Thermodilution cardiac output determination : the effect of injectate temperature on cardiac rate and rhythm in patients with flow-directed pulmonary artery catheters

Bibliography: pages [39]-41A 440-bed Midwest hospital noted a small number of patients who experienced changes in cardiac rate or rhythm immediately after thermodilution cardiac output determinations were done using iced injectate. For this reason, a quasi-experimental study was done to determine the affect of injectate temperature on cardiac rate and rhythm in 12 critically ill medical-surgical subjects when thermodilution cardiac outputs were done. No acute cardiac patients were included in this study. It was hypothesized that iced injectate would produce more changes in heart rate and rhythm than room temperature injectate. Twelve subjects were chosen by convenience sampling and served as their own control, receiving both temperatures of injectate in a random order. No subject showed a change in cardiac rate or rhythm with either temperature injectate. Analysis of the data indicated a significant difference between the cardiac output values obtained at room temperature and at 0 degrees C, using the paired t-test. The values were further tested for their correlation with an r=.96. The results were inconclusive to support the hypothesis that there would be a higher incidence of changes in rate and rhythm when thermodilution cardiac outputs are done with iced injectate than with room temperature injectate. Therefore, it cannot be concluded that either temperature injectate can be used without increasing the risk for rate and rhythm changes. However, it can be concluded that room temperature and 0 degree C thermodilution cardiac outputs are, indeed, significantly different, yet highly correlated.M.S. (Master of Science