Research

Cross-comparison of cardiac output trending accuracy of LiDCO, PiCCO, FloTrac and pulmonary artery catheters

Mehrnaz Hadian^1,3, Hyung Kook Kim¹, Donald A Severyn² and Michael R Pinsky^1*

• * Corresponding author: Michael R Pinsky pinskymr@upmc.edu

Author Affiliations

¹ Department of Critical Care Medicine, University of Pittsburgh Medical Center, 230 Lothrop Street, Pittsburgh, PA 15261, USA

² Cardiothoracic Surgery, University of Pittsburgh Medical Center, 230 Lothrop Street, Pittsburgh, PA 15261, USA

³ Current address: Eisenhower Medical Center, 39000 Bob Hope Drive, Rancho Mirage, CA 92270, USA

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Critical Care 2010, 14:R212 doi:10.1186/cc9335

See related commentary by Critchley, http://ccforum.com/content/15/1/106 and related letter by Pinsky, http://ccforum.com/content/15/2/406.

Published: 23 November 2010

Abstract

Introduction

Although less invasive than pulmonary artery catheters (PACs), arterial pulse pressure analysis techniques for estimating cardiac output (CO) have not been simultaneously compared to PAC bolus thermodilution CO (COtd) or continuous CO (CCO) devices.

Methods

We compared the accuracy, bias and trending ability of LiDCO™, PiCCO™ and FloTrac™ with PACs (COtd, CCO) to simultaneously track CO in a prospective observational study in 17 postoperative cardiac surgery patients for the first 4 hours following intensive care unit admission. Fifty-five paired simultaneous quadruple CO measurements were made before and after therapeutic interventions (volume, vasopressor/dilator, and inotrope).

Results

Mean CO values for PAC, LiDCO, PiCCO and FloTrac were similar (5.6 ± 1.5, 5.4 ± 1.6, 5.4 ± 1.5 and 6.1 ± 1.9 L/min, respectively). The mean CO bias by each paired method was -0.18 (PAC-LiDCO), 0.24 (PAC-PiCCO), -0.43 (PAC-FloTrac), 0.06 (LiDCO-PiCCO), -0.63 (LiDCO-FloTrac) and -0.67 L/min (PiCCO-FloTrac), with limits of agreement (1.96 standard deviation, 95% confidence interval) of ± 1.56, ± 2.22, ± 3.37, ± 2.03, ± 2.97 and ± 3.44 L/min, respectively. The instantaneous directional changes between any paired CO measurements displayed 74% (PAC-LiDCO), 72% (PAC-PiCCO), 59% (PAC-FloTrac), 70% (LiDCO-PiCCO), 71% (LiDCO-FloTrac) and 63% (PiCCO-FloTrac) concordance, but poor correlation (r² = 0.36, 0.11, 0.08, 0.20, 0.23 and 0.11, respectively). For mean CO < 5 L/min measured by each paired devices, the bias decreased slightly.

Conclusions

Although PAC (CO_TD/CCO), FloTrac, LiDCO and PiCCO display similar mean CO values, they often trend differently in response to therapy and show different interdevice agreement. In the clinically relevant low CO range (< 5 L/min), agreement improved slightly. Thus, utility and validation studies using only one CO device may potentially not be extrapolated to equivalency of using another similar device.