Cerebral oxygenation monitoring in critical care patients with traumatic brain injury
© Tokutomi et al; licensee BioMed Central Ltd. 2009
Published: 13 March 2009
One of the most controversial areas of traumatic brain injury (TBI) critical care is the management of cerebral perfusion pressure (CPP). Since optimal CPP levels depend on whether cerebral autoregulation is preserved, these levels must be determined for individual cases. The aim of this study was to investigate the role of jugular venous saturation (SjO2) and brain tissue oxygen tension (PbrO2) monitoring in addition to CPP and intracranial pressure (ICP) monitoring in the acute management of patients with TBI.
Thirty-six severe TBI patients (ages 16 to 69 years, GCS score 4 to 7) admitted to our neurosurgical critical care unit were evaluated. ICP (Camino), CPP, and SjO2 (Abbott) were continuously monitored in the 36 patients, and PbrO2 (LICOX) was continuously monitored in the last 10 patients. The treatment goal was aimed at keeping ICP <20 mmHg and CPP >60 mmHg. Patients with good recovery or moderate disability on the Glasgow Outcome Scale at 6 months after injury were regarded as having favorable outcomes, and those with severe disability, vegetative state, or death were regarded as having unfavorable outcomes.
Thirteen patients had favorable outcomes. PbrO2 values showed a positive correlation with CPP (r = 0.380, P < 0.0001). SjO2 tended to be abnormally high when the simultaneous PbrO2values were <15 or >45 mmHg. High SjO2 combined with low CPP or low PbrO2 was associated with unfavorable outcome. The occurrence rate of CPP above 60 mmHg during the first 5 days of monitoring was 89.8% of the measurements in favorable outcome patients vs. 72.7% of those in unfavorable outcome patients (likelihood ratio = 1.2). These proportions were altered to 70.3% vs. 46.8% (likelihood ratio = 1.5) when the simultaneous SjO2 values were normal, and to 85.8% vs. 51.2% (likelihood ratio = 1.7) when the simultaneous PbrO2 values were more than 20 mmHg.
The present data emphasize the clinical significance of brain oxygen monitoring in TBI and provide evidence for high SjO2 caused by cerebral hypoperfusion. SjO2 and PbrO2 measurements in combination with ICP and CPP should help in improving the accuracy of monitoring intracranial pathophysiology and response to treatment.
This article is published under license to BioMed Central Ltd.