tailieunhanh - Báo cáo y học: " Why measure cardiac output"

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: Why measure cardiac output? | Critical Care April 2003 Vol 7 No 2 Pinsky Commentary Why measure cardiac output Michael R Pinsky Professor of Critical Care Medicine Department of Critical Care Medicine University of Pittsburgh Medical Center Pittsburgh Pennsylvania USA Correspondence Michael R. Pinsky pinskymr@ Published online 10 January 2003 Critical Care 2003 7 114-116 DOI cc1863 This article is online at http content 7 2 114 2003 BioMed Central Ltd Print ISSN 1364-8535 Online ISSN 1466-609X Abstract Although cardiac output is a primary determinant of global O2 transport there are no absolute values that reflect circulatory adequacy though very low values are of negative prognostic use. There is no agreement as to what constitutes a clinically relevant change in cardiac output. A recent clinical trial suggests that early goal-directed therapy aimed at increasing cardiac output improves survival. Thus in some patients measurement of cardiac output is indicated as an aid to prognosis diagnosis and to monitor the adequacy of therapy. Gonzalez et al. compared PAC thermodilution cardiac output with indirect Fick measures of cardiac output. They found that at lower cardiac outputs 5 l min the agreement between the two techniques is good whereas at higher flows increased differences exist between the two measures. As discussed in this commentary this study did not address the three potential questions related to PAC monitoring of cardiac output. These questions are can the PAC cardiac output data be used to monitor cardiac output Do technical and physiological constraints limit the accuracy of PAC cardiac output And are PAC cardiac output measurement errors due to respiratory variation in pulmonary blood flow Ways of answering each question are given. Keywords clinical trial circulatory shock hemodynamic monitoring Cardiac output is a primary determinant of global oxygen transport from the heart to the body. Also because the major function of the cardiovascular system