tailieunhanh - Báo cáo y học: " Interactions between the increase in venous return and right ventricular functio"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về y học đề tài: Interactions between the increase in venous return and right ventricular function. | Available online http content 7 3 247 Letter Interactions between the increase in venous return and right ventricular function Massimo Bertolissi1 and Ugo Da Broi2 1 Senior Staff Consultant Second Department of Anaesthesia and Intensive Care Medicine Azienda Ospedaliera S Maria della Misericordia Udine Italy 2Consultant Second Department of Anaesthesia and Intensive Care Medicine Azienda Ospedaliera S Maria della Misericordia Udine Italy Correspondence Massimo Bertolissi bertolissi@ Published online 7 May 2003 Critical Care 2003 7 247 DOI cc2188 This article is online at http content 7 3 247 2003 BioMed Central Ltd Print ISSN 1364-8535 Online ISSN 1466-609X The present article is a response to the letter written by McHugh 1 regarding our recent publication in Critical Care 2 . Our intention was to make a second complete haemodynamic evaluation with the legs still elevated in order to investigate the duration of changes observed at time point 3 1 min after the legs were simultaneously raised at 60 . However this was not possible because our surgeons did not permit a further loss of time. For this reason we did not examine the haemodynamic effects of head-down tilt. Several authors have reported however that the haemodynamic effects of passive leg elevation PLE vanish with time and rarely exceed a 10 min duration 3 . Boulain and other workers have recently shown that PLE produces a rapid and sustained rise in stroke volume over a period of 4 min and that the amount of blood volume shifted from the legs toward the central compartment during the postural change is about 300 ml 4 5 . Considering the effects of PLE on the right ventricle RV with a reduced basal ejection fraction 2 no variations in the coronary perfusion pressure and the cardiac index and a marked reduction in RV compliance we believe that a quick increase in preload even lasting a few minutes can be harmful because it can decompensate the RV oxygen supply demand .