OBJECTIVE: To evaluate the agreement between cardiac output (CO) values obtained using a transpulmonary thermodilution technique (TPTDCO) and conventional thermodilution technique (TDCO) in anaesthetized dogs with fluid overload. STUDY DESIGN: Prospective experimental study. ANIMALS: Six healthy Beagle dogs aged 7-8 years. METHODS: Dogs were anaesthetized with sevoflurane in oxygen, and catheters were inserted for TPTDCO and TDCO measurement. After instrumentation, baseline CO was measured using each technique at a central venous pressure (CVP) of 3-7 mmHg. Dogs were subsequently administered lactated Ringer's solution and 6% hydroxyethyl starch to induce fluid overload. CO measurements were obtained using each technique at CVP values of 8-12 mmHg, 13-17 mmHg, 18-22 mmHg and 23-27 mmHg. Agreements between CO measurements obtained with the respective techniques were analysed using Dunnett's test, Pearson's correlation coefficient and Bland-Altman analysis. RESULTS: Thirty pairs of CO values were obtained, ranging from 1.45 L minute(-1) to 4.69 L minute(-1) for TPTDCO and from 1.30 L minute(-1) to 4.61 L minute(-1) for TDCO. TPTDCO and TDCO values correlated strongly (r(2) = 0.915, p < 0.001). The bias and mean relative bias between TPTDCO and TDCO were 0.26 ± 0.30 L minute(-1) (limits of agreement - 0.29 to 0.81 L minute(-1) ) and 9.7%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: TPTDCO and TDCO measurements obtained in anaesthetized dogs during fluid overload exhibited good agreement. Accordingly, transpulmonary thermodilution provides an accurate measurement of CO in dogs with fluid overload.
OBJECTIVE: To evaluate the agreement between cardiac output (CO) values obtained using a transpulmonary thermodilution technique (TPTDCO) and conventional thermodilution technique (TDCO) in anaesthetized dogs with fluid overload. STUDY DESIGN: Prospective experimental study. ANIMALS: Six healthy Beagle dogs aged 7-8 years. METHODS:Dogs were anaesthetized with sevoflurane in oxygen, and catheters were inserted for TPTDCO and TDCO measurement. After instrumentation, baseline CO was measured using each technique at a central venous pressure (CVP) of 3-7 mmHg. Dogs were subsequently administered lactated Ringer's solution and 6% hydroxyethyl starch to induce fluid overload. CO measurements were obtained using each technique at CVP values of 8-12 mmHg, 13-17 mmHg, 18-22 mmHg and 23-27 mmHg. Agreements between CO measurements obtained with the respective techniques were analysed using Dunnett's test, Pearson's correlation coefficient and Bland-Altman analysis. RESULTS: Thirty pairs of CO values were obtained, ranging from 1.45 L minute(-1) to 4.69 L minute(-1) for TPTDCO and from 1.30 L minute(-1) to 4.61 L minute(-1) for TDCO. TPTDCO and TDCO values correlated strongly (r(2) = 0.915, p < 0.001). The bias and mean relative bias between TPTDCO and TDCO were 0.26 ± 0.30 L minute(-1) (limits of agreement - 0.29 to 0.81 L minute(-1) ) and 9.7%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: TPTDCO and TDCO measurements obtained in anaesthetized dogs during fluid overload exhibited good agreement. Accordingly, transpulmonary thermodilution provides an accurate measurement of CO in dogs with fluid overload.