Determination of cardiac output in neonatal foals by ultrasound velocity dilution and its comparison to the lithium dilution method.
OBJECTIVE
To compare cardiac output (CO) measured by use of lithium dilution (LiDCO) and ultrasound velocity dilution (UDCO) in conditions of high, intermediate, and low CO in anesthetized foals.


METHODS
Original prospective study.


METHODS
University teaching hospital.


METHODS
Six foals 1-3 days of age (38-45 kg).


METHODS
Neonatal foals were anesthetized and instrumented to measure direct blood pressure, heart rate, arterial blood gases, and CO. The CO was measured by use of LiDCO and UDCO techniques. Measurements were obtained from each foal at baseline and during low, intermediate, and high CO states. Measurements were converted to cardiac index (cardiac index=CO/body weight) values for statistical analysis. Agreement between the 2 methods was determined using Bland and Altman analysis and concordance correlation coefficients.


RESULTS
LiDCO determinations of CO ranged between 4.0 and 14.0 L/min resulting in cardiac index ranging between 75.5 and 310 mL/kg/min. There was no significant effect of blood pressure variation on bias or relative bias (P=0.62 and 0.93, respectively). The mean bias and relative bias of UDCO (+/-SD) compared with LiDCO were -20.1+/-39.2 mL/kg/min and -7.7+/-23.4%, respectively. Concordance correlation coefficient between LiDCO and UDCO was 0.833.


CONCLUSIONS
When compared with LiDCO, the UDCO technique has acceptable clinical utility for measuring CO in healthy anesthetized newborn foals.
Shih
Andre
A
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA. shiha@vetmed.ufl.edu
Giguère
Steeve
S
Sanchez
L Chris
LC
Valverde
Alexander
A
Bandt
Carsten
C
Jankunas
Hope
H
Robertson
Sheilah
S
D000818:Animals; D000831:Animals, Newborn; D002302:Cardiac Output / Q000502:physiology*; D006334:Heart Function Tests / Q000379:methods / Q000662:veterinary; D006736:Horses / Q000502:physiology*; D018021:Lithium Chloride / Q000008:administration & dosage* / Q000097:blood; D011446:Prospective Studies; D014463:Ultrasonography / Q000379:methods / Q000662:veterinary*
D018021:Lithium Chloride