Martielo Ivan Gehrcke

Farmacocinética do propofol em nanoemulsão em gatos

Propofol nanoemulsion is a new formulation consisting of nanoemulsified systems, characterized by the absence of lipid vehicle. Changes in drug vehicle may alter the pharmacokinetics and result in different distribution and elimination rates of propofol. The aim of this study was to evaluate the pharmacokinetics of a new oil in water propofol nanoemulsion formulation, compared to the traditional lipid emulsion. Six neutered female mixed-breed dogs were used (10.7±1.5kg) in a randomized and self control trial with 30 days interval. They received both propofol formulations administered as a bolus dose of 8mg kg-1 followed by 60 minutes continuous infusion at 0.4mg kg-1 min-1 rate. Arterial blood samples were collected just before induction (0), 2, 5, 10, 15, 30, and 60 minutes after the bolus dose, and after the end of the infusion at five, 10, 15, 30, 60, and 90 minutes and 2, 3, 4, 6, 10, and 24 hours. There were no significant differences in the evaluated pharmacokinetics parameters that included volume of distribution, clearance, elimination rate constant, half-life, and distribution constants, demonstrating that propofol nanoemulsion has no pharmacokinetics differences when compared to the traditional formulation.

Efeitos da associação de tiletamina/zolazepam ou cetamina S(+)/midazolam/tramadol para contenção química em bugios-ruivos (Allouatta guariba clamitans)

Two protocols for chemical restraint in howler-redheads were evaluated. We used 12 healthy red howler monkeys, weighing 6.4±0.4 kg, which were fasted and without water six and two hours, respectively. The animals were divided into two groups that received intramuscular injection: TZ (n=6) which received tiletamine-zolazepam (Zoletil®) at a dose of 3.6mg/kg and CEMTRA (n=6) which received ketamine S (+), tramadol and midazolan (Cemtra®, pilot batch 001/10, Ouro Fino Saude Animal Ltda, Cravinhos/SP, Brazil, comprising 100mg/ml of ketamine S (+), tramadol 20mg/ml and 10mg/ml of midazolam) in dose of 1ml of the association for each 10kg of body weight, equivalent doses of 10mg/kg, 1mg/kg and 2mg/kg, respectively. Prior to administration of drugs (M0) were evaluated: heart rate (HR), respiratory rate (RR), rectal temperature (RT), capillary refill time (CRT), systolic arterial pressure (SAP), hemoglobin oxygen saturation (SpO2 ), presence of salivation, degree of muscle relaxation and sedation, Bispectral index (BIS) and Signal Quality BIS (SQI), interdigital pinch response and latency times, ambulation and total recovery (TRT). The parameters were reassessed M5, M10, M20, M30, M40 and M50 (5, 10, 20, 30, 40 and 50 minutes after drug administration). In TZ animals were more responsive to the interdigital pinch over time. The animals of CEMTRA showed a higher degree of muscle relaxation and sedation. The RR of CEMTRA was lower after administration of treatment at all times in relation to M0. Among the groups RR of CEMTRA was lower compared to the TZ in M2 and M4. The total time of sedation and recovery was 48±4 min and 150.1±42.1 for the CEMTRA and 38±7 and 73.1±20.6 for the TZ. We conclude that both formulations are safe for containing chemical howler, and the CEMTRA showed better sedation and muscle relaxant.

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,

Volume replacement with hydroxyethyl starch or Ringer Lactate solution in hemorrhagic gastroenteritis dogs with parvovirus.

Parvovirus is an infectious viral disease, highly contagious, affecting dogs causing acute enteritis. Dehydration is a minor problem and acute evolution, which is the main focus of treatment. The objective of this study was to evaluate two treatments volume replacement in dogs with confirmed diagnosis of parvovirus infection by antigen detection in stool by ELISA. A total of 15 dogs, mixed, male and female, aged from 3 to 6 months, these four they had died during treatment and 11 were included in the study. Patients were randomly divided into two groups: hydroxyethyl starch 130/0.4 (HES, n=6) and Group Ringer Lactate (RL, n=5), which received fluid resuscitation with hydroxyethyl starch 130/0.4 and Ringer’s solution lactate, respectively, based on calculations of fluid deficit. All animals received intravenously: cephalothin, metronidazole, ranitidine and metoclopramide. During hospitalization, every 12 hours were evaluated arterial blood gas, electrolyte dosing and clinical examination (heart rate, respiratory rate, rectal temperature, capillary refill time, vomiting, appetite, dehydration, weight gain, hematochezia, melena, hematemesis and presence abdominal pain) and 24 hours each blood count was performed. In group RL was increase in the values of PaO2 and decreases in hemoglobin, hematocrit, phosphorus and magnesium, and group HES, a decrease in the percentage of dehydration, hemoglobin, phosphorus and potassium. There were no differences in other parameters between the groups. Both treatments were effective in fluid replacement of patients, no difference in any variable analyzed.

Indução anestésica com nanoemulsão ou emulsão lipídica de propofol durante dias consecutivos em gatas

O objetivo deste estudo foi comparar os efeitos clinicos da inducao com propofol em nanoemulsao e em emulsao lipidica em gatas, apos repetidas administracoes. Utilizaram-se 12 gatas, higidas, SRD, com peso medio de 2,9±0,6kg, distribuidas aleatoriamente em dois grupos: NANO (n=6) e EMU (n=6), que receberam propofol em nanoemulsao na dose de 9,5mg kg-1 e em emulsao lipidica na dose de 10mg kg-1, respectivamente, ambos pela via intravenosa, durante cinco dias consecutivos. Hemograma e funcao renal e hepatica foram realizados a cada 24 horas e ate 168 horas apos a primeira inducao. Os parâmetros clinicos de frequencia cardiaca (FC) e respiratoria (f) e temperatura retal (TR) foram avaliados antes dos tratamentos e 5, 10, 20 e 30 minutos apos a administracao de propofol. Em relacao aos valores basais, observou-se diminuicao da FC no EMU ate o 3° dia e da f e TR em ambos os grupos ate o ultimo dia, sem diferenca entre os dias. As enzimas ALT e FA diminuiram apos 24 a 96 horas e 48 a 144 horas, respectivamente, no grupo EMU. Os valores de eritrograma diminuiram ate o quinto dia em ambos os grupos. Os tempos para hipnose, extubacao e para decubito esternal nao diferiram entre grupos e entre os dias. O tempo para recuperacao total do grupo EMU foi maior no 4° e 5° dias em relacao ao 1°. Conclui-se que a inducao com propofol e segura e que o propofol em emulsao lipidica apresenta maior efeito cumulativo apos repetidas administracoes em gatas.