Ricardo Miyasaka de Almeida

Comparison of analgesia provided by lidocaine, lidocaine-morphine or lidocaine-tramadol delivered epidurally in dogs following orchiectomy

OBJECTIVE To evaluate and compare the postoperative analgesia provided by epidural lidocaine, lidocaine/morphine or lidocaine/tramadol in dogs following elective orchiectomy. STUDY DESIGN Prospective experimental trial. ANIMALS Thirty-six mongrel dogs aged 2-8 years old, weighing 6.6-22 kg. METHODS The dogs received 6.0 mg kg(-1) of lidocaine combined with 1.0 mg kg(-1) of tramadol, 0.1 mg kg(-1) of morphine or 0.01 mL kg(-1) of 0.9% NaCl epidurally. Analgesia was assessed at 4, 8, 12, 18 and 24 hours (T4, T8, T12 and T24) after the offset of lidocaine using a scale composed of physiologic and behavioral parameters. Rescue analgesia with morphine (0.2 mg kg(-1) , IM) was performed if the evaluation score exceeded 10 during the postoperative period. The scores over time were analyzed using the Friedmans two-way analysis of variance and the comparison between groups was made by the Kruskal-Wallis test with statistical significances accepted if p ≤ 0.05. RESULTS There were no differences in the pain scores between the morphine and tramadol groups over time and no rescue analgesia was administered. In the NaCl group, rescue analgesia was needed at T4, T8 and T12. Within this group, the final evaluation times (T18 and T24) had lower pain scores than at T4, T8 and T12. CONCLUSIONS AND CLINICAL RELEVANCE Epidural lidocaine/tramadol provided an analgesic effect comparable to that of epidural lidocaine/morphine during the first 12 hours after surgical castration without substantial side effects, suggesting that tramadol may be an effective postoperative analgesic in dogs submitted to this surgical procedure.

Brachial plexus blockade in chickens with 0.75% ropivacaine

OBJECTIVE To evaluate the quality of brachial plexus blockade with 0.75% ropivacaine in domestic chickens. STUDY DESIGN Prospective experimental trial. ANIMALS Six 30-week-old female chickens, weighing 4.5 +/- 0.4 kg. METHODS Six brachial plexus injections were performed after anesthetic induction with isoflurane. After achieving adequate muscle relaxation, the animals were positioned in dorsal recumbency and injected with ropivacaine (1 mL kg(-1)). The birds recovered and assessments of motor function and response to pinch were scored every 5 minutes for 180 minutes. The scores were from zero (no response) to three (greatest response). The scores over time were analyzed using a Wilcoxon nonparametric test with statistical significance accepted if p <or= 0.05. RESULTS There was a significant difference (p < 0.05) from 15 to 130 minutes and 15 to 120 minutes for motor and sensory blocks, respectively. The onset of both blocks took 15 minutes and the effective periods of sensory and motor anesthesia were 105 and 115 minutes, respectively. Comparison between blocks at different times did not demonstrate significant differences (p > 0.05). CONCLUSIONS AND CLINICAL RELEVANCE No complications were observed after the technique. Brachial plexus blockade with 0.75% ropivacaine is a simple and effective technique for procedures on the thoracic limb of domestic chickens.

Whole-body prepulse inhibition protocol to test sensorymotor gating mechanisms in monkeys.

Prepulse inhibition (PPI) is the decrease of startle reflex amplitude when a slight stimulus is previously generated. This paradigm may provide valuable information about sensorimotor gating functionality. Here we aimed at determining the inhibited and uninhibited startle response of capuchin monkeys (Sapajus spp.), and to evaluate the role of the superior colliculus in PPI. Capuchin monkeys were tested in a whole-body protocol, to determine the best startle amplitude and interstimuli interval. Additionally we tested two subjects with bilateral superior colliculus damage in this protocol. Results show that 115 dB auditory pulse has induced the best startle response. In contrast to reports in other species, no habituation to the auditory stimuli was observed here in capuchins. Also, startle reflex inhibition was optimal after 120 msec interstimuli interval. Finally, there was a downward tendency of percentage inhibition in superior colliculus-lesioned monkeys. Our data provides the possibility of further studies with whole-body protocol in capuchin monkeys and reinforces the importance of the superior colliculus in PPI.

Long‐term evaluation of a new ventriculoperitoneal shunt valve system in a dog

OBJECTIVE To report on the use of a new ventriculoperitoneal shunt (VPS) valve system utilized in a dog with hydrocephalus and to describe the clinical course over 20 months after implantation. CASE SUMMARY A 3-month-old female Lhasa Apso dog was presented with lateral strabismus, domed calvarium, and visual deficits. A lateral skull radiograph revealed a persistent fontanelle. Transfontanellar ultrasonographic examination and computed tomographic examination showed excessive accumulation of fluid within the ventricles. The owner had observed symptoms as early as 1 month after birth, suggesting congenital hydrocephalus. A VPS with a new valve system that inhibits cerebrospinal fluid overdrainage and obstruction of the catheter was implanted. The dog showed clinical improvement 48 hours after the procedure. Twenty days after shunt implantation, another computed tomography scan was performed that showed reduction in ventricle size. The evaluation of VPS patency was carried out 20 months after surgery and demonstrated that the system was working properly without obstruction. NEW OR UNIQUE INFORMATION PROVIDED There are reports in the literature describing the use of several devices to perform VPS in dogs. A new device not previously described in the veterinary literature was used in this case report, and according to the manufacturers description, this device inhibits proteinaceous build-up, which is usually responsible for subsequent catheter obstructions.Objective – To report on the use of a new ventriculoperitoneal shunt (VPS) valve system utilized in a dog with hydrocephalus and to describe the clinical course over 20 months after implantation. Case Summary – A 3-month-old female Lhasa Apso dog was presented with lateral strabismus, domed calvarium, and visual deficits. A lateral skull radiograph revealed a persistent fontanelle. Transfontanellar ultrasonographic examination and computed tomographic examination showed excessive accumulation of fluid within the ventricles. The owner had observed symptoms as early as 1 month after birth, suggesting congenital hydrocephalus. A VPS with a new valve system that inhibits cerebrospinal fluid overdrainage and obstruction of the catheter was implanted. The dog showed clinical improvement 48 hours after the procedure. Twenty days after shunt implantation, another computed tomography scan was performed that showed reduction in ventricle size. The evaluation of VPS patency was carried out 20 months after surgery and demonstrated that the system was working properly without obstruction. New or Unique Information Provided – There are reports in the literature describing the use of several devices to perform VPS in dogs. A new device not previously described in the veterinary literature was used in this case report, and according to the manufacturers description, this device inhibits proteinaceous build-up, which is usually responsible for subsequent catheter obstructions.

Efeitos da administração epidural de amitraz, xilazina ou dimetil sulfóxido em vacas

Avaliaram-se os efeitos da injecao epidural de amitraz (0,4mg/kg), xilazina (0,05mg/kg) ou dimetil sulfoxido 10% (5,0ml) sobre a frequencia cardiaca (FC), pressao arterial sistolica (PAS), frequencia respiratoria (FR), motilidade ruminal (MR), temperatura retal (TR), altura de cabeca (AC) e latencia das respostas a estimulos nociceptivos nas regioes da coxa (LECC) e coroa do casco (LRRM) de vacas. Houve diminuicao da FC e da MR nos grupos xilazina e amitraz. O tratamento com xilazina resultou em alteracoes na FR, PAS e AC. LECC e LRRM foram maiores nos tratamentos com agonistas a-2. Nas doses utilizadas, o amitraz aumentou a latencia de resposta a estimulo nociceptivo em menor grau que a xilazina, sem induzir efeitos colaterais sistemicos severos, em vacas.

Treatment of a Periarticular Tibial Fracture in a Foal with a Hybrid External Fixator

OBJECTIVE To report repair of a right proximal tibial Salter-Harris type II fracture in a foal with a hybrid external fixator (HEF). STUDY DESIGN Case report. ANIMALS A 5-month-old male foal. METHODS After open surgical reduction, an HEF built with wires, 2 half-rings, 3 half-threaded connecting rods, and Schanz pins was used to stabilize the fracture. RESULTS Immediately after surgery, the foal had relatively good weight bearing. The HEF was removed at 60 days after radiographic confirmation of healing. CONCLUSIONS HEF can be used to stabilize a proximal tibial Salter-Harris type II fracture in a 5-month-old foal. CLINICAL RELEVANCE HEF should be considered as another option for repair of proximal tibial Salter-Harris type II fractures in foals.

Sobre a analgesia pós-operatória da morfina, cetamina ou da associação em cadelas submetidas à ovariossalpingohisterectomia eletiva

This study aimed to evaluate the post operative analgesic effects of morphine or ketamine alone or their combination in 24 healthy bitches, weighing 11.01±8.69kg and aging 27±17 months, submitted to elective ovariohysterectomy. The animals were distributed to one of the three treatments after the anaesthetic induction: morphine (GM, n=8, 0.5mg kg-1 IM), ketamine (GK, n=8, 2.5mg kg-1 IM) or ketamine combined to morphine (GKM) using the same doses previously described. Sedation score and pain assessment were performed blindly two hours before surgery and at 1, 2, 4, 8, 12, and 24 hours after extubation, using the Dobbins scale (sedation) and visual analogue scale (pain) and Glasgow modified pain scale (GMPS). Rescue analgesia was performed with 1.0mg kg-1 of morphine and if not sufficient, followed by 0.2mg kg-1 of meloxicam, both IM, when the GMPS reached above 33% of the total score. Non parametric data were analyzed using Friedman´s test followed by Dunn´s test for differences in time. Kruskal-Wallis´ test followed by Dunn´s test were used to investigate differences in the number of analgesic rescues and among groups at each time. Parametric data were evaluated by ANOVA followed by Tukeys test (P<0.05). Except for GMPS, where the values of GM were greater than for GKM at 1h post-extubation, there were no other differences among groups. The number of rescue analgesia was greater in GM (11 in total; twice in 3 animals,) when compared to GKM (3; twice in 1 animal) and GK (2; twice in 1 animal). Analgesia provided by pre-incisional ketamine was more effective when compared to morphine. According to that, ketamine alone may be used as a preemptive analgesic in bitches undergoing ovariohysterectomy; however, rescue analgesia may be necessary.

EFFECTS OF TRAMADOL ON THE MINIMUM ANESTHETIC CONCENTRATION OF ISOFLURANE IN WHITE-EYED PARAKEETS (PSITTACARA LEUCOPHTHALMUS)

Abstract The aim of this study was to determine the minimum anesthetic concentration (MAC) of isoflurane, and to investigate if tramadol changes the isoflurane MAC in white-eyed parakeets (Psittacara leucophthalmus). Ten adult birds weighing 157 ± 9 g were anesthetized with isoflurane in oxygen under mechanical ventilation. Isoflurane concentration for the first bird was adjusted to 2.2%, and after 15 min an electrical stimulus was applied in the thigh area to observe the response (movement or nonmovement). Isoflurane concentration for the subsequent bird was increased by 10% if the previous bird moved, or decreased by 10% if the previous bird did not move. This procedure was performed serially until at least four sequential crossover events were detected. A crossover event was defined as a sequence of two birds with different responses (positive or negative) to the electrical stimulus. Isoflurane MAC was calculated as the mean isoflurane concentration value at the crossover events. After 1 wk, the same birds were reanesthetized with isoflurane and MAC was determined at 15 and 30 min after intramuscular administration of 10 mg/kg of tramadol using the same method. A paired t-test (P < 0.05%) was used to detect significant differences for MAC between treatments. Isoflurane MAC in this population of white-eyed parakeets was 2.47 ± 0.09%. Isoflurane MAC values 15 and 30 min after tramadol administration were indistinguishable from each other (pooled value was 2.50 ± 0.18%); they were also indistinguishable from isoflurane MAC without tramadol. The isoflurane MAC value in white-eyed parakeets is higher than reported for other bird species. Tramadol (10 mg/kg, i.m.) does not change isoflurane MAC in these birds.

INFLUÊNCIA DA PRÉ-MEDICAÇÃO COM AMITRAZ OU XILAZINA NA INDUÇÃO ANESTÉSICA DE BOVINOS COM CETAMINA

The alpha-2 agonists have sedative, analgesic and muscle relaxation properties in cattle. The ketamine is useful in anesthetic protocols as an inductor agent and it produces analgesia and anesthesia. The combination of ketamine with other drugs is necessary considering that it causes deleterious effects like catalepsy and muscle spasticity if given alone. This study evaluated clinical and behavioral effects of xylazine-ketamine or amitraz-ketamine combinations in twenty–one calves. The ketamine increased heart rate in amitraz and control groups. The respiratory rate increased in all experimental groups, restoring the basal values after 25 minutes. The ruminal motility was kept inhibited along whole observation period. It was concluded that xylazine-ketamine combination produced better sedation and muscle relaxation than amitraz-ketamine combination, characterized by a larger incidence of recumbency and by the absence of catalepsy. Both anesthetic protocols were safe for use in cattle, however, xylazine showed a better option as a preanesthetic medication. KEY WORDS: Amitraz, cattle, ketamine, xylazine.

Propofol-cetamina racêmica e propofol-cetamina levógira em cadelas: parâmetros eletrocardiográficos e outras variáveis fisiológicas

The effects of propofol and ketamine on physiological parameters, electrocardiography, and analgesia were evaluated in twelve dogs that received propofol-ketamine (0.4mg/kg/min + 0.2mg/kg/min, n=6, PK group) or propofol-S+ketamine (0.4mg/kg/min + 0.1mg/kg/min, n=6, PKS group) after induction of anesthesia with propofol (8.0mg/kg). Assessments of pain; heart rate (HR); electrocardiography (ECG); respiratory rate (RR); systolic, medium, and diastolic arterial pressures (SAP, MAP, DAP); saturation of hemoglobin (SpO2); and rectal temperature (RT) were conducted. There was a rise in HR with no electrocardiographically changes, but an increase in amplitude of T wave in one animal of each group. RR decreased and SpO2 were lower than 90% in two moments of both groups. SAP, MAP, and DAP were reduced during the experimental period, but with no statistical difference between the protocols. There was no analgesia in seven bitches, mild analgesia was observed in three, and satisfactory analgesia in only two animals tested. It was concluded that the protocols are safe for dogs, but there is no analgesia for surgical procedures. The changes in ECG are related to HR and amplitude of T wave, which may be due to myocardial hypoxia.