Felipe Comassetto

Correlation between visual analog scales, Glasgow, Colorado and Melbourne in the evaluation of postoperative pain in dogs undergoing total unilateral mastectomy

RESUMO Objetivou-se correlacionar a necessidade de resgate analgesico pos-operatorio por meio das escalas analogica visual (EVA), de Glasgow, Colorado e Melbourne, por meio de um avaliador experiente (AE) e outro nao experiente (ANE), em cadelas submetidas a mastectomia unilateral total. Foram utilizadas 24 cadelas, higidas, internadas 24 horas antes do procedimento cirurgico, para avaliacao do seu comportamento, com o auxilio das escalas descritas acima no momento basal (M0). Foram pre-medicadas com acepromazina e morfina (0,02 e 0,5mg/kg) e induzidas a anestesia geral com propofol (4mg/kg), mantidas em plano anestesico com CAM de isoflurano 1%. A manutencao analgesica transoperatoria foi realizada com cetamina e fentanil (10µg/kg/min e 10µg/kg/h). As demais avaliacoes ocorreram em uma, duas, quatro, seis, oito, 12 e 24 horas de pos-operatorio, sendo os resgates realizados com morfina (0,5mg/kg), pela via intramuscular, quando fosse observada uma pontuacao maior ou igual a 50, seis, dois e nove pontos, respectivamente, para as escalas descritas, quando observada pelo AE e quando ao menos duas das escalas demonstrassem esses valores. Houve aumento dos escores de dor do M1 ao M12 para o AE e para o ANE para a EVA. Na analise de Colorado, maiores pontuacoes de dor ocorreram em relacao ao M0 entre o M2 e o M8 para o AE e do M1 ao M12 para o ANE. Na analise de Glasgow, maiores escores foram detectados entre o M1 e o M12 para o AE e do M1 ao M24 para o ANE. E para a de Melbourne, maiores valores foram observados do M1 e do M24 para o AE e o ANE. A melhor correlacao entre as escalas foi de 0,775 entre Glasgow e Colorado e entre os avaliadores de 0,925 para a Glasgow. Conclui-se que a escala de Glasgow apresentou-se mais sensivel para detectar resgates analgesicos em cadelas submetidas a mastectomia total unilateral, que a inexperiencia do avaliador nao compromete a qualidade das avaliacoes de dor e sugere-se reduzir a pontuacao da EVA e Melbourne para aumentar a sua capacidade em detectar resgates analgesicos pos-operatorios. Palavras-chave: cao, avaliacao da dor, escalas compostas, dor aguda, mastectomia ABSTRACT

Arterial, mixed venous or central venous hemogasometry and end tidal CO2 in dogs under different hemodynamic states

Background: Hemogasometric analysis is used in the interpretation of acid-base balance (ABB) and to access pulmonary ventilation. Already mixed venous oxygen saturation obtained at pulmonary artery correlates with tissue oxygenation. However, both samples can be difficult to access because of the difficulties in arterial and pulmonary catheterization. The aim of this study was to evaluate the feasibility of replacing the arterial and mixed venous bloods, the end tidal pressure of carbon dioxide (EtCO2) and central venous blood in the analysis of pulmonary ventilation, tissue oxygenation and ABB in dogs under different hemodynamic states. Material, Methods & Results: Nine dogs were used with an average weight of 19.6 ± 1.3 kg, anesthetized with isoflurane at 1.4 V% diluted on oxygen 60% (Baseline), and subsequently undergoing mechanical ventilation (MV) and the hypodinamic state (Hypo) with isoflurane at 3.5V% and mean arterial pressure (MAP) lower than 50 mmHg and hyperdynamic state (Hyper) by dobutamine infusion at 5 μg/kg/min and with MAP 30% higher than baseline. For each time allowed a 15 min of stabilization by each hemodynamic status. Simultaneously were collected samples of 0.6 mL of arterial blood by metatarsal artery, mixed and central venous blood by pulmonary artery and right atrium for hemogasometric analysis. To access lung function we correlated and compared the EtCO2 values obtained by gas analyzer with expired carbon dioxide pressure in the arterial blood (PaCO2), mixed venous blood (PmvCO2) and central venous blood (PcvCO2). For the interpretation of tissue oxygenation we correlated and compared the values of mixed (SmvO2) and central (ScvO2) venous oxygen saturation. For the acid-base balance we used the correlation of potencial hydrogen (pH); carbon dioxide pressure (PCO2); bicarbonate ion (HCO3-); base excess (BE); anion GAP (AG); sodium ions (Na+), chlorine ions (Cl-), potassium ions (K+) and ionized calcium (iCa) of arterial (a) mixed venous (mv) and central venous (CV) bloods. Statistical analysis was performed using ANOVA-RM followed by Dunnet test for differences between times and Tukey’s test for differences among the samples (P ≤ 0.05). Pearson correlation analysis was performed using linear regression and for comparison methods we used the Bland-Altman analysis The EtCO2 values correlated (r = 0.87) and were according to Bland-Altman analysis with PaCO2 values (mean difference of -1.6 ± 2,9 mmHg for PaCO2. There were no differences (P ≤ 0.05) from SmvO2 and ScvO2. ScvO2 correlated (r = 0.91) with SmvO2 at different hemodynamic states and with a mean difference of -0.4 ± 2.5%. Both venous bloods were correlated with the analysis of arterial blood acid-base balance and electrolytes in different hemodynamic states. However, the ionized calcium levels were 40% lower in arterial blood. Discussion: EtCO2 measurement depends of monitor technology and proper pulmonar ventilation and perfusion. In this study the limiting factor in replacing the PaCO2 hair EtCO2 was spontaneous ventilation because in this state pulmonary ventilation is compromissed. With the use of MV was possible get up similar results in the pulmonar function analysis using the EtCO2 and PaCO2. The use of central venous blood instead mixed venous blood at oxygen saturation analysis provided adequate estimate this parameter. This being easier and less invasive technique. ABB was possible with all samples with own reference values for venous and arterial samples. This is an interesting result for critical patients where the arterial sample is difficult. In electrolytes the sample was indifferent except for calcium because pH interfere in this values. It was conclude that the values of EtCO2 and central venous blood are correlated and can replace arterial and mixed venous bloods in the analysis of lung function, tissue oxygenation and acid base balance.

Anestesia geral inalatória ou total intravenosa associada a anestesia subaracnóidea, em ovinos

The purpose of this study was to evaluate the efficacy and safety of sheep submitted to inhalation anesthesia with isoflurane or total intravenous anesthesia with propofol, both associated with subarachnoid anesthesia. Fourteen animals were pre-medicated with 0.3mg.kg-1 morphine IM, and 5 minutes later received 20mcg.kg-1 detomidine IV. Then they were allocated into two groups: GISO (n=7), which were induced with 0.5mg.kg-1 of diazepam and 5mg.kg-1 of ketamine IV, and anesthesia maintenance was performed by isoflurane diluted in 100% oxygen; or GPRO (n=7), where animals were induced with 4mg.kg-1 propofol IV and subsequent maintenance anesthesia with its own infusion of 0.3mg.kg.min-1. To perform the bilateral tibial osteotomy, all animals received 0.5mg.kg-1 0.75% ropivacaine combined with 0.1mg.kg-1 morphine by the intrathecal route. There was a 40% reduction in mean heart rate after the sedative protocol in both groups, resulting in a 23% average reduction until the end of the review. Mean arterial pressure showed transient elevation of around 16%, after induction of anesthesia in GISO, but reducing it to the end of the procedure, as well as in GPRO. The average EtISO was 0.57 V% and average infusion rate of propofol was 0.24mg.kg-1.min-1. The total time of surgery, anesthesia and extubation was 66± 9.8, 92±7.0 and 13.8±1.5 minutes in GISO and 56±2.4, 82.9±4.6 and 5.4±1.5 minutes in GPRO. The maintenance of anesthesia with propofol or isoflurane produced similar anesthesia with minimal cardiovascular and blood gas effects, which are well tolerated in healthy sheep.

Calorimetria indireta na monitoração hemodinâmica e metabólica em cães sob diferentes situações hemodinâmicas

Monitoring the hemodynamic state seeks a balance between the supply and demand of oxygen by tissues. The aim of this study was to evaluate the use of indirect calorimetry (IC) compared to thermodilution (TD) in dogs under different hemodynamic states. Nine dogs weighing 19.6±1.3kg were anesthetized with isoflurane at 1.4 V% (Baseline) and subjected to mechanical ventilation (MV), a hypodynamic state (Hypo) with isoflurane at 3.5V% and hyperdynamic state (Hyper) with dobutamine infusion at 5μg/kg/min. We used a Swan-Ganz catheter for measurement of cardiac index (CI) by TD, calculation of oxygen consumption by Ficks method (VO2 Fick ) and to collect central and mixed venous blood. With the IC we obtained oxygen consumption (VO2), CO2 production (VCO2) and end tidal CO2 (EtCO2). For the determination of CI by IC we used the Ficks principle with VO2 values, and arterial and mixed venous blood (Fick mix ) or arterial and central venous blood (Fick vc ); and by the ratio of the values of VCO2 and EtCO2 (Fick CO2 ). We performed the statistical analysis by Dunnet tests, for the difference between the states, and Tukey for differences between methods (P≤0.05). Pearson correlation and Bland-Altman analysis was performed for correlation and agreement analysis. IC provided VO2 values 30 to 40% higher than the VO2 Fick but identified the reduction in VO2 after VM and Hypo,