Evaluation of Hospital Admission Status for Emergency Department Patients Seen for Chronic Obstructive Pulmonary Disease Exacerbation: A Retrospective Observational Study.

Background: Chronic obstructive pulmonary disease (COPD) is a common and preventable condition. The disease accounts for a large economic burden in the US health care system. Better control and prevention of COPD exacerbations can help prevent presentations to already-crowded emergency departments (EDs) and hospitals. The objective of our study was to identify variables associated with hospital admission status in ED patients presenting with COPD exacerbation. Methods: We conducted a retrospective observational study of patients seen at 1 of 3 US EDs from 2012 to 2014 with a primary diagnosis related to COPD exacerbation. Hospital admission status was modeled using patient characteristic data via adaptive least absolute shrinkage and selection operator logistic regression. Study results are presented as adjusted odds ratios with 95% CIs. Planned post hoc model dependency and external data sensitivity analyses were conducted. Results: The study sample included 1,165 unique patients with COPD with an ED encounter related to exacerbation at 1 of the 3 reviewed hospitals. Approximately half of these patients had a hospital admission. Variables inversely associated with an admission included oxygen saturation and number of prior ED encounters for COPD exacerbation. Variables positively associated with admission were initial ED heart rate, patient age, and documented comorbidities of anxiety and/or depression. These mental health comorbidities had the strongest association with admission status. Conclusion: Understanding the characteristics of admitted patients may help direct resources and outpatient services to prevent encounters. Of note, the study revealed mental health variables as being strongly associated with admission status.

Computational study on the mechanism and selectivity of C-H bond activation and dehydrogenative functionalization in the synthesis of rhazinilam.

The key platinum mediated C-H bond activation and functionalization steps in the synthesis of (-)-rhazinilam (Johnson, J. A.; Li, N.; Sames, D. J. Am. Chem. Soc. 2002, 124, 6900) were investigated using the M06 and B3LYP density functional approximation methods. This computational study reveals that ethyl group dehydrogenation begins with activation of a primary C-H bond in preference to a secondary C-H bond in an insertion/methane elimination pathway. The C-H activation step is found to be reversible while the methane elimination (reductive elimination) transition state controls rate and diastereoselectivity. The chiral oxazolinyl ligand induces ethyl group selectivity through stabilizing weak interactions between its phenyl group (or cyclohexyl group) and the carboxylate group. After C-H activation and methane elimination steps, Pt-C bond functionalization occurs through ß-hydride elimination to give the alkene platinum hydride complex.