Evaluation of an oesophageal Doppler device for monitoring cardiac output in anaesthetised healthy normotensive dogs.
OBJECTIVE
To compare cardiac output measured by oesophageal Doppler and by thermodilution monitoring and to correlate the Doppler cardiac output-generated minute distance with thermodilution cardiac output in healthy anaesthetised beagle dogs.


METHODS
Prospective experimental study. Six healthy adult beagle dogs were pre-medicated with intramuscular acepromazine (0 · 05 mg/kg) and methadone (0 · 3 mg/kg). Anaesthesia was induced with intravenous propofol (dose-effect) and maintained with isoflurane in oxygen. Simultaneously, a constant rate infusion of dopamine (3 µg/kg/minute) was administered to the dogs to prevent hypotension. The minute distance, Doppler and thermodilution cardiac outputs were assessed at three different end-tidal concentrations of isoflurane (1 · 0, 1 · 3 and 2 · 0%).


RESULTS
Correlation between Doppler and thermodilution cardiac output (r(2)  = 0 · 582) and between minute distance and thermodilution cardiac output (r(2)  = 0 · 658) were moderately good, but the limits of agreement between Doppler and thermodilution cardiac outputs were above the recommended values (±39%, for a recommended value up to 30%).


CONCLUSIONS
Doppler and minute distance cannot be considered as an alternative method to thermodilution to monitor cardiac output in the healthy anaesthetised dog.
Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, 28040, Spain.
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Canfrán
Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, 28040, Spain.
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Cediel
Itinerant Anaesthesiology Service, Sinergia Veterinaria, Madrid, Spain.
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Sández
Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, 28040, Spain.
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Caro-Vadillo
Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, Madrid, 28040, Spain.
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Gómez de Segura
D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output / Q000502:physiology*; D004285:Dogs / Q000502:physiology*; D017548:Echocardiography, Transesophageal / Q000662:veterinary; D006339:Heart Rate; D007530:Isoflurane / Q000008:administration & dosage; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000662:veterinary*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013815:Thermodilution / Q000662:veterinary
D007530:Isoflurane