Download or read book Non-invasive Cardiac Output of Children in Health and Disease: Respiratory Gas Techniques written by Jane Ellen Schneiderman and published by . This book was released on 2011 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cardiac output (Q) is an important determinant of the cardiovascular system's ability to meet the oxygen needs of the body. This dissertation addresses the non-invasive measurement of Q, in healthy children and those with heart and lung disease. 1) The correction factors for collision broadening, downstream difference and end tidal CO2 (PetCO2), used in the CO 2 rebreathe (equilibrium) method, were evaluated. In lung disease, one is unable to assume a normal dead space to estimate arterial CO2 (PaCO2), and the use of any of these correction factors alone should be used with caution as they each exert a profound effect on the Q measurement. 2) A new equation to predict PaCO2 from PetCO2 in patients with CF was derived via multiple regression analysis, taking into account disease severity. 3) The validity and reliability of Q measures via the inert gas rebreathing technique (Innocor(TM) device) were evaluated. The highest intraclass correlation coefficients were attained during exercise (0.7- 0.98), indicating excellent reliability of the device. Comparisons of Q measures from the Innocor(TM) (QInn) to the AM IS mass spectrometer system (QAmis) were made to assess validity. The bias (QInn -QAmis) and limits of agreement (+/-2SD) were 0.45 +/- 1.9 L.min-1 and 0.27 +/- 2.1 for children with congenital heart disease and healthy controls respectively, with no systematic differences between the two methods. 4) Assessment of cardiac output in Fontan patients demonstrated that an individualized, atrioventricular (AV) delay optimization was required. Moreover, there was a small but significant improvement in heart function with AV synchronized pacing (DDI) versus ventricular pacing (VVI), suggesting that further study with a larger sample of patients is warranted. The limitations and strengths of the measurement of non-invasive cardiac output in children, primarily via respiratory gas analysis, were delineated and recommendations were made for their use.