23-11-2012, 01:35 PM
CARDIAC OUTPUT: THERMODILUTION METHOD
THERMAL DILUTION Presentation.pptx (Size: 729.74 KB / Downloads: 29)
CARDIAC OUTPUT
Volume of blood pumped by heart in a unit time
Measured using invasive and non-invasive techniques
FLOAT PA CATHETER
A cold saline is injected as a thermal indicator into the right atrium.
After mixing,it is detected in the pulmunary artery by thermistor (mounted at the tip of a miniature catheter probe)
PROCEDURE
1. Catheter is inserted into vein, and the balloon is inflated so that the catheter gets floated in the blood
2. The returning venous blood carries it until its tip is positioned in pulmunary artery
3. The thermistor is connected into a bridge circuit which gives measurement and recording of blood temp during injection.
The temperature difference between the injectate temperature and the circulating blood temperature in the pulmunary artery is measured and displayed in the output device.