Search results for "Venous return curve"
showing 3 items of 3 documents
Portal vein thrombosis and Budd-Chiari syndrome as onset of polycythemia vera
2013
Budd-Chiari syndrome may be defined as a heterogeneous group of vascular disorders characterized by obstruction of hepatic venous return to the level of hepatic venules, supra-hepatic veins, inferior vena cava or right atrium. The main cause of this syndrome is represented by myeloproliferative diseases and, in particular, by polycythemia vera. The latter may cause multiple splanchnic thrombosis, including portal vein thrombosis, particularly important for its clinical outcomes (ascites, collateral vessels genesis, etc.). We report 2 cases of a Budd-Chiari syndrome induced by polycythemia vera characterized by an abnormal clinical onset, both as regards subjects’ age (29 and 39 years old, r…
Influence of PEEP on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome.
2013
High levels of positive end-expiratory pressure (PEEP), as part of the treatment in patients with acute respiratory distress syndrome (ARDS), may prevent alveolar collapse and maintain oxygenation. PEEP potentially reduces cerebral venous return, increases intracranial blood volume, and may, therefore, affect cerebral blood flow (CBF) and cerebrovascular autoregulation (AR). This study investigates the effect of PEEP on CBF and AR in patients with respiratory failure.CBF velocity was measured using transcranial doppler and correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx0.3 indicates impaired AR). Mx was measured at lower PEEP levels and after i…
Biophysics of venous return from the brain from the perspective of the pathophysiology of chronic cerebrospinal venous insufficiency
2011
This article discusses the biophysical aspects of venous outflow from the brain in healthy individuals and in patients with chronic cerebrospinal venous insufficiency. Blood flows out of the brain differently, depending on body position. In the supine position it flows out mainly through internal jugular veins, while in the upright position it uses the vertebral veins. This phenomenon is probably not due to the active regulation of the flow but instead results from the collapse of jugular veins when the head is elevated. Such a collapse is associated with a significant increase in flow resistance, which leads to redirection of the flow towards the vertebral pathway. Theoretical calculations…