Etiologies of altered mental status in patients with presumed ethanol intoxication.

BACKGROUND: Altered mental status is a commonly evaluated problem in the ED. Ethanol intoxication is common, and prehospital history may bias emergency physicians to suspect this as the cause of altered mental status. Quantitative ethanol measurement can rapidly confirm the diagnosis, or if negative, prompt further evaluation. Our objective was to identify the etiologies of altered mental status in ED patients initially presumed to be intoxicated with ethanol but found to have negative quantitative ethanol levels. METHODS: This was a 5-year (2012-2016) electronic medical record review of ED patients presenting with altered mental status. Patients were included if they presented with presumed ethanol intoxication and had an initial ethanol concentration of zero. Etiologies of altered mental status were categorized into medical, traumatic, psychiatric, and drug-related causes. RESULTS: 29,322 patients presented during the study period with presumed alcohol intoxication, 1875 patients had negative ethanol levels. The etiology of altered mental status was due to illicit substances in 1337 patients (71%), psychiatric causes in 354 patients (19%), medical causes in 166 patients (9%) and trauma in 18 patients (1%). A total of 179 patients (10%) were admitted to the hospital; 19 patients (1%) to the ICU. CONCLUSIONS: The presumptive diagnosis of ethanol intoxication in patients presenting to the ED with altered mental status was inaccurate in 5% of patients. The etiology of altered mental status was serious and required hospitalization in 10% of the cohort. Rapid assessment of quantitative ethanol levels should be performed, breathalyzers may be preferred over serum testing.

Microstructural and mechanical differences between digested collagen-fibrin co-gels and pure collagen and fibrin gels.

Collagen and fibrin are important extracellular matrix (ECM) components in the body, providing structural integrity to various tissues. These biopolymers are also common scaffolds used in tissue engineering. This study investigated how co-gelation of collagen and fibrin affected the properties of each individual protein network. Collagen-fibrin co-gels were cast and subsequently digested using either plasmin or collagenase; the microstructure and mechanical behavior of the resulting networks were then compared with the respective pure collagen or fibrin gels of the same protein concentration. The morphologies of the collagen networks were further analyzed via three-dimensional network reconstruction from confocal image z-stacks. Both collagen and fibrin exhibited a decrease in mean fiber diameter when formed in co-gels compared with the pure gels. This microstructural change was accompanied by an increased failure strain and decreased tangent modulus for both collagen and fibrin following selective digestion of the co-gels. In addition, analysis of the reconstructed collagen networks indicated the presence of very long fibers and the clustering of fibrils, resulting in very high connectivities for collagen networks formed in co-gels.