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Variability of Doppler ultrasound measurements of hindlimb blood flow in conscious horses
Author(s) -
Raisis A. L.,
Young L. E.,
Meire H. B.,
Taylor P. M.,
Walsh K.,
Lekeux P.
Publication year - 2000
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.2746/042516400777591561
Subject(s) - blood flow , horse , medicine , ultrasound , femoral vein , femoral artery , doppler effect , anatomy , hemodynamics , anesthesia , cardiology , geology , radiology , physics , paleontology , astronomy
Summary Ultrasonography of the left and right femoral artery and vein was performed in 5 conscious horses. Velocity waveforms, recorded using low pulse repetition frequency, were used to calculate time‐averaged mean velocity (TAV), velocity of component a (TaVa), velocity of component b (TaVb) and volumetric flow. Waveform analysis included calculation of early diastolic deceleration slope (EDDS) and pulsatility index (PI) and subjective description of the waveform. Measurements were recorded at monthly intervals for 6 months. The repeated measurements were used to determine the within‐horse variation. Horses were then anaesthetised with halothane and the same measurements recorded 60 min afterinduction. Differences between measurements recorded in conscious and anaesthetised horses were determined. Within‐horse variability fordiameters of femoral arteries and veins was small (CV<10%). Within variability for all other measurements was marked (CV>11%), with within‐horse variability being the largest for femoral venous flow (CV>35%). Source of variability was measurement errorand biological variation. Despite variability in conscious horses it was possible to detect changes in blood flow during anaesthesia. In the femoral arteries, volumetric flow was lower and EDDS and PI was higher in anaesthetised horses. In the femoral veins, volumetric flow was also lower in anaesthetised horses. Therefore Doppler ultrasound appears to be a useful technique for studying blood flow in conscious and anaesthetised horses.