TECHNICAL NOTE - MEASURING PORTAL BLOOD-FLOW IN SHEEP USING AN ULTRASONIC TRANSIT-TIME FLOW PROBE

Our objective was to validate the use of an ultrasonic transit-time fl owmeter for the measurement of portal blood flow (PBF) in sheep. Data recorded with this technique were compared with those obtained with an indicator dilution method, and probes were calibrated in vivo. Wether s were fitted with catheters in the portal, jejunal, and ruminal veins and in a mesenteric artery. Ultrasonic flow probes were implanted aro und the portal vein: S-series probes in three wethers, and A-series pr obes in four wethers. The PBF measured with A-series probes was within 10% of that measured by indicator dilution, but PBF measured with S-s eries probes were 52 to 77% of that determined by indicator dilution. In vivo calibration indicated that A-series probes provided accurate m easurement of PBF (absolute accuracy: 5% +/- zero flow error). In conc lusion, an ultrasonic transit-time flowmeter, with an A-series probe, can be used to reliably measure PBF in sheep.