Room-temperature thermodilution cardiac output: central venous vs right ventricular port

OBJECTIVE: To assess the accuracy of room-temperature thermodilution cardiac output measurements from the right ventricular port. In addition, waveform patterns were evaluated to determine the actual location of the right ventricular port. DESIGN: Central venous port cardiac output measurements were compared with right ventricular port cardiac output measurements using the same right-heart catheter. SETTING: The general intensive care unit of Memorial Sloan-Kettering Cancer Center. PATIENTS: Thirty-seven critically ill cancer patients with 38 different right-heart catheters were evaluated. INTERVENTION: Four injections of 10 mL normal saline at room temperature were made through each port; the results of the last three injections were averaged. Cardiac output determinations from both ports were completed in less than 10 minutes. The order of port injection was random. RESULTS: No difference was noted between cardiac output determinations from the two ports in a paired t test. Of 38 right-heart catheters, 17 were in the right ventricle and the other 21 in the right atrium. A comparison of ports in the 17 right ventricle catheters showed no difference with a significant (P < .01; R2 = 0.96) correlation. CONCLUSION: Thermodilution cardiac output measurements using 10 mL normal saline at room temperature can be determined accurately using the right ventricular port if the central venous port becomes nonfunctional.