Accuracy of brain multimodal monitoring to detect cerebral hypoperfusion after traumatic brain injury*.
OBJECTIVE
To examine the accuracy of brain multimodal monitoring-consisting of intracranial pressure, brain tissue PO2, and cerebral microdialysis--in detecting cerebral hypoperfusion in patients with severe traumatic brain injury.


METHODS
Prospective single-center study.


METHODS
Patients with severe traumatic brain injury.


METHODS
Medico-surgical ICU, university hospital.


METHODS
Intracranial pressure, brain tissue PO2, and cerebral microdialysis monitoring (right frontal lobe, apparently normal tissue) combined with cerebral blood flow measurements using perfusion CT.


RESULTS
Cerebral blood flow was measured using perfusion CT in tissue area around intracranial monitoring (regional cerebral blood flow) and in bilateral supra-ventricular brain areas (global cerebral blood flow) and was matched to cerebral physiologic variables. The accuracy of intracranial monitoring to predict cerebral hypoperfusion (defined as an oligemic regional cerebral blood flow < 35 mL/100 g/min) was examined using area under the receiver-operating characteristic curves. Thirty perfusion CT scans (median, 27 hr [interquartile range, 20-45] after traumatic brain injury) were performed on 27 patients (age, 39 yr [24-54 yr]; Glasgow Coma Scale, 7 [6-8]; 24/27 [89%] with diffuse injury). Regional cerebral blood flow correlated significantly with global cerebral blood flow (Pearson r = 0.70, p < 0.01). Compared with normal regional cerebral blood flow (n = 16), low regional cerebral blood flow (n = 14) measurements had a higher proportion of samples with intracranial pressure more than 20 mm Hg (13% vs 30%), brain tissue PO2 less than 20 mm Hg (9% vs 20%), cerebral microdialysis glucose less than 1 mmol/L (22% vs 57%), and lactate/pyruvate ratio more than 40 (4% vs 14%; all p < 0.05). Compared with intracranial pressure monitoring alone (area under the receiver-operating characteristic curve, 0.74 [95% CI, 0.61-0.87]), monitoring intracranial pressure + brain tissue PO2 (area under the receiver-operating characteristic curve, 0.84 [0.74-0.93]) or intracranial pressure + brain tissue PO2+ cerebral microdialysis (area under the receiver-operating characteristic curve, 0.88 [0.79-0.96]) was significantly more accurate in predicting low regional cerebral blood flow (both p < 0.05).


CONCLUSIONS
Brain multimodal monitoring-including intracranial pressure, brain tissue PO2, and cerebral microdialysis--is more accurate than intracranial pressure monitoring alone in detecting cerebral hypoperfusion at the bedside in patients with severe traumatic brain injury and predominantly diffuse injury.
1Department of Intensive Care Medicine, Neuroscience Critical Care Research Group, CHUV-Lausanne University Hospital, Faculty of Biology and Medicine, Lausanne, Switzerland. 2Joseph Fourier University, Grenoble, France. 3Department of Internal Medicine, CHUV-Lausanne University Hospital, Faculty of Biology and Medicine, Lausanne, Switzerland. 4Department of Radiology, CHUV-Lausanne University Hospital, Faculty of Biology and Medicine, Lausanne, Switzerland. 5Department of Anesthesiology, CHUV-Lausanne University Hospital, Faculty of Biology and Medicine, Lausanne, Switzerland. 6Clinical Neurosciences, Division of Neurosurgery, CHUV-Lausanne University Hospital, Faculty of Biology and Medicine, Lausanne, Switzerland.
Pierre
P
Bouzat
Pedro
P
Marques-Vidal
Jean-Baptiste
JB
Zerlauth
Nathalie
N
Sala
Tamarah
T
Suys
Patrick
P
Schoettker
Jocelyne
J
Bloch
Roy T
RT
Daniel
Marc
M
Levivier
Reto
R
Meuli
Mauro
M
Oddo
D000328:Adult; D001774:Blood Chemical Analysis; D001921:Brain / Q000503:physiopathology; D001930:Brain Injuries / Q000097:blood / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007427:Intracranial Pressure / Q000502:physiology; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D014057:Tomography, X-Ray Computed