Can hyperventilation improve cerebral microcirculation in patients with high ICP?

Autor: M, Oertel, D F, Kelly, J H, Lee, T C, Glenn, P M, Vespa, N A, Martin
Rok vydání: 2002
Předmět:
Zdroj: Acta neurochirurgica. Supplement. 81
ISSN: 0065-1419
Popis: Gosling's pulsatility index (PI) is generally thought to reflect cerebrovascular resistance. Hyperventilation and increased intracranial pressure (ICP) usually increase PI. In this study, the effect of hyperventilation on PI was assessed in head injured patients with and without elevated ICP. A total of 73 hyperventilation studies were conducted on 20 intubated TBI patients. EtCO2, ICP, MCA flow velocity and MCA PI bilaterally were recorded simultaneously. Hemispheric CO2-Reactivity (hCO2R) was calculated. Only studies with a baseline ICP15 or30 mm Hg were included for analysis. With hyperventilation pCO2 decreased on average from 33.54.2 to 26.84.8 mmHg. PI increased significantly in patients with baseline ICP15 mmHg (11.8%; p0.0001) but decreased significantly if baseline ICP was30 mm Hg (12.21%; p = 0.0013). High baseline ICP, low initial GCS and impaired hCO2R were associated with the decrease of PI. Hyperventilation unexpectedly reduced PI in patients with high ICP. Because decreased PI suggests decreased CVR, it is postulated that hyperventilation in the setting of raised ICP improves cerebral microcirculation.
Databáze: OpenAIRE