Clinical Characterization of Patients With COVID-19 in Primary Care in Catalonia: Retrospective Observational Study.

BACKGROUND: The country of Spain has one of the highest incidences of COVID-19, with more than 1,000,000 cases as of the end of October 2020. Patients with a history of chronic conditions, obesity, and cancer are at greater risk from COVID-19; moreover, concerns surrounding the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin type II receptor blockers (ARBs) and its relationship to COVID-19 susceptibility have increased since the beginning of the pandemic. OBJECTIVE: The objectives of this study were to compare the characteristics of patients diagnosed with COVID-19 to those of patients without COVID-19 in primary care; to determine the risk factors associated with the outcome of mortality; and to determine the potential influence of certain medications, such as ACEIs and ARBs, on the mortality of patients with COVID-19. METHODS: An observational retrospective study of patients diagnosed with COVID-19 in the Catalan Central Region of Spain between March 1 and August 17, 2020, was conducted. The data were obtained from the Primary Care Services Information Technologies System of the Catalan Institute of Health in Barcelona, Spain. RESULTS: The study population included 348,596 patients (aged >15 years) registered in the Primary Care Services Information Technologies System of the Catalan Central Region. The mean age of the patients was 49.53 years (SD 19.42), and 31.17% of the patients were aged ≥60 years. 175,484/348,596 patients (50.34%) were women. A total of 23,844/348,596 patients (6.84%) in the population studied were diagnosed with COVID-19 during the study period, and the most common clinical conditions of these patients were hypertension (5267 patients, 22.1%) and obesity (5181 patients, 21.7%). Overall, 2680/348,596 patients in the study population (0.77%) died during the study period. The number of deaths among patients without COVID-19 was 1825/324,752 (0.56%; mean age 80.6 years, SD 13.3), while among patients diagnosed with COVID-19, the number of deaths was 855/23,844 (3.58%; mean age 83.0 years, SD 10.80) with an OR of 6.58 (95% CI 6.06-7.15). CONCLUSIONS: We observed that women were more likely to contract COVID-19 than men. In addition, our study did not show that hypertension, obesity, or being treated with ACEIs or ARBs was linked to an increase in mortality in patients with COVID-19. Age is the main factor associated with mortality in patients infected with SARS-CoV-2.

Review of the main surgical and angiographic-oriented classifications of the course of the internal carotid artery through a novel interactive 3D model.

The course of the internal carotid artery (ICA) and its segment classifications were reviewed by means of a new and freely available 3D interactive model of the artery and the skull base, based on human neuroimages, that can be freely downloaded at the Public Repository of the University of Barcelona (http://diposit.ub.edu/dspace/handle/2445/112442) and runs under Acrobat Reader in Mac and Windows computers and Windows 10 tablets. The 3D-PDF allows zoom, rotation, selective visualization of structures, and a predefined sequence view. Illustrative images of the different classifications were obtained. Fischer (Zentralbl Neurochir 3:300-313, 1938) described five segments in the opposite direction to the blood flow. Gibo-Rothon (J Neurosurg 55:560-574, 1981) follow the blood flow, incorporated the cervical and petrous portions, and divided the subarachnoid course-supraclinoid-in ophthalmic, communicating, and choroidal segments, enhancing transcranial microscopic approaches. Bouthillier (Neurosurgery 38:425-433, 1996) divided the petrous portion describing the lacerum segment (exposed in transfacial procedures and exploration of Meckel's cave) and added the clinoid segment between the proximal and distal dural rings, of interest in cavernous sinus surgery. The Kassam's group (2014), with an endoscopic endonasal perspective, introduces the "paraclival segment," including the "lacerum segment" and part of the intracavernous ICA, and details surgical landmarks to minimize the risk of injury. Other classifications are also analyzed. This review through an interactive 3D tool provides virtual views of the ICA and becomes an innovative perspective to the segment classifications and neuroanatomy of the ICA and surrounding structures.

Unintentional subdural placement of epidural catheters during attempted epidural anesthesia: an anatomic study of spinal subdural compartment.

BACKGROUND: Although infrequent, subdural block is a complication of epidural anesthesia with obvious implications. Knowledge of the spinal subdural compartment (dura-arachnoid interface) may help elucidate controversies arising from evidence that subdural catheter placement is feasible and may be difficult to identify clinically. METHODS: Samples of arachnoid lamina obtained during in vivo lumbosacral surgery (n = 4) and from cadavers (n = 6) were obtained and prepared for transmission electron microscopy and scanning electron microscopy. Subdural spaces were artificially produced in suitable samples, and an epidural catheter was inserted between the arachnoid and dura to compare the dimensions of meninges in relation to epidural catheters. RESULTS: Scanning electron microscopy of the dural sac showed areas of continuity between the arachnoid lamina and dura mater and other parts with both membranes separated by a subdural space. Transmission electron microscopy allowed the study of such border zones, where alternating cellular and collagen layers could be seen. A layer rich in collagen fibers and some fibroblasts separated arachnoid and neurothelial cells (dural border cells). Few specialized membrane junctions were found among cells adjacent to collagen fibers. Dura mater had an average thickness of 260 to 400 µm, with a dural lamina of approximately 4 to 6 µm. In areas where the arachnoid appeared separated from the dural lamina, its thickness measured 35 to 45 µm. Catheters with a diameter of 700 µm were successfully inserted inside the subdural space, between the dura mater and the arachnoid lamina. CONCLUSIONS: Dura mater and arachnoid layers act as a single unit but may be pulled apart by traction forces during cadaver processing of the dural sac or in vivo placement of catheters. This generates subdural spaces, either parallel or concentric, because of the minimal resistance offered by the tissue, which may be explained by its few specialized membrane junctions.