Arterial thermodilution: an alternative to pulmonary artery catheter for cardiac output assessment in burn patients

Study objective: To study the agreement between cardiac output measurements with the pulmonary artery catheter and with the transpulmonary thermodilution technique in patients with burns. Design: Prospective, clinical study. Patients: 23 patients with serious burns and an abbreviated burn severity index score (ABSI)>6. Setting: intensive care unit for severely burned in a burn center in Germany. Results: A total number of 218 cardiac output measurements obtained during the first 72 h postburn were analysed. In the pulmonary artery group, mean cardiac index was 3.93 l/min/m2 and ranged from 0.96 to 9.58. In the transpulmonary group the cardiac index measurements ranged from 0.96 to 9.61 with a mean of 4.0 l/min/m2. During the entire observation period cardiac index was consistently higher in the transpulmonary group than in the pulmonary artery group with a bias of 0.32 l/min/m2 and a standard deviation (S.D.) of 0.29 l/min/m2. Linear regression analysis revealed CIarterial=0.98×CIpulm+0.22l/min/m2 (r=0.9678, P<0.038). Bias and precision to each time point according to Bland and Altman demonstrated a good agreement between both techniques. Conclusion: The transpulmonary thermodilution offers an attractive, less invasive alternative to the pulmonary artery catheter in patients with burns. Arterial thermodilution for CO measurements is as precise as PA thermal dilution, and COpulm can be replaced by CIarterial when basic methodological principles are respected.