Background: Cardiac output (CO) is an important hemodynamic parameter during sepsis and septic shock resuscitation. Conventionally, this value is obtained at bedside by the thermodilution technique, which requires a pulmonary artery catheter (PAC). Estimated Continuous Cardiac Output (esCCO, Nihon Kohden, Japan) calculated from pulse-wave transit time (PWTT) was examined here as an alternative.
Material and method: A prospective study was performed in a 14-bed ICU facility. Patients with severe sepsis and septic shock who had PAC placed were included. Serial thermodilution cardiac outputs (CO(IBT)) and esCCO (COesCCO) were obtained at the beginning of resuscitation (t0), at 48 hours (t48), and at 72 hours (t72). Other parameters from the tested device; namely, estimated continuous cardiac index (esCCI), estimated stroke volume (esSV), and estimated stroke volume index (esSVI), were also achieved.
Results: A total of 90-paired readings from ten ICU patients were collected. The overall correlation coefficient (R) between COesCCO and CO(IBT) was 0.76. When focusing on the correlation from each time point, we found R at t0 = 0.65, t48 = 0.74, and t72 = 0.84 (all p < 0.001). Bland and Altman analysis corrected for repeated measures showed a bias of 1.2 liter/min and limits of agreement from -2.8 to +5.2 liter/min. Results also showed fair to poor correlation with other parameters that derived from this device (esCCI, esSV esSVI).
Conclusion: The estimated continuous cardiac output (esCCO) correlated well with the cardiac output obtained by thermodilution techniques, especially when patients were out of shock.