes in CBF in response to changes in PaCO2. Transcranial Doppler has allowed exploring its effects "on line".
Centro de Tratamiento Intensivo, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Avenida Brasil 3054 ap 401, 11300 Montevideo, Uruguay. coripuppo@gmail.com