Comparison between two methods for cardiac output measurement in propofol-anesthetized dogs: thermodilution and Doppler

ObjectiveTo compare cardiac output (CO) measured by Doppler echocardiography and thermodilution techniques in spontaneously breathing dogs during continuous infusion of propofol. To do so, CO was obtained using the thermodilution method (CO(TD)) and Doppler evaluation of pulmonary flow (CO(DP)) and aortic flow (CO(DA)).Study designProspective cohort study.AnimalsEight adult dogs weighing 8.3 +/- 2.0 kg.MethodsPropofol was used for induction (7.5 +/- 1.9 mg kg-1 IV) followed by a continuous rate infusion at 0.7 mg kg-1 minute-1. The animals were positioned in left lateral recumbency on an echocardiography table that allowed for positioning of the transducer at the 3rd and 5th intercostal spaces of the left hemithorax for Doppler evaluation of pulmonary and aortic valves, respectively. CO(DP) and CO(DA) were calculated from pulmonary and aortic velocity spectra, respectively. A pulmonary artery catheter was inserted via the jugular vein and positioned inside the lumen of the pulmonary artery in order to evaluate CO(TD). The first measurement of CO(TD), CO(DP) and CO(DA) was performed 30 minutes after beginning continuous infusion (T0) and then at 15-minute intervals (T15, T30, T45 and T60). Numeric data were submitted to two-way anova for repeated measurements, Pearson's correlation coefficient and Bland & Altman analysis. Data are presented as mean +/- SD.ResultsAt T0, CO(TD) was lower than CO(DA). CO(DA) was higher than CO(TD) and CO(DP) at T30, T45 and T60. The difference between the CO(TD) and CO(DP), when all data were included, was -0.04 +/- 0.22 L minute-1 and Pearson's correlation coefficient (r) was 0.86. The difference between the CO(TD) and CO(DA) was -0.87 +/- 0.54 L minute-1 and r = 0.69. For CO(TD) and CO(DP), the difference was -0.82 +/- 0.59 L minute-1 and r = 0.61.ConclusionDoppler evaluation of pulmonary flow was a clinically acceptable method for assessing the CO in propofol-anesthetized dogs.

Hemodynamic effects of butorphanol in desflurane-anesthetized dogs

Objective To evaluate the effects of butorphanol on cardiopulmonary parameters in dogs anesthetized with desflurane and breathing spontaneously.Study design Prospective, randomized experimental trial.Animals Twenty dogs weighing 12 +/- 3 kg.Methods Animals were distributed into two groups: a control group (CG) and butorphanol group (BG). Propofol was used for induction and anesthesia was maintained with desflurane (10%). Forty minutes after induction, the dogs in the CG received sodium chloride 0.9% (0.05 mL kg(-1) IM), and dogs in the BG received butorphanol (0.4 mg kg(-1) IM). The first measurements of body temperature (BT), heart rate (HR), arterial pressures (AP), cardiac output (CO), cardiac index (CI), central venous pressure (CVP), stroke volume index (SVI), pulmonary arterial occlusion pressure (PAOP), mean pulmonary arterial pressure (mPAP), left ventricular stroke work (LVSW), systemic (SVR) and pulmonary (PVR) vascular resistances, respiratory rate (fR), and arterial oxygen (PaO(2)) and carbon dioxide (PaCO(2)) partial pressures were taken immediately before the administration of butorphanol or sodium chloride solution (T0) and then at 15-minute intervals (T15-T75).Results In the BG, HR, AP, mPAP and SVR decreased significantly from T15 to T75 compared to baseline. fR was lower at T30 than at T0 in the BG. AP and fR were significantly lower than in the CG from T15 to T75. PVR was lower in the BG than in the CG at T30, while PaCO(2) was higher compared with T0 from T30 to T75 in the BG and significantly higher than in the CG at T30 to T75.Conclusions and clinical relevance At the studied dose, butorphanol caused hypotension and decreased ventilation during desflurane anesthesia in dogs. The hypotension (from 86 +/- 10 to 64 +/- 10 mmHg) is clinically relevant, despite the maintenance of cardiac index.

Efeitos da dexmedetomidina administrada em infusão intravenosa contínua, associada ou não ao butorfanol, em equinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparação entre a variação da pressão de pulso e o índice de variabilidade pletismográfica como índices dinâmicos de pré-carga em cães anestesiados com isoflurano submetidos à hemorragia hipotensiva por reposição volêmica

Pós-graduação em Anestesiologia - FMB

Concordância entre o débito cardíaco estimado através das técnicas de termodiluição transpulmonar e de análise de contorno de pulso e a técnica de termodiluição de artéria pulmonar em cães anestesiados com isoflurano

Pós-graduação em Anestesiologia - FMB

Comparação entre índices dinâmicos e volumétricos de pré-carga em cães submetidos à hemorragia moderada seguida de reposição volêmica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)