Validation Study of PulseCO System for Continuous Cardiac Output Measurement

Abstract

Ultrasonic flow probes have been used to optimize biventricular pacing immediately after cardiopulmonary bypass, improving cardiac output (CO) by 10%; however, flow probes must be removed with chest closure. The PulseCO system (LiDCO Limited, Cambridge, UK) may extend optimization into the postoperative period, but controlled validations have not been reported. Six anesthetized pigs were instrumented for right heart bypass. Flow was varied from 3 to 1 L/min and then back to 3 in 0.5 L/min increments for 60 second intervals. CO was measured by ultrasonic flow probe on the aorta and by PulseCO using a femoral arterial line. PulseCO and flow probe accurately measured CO (PulseCO R2: 0.79-0.95; flow probe R2: 0.96-0.99). At flow of 2 L/min, when the heart was paced 30 bpm over the sinus rate, PulseCO falsely indicated an increase in CO (2.13 vs. 2.30 L/min, p = 0.014). When mean arterial pressure was increased by 20% using a phenylephrine infusion, PulseCO falsely indicated an increase in CO (2.13 vs. 2.47 L/min, p = 0.014). When mean arterial pressure was decreased by 20% using a nitroprusside infusion, PulseCO falsely indicated a decrease in CO (2.13 vs. 1.79 L/min, p = 0.003). PulseCO appears to be useful for assessing acute changes in CO if its limitations are recognized.

The hemodynamics of oxytocin and other vasoactive agents during neuraxial anesthesia for cesarean delivery: findings in six cases

“…This report demonstrates in obstetric patients a new cardiovascular monitoring technology called pulse contour or pulse power analysis (PulseCO system, LiDCO Ltd. Cambridge, UK) that allows MAP, SVR and CO to be monitored in real time with only an arterial line. [6][7][8][9][10][11] Formal calibration by lithium dilution can be performed to obtain correct absolute values for SVR and CO, but, as in the present case series, trends in predicted, or nominal, hemodynamic values can be followed without resorting to the somewhat laborious calibration procedure. The nominal hemodynamic values are derived in real time from the arterial pressure waveform and algorithms that use the patient's height, weight and age to predict aortic compliance.…”

Perioperative hemodynamics obtained by pulse contour analysis facilitated the management of a patient with chronic hypertension, renal insufficiency, and superimposed preeclampsia during cesarean delivery

“…Experiments in pigs showed good agreement between LiDCO and PulseCO over a CO range of three L/min to one L/min, but only after sufficient time had passed (roughly 30 sec) to allow the MAP to stabilize at its new level [20].…”

Effect of lower limb compression devices on thermodilution cardiac output measurement*

“…The PCCO is a temperature-independent method of calculating changes in CO obtained from analysis of the arterial catheter waveform. A validation study of PCCO for continuous CO measurement has been reported (22). The PCCO was calibrated to CO from the PAC when SCDs were deflated before the start of the study.…”