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M. Sean Kincaid, Michael J. Souter, Miriam M. Treggiari, N. David Yanez, Anne Moore, and Arthur M. Lam

Object

The goal of this study was to assess the accuracy of the routine clinical use of transcranial Doppler (TCD) ultrasonography and SPECT in predicting angiographically demonstrated vasospasm.

Methods

Following receipt of institutional review board approval, the authors reviewed the records of patients with subarachnoid hemorrhage who had been admitted between 2004 and 2005 and underwent TCD ultrasonography and SPECT evaluations within 24 hours of cerebral angiography. Patients were categorized based on the presence or absence of vasospasm and/or hypoperfusion in the anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs), and basilar arteries (BAs) or posterior cerebral arteries (PCAs) according to each imaging modality. Logistic regression was used to estimate the odds ratio (OR) of an angiographically demonstrated vasospasm also detected on TCD ultrasonography and SPECT.

Results

One hundred fifty-two patients (101 women) with a mean age (± standard deviation) of 53 ± 13 years were included in the study. In the ACA, the OR of a vasospasm on TCD ultrasonography was 27 (95% confidence interval [CI] 3–243) and on SPECT 0.97 (95% CI 0.36–2.6); in the MCA, 17 (95% CI 5.4–55) and 2.0 (95% CI 0.71–5.5), respectively; in the BA, 4.4 (95% CI 0.72–27) and 5.6 (95% CI 0.89–36), respectively. There was no substantial change in the relative odds of a vasospasm when the findings on TCD ultrasonography and SPECT were considered jointly.

Conclusions

Transcranial Doppler ultrasonography appears to be highly predictive of an angiographically demonstrated vasospasm in the MCA and ACA; however, its diagnostic accuracy was lower with regard to vasospasm in the BA. Single-photon emission computed tomography was not predictive of a vasospasm in any of the vascular territories assessed.

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Ross P. Martini, Steven Deem, N. David Yanez, Randall M. Chesnut, Noel S. Weiss, Stephen Daniel, Michael Souter, and Miriam M. Treggiari

Object

The authors sought to describe changes in clinical management associated with brain tissue oxygen (PbO2) monitoring and how these changes affected outcomes and resource utilization.

Methods

The cohort study comprised 629 patients admitted to a Level I trauma center with a diagnosis of severe traumatic brain injury over a period of 3 years. Hospital mortality rate, neurological outcome, and resource utilization of 123 patients who underwent both PbO2 and intracranial pressure (ICP) monitoring were compared with the same measures in 506 patients who underwent ICP monitoring only. The main outcomes were hospital mortality rate, functional independence at hospital discharge, duration of mechanical ventilation, hospital length of stay, and hospital cost. Multivariable regression with robust variance was used to estimate the adjusted differences in the main outcome measures between patient groups. The models were adjusted for patient age, severity of injury, and pathological features seen on head CT scan at admission.

Results

On average, patients who underwent ICP/PbO2 monitoring were younger and had more severe injuries than patients who received ICP monitoring alone. Relatively more patients treated with PbO2 monitoring received osmotic therapy, vasopressors, and prolonged sedation. After adjustment for baseline characteristics, the hospital mortality rate was, if anything, slightly higher in patients undergoing PbO2-guided management than in patients monitored with ICP only (adjusted mortality difference 4.4%, 95% CI −3.9 to 13%). Patients who underwent PbO2-guided management also had lower adjusted functional independence scores at hospital discharge (adjusted score difference −0.75, 95% CI −1.41 to −0.09). There was a 27% relative increase (95% CI 6–53%) in the median hospital length of stay when the PbO2 group was compared with the ICP-only group.

Conclusions

The mortality rate in patients with traumatic brain injury whose clinical management was guided by PbO2 monitoring was not reduced in comparison with that in patients who received ICP monitoring alone. Brain tissue oxygen monitoring was associated with worse neurological outcome and increased hospital resource utilization.