Carotid stenosis involves narrowing of the lumen in the carotid artery potentially leading to a stroke, which is the third leading cause of death in the U.S. Several recent investigations have demonstrated that the plaque structure and composition may represent a more direct biomarker of plaque rupture risk compared to the degree of stenosis. In this study, Pulse Wave Imaging (PWI) was applied in eleven (n =11 patients, N =13 plaques) patients diagnosed with moderate (>50%) to severe (>80%) carotid artery stenosis in order to investigate the feasibility of characterizing plaque properties based on the pulse wave-induced arterial wall dynamics captured by PWI. Five (n =5 subjects, N =20 measurements) healthy volunteers were also imaged as a control group.Both conventional and high-frame rate plane wave RF imaging sequence were used to generate piecewise maps of the pulse wave velocity (PWV) at a single depth along stenotic carotid segments, as well as intra-plaque PWV mapping at multiple depths. Intra-plaque cumulative displacement and strain maps were also calculated for each plaque region. The Bramwell-Hill equation was used to estimate the compliance of the plaque regions based on the PWV and diameter.
Measurements: We captured baseline demographic, pre-hospitalization antiplatelet medication use, and clinical encounter data for all patients who met inclusion criteria. The primary endpoint was peak score on a 6point modified ordinal scale (MOS), which is based on World Health Organization blueprint R&S groups, used to grade severity of illness through clinical outcomes of interest. Scores indicate the following: 1 À COVID-19 infection not requiring hospitalization, 2 À requiring hospitalization but not supplemental oxygen, 3 À hospitalization requiring supplemental oxygen, 4 À hospitalization requiring high-flow nasal cannula (HFNC) or non-invasive positive pressure ventilation (NIPPV), 5 À hospitalization requiring intubation or extracorporeal membrane oxygenation (ECMO), 6 À death. Multivariable adjusted partial proportional odds model (PPOM) was performed to examine the association between pre-hospitalization antiplatelet medication use and likelihood of each MOS score. Main Results: Of 762 people admitted with COVID-19, 239 (31.4%) used antiplatelet medications pre-hospitalization while 523 (68.6%) did not. Antiplatelet users were older and had more co-morbidities at baseline. Before adjusting for covariates, patients who used antiplatelet medications pre-hospitalization were more likely than non-users to have peak MOS score 6 (death, OR 1.75, 95% CI 1.21À2.52), peak MOS score 5 (intubation/ECMO or death, OR 1.4, 95% CI 1.00À1.98) and peak MOS score 4 (HFNC, NIPPV, intubation/ECMO or death, OR 1.40, 95% CI 1.01À1.94). On multivariable adjusted PPOM analysis controlling for 13 covariates, there were no longer any significant differences in peak MOS scores between users and non-users. Conclusions: After adjusting for covariates, pre-hospital antiplatelet use was not associated with COVID-19 severity in hospitalized patients.
The routine assessment and monitoring of hypertension may benefit from the evaluation of arterial pulse pressure (PP) at more central locations (e.g. the aorta) rather solely at the brachial artery. Pulse Wave Ultrasound Manometry (PWUM) was previously developed by our group to provide direct, noninvasive aortic PP measurements using ultrasound elasticity imaging. Using PWUM, radial applanation tonometry, and brachial sphygmomanometry, this study investigated the feasibility of noninvasively obtaining direct PP measurements at multiple arterial locations in normotensive, pre-hypertensive, and hypertensive human subjects. Two-way ANOVA indicated a significantly higher aortic PP in the hypertensive subjects, while radial and brachial PP were not significantly different among the subject groups. No strong correlation (r2 < 0.45) was observed between aortic and radial/brachial PP in normal and pre-hypertensive subjects, suggesting that increases in PP throughout the arterial tree may not be uniform in relatively compliant arteries. However, there was a relatively strong positive correlation between aortic PP and both radial and brachial PP in hypertensive subjects (r2 = 0.68 and 0.87, respectively). PWUM provides a low-cost, non-invasive, and direct means of measuring the pulse pressure in large central arteries such as the aorta. When used in conjunction with peripheral measurement devices, PWUM allows for the routine screening of hypertension and monitoring of BP-lowering drugs based on the PP from multiple arterial sites.
BackgroundThough often used to control outbreaks, the efficacy of ward closure is unclear. This systematic review sought to identify studies defining and describing ward closure in outbreak control and to determine impact of ward closure as an intervention on outbreak containment.MethodsWe searched these databases with no language restrictions: MEDLINE, 1946 to 7 July 2014; EMBASE, 1974 to 7 July 2014; CINAHL, 1937 to 8 July 2014; and Cochrane Database of Systematic Reviews, 2005 to May 2014. We also searched the following: IndMED; LILACS; reference lists from retrieved articles; conference proceedings; and websites of the CDCP, the ICID, and the WHO. We included studies of patients hospitalized in acute care facilities; used ward closure as a control measure; used other control measures; and discussed control of the outbreak(s) under investigation. A component approach was used to assess study quality.ResultsWe included 97 English and non-English observational studies. None included a controlled comparison between ward closure and other interventions. We found that ward closure was often used as part of a bundle of interventions but could not determine its direct impact separate from all the other interventions whether used in parallel or in sequence with other interventions. We also found no universal definition of ward closure which was widely accepted.ConclusionsWith no published controlled studies identified, ward closure for control of outbreaks remains an intervention that is not evidence based and healthcare personnel will need to continue to balance the competing risks associated with its use, taking into consideration the nature of the outbreak, the type of pathogen and its virulence, mode of transmission, and the setting in which it occurs. Our review has identified a major research gap in this area.Electronic supplementary materialThe online version of this article (doi:10.1186/s13643-015-0131-2) contains supplementary material, which is available to authorized users.
Background. Timely pulmonary function testing is crucial to improving diagnosis and treatment of pulmonary diseases. Perceptions of poor access at an academic pulmonary function laboratory prompted analysis of system demand and capacity to identify factors contributing to poor access. Methods. Surveys and interviews identified stakeholder perspectives on operational processes and access challenges. Retrospective data on testing demand and resource capacity was analyzed to understand utilization of testing resources. Results. Qualitative analysis demonstrated that stakeholder groups had discrepant views on access and capacity in the laboratory. Mean daily resource utilization was 0.64 (SD 0.15), with monthly average utilization consistently less than 0.75. Reserved testing slots for subspecialty clinics were poorly utilized, leaving many testing slots unfilled. When subspecialty demand exceeded number of reserved slots, there was sufficient capacity in the pulmonary function schedule to accommodate added demand. Findings were shared with stakeholders and influenced scheduling process improvements. Conclusion. This study highlights the importance of operational data to identify causes of poor access, guide system decision-making, and determine effects of improvement initiatives in a variety of healthcare settings. Importantly, simple operational analysis can help to improve efficiency of health systems with little or no added financial investment.
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