Details

Autor(en) / Beteiligte

• Pedersen, Michael
• Brandt, Christian T
• Knudsen, Gitte M
• Ostergaard, Christian
• Skinhoj, Peter
• Frimodt-Moller, Niels
• Moller, Kirsten

Titel

Cerebral blood flow autoregulation in early experimental S. pneumoniae meningitis

Ist Teil von

• Journal of applied physiology (1985), 2007-01, Vol.102 (1), p.72-78

Ort / Verlag

Bethesda, MD: Am Physiological Soc

Erscheinungsjahr

2007

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• 1 Department of Infectious Diseases and 2 Neurobiology Research Unit, Rigshospitalet, Copenhagen University Hospital; and 3 National Center for Antimicrobial and Infection Control, Copenhagen, Denmark Submitted 20 June 2006 ; accepted in final form 20 September 2006 We studied cerebral blood flow (CBF) autoregulation and intracranial pressure (ICP) during normo- and hyperventilation in a rat model of Streptococcus pneumoniae meningitis. Meningitis was induced by intracisternal injection of S. pneumoniae . Mean arterial blood pressure (MAP), ICP, cerebral perfusion pressure (CPP, defined as MAP – ICP), and laser-Doppler CBF were measured in anesthetized infected rats ( n = 30) and saline-inoculated controls ( n = 30). CPP was either incrementally reduced by controlled hemorrhage or increased by intravenous norepinephrine infusion. Twelve hours postinoculation, rats were studied solely during normocapnia, whereas rats studied after 24 h were exposed to either normocapnia or to acute hypocapnia. In infected rats compared with control rats, ICP was unchanged at 12 h but increased at 24 h postinoculation (not significant and P < 0.01, respectively); hypocapnia did not lower ICP compared with normocapnia. Twelve hours postinoculation, CBF autoregulation was lost in all infected rats but preserved in all control rats ( P < 0.01). Twenty-four hours after inoculation, 10% of infected rats had preserved CBF autoregulation during normocapnia compared with 80% of control rats ( P < 0.01). In contrast, 60% of the infected rats and 100% of the control rats showed an intact CBF autoregulation during hypocapnia ( P < 0.05 for the comparison of infected rats at normocapnia vs. hypocapnia). In conclusion, CBF autoregulation is lost both at 12 and at 24 h after intracisternal inoculation of S. pneumoniae in rats. Impairment of CBF autoregulation precedes the increase in ICP, and acute hypocapnia may restore autoregulation without changing the ICP. bacterial meningitis; cerebral perfusion pressure Address for reprint requests and other correspondence: M. Pedersen, Dept. of Infectious Diseases, Rigshospitalet, Copenhagen Univ. Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark (e-mail: m.pedersen{at}dadlnet.dk )