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Hypovolemia is characterized by body fluid loss leading to an inadequate circulatory flow and consequently tissue injury. The aim of this study was to compare the volume expansion using hypertonic saline solution (NaCl 7.5%) alone or in combination with hydroxyethylstarch 130/0.4 (HES 130/ 0.4) in cats under general anesthesia with isoflurane and exposed to experimental hypovolemia. Twelve adult mixed breed cats, average weight of 3.07±0.56kg were used in this study. The queens were anesthetized using isoflurane and after surgical prepare, anesthesia were maintained with 1 MAC of isoflurane and the animals were mechanically ventilated. After waiting for anesthesia stabilization, baseline cardiovascular and hemogasometric parameters were recorded. Hypovolemia was induced by withdrawing 30mL kg-1 of blood from the femoral artery, after an hour, data were reassessed, and then, the animals were allocated into two groups: HSG (hypertonic saline group, n=6), which received 4mL kg-1 of 7.5% NaCl, and HSCG (hypertonic saline, associated to HES 130/0,4 group n=6) which received 4mL kg-1 of 7.5% NaCl associated to 30ml kg-1 of HES 130/0.4. After the treatments, cardiovascular and hemogasometric parameters were assessed for 120 minutes. Systolic blood pressure (SAP), diastolic blood pressure (DAP), mean arterial pressure (MAP) were significantly higher after volemic expansion on HSG at T0. From T45 to T120, SAP, DAP and MAP were significantly higher in HSCG when compared to HSG. Central venous pressure was higher in HSCG up to T60. There were no significant differences between groups on heart rate, respiratory rate, Na+, K+, base excess, bicarbonate, hemoglobin saturation, glucose, PaCO2, PaO2 and pH. The administration of 7.5% NaCl, promoted a faster increase in MAP, SAP and DAP in cats with induced hypovolemia and these effects were maintained for 30 minutes while the administration of HES 130/0.4 in combination with 7.5% NaCl promoted a delayed reestablishment (30 minutes after treatment) of MAP, SAP and DAP in cats with induced hypovolemia, but lasting up to T120. The combination of HES 130/0.4 and NaCl 7.5% promoted a significant increase on CVP for up to 60 minutes after the treatment. [ABSTRACT FROM AUTHOR]

Proper monitoring of cardiac index (CI) in critically ill patients requires accurate and minimally invasive methods. The aim of this study was to compare the CI values obtained by thermodilution or echocardiography using different methods in dogs in different hemodynamic states. Nine dogs weighing 19.6±1.3kg were anesthetized with isoflurane at 1.4V% (Baseline) and subjected to mechanical ventilation (MV),a hypodynamic state (Hypo) with isoflurane at 3.5V% and hyperdynamic state (hyper) with dobutamine infusion at 5µgkg-1min-1. CI analysis was performed by thermodilution (TD) and using the modified Simpson's method, aortic velocitytime integral (A-VTI) method and pulmonary VTI (P-VTI) method. We performed Pearson's correlation and Bland- Altman analysis. The CI values (Lm-2min-1) of the animals in the Baseline, MV, Hypo and Hyper states were 4.3±1, 3.6±0.7, 2.9±0.66 and 6.1±2, for TD; 2.8±0.7, 2.4±0.3, 1.7±0.7 and 4.4±1.2, for Simpson's method; 3.4±0.9, 3.1±0.7, 2.6±3.4, 6.1±1.8 for A-VTI; and 3.6±0.8, 3.6±0.8, 2.7±0.6 and 6.2±1.5, for P-VTI. The CI values using Simpson's method were lower than those obtained by TD in all states, and it was observed a significant correlation in the Hypo (r=0.89) and Hyper (r=0.76) groups. In addition, the percent error in the Hypo group using Simpson's method was 26% relative to TD, which allowed for the identification of the different hemodynamic states. With respect to the other methods and states, there was no agreement or correlation between the methods and TD. We concluded that none of the tested echocardiography methods exhibited acceptable agreement with thermodilution at different hemodynamic states. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the cardiorespiratory and metabolic effects from lipid emulsion and microemulsion of propofol in cats. Twelve healthy adult cats were included, and divided into two groups: microemulsion group (MICRO, n=6) and lipid emulsion (EMU, n=6), where they received propofol in the respective formulation, in a dosesufficient for intubation. The animals were then intubated and provided with 100% oxygen through a non-rebreathing circuit. Immediately after, the infusion of propofol was initiated (0.3mg kg'min ') and maintained for 90 minutes. The dose required forinduction was 9.5±1.3mg kg'1 and 10±lmg kg'1 in MICRO and EMU, respectively. The SAP, MAP, DAP and pH values were lower in all moments in EMU when compared to MICRO; the RR in EMU was lower from T30 to T75 in comparison to MICRO. The paCO, was greater in the EMU from T15 to T90. The times toextubation, sternal recumbency, ambulation and total recovery were 40.6±30.7, 91±37.5, 134.5±54.5 and 169.1±55.4minutes in MICRO and 68.8±37.3, 133.3±85.3, 171.3±77.1and 233.1±60.6 minutes in EMU, respectively. There was anincrease of the enzyme alanine amino transferase from 12 to 72hours in EMU and in MICRO from 48 to 72 hours. The propofol inmicroemulsion presents clinical characteristics of induction and maintenance, and metabolic effects similar to the formulation in lipid emulsion. The microemulsion formulation provides abetter cardiovascular and respiratory stability for induction and continuous infusion in healthy cats. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate the clinical and cardiorespiratory effects of a propofol formulation with nanometer droplet diameter in dogs. Six adult healthy female dogs weighing 14.8±1.2kg were used in this study. Each dog received two treatments with a 15-day washout period. A microemulsion (MICRO) or lipid emulsion (EMU) of propofol was administered intravenously (IV) for induction and maintenance of anesthesia. Anesthesia was maintained with a constant rate infusion of propofol (0.4mg kg-1 minute-1). Cardiorespiratory variables were recorded before induction (baseline), immediately after and at 15-minute intervals for 90 minutes after treatment. Arterial blood samples were also taken for blood gas analysis, except at 45 and 75 minutes after induction. The mean arterial pressure decreased significantly during both treatments, while the cardiac index decreased significantly only in MICRO treatment. The time to extubation, sternal recumbency, ambulation and total recovery was similar in both treatments. Opisthotonos was observed in 33% of the animals in each treatment. The propofol microemulsion presented clinical and respiratory parameters similar to those obtained with the lipid emulsion commercially available, but had some significantly different hemodynamic characteristics when used for inducing and maintaining anesthesia. Based only in these results, no advantages are seen in the use of this new microemulsion [ABSTRACT FROM AUTHOR]

Male and female sterilization have been established as the main technique to reduce the huge number of mongrel dogs. However, there are several barriers regarding to the choice of the best anesthetic protocol, in terms of efficacy, security and cost reduction. The aim of this study was to evaluate the analgesic, cardiorespiratory and hemogasometric effects of epidural anesthesia with a large volume of lidocaine in combination with morphine in female dogs submitted to ovariosalpingohisterectomy (OSH), with or without oxygen supplementation. Twelve adult female dogs were used, with average weight of 11.5±3.7kg and age of 1 to 4 years. The animals received acepromazine (0.1mg kg-1) and meperidine (5mg kg-1) as premedication, administered by the intramuscular route. Fifteen minutes later, thiopental (10mg kg-1) was administered by intravenous route, followed by endotracheal intubation. The animals were allocated into two groups: GCO (group with oxygen, n=06), where the animals received 100% oxygen supplementation and GSO (group without oxygen supplementation, n=6), mantained with endotracheal intubation, but without oxygen supplementation. After intubation, epidural with morphine (0,1mg kg-1), adjusted to 1mL 3kg-1 in lidocaine 2% without epinepherine was administered. Immediately after epidural administration, the animals were positioned in dorsal recumbency, with the head in the same level of the body. In both groups, surgery was performed without the need of additional analgesia and without signs of pain. Mean arterial pressure (MAP) was lower in GSO in all moments compared to baseline values. In GCO, MAP was lower after premedication and epidural anesthesia. Respiratory rate was lower from M1 to M6 in GSO. The SaO2 and PaO2 were higher in GCO when compared to GSO. The pH was lower in GCO after 15 minutes after premedication, until 40 minutes after the epidural administration, compared to GSO. It was concluded that the epidural administration using morphine and lidocaine in the dosage and volume proposed are effective to OSH procedure in dogs. The lack of oxygen supplementation promoted minimal cardiovascular and hemogasometric alterations, which is feasible in sterilizations campaigns where there is no possibility of oxygen supplementation of the animals. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the volemic expansion effects produced by hydroxyethyl starch 130/0.4 (HES 130/0.4) or blood, in female cats with induced hypovolemia. Twelve healthy adult female cats, crossbreed and weighing an average of 2.85±0.28kg were used. They were induced into general anesthesia with isofluorane at 5V%, intubated and connected to a non-rebreathing system. After instrumentation, the animals were maintained under anesthesia with isofluorane at 1.3V% and maintained on pressure cycled mechanic ventilation. Afterwards, hypovolemia was induced by withdrawal of 30ml kg-1 of blood from the femoral artery. After 60 minutes of stabilization of the patient, the treatments were initiated. In the hydroxyethyl starch group (GH, n=06) the animals received hydroxyethyl starch 130/0.4 as volemic expansion at the same volume of blood withdrawed, in the blood group (GS, n=06) the animals received their own withdrawed blood, being considered the control group. The systolic, diastolic and mean arterial pressures and central venous pressure increased after volemic expansion in both groups. An increase of PaCO2 at T15, T30 and T60 in GH was observed. In addition, there was reduction of pH at T30 and T45 and Na+ ions at T90 in GH. The arterial pressure restoration with the use of HES 130/0.4 was similar to the control group; the volemic expansion with HES 130/0,4 produces accentuated increase of CVP; the use of HES 130/0,4 in female cats submitted to hypovolemia did not produce clinically significant alterations in acid-base equilibrium. [ABSTRACT FROM AUTHOR]