✓ The authors review literature that challenges the view that vasospasm involving large arteries is the exclusive cause of delayed ischemic neurological deficits (DINDs) following subarachnoid hemorrhage. They discuss alternative mechanisms and review the evidence supporting a potential role for thromboembolism. They conclude that vasospasm and thromboembolism play interrelated and additive roles in the development of DINDs, and that this interaction provides opportunities for novel therapeutic approaches.
Sherman C. Stein, Joshua M. Levine, Seema Nagpal and Peter D. LeRoux
Robert G. Whitmore, Jayesh P. Thawani, M. Sean Grady, Joshua M. Levine, Matthew R. Sanborn and Sherman C. Stein
The object of this study was to determine whether aggressive treatment of severe traumatic brain injury (TBI), including invasive intracranial monitoring and decompressive craniectomy, is cost-effective.
A decision-analytical model was created to compare costs, outcomes, and cost-effectiveness of 3 strategies for treating a patient with severe TBI. The aggressive-care approach is compared with “routine care,” in which Brain Trauma Foundation guidelines are not followed. A “comfort care” category, in which a single day in the ICU is followed by routine floor care, is included for comparison only. Probabilities of each treatment resulting in various Glasgow Outcome Scale (GOS) scores were obtained from the literature. The GOS scores were converted to quality-adjusted life years (QALYs), based on expected longevity and calculated quality of life associated with each GOS category. Estimated direct (acute and long-term medical care) and indirect (loss of productivity) costs were calculated from the perspective of society. Sensitivity analyses employed a 2D Monte Carlo simulation of 1000 trials, each with 1000 patients. The model was also used to estimate these values for patients 40, 60, and 80 years of age.
For the average 20-year-old, aggressive care yields 11.7 (± 1.6 [SD]) QALYs, compared with routine care (10.0 ± 1.5 QALYs). This difference is highly significant (p < 0.0001). Although the differences in effectiveness between the 2 strategies diminish with advancing age, aggressive care remains significantly better at all ages. When all costs are considered, aggressive care is also significantly less costly than routine care ($1,264,000 ± $118,000 vs $1,361,000 ± $107,000) for the average 20-year-old. Aggressive care remains significantly less costly until age 80, at which age it costs more than routine care. However, even in the 80-year-old, aggressive care is likely the more cost-effective approach. Comfort care is associated with poorer outcomes at all ages and with higher costs for all groups except 80-year-olds.
When all the costs of severe TBI are considered, aggressive treatment is a cost-effective option, even for older patients. Comfort care for severe TBI is associated with poor outcomes and high costs, and should be reserved for situations in which aggressive approaches have failed or testing suggests such treatment is futile.
Michael D. Cusimano, Katrina Zanetti and Conor Sheridan
Matthew R. Sanborn, Stephen R. Thom, Leif-Erik Bohman, Sherman C. Stein, Joshua M. Levine, Tatyana Milovanova, Eileen Maloney-Wilensky, Suzanne Frangos and Monisha A. Kumar
Microparticles (MPs), small membrane fragments shed from various cell types, have been implicated in thrombosis, inflammation, and endothelial dysfunction. Their involvement in subarachnoid hemorrhage (SAH) and the development of cerebral infarction and clinical deterioration caused by delayed cerebral ischemia (DCI) remain ill defined. The authors sought to quantify the magnitude of elevations in MPs, delineate the temporal dynamics of elevation, and analyze the correlation between MPs and DCI in patients with SAH.
On the day of hemorrhage and on Days 1, 3, 5, 7, and 10 after hemorrhage, peripheral blood samples were drawn from 22 patients with SAH. Plasma samples were labeled with Annexin V and CD142, CD41a, CD235a, CD146, CD66b, or von Willebrand factor (vWF) and were quantified by flow cytometry. Clinical data, including the 3-month extended Glasgow Outcome Scale (GOS-E) scores, infarction as measured on MRI at 14 days after SAH, and vasospasm as measured by transcranial Doppler ultrasonography and angiography, were collected and compared with the MP burden.
When averaged over time, all MP subtypes were elevated relative to controls. The CD235a+(erythrocyte)−, CD66b+(neutrophil)−, and vWF-associated MPs peaked on the day of hemorrhage and quickly declined. The CD142+(tissue factor [TF])–associated MPs and CD146+(endothelial cell)–associated MPs were significantly elevated throughout the study period. There was a strong negative correlation between TF-expressing and endothelial-derived MPs at Day 1 after SAH and the risk of infarction at Day 14 after SAH.
Microparticles of various subtypes are elevated following SAH; however, the temporal profile of this elevation varies by subtype. Those subtypes closely associated with thrombosis and endothelial dysfunction, for example, CD145+(TF)-associated MPs and CD146+(endothelial cell)–associated MPs, had the most durable response and demonstrated a significant negative correlation with radiographic infarction at 14 days after SAH. Levels of these MPs predict infarction as early as Day 1 post-SAH.