Comparison between continuous non-invasive estimated cardiac output by pulse wave transit time and thermodilution method.

Aims and Objectives: Cardiac output (CO) measurement is essential for many therapeutic decisions in anesthesia and critical care. Most available non‑invasive CO measuring methods have an invasive component. We investigate “pulse wave transit time” (estimated continuous cardiac output [esCCO]) a method of CO measurement that has no invasive component to its use. Materials and Methods: After institutional ethical committee approval, 14 adult (21–85 years) patients undergoing surgery and requiring pulmonary artery catheter (PAC) for measuring CO, were included. Postoperatively CO readings were taken simultaneously with thermodilution (TD) via PAC and esCCO, whenever a change in CO was expected due to therapeutic interventions. Both monitoring methods were continued until patients’ discharge from the Intensive Care Unit and observer recording values using TD method was blinded to values measured by esCCO system. Results: Three hundred and one readings were obtained simultaneously from both methods. Correlation and concordance between the two methods was derived using Bland‑Altman analysis. Measured values showed significant correlation between esCCO and TD (r = 0.6, P < 0.001, 95% confidence limits of 0.51-0.68). Mean and (standard deviation) for bias and precision were 0.13 (2.27) L/min and 6.56 (2.19) L/min, respectively. The 95% confidence interval for bias was ‑ 4.32 to 4.58 L/min and for precision 2.27 to10.85 L/min. Conclusions: Although, esCCO is the only true non‑invasive continuous CO monitor available and even though its values change proportionately to TD method (gold standard) with the present degree of error its utility for clinical/therapeutic decision‑making is questionable.

Evaluation of ultrasonic technology for monitoring children's cardiac output / 中国小儿急救医学

Objective To explore the accuracy of the ultrasonic cardiac output monitor(USCOM) device for estimation of children's cardiac output.Methods We conducted a prospective study in Beijing Children's Hospital.Sixty healthy children were enrolled in this study.We evaluated the accuracy of USCOM monitor device in the measurement of cardiac output by comparing with the measurements obtained by the M-Teichholz formula and the Doppler aortic blood flow method.Results The data from the USCOM monitor device had better consistency with those from the M-Teichholz formula (r=0.88,P<0.05),and there was no significant difference (P>0.05) between the two methods.The similar results were found between the USCOM method and the Doppler aortic blood flow method (r=0.83,P<0.05).Conclusion This study shows that cardiac output monitoring by USCOM is accurate,and USCOM is a promising technique in cardiac output monitoring.