Robert G. Kowalski

Functional recovery after moderate/severe traumatic brain injury: a role for cognitive reserve?

Objective: To evaluate the hypothesis that educational attainment, a marker of cognitive reserve, is a predictor of disability-free recovery (DFR) after moderate to severe traumatic brain injury (TBI). Methods: Retrospective study of the TBI Model Systems Database, a prospective multicenter cohort funded by the National Institute on Disability and Rehabilitation Research. Patients were included if they were admitted for rehabilitation after moderate to severe TBI, were aged 23 years or older, and had at least 1 year of follow-up. The main outcome measure was DFR 1 year postinjury, defined as a Disability Rating Scale score of zero. Results: Of 769 patients included, 214 (27.8%) achieved DFR at 1 year. In total, 185 patients (24.1%) had <12 years of education, while 390 (50.7%) and 194 patients (25.2%) had 12 to 15 years and ≥16 years of education, respectively. DFR was achieved by 18 patients (9.7%) with <12 years, 120 (30.8%) with 12 to 15 years, and 76 (39.2%) with ≥16 years of education (p < 0.001). In a logistic regression model controlling for age, sex, and injury- and rehabilitation-specific factors, duration of education of ≥12 years was independently associated with DFR (odds ratio 4.74, 95% confidence interval 2.70–8.32 for 12–15 years; odds ratio 7.24, 95% confidence interval 3.96–13.23 for ≥16 years). Conclusion: Educational attainment was a robust independent predictor of 1-year DFR even when adjusting for other prognostic factors. A dose-response relationship was noted, with longer educational exposure associated with increased odds of DFR. This suggests that cognitive reserve could be a factor driving neural adaptation during recovery from TBI.

Improved aneurysmal subarachnoid hemorrhage outcomes: A comparison of 2 decades at an academic center

OBJECTIVE Management of aneurysmal subarachnoid hemorrhage (aSAH) has evolved over the past 2 decades, including refinement of neurosurgical techniques, availability of endovascular options, and evolution of neurocritical care; their impact on SAH outcomes is unclear. DESIGN/METHODS Prospectively collected data of patients with aSAH admitted to Johns Hopkins Medical Institutions between 1991 and 2009 were analyzed. We compared survival to discharge and functional outcomes at initial clinic appointment postdischarge (30-120 days) in patients admitted between 1991 and 2000 (phase 1 [P1]) and 2000 and 2009 (phase 2 [P2]), respectively, using dichotomized Glasgow Outcome Scale (good outcome: Glasgow Outcome Scale 4-5). RESULTS A total of 1134 consecutive patients with aSAH were included in the analysis (P1 46.4%, P2 53.6%). There were higher rates of poor grade Hunt and Hess (P1 23%, P2 28%; P < .05), admission Glasgow Coma Scale score lower than 8 (P1 14%, P2 21%; P < .005), known medical comorbidites (P1 54%, P2 64%; P = .005), associated intraventricular hemorrhage (P1 47%, P2 55%; P < .05), and older population (P1 51.5%, P2 53.5%; P < .05) in P2. Good outcomes were more common in P2 (71.5%) compared with P1 (65.2%), with 2-fold adjusted odds of good outcomes after correction for various confounding factors (P < .001). CONCLUSIONS Our institutional experience over 2 decades confirms that patients with aSAH have shown significant outcome improvements over time.

Critical Care of Traumatic Spinal Cord Injury

Approximately 11 000 people suffer traumatic spinal cord injury (TSCI) in the United States, each year. TSCI incidences vary from 13.1 to 52.2 per million people and the mortality rates ranged from 3.1 to 17.5 per million people. This review examines the critical care of TSCI. The discussion will focus on primary and secondary mechanisms of injury, spine stabilization and immobilization, surgery, intensive care management, airway and respiratory management, cardiovascular complication management, venous thromboembolism, nutrition and glucose control, infection management, pressure ulcers and early rehabilitation, pharmacologic cord protection, and evolving treatment options including the use of pluripotent stem cells and hypothermia.

Impact of Acute Cocaine Use on Aneurysmal Subarachnoid Hemorrhage

Background and Purpose— Acute cocaine use has been temporally associated with aneurysmal subarachnoid hemorrhage (aSAH). This study analyzes the impact of cocaine use on patient presentation, complications, and outcomes. Methods— Data of patients admitted with aSAH between 1991 and 2009 were reviewed to determine impact of acute cocaine use (C). These patients were compared with aSAH patients without recent cocaine exposure (NC) in relation to their presentation, complications such as aneurysmal rerupture and delayed cerebral ischemia, and outcomes including hospital mortality and functional outcome. Results— Data of 1134 aSAH patients were reviewed; 142 patients (12.5%) had associated cocaine use. Cocaine users were more likely to be younger (mean age: C, 49±11; NC, 53±14; P<0.001). There were no differences in rates of poor-grade Hunt and Hess (4–5); (C, 21%; NC, 26%; P>0.05), associated intraventricular hemorrhage (C, 56%; NC, 51%; P>0.05), or hydrocephalus on admission Head CT (C, 49%; NC, 52%; P>0.05). Aneurysm rerupture incidence was higher among cocaine users (C, 7.7%; NC, 2.7%; P<0.05). The association of cocaine use with higher risk of delayed cerebral ischemia (C, 22%; NC, 16%; P<0.05) was not significant after correcting for other factors. Cocaine users were less likely to survive hospitalization compared with nonusers (mortality: C, 26%; NC, 17%; P<0.05); the adjusted odds of hospital mortality were 2.9 times higher among cocaine users (P<0.001). There were no differences in functional outcomes between the 2 groups. Conclusions— Acute cocaine use was associated with a higher risk of aneurysm rerupture and hospital mortality after aSAH.

Impact of pattern of admission on outcomes after aneurysmal subarachnoid hemorrhage

OBJECTIVE Patients with aneurysmal subarachnoid hemorrhage (aSAH) require management in centers with neurosurgical expertise necessitating emergent interhospital transfer (IHT). Our objective was to compare outcomes in aSAH IHTs to our institution with aSAH admissions from our institutional emergency department (ED). METHODS Data for consecutive patients with aSAH admitted to Johns Hopkins Medical Institutions between 1991 and 2009 were analyzed from a prospectively obtained database. We compared in-hospital mortality and functional outcomes at first clinical appointment post-aSAH (30-120 days) using dichotomized Glasgow Outcome Scale (good outcome: Glasgow Outcome Scale 4-5) in ED admissions with IHTs. RESULTS A total of 1134 consecutive patients with aSAH were included in analysis (ED 40.1%, IHT 59.9%). Direct ED admissions had a higher incidence of poor Hunt and Hess grade (4/5) and major medical comorbidities, with no significant differences between the 2 groups in age, intraventricular hemorrhage, and hydrocephalus. In-hospital mortality for ED admissions (14.9%) was significantly lower than that for IHTs (20.5%), with 1.8 times greater adjusted odds of survival after multivariate analysis (P = .001). Emergency department admissions had nearly 2-fold greater odds of good outcomes (odds ratio, 1.89; P < .001) after multivariate analysis. CONCLUSIONS Our institutional ED SAH admissions had significantly better outcomes than did IHTs, suggesting that delays in optimizing care before transfer could deleteriously impact outcomes.

Impact of case volume on aneurysmal subarachnoid hemorrhage outcomes

PURPOSE To compare aneurysmal subarachnoid hemorrhage (aSAH) outcomes between high- and low-volume referral centers with dedicated neurosciences critical care units (NCCUs) and shared neurosurgical, endovascular, and neurocritical care practitioners. MATERIALS AND METHODS Prospectively collected data of aSAH patients admitted to 2 institutional NCCUs were reviewed. NCCU A is a 22-bed unit staffed 24/7 with overnight in-house NCCU fellow and resident coverage. NCCU B is a 14-bed unit with home call by NCCU attending/fellow and in-house residents. RESULTS A total of 161 aSAH patients (27%) were admitted to NCCU B compared with 447 at NCCU A (73%). Among factors that independently impacted hospital mortality, there were no differences in baseline characteristics: mean age (A: 53.5 ± 14.1 years, B: 53.1 ± 13.6 years), poor grade Hunt and Hess (A: 28.2%, B: 26.7%), presence of multiple medical comorbidities (A: 28%, B: 31.1%), and associated cocaine use (A: 11.6%, B: 14.3%). There was no significant difference in hospital mortality (A: 17.9%, B: 18%), poor functional outcome (A: 30%, B: 25.4%), aneurysm rerupture (A: 2.8%, B: 2.4%), or delayed cerebral ischemia (A: 14.1%, B: 16.1%). CONCLUSIONS The noninferior outcomes at the lower SAH volume center suggests that provider expertise, not patient volume, is critical to providing high-quality specialized care.

Elevated relative risk of aneurysmal subarachnoid hemorrhage with colder weather in the mid-Atlantic region

We have previously reported an increase of 0.6% in the relative risk of aneurysmal subarachnoid hemorrhage (aSAH) in response to every 1°F decrease in the maximum daily temperature (Tmax) in colder seasons from patients presenting to our regional tertiary care center. We hypothesized that this relationship would also be observed in the warmer summer months with ambient temperatures greater than 70°F. From prospectively collected incidence data for aSAH patients, we investigated absolute Tmax, average daily temperatures, intraday temperature ranges, and the variation of daily Tmax relative to 70°F to assess associations with aSAH incidence for patients admitted to our institution between 1991 and 2009 during the hottest months and days on which Tmax>70°F. For all days treated as a group, the mean Tmax (± standard deviation) was lower when aSAH occurred than when it did not (64.4±18.2°F versus 65.8±18.3°F; p=0.016). During summer months, the odds ratio (OR) of aSAH incidence increased with lower mean Tmax (OR 1.019; 95% confidence interval 1.001-1.037; p=0.043). The proportion of days with aSAH admissions was lower on hotter days than the proportion of days with no aSAH (96% versus 98%; p=0.006). aSAH were more likely to occur during the summer and on days with a temperature fluctuation less than 10°F (8% versus 4%; p=0.002). During the hottest months of the year in the mid-Atlantic region, colder maximum daily temperatures, a smaller heat burden above 70°F, and smaller intraday temperature fluctuations are associated with increased aSAH admissions in a similar manner to colder months. These findings support the hypothesis that aSAH incidence is more likely with drops in temperature, even in the warmer months.