Citation

Coles JP, Fryer TD, Coleman MR, Smielewski P, Gupta AK, Minhas PS, Aigbirhio F, Chatfield DA, Williams GB, Boniface S, Carpenter TA, Clark JC, Pickard JD, Menon DK. Crit. Care Med. 2007; 35(2): 568-578.

Affiliation

Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. jpc44@wbic.cam.ac.uk

Comment In:

Ann Fr Anesth Reanim 2007;26(4):396-7.

Copyright

(Copyright © 2007, Society of Critical Care Medicine, Publisher Lippincott Williams and Wilkins)

DOI

10.1097/01.CCM.0000254066.37187.88

PMID

17205016

Abstract

OBJECTIVE: To determine whether hyperventilation exacerbates cerebral ischemia and compromises oxygen metabolism (CMRO2) following closed head injury. DESIGN: A prospective interventional study. SETTING: A specialist neurocritical care unit. PATIENTS: Ten healthy volunteers and 30 patients within 10 days of closed head injury. INTERVENTIONS: Subjects underwent oxygen-15 positron emission tomography imaging of cerebral blood flow, cerebral blood volume, CMRO2, and oxygen extraction fraction. In patients, positron emission tomography studies, somatosensory evoked potentials, and jugular venous saturation (SjO2) measurements were obtained at Paco2 levels of 36+/-3 and 29+/-2 torr. MEASUREMENTS AND MAIN RESULTS: We estimated the volume of ischemic brain and examined the efficiency of coupling between oxygen delivery and utilization using the sd of the oxygen extraction fraction distribution. We correlated CMRO2 to cerebral electrophysiology and examined the effects of hyperventilation on the amplitude of the cortical somatosensory evoked potential response. Patients showed higher ischemic brain volume than controls (17+/-22 vs. 2+/-3 mL; p

Language: en