Epidural regional hypothermia for prevention of paraplegia after aortic occlusion : experimental evaluation in a rabbit model

Producción CientíficaThe efficacy of epidural regional hypothermia in the prevention of acute and delayed-onset paraplegia, as well as possible complications and limitations of this technique to a clinically acceptable form, were evaluated in 49 New Zealand white rabbits. Methods: A modified rabbit spinal cord ischemia model of infrarenal aortic occlusion for 30 minutes was employed. The study was performed in two phases. In phase I (n = 20), regional hypothermia induced by epidural perfusion of iced normal saline solution (4 ~ C) was tested versus control in 10 rabbits each (groups A and B). In phase II (n = 29) the animals were subdivided into three groups to study the kinetics of absorption and distribution of methylene blue (group C; n = 10), radiographic contrast material (group D; n = 9), and measurement ofcerebrospinal pressure while an epidural iced solution was or was not infused (group E; n = 10). Results: At 24 and 48 hours, all of the normothermic animals showed irreversible paraplegia (Tarlov score 0). In contrast, at 24 hours none of the rabbits undergoing epidural cold infusion were paraplegic, although at 48 hours one animal had weakness of a hindiimb (Tarlov score 3). Plasma concentration-time profiles of a continuous epidural perfusion with methylene blue showed that the spinal canal is a highly compliant space. Epidurographs showed that epidural perfusion tends to spread more in a cephalic than caudal direction and the main uptake is by the vascular compartiiient. Despite the large volumes infused (78.75 ml/hr; range, 50 to 100 ml), we observed only a modest transient increase in cerebrospinal fluid pressure (from 2.5 -+ 0.3 mm Hg to 5.4 -+ 0.1 mm Hg), although some animals had intracranial hypertension. Conclusions: Regional hypothermia induced by epidural cold perfusion has a highly protective effect against the ischemic spinal cord damage. However, this method probably does not avoid the risk of delayed-onset paraplegia. An important limitation of this technique is the difficulty of controlling the intrathecal pressures

Demographic, clinical, and functional determinants of antithrombotic treatment in patients with nonvalvular atrial fibrillation

Altres ajuts: Alliance Bristol-Myers Squibb/Pfizer.Background: This study assessed the sociodemographic, functional, and clinical determinants of antithrombotic treatment in patients with nonvalvular atrial fibrillation (NVAF) attended in the internal medicine setting. Methods: A multicenter, cross-sectional study was conducted in NVAF patients who attended internal medicine departments for either a routine visit (outpatients) or hospitalization (inpatients). Results: A total of 961 patients were evaluated. Their antithrombotic management included: no treatment (4.7%), vitamin K antagonists (VKAs) (59.6%), direct oral anticoagulants (DOACs) (21.6%), antiplatelets (6.6%), and antiplatelets plus anticoagulants (7.5%). Permanent NVAF and congestive heart failure were associated with preferential use of oral anticoagulation over antiplatelets, while intermediate-to high-mortality risk according to the PROFUND index was associated with a higher likelihood of using antiplatelet therapy instead of oral anticoagulation. Longer disease duration and institutionalization were identified as determinants of VKA use over DOACs. Female gender, higher education, and having suffered a stroke determined a preferential use of DOACs. Conclusions: This real-world study showed that most elderly NVAF patients received oral anticoagulation, mainly VKAs, while DOACs remained underused. Antiplatelets were still offered to a proportion of patients. Longer duration of NVAF and institutionalization were identified as determinants of VKA use over DOACs. A poor prognosis according to the PROFUND index was identified as a factor preventing the use of oral anticoagulation