tailieunhanh - Báo cáo khoa học: "Vital organ blood flow during high-frequency ventilation"

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 ngành y học đề tài: Vital organ blood flow during high-frequency ventilation. | Available online http content 10 6 426 Letter Vital organ blood flow during high-frequency ventilation Patrick Meybohm Jens Scholz and Berthold Bein University Hospital Schleswig-Holstein Campus Kiel Department of Anaesthesiology and Intensive Care Medicine Schwanenweg 21 24105 Kiel Germany Corresponding author Patrick Meybohm meybohm@ Published 14 November 2006 This article is online at http content 10 6 426 2006 BioMed Central Ltd See related research by David et al. http content 10 4 R100 Critical Care 2006 10 426 doi ee5075 We read with interest the article by David and colleagues 1 comparing the effects of high-frequency oscillatory ventilation with pressure controlled ventilation with respect to vital organ blood flow in an animal model of acute lung injury. However there are some points we wish to comment on. Firstly the authors state that their study is limited due to the lack of more frequent blood flow measurements as all parameters were measured only once thirty minutes after switching to a new mean airway pressure Pmean . Indeed changes in hemodynamic variables are most pronounced straight after increasing mean airway pressure 2 . It has been shown that cardiac output initially decreased substantially after an increase in positive end-expiratory pressure PEEP but that it adapted to the increased PEEP thereafter due to dynamic hemodynamic changes 3 . Consequently compensatory mechanisms missed by insufficient data sampling could explain the only slightly decreased cardiac output and unchanged organ blood flow seen in the study by David and colleagues 1 . Therefore it is of paramount importance to investigate parameters of individual organ perfusion more frequently and obtain variables of tissue oxygenation and metabolism. Furthermore brain tissue is extremely susceptible to ischemia and even a few minutes of compromised cerebral perfusion affect the rate of cerebral oxygen metabolism and