Non-invasive rodent cardiac output: comparison of a compact clinical monitor with echocardiography

Sturgess, David, Haluska, Brian, Jones, Mark and Venkatesh, Bala (2010) Non-invasive rodent cardiac output: comparison of a compact clinical monitor with echocardiography. WebmedCentral, .

Author Sturgess, David
Haluska, Brian
Jones, Mark
Venkatesh, Bala
Title Non-invasive rodent cardiac output: comparison of a compact clinical monitor with echocardiography
Journal name WebmedCentral   Check publisher's open access policy
ISSN 2046-1690
Publication date 2010-09-29
Sub-type Article (original research)
Open Access Status
Subject 110201 Cardiology (incl. Cardiovascular Diseases)
Formatted abstract
BACKGROUND: There are limited options for non-invasive cardiac output (CO) measurement in rodents. This study aimed to compare a commercially available human CO monitor, USCOM® (USCOM Ltd, Sydney, Australia), with specialised rodent echocardiography for rat CO measurement.

METHODS: With institutional ethics committee approval, twenty-one anaesthetised, mechanically-ventilated male Sprague-Dawley rats (573±96g) were studied during refinement and study of an endotoxic shock model. Pulsed-wave Doppler echocardiography (15MHz rodent probe) was used to measure left ventricular (LV) outflow velocity and calculate stroke volume and CO. USCOM (v1.7; 2.2MHz) CO measurements followed each echocardiographic examination. USCOM CO was measured by combining continuous wave Doppler with predicted outflow tract diameter (OTD-U).

RESULTS: 21 paired measurements were analysed. Mean echocardiographic CO was 113mL/min (range 46–236). Mean USCOM CO was 245mL/min (range 75-553). Paired echocardiographic and USCOM measurements demonstrated significant correlations for heart rate (r=0.92, P≤0.0001) and CO (r=0.68, P=0.001). Bland Altman analysis of CO demonstrated mean bias of -131mL/min and precision of 52mL/min. Linear regression analysis yielded a simple correction factor for USCOM OTD estimation. Following application of this correction factor (0.68*OTD-U), mean bias improved to -0.1mL/min with precision of 38mL/min.

CONCLUSIONS: USCOM (v1.7) is not interchangeable with pulsed-wave Doppler echocardiography for measuring rat CO. We propose a simple correction factor that should improve performance of this device in the rodent laboratory. Incorporation into a rat-specific algorithm should be evaluated prospectively across a range of potential applications.
Keyword Hemodynamics
Bland Altman
Doppler
Rat
Endotoxin
Q-Index Code CX
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Article ID: WMC00759 -- Referred to M.M. - MC 8Dec10

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
School of Medicine Publications
 
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Created: Wed, 17 Nov 2010, 07:59:05 EST by Dr David Sturgess on behalf of Anaesthesiology and Critical Care - PAH