Thermodilution cardiac output values obtained by using a centrally placed introducer sheath and right atrial port of a pulmonary artery catheter.

Thermodilution cardiac output measurements obtained using a centrally placed introducer sheath were compared with thermodilution cardiac outputs obtained using the right atrial port of a balloon-tip, flow-directed pulmonary artery catheter in 15 patients with cardiac failure. Cardiac output values were obtained by manually injecting 10 ml of iced, D5W alternately through the introducer sheath and the right atrial port of the flow-directed catheter. Thirty cardiac output readings were obtained in the 15 patients. Cardiac outputs obtained using the right atrial port (CORA) did not differ significantly from cardiac outputs obtained using the introducer sheath (COSP) (5.3 +/- 0.2 vs. 5.2 +/- 0.2 L/min). The correlation between CORA and COSP was significant (r = .94, p less than .0001) and could be described by the formula CORA = 0.33 + 0.96 COSP. We conclude that when the right atrial port of a flow-directed catheter is nonfunctional, a thermodilution cardiac output obtained using a centrally placed introducer sheath offers a reliable alternative.