Comparison between the Doppler flowmetry and the free flow of dog's internal thoracic artery with and without use norepinephrine.

OBJECTIVE This work aims to study comparatively the free flow and the Doppler flowmetry of the internal thoracic artery in anesthetized dogs, with and without continuous intravenous administration of norepinephrine. METHODS The sample was made up of ten mongrel dogs, which dissected the left and right internal thoracic arteries and evaluated your stream; first, by Doppler flowmetry and then by free flow. The mean arterial pressure and the diameter of the arteries at the beginning of the procedure were registered. The workflow checks by two methods occurred in three times: time zero, 10 and 25 minutes. After the first check in time zero, the continuous infusion of norepinephrine in the right atrium; other checks were made in the same way that the first time, to 10 and 25 minutes, in the same arteries and by two methods, each one in his artery, noting the results, as well as the corresponding average blood pressure. RESULTS The results of the scan of the stream, between Doppler flowmetry and free flow, there were similar; being the first, zero times, ten and twenty-five minutes, respectively, 183, 230.1 and 237 ml/min compared to seconds, 168.6, 226.8 and 226.4 ml/min (P = 0.285). The mean arterial pressures of three times and the average diameter of the arteries, showed no statistically significant differences between the methods, so did not influence on the comparison of the results. CONCLUSION The evaluations, both from Doppler flowmetry and free flow, were similar in three times checked.