Long-term cognitive impairment after critical illness.

BACKGROUND: Survivors of critical illness often have a prolonged and disabling form of cognitive impairment that remains inadequately characterized. METHODS: We enrolled adults with respiratory failure or shock in the medical or surgical intensive care unit (ICU), evaluated them for in-hospital delirium, and assessed global cognition and executive function 3 and 12 months after discharge with the use of the Repeatable Battery for the Assessment of Neuropsychological Status (population age-adjusted mean [±SD] score, 100±15, with lower values indicating worse global cognition) and the Trail Making Test, Part B (population age-, sex-, and education-adjusted mean score, 50±10, with lower scores indicating worse executive function). Associations of the duration of delirium and the use of sedative or analgesic agents with the outcomes were assessed with the use of linear regression, with adjustment for potential confounders. RESULTS: Of the 821 patients enrolled, 6% had cognitive impairment at baseline, and delirium developed in 74% during the hospital stay. At 3 months, 40% of the patients had global cognition scores that were 1.5 SD below the population means (similar to scores for patients with moderate traumatic brain injury), and 26% had scores 2 SD below the population means (similar to scores for patients with mild Alzheimer's disease). Deficits occurred in both older and younger patients and persisted, with 34% and 24% of all patients with assessments at 12 months that were similar to scores for patients with moderate traumatic brain injury and scores for patients with mild Alzheimer's disease, respectively. A longer duration of delirium was independently associated with worse global cognition at 3 and 12 months (P=0.001 and P=0.04, respectively) and worse executive function at 3 and 12 months (P=0.004 and P=0.007, respectively). Use of sedative or analgesic medications was not consistently associated with cognitive impairment at 3 and 12 months. CONCLUSIONS: Patients in medical and surgical ICUs are at high risk for long-term cognitive impairment. A longer duration of delirium in the hospital was associated with worse global cognition and executive function scores at 3 and 12 months. (Funded by the National Institutes of Health and others; BRAIN-ICU ClinicalTrials.gov number, NCT00392795.).

The correlation between the severity of peripheral arterial disease and carotid occlusive disease.

Peripheral arterial disease (PAD) and carotid occlusive disease (COD) are both known to be specific manifestations of atherosclerosis. Because they both have a common cause, it is reasonable to hypothesize that they should correlate with each other to a certain extent, and previous studies have shown that there is a correlation between the prevalence of PAD and COD. The purpose of this study was to determine whether a correlation exists between the severity of PAD and the severity of COD by retrospectively looking at a group of 203 patients who underwent non-invasive testing for suspicion of PAD at the San Diego VA Hospital or UCSD Medical Center, and who also had a non-invasive duplex carotid scan. The severity of PAD was assessed by segmental blood pressure ratios (leg segment/arm ratio) in each leg taken at the toe, ankle, and below the knee, as well as the peak flow velocity of the posterior tibial artery. The severity of COD was assessed by duplex ultrasound scans of six distinct segments of the carotid artery system: the right and left common, internal, and external carotid arteries. Correlation analysis showed r=0.23 (p=0.001) when comparing a PAD aggregate standard score with the number of diseased carotid arteries (>50% stenosis), and r=0.23 (p=0.001) when comparing a PAD aggregate standard score with an average COD score. Because about 50% of the patients had undergone surgical intervention on their leg or carotid arteries, another correlation analysis restricted to patients with no surgical interventions (n = 97) was performed. The above correlations were slightly attenuated in this analysis, r=0.21 (p=0.043) and r=0.17 (p= 0.092), respectively. The results indicate that there is a modest but significant correlation between the severity of PAD and the severity of COD in a population with a high prevalence of both.