Sustained moderate reductions in arterial CO2 after brain trauma time-course of cerebral blood flow velocity and intracranial pressure.
Détails
ID Serval
serval:BIB_E5182093CBE4
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Sustained moderate reductions in arterial CO2 after brain trauma time-course of cerebral blood flow velocity and intracranial pressure.
Périodique
Intensive Care Medicine
ISSN
0342-4642
Statut éditorial
Publié
Date de publication
2004
Peer-reviewed
Oui
Volume
30
Numéro
12
Pages
2180-2187
Langue
anglais
Résumé
OBJECTIVE: In healthy volunteers cerebral blood flow starts to recover towards baseline within a few minutes of continued hyperventilation due to normalisation of perivascular pH. We investigated the time-course of changes in middle cerebral artery mean flow velocity (FVm) and intracranial pressure (ICP) in head-injured patients during sustained moderate reductions in arterial partial pressure of CO(2) (PaCO(2)). DESIGN: Observational study. PATIENTS: Twenty-seven sedated, mechanically ventilated patients with severe head injury. INTERVENTIONS: Measurements were made during and after routine determination of CO(2)-reactivity: an acute 20% increase in respiratory minute volume was followed by a 10-min stabilisation period and 50 min of continued moderate hyperventilation at a constant PaCO(2) (>3.5 kPa). MEASUREMENTS AND RESULTS: FVm was monitored with transcranial Doppler, ICP was monitored with intraparenchymal probes. During the 50-min period with stable PaCO(2) FVm increased in 36% of patients. All other patients showed a decline in FVm over the same time period. Overall FVm recovery was -0.03+/-0.14%.min(-1). The time-course of ICP changes was significantly different from that of FVm, with ICP reaching its lowest value earlier than FVm (23+/-12 vs 37+/-20 min; P = 0.001) and returning more rapidly towards baseline than FVm (0.23+/-0.23 vs -0.03+/-0.14%.min(-1); P< 0.0001). CONCLUSIONS: Head-injured patients may adapt differently to hyperventilation than healthy volunteers. Potentially harmful reductions in cerebral blood flow may persist beyond the duration of useful ICP reduction.
Mots-clé
Adolescent, Adult, Aged, Blood Flow Velocity, Blood Pressure, Brain Injuries/physiopathology, Carbon Dioxide/metabolism, Female, Glasgow Coma Scale, Humans, Hyperventilation/metabolism, Intracranial Pressure, Male, Middle Aged, Time Factors
Pubmed
Web of science
Création de la notice
16/12/2009 16:00
Dernière modification de la notice
20/08/2019 17:08