Effects of metaraminol bitartrate on intraocular pressure in dogs under halothane anesthesia

The effects of metaraminol bitartrate on intraocular pressure (IOP) were studied in dogs anesthetized with halothane. Forty-five healthy, adult, mixed-breed dogs, of both sexes, were divided into three groups of 15 dogs each (GI, GII and GIII) and maintained under general anesthesia with halothane after tranquilization with levomepromazine and induction with thiopental. Saline (0.9%) was administered intravenously (IV) to GI through continuous infusion, at a velocity of 0.125 mL kg -1 min -1. GII and GIII received metaraminol 0.004% IV, at a dose of 5 μg kg -1 min -1, at 0.125 mL kg -1 min -1 and at a dose of 2 μg kg -1 min -1, at 0.06 mL kg -1 min -1, respectively. IOP was measured by applanation tonometry (Tono-Pen) before and during anesthesia. Results showed that IOP decreased in GI, increased in GII, and remained at basal levels in GIII. Continuous infusion of metaraminol at 2 μg kg min -1 maintained IOP at pretest levels, while infusion at 5 μg kg -1 min -1 produced an elevation of IOP.

Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs

Constant rate infusion (CRI) shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran), and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%), 35 (26.3%), and 19 (14.2%) dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol %) reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl-lidocaine-ketamine CRI groups (p<0.05). In conclusion, CRI is a valid component of balanced anesthesia in dogs, safe, and has a low incidence of adverse effects. However, future studies are warranted to describe the results of the clinical use of CRI to better characterize and refine this technique.

Comparison of oxidative stress in ASA physical status I patients scheduled for minimally invasive surgery under balanced or intravenous anesthesia

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

Evaluation of cardiorespiratory and biochemical effects of ketamine-propofol and guaifenesin-ketamine-xylazine anesthesia in donkeys (Equus asinus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inhibition of Autonomic Storm by Epidural Anesthesia Does Not Influence Cardiac Inflammatory Response After Brain Death in Rats

Background. After brain death (BD) donors usually experience cardiac dysfunction, which is responsible for a considerable number of unused organs. Causes of this cardiac dysfunction are not fully understood. Some authors argue that autonomic storm with severe hemodynamic instability leads to inflammatory activation and myocardial dysfunction. Objectives. To investigate the hypothesis that thoracic epidural anesthesia blocks autonomic storm and improves graft condition by reducing the inflammatory response. Methods. Twenty-eight male Wistar rats (250-350 g) allocated to four groups received saline or bupivacaine via an epidural catheter at various times in relation to brain-death induction. Brain death was induced by a sudden increase in intracranial pressure by rapid inflation of a ballon catheter in the extradural space. Blood gases, electrolytes, and lactate analyses were performed at time zero, and 3 and 6 hours. Blood leukocytes were counted at 0 and 6 hours. After 6 hours of BD, we performed euthanasia to measure vascular adhesion molecule (VCAM)-1, intracellular adhesion molecule (ICAM)-1, interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, Bcl-2 and caspase-3 on cardiac tissue. Results. Thoracic epidural anesthesia was effective to block the autonomic storm with a significant difference in mean arterial pressure between the untreated (saline) and the bupivacaine group before BD (P < .05). However, no significant difference was observed for the expressions of VCAM-1, ICAM-1, TNF-alpha, IL-1 beta, Bcl-2, and caspase-3 (P > .05). Conclusion. Autonomic storm did not seem to be responsible for the inflammatory changes associated with BD; thoracic epidural anesthesia did not modify the expression of inflammatory mediators although it effectively blocked the autonomic storm.

Comparison of analgesic efficacy of preoperative or postoperative carprofen with or without preincisional mepivacaine epidural anesthesia in canine pelvic or femoral fracture repair

OBJECTIVE: To compare analgesic efficacy of preoperative versus postoperative administration of carprofen and to determine, if preincisional mepivacaine epidural anesthesia improves postoperative analgesia in dogs treated with carprofen. STUDY DESIGN: Blind, randomized clinical study. ANIMALS: Dogs with femoral (n=18) or pelvic (27) fractures. METHODS: Dogs were grouped by restricted randomization into 4 groups: group 1 = carprofen (4 mg/kg subcutaneously) immediately before induction of anesthesia, no epidural anesthesia; group 2 = carprofen immediately after extubation, no epidural anesthesia; group 3 = carprofen immediately before induction, mepivacaine epidural block 15 minutes before surgical incision; and group 4 = mepivacaine epidural block 15 minutes before surgical incision, carprofen after extubation. All dogs were administered carprofen (4 mg/kg, subcutaneously, once daily) for 4 days after surgery. Physiologic variables, nociceptive threshold, lameness score, pain, and sedation (numerical rating scale [NRS], visual analog scale [VAS]), plasma glucose and cortisol concentration, renal function, and hemostatic variables were measured preoperatively and at various times after surgery. Dogs with VAS pain scores >30 were administered rescue analgesia. RESULTS: Group 3 and 4 dogs had significantly lower pain scores and amount of rescue analgesia compared with groups 1 and 2. VAS and NRS pain scores were not significantly different among groups 1 and 2 or among groups 3 and 4. There was no treatment effect on renal function and hemostatic variables. CONCLUSIONS: Preoperative carprofen combined with mepivacaine epidural anesthesia had superior postoperative analgesia compared with preoperative carprofen alone. When preoperative epidural anesthesia was performed, preoperative administration of carprofen did not improve postoperative analgesia compared with postoperative administration of carprofen. CLINICAL RELEVANCE: Preoperative administration of systemic opioid agonists in combination with regional anesthesia and postoperative administration of carprofen provides safe and effective pain relieve in canine fracture repair.

Alfaxalone anesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

OBJECTIVES To establish an effective alfaxalone concentration to be used for bath immersion of fire-bellied toads (Bombina orientalis) and to describe its effects. STUDY DESIGN Prospective experimental study. ANIMALS Thirteen oriental fire-bellied toads. METHODS The study was carried out in two phases. The pilot phase involved five animals and aimed to identify an alfaxalone concentration capable of producing induction of anesthesia, defined as immobility with a head down position and loss of responsiveness to stimulation with a stick. The following trial in an additional eight toads used the effective alfaxalone concentration established during the pilot phase. Data from 11 animals (three toads in the pilot study and the eight additional toads) were analyzed. Twenty minutes after immersion in the anesthetic solution, the toads were removed from the bath, and heart rate, respiratory rate, the righting, myotactic and the nociceptive withdrawal reflexes were evaluated every 5 minutes. The loss of both righting and nociceptive withdrawal reflexes was considered indicative of a surgical depth of anesthesia. The time elapsed from anesthetic induction to return of righting reflex, the quality of recovery and the occurrence of undesired effects were observed and recorded. RESULTS Immersion was found to be a suitable anesthetic technique for oriental fire-bellied toads and 200 mg L(-1) alfaxalone concentration produced anesthetic induction in 10 out of 11 toads. Side effects, such as skin irritation, erythema and changes in cutaneous pigmentation, were not observed in any animal. The duration of anesthesia ranged from 10 to 30 minutes after removal of the toads from the alfaxalone bath, and surgical depth of anesthesia was never achieved. CONCLUSIONS AND CLINICAL RELEVANCE It was concluded that alfaxalone anesthesia induced by immersion in a concentration of 200 mg L(-1) is only suitable for toads undergoing non-invasive short procedures.

Ikkε Is Key To Induction Of Insulin Resistance In The Hypothalamus, And Its Inhibition Reverses Obesity.

IKK epsilon (IKKε) is induced by the activation of nuclear factor-κB (NF-κB). Whole-body IKKε knockout mice on a high-fat diet (HFD) were protected from insulin resistance and showed altered energy balance. We demonstrate that IKKε is expressed in neurons and is upregulated in the hypothalamus of obese mice, contributing to insulin and leptin resistance. Blocking IKKε in the hypothalamus of obese mice with CAYMAN10576 or small interfering RNA decreased NF-κB activation in this tissue, relieving the inflammatory environment. Inhibition of IKKε activity, but not TBK1, reduced IRS-1(Ser307) phosphorylation and insulin and leptin resistance by an improvement of the IR/IRS-1/Akt and JAK2/STAT3 pathways in the hypothalamus. These improvements were independent of body weight and food intake. Increased insulin and leptin action/signaling in the hypothalamus may contribute to a decrease in adiposity and hypophagia and an enhancement of energy expenditure accompanied by lower NPY and increased POMC mRNA levels. Improvement of hypothalamic insulin action decreases fasting glycemia, glycemia after pyruvate injection, and PEPCK protein expression in the liver of HFD-fed and db/db mice, suggesting a reduction in hepatic glucose production. We suggest that IKKε may be a key inflammatory mediator in the hypothalamus of obese mice, and its hypothalamic inhibition improves energy and glucose metabolism.

Association Of Lipophilic Opioids And Hyperbaric Bupivacaine In Spinal Anesthesia For Elective Cesarean Section. Randomized Controlled Study.

To evaluate the efficacy and side-effects of fentanyl and sufentanil combined with hyperbaric spinal bupivacaine in elective cesarean section. A prospective, randomized, double-blind study with 64 term parturients, distributed into 2 groups according to the opioid combined with hyperbaric bupivacaine 0.5% (10mg): GF - fentanyl (25 µg) and GS - sufentanil (5.0 µg). The latency and maximum sensory block level; degree and duration of motor block; duration and quality of analgesia; maternal-fetal repercussions were evaluated. This was an intention-to-treat analysis with a 5% significance level. The latency period, maximum sensory block level, motor block degree and perioperative analgesia were similar in both groups. Motor block and analgesia had a longer duration in the sufentanil group. Maternal adverse effects and neonatal repercussions were similar. The incidence of hypotension was higher in the fentanyl group. In both groups, there was a predominance of patients who were awake and either calm or sleepy. The addition of fentanyl and sufentanil to hyperbaric subarachnoid bupivacaine was shown to be effective for the performance of cesarean section, and safe for the mother and fetus. Analgesia was more prolonged with sufentanil.

[comparative Study Between Fast And Slow Induction Of Propofol Given By Target-controlled Infusion: Expected Propofol Concentration At The Effect Site. Randomized Controlled Trial].

studies have shown that rate of propofol infusion may influence the predicted propofol concentration at the effect site (Es). The aim of this study was to evaluate the Es predicted by the Marsh pharmacokinetic model (ke0 0.26min(-1)) in loss of consciousness during fast or slow induction. the study included 28 patients randomly divided into two equal groups. In slow induction group (S), target-controlled infusion (TCI) of propofol with plasma, Marsh pharmacokinetic model (ke0 0.26min(-1)) with target concentration (Tc) at 2.0-μg.mL(-1) were administered. When the predicted propofol concentration at the effect site (Es) reached half of Es value, Es was increased to previous Es + 1μg.mL(-1), successively, until loss of consciousness. In rapid induction group (R), patients were induced with TCI of propofol with plasma (6.0μg.ml(-1)) at Es, and waited until loss of consciousness. in rapid induction group, Tc for loss of consciousness was significantly lower compared to slow induction group (1.67±0.76 and 2.50±0.56μg.mL(-1), respectively, p=0.004). the predicted propofol concentration at the effect site for loss of consciousness is different for rapid induction and slow induction, even with the same pharmacokinetic model of propofol and the same balance constant between plasma and effect site.

Histopathological evaluation of different methods of experimental induction of periapical periodontitis

This study evaluated histopathologically different methods of experimental induction of periapical periodontitis. The radiographic and microbiological evaluations have been performed in a previous investigation. Fifty-seven root canals from dogs' teeth were assigned to 4 groups. In GI (n=14) and GII (n=14), the root canals were exposed to oral environment for 180 days; in GIII (n=14) and GIV (n=15) the root canals were exposed for 7 days and then the access cavities were restored and remained sealed for 53 days. The root apices of GI and GIII were perforated, whilst those of GII and GIV remained intact. After induction of periapical periodontitis, the dogs were euthanized. Serial sections were obtained and stained with hematoxylin and eosin. Data of the histopathological evaluation were submitted to Kruskal-Wallis and Dunn's tests at 5% significance level. The inflammatory periapical reaction and resorption of mineralized tissues were less intense in GII than in the other groups (p<0.05). There was no histopathological difference among the experimentally induced periapical lesions in the teeth with coronal sealing. On the other hand, when coronal sealing was not performed, greater intensity of induced periapical periodontitis was observed in the teeth with apical perforation.

Microbial distribution in the root canal system after periapical lesion induction using different methods

The aim of this study was to evaluate the microbial distribution in the root canal system after periapical lesion induction in dogs' teeth using different methods. Fifty-two root canals were assigned to 4 groups (n=13). Groups I and II: root canals were exposed to the oral cavity for 180 days; groups III and IV: root canals were exposed for 7 days and then the coronal openings were sealed for 53 days. The root apices of groups I and III were perforated, while those of groups II and IV remained intact. After the experimental periods, the animals were euthanized and the anatomic pieces containing the roots were processed and stained with the Brown & Brenn method to assess the presence and distribution of microorganisms. The incidence of microorganisms at different sites of the roots and periapical lesions was analyzed statistically by the chi-square test at 5% significance level. All groups presented microorganisms in the entire root canal system. A larger number of microorganisms was observed on the root canal walls, apical delta and dentinal tubules (p<0.05), followed by cementum and cemental resorption areas. In spite of the different periods of exposure to the oral environment, the methods used for induction of periapical periodontitis yielded similar distribution of microorganisms in the root canal system.

Efeito anestésico do óleo de cravo em alevinos de lambari

Para avaliar o efeito anestésico do óleo de cravo em lambaris (Astyanax altiparanae), cinco grupos de 30 alevinos (0,6±0,1g) foram expostos às concentrações de 50, 75, 100, 125 e 150mg L-1, medindo-se, respectivamente: tempo de indução à anestesia profunda (caracterizada pela perda de equilíbrio, pela ausência de natação, pela redução dos movimentos operculares e pelas respostas apenas a estímulos táteis mais intensos), tempo de recuperação e taxa de mortalidade após a exposição. Em uma segunda etapa (10 peixes/tratamento), registraram-se, para cada concentração, os tempos de indução e de recuperação após anestesia cirúrgica (movimentos operculares lentos e irregulares e perda de reações a estímulos), anotando-se a mortalidade após seis minutos de exposição. Observou-se redução linear no tempo de indução à anestesia (0,01min mg-1 de anestésico acrescido) e aumento quadrático do tempo de recuperação com a elevação da concentração (resposta máxima estimada em 7,1 minutos). A anestesia profunda foi alcançada em tempo inferior a 1,5 minuto para todas as concentrações, com recuperação mais rápida e sem mortalidade para 50mg L-1. Para indução à anestesia cirúrgica, foram registrados menores tempos nas concentrações 75 e 100mg L-1; porém, com mortalidade de 80% e 100%, respectivamente. A concentração 50mg L-1 promoveu anestesia cirúrgica e recuperação em 3,29±0,71 e 4,97±0,63 minutos, respectivamente, sem mortalidade. Concluiu-se que o óleo de cravo possui efeito anestésico para alevinos de lambari, sendo 50mg L-1 a concentração eficiente e segura para indução à anestesia profunda em até 1,5 minuto e de anestesia cirúrgica em até 3,3 minutos de exposição.

Controle de temperatura em intervenção cirúrgica abdominal convencional: comparação entre os métodos de aquecimento por condução e condução associada à convecção

JUSTIFICATIVA E OBJETIVOS: Hipotermia intra-operatória é complicação frequente, favorecida por operação abdominal. A eficácia da associação dos métodos de aquecimento por condução e convecção na prevenção de hipotermia e seus efeitos no período de recuperação pós-operatória foram os objetivos deste estudo. MÉTODO: Quarenta e três pacientes de ambos os sexos de 18 a 88 anos de idade, submetidos à laparotomia xifopúbica sob anestesia geral e monitorização da temperatura esofágica, foram distribuídos de modo aleatório em dois grupos de aquecimento: COND (n = 24), com colchão de circulação de água a 37°C no dorso e COND + CONV (n = 19), com a mesma condição associada à manta de ar aquecido a 42°C sobre o tórax e membros superiores. Analisados peso, sexo, idade, duração da operação e anestesia, temperaturas na indução anestésica (Mi), horas consecutiva (M1, M2), final da operação (Mfo) e anestesia (Mfa), entrada (Me-REC) e saída (Ms-REC) da recuperação pós-anestésica (SRPA), além das incidências de tremores e queixas de frio no pós-operatório. RESULTADOS: Os grupos foram semelhantes em todas as variáveis analisadas, exceto nas temperaturas em M2, M3, M4, Mfo e Mfa. O grupo COND reduziu a temperatura a partir da segunda hora da indução anestésica, mas o grupo COND + CONV só na quarta hora. Em COND, observou-se hipotermia na entrada e saída da SRPA. CONCLUSÕES: Associar métodos de aquecimento retardou a instalação e diminui a intensidade da hipotermia intra-operatória, mas não reduziu a incidência das queixas de frio e tremores.

Cognitive control associated with irritability induction: an autobiographical recall fMRI study

OBJECTIVE: Despite the relevance of irritability emotions to the treatment, prognosis and classification of psychiatric disorders, the neurobiological basis of this emotional state has been rarely investigated to date. We assessed the brain circuitry underlying personal script-driven irritability in healthy subjects (n = 11) using functional magnetic resonance imaging. METHOD: Blood oxygen level-dependent signal changes were recorded during auditory presentation of personal scripts of irritability in contrast to scripts of happiness or neutral emotional content. Self-rated emotional measurements and skin conductance recordings were also obtained. Images were acquired using a 1,5T magnetic resonance scanner. Brain activation maps were constructed from individual images, and between-condition differences in the mean power of experimental response were identified by using cluster-wise nonparametric tests. RESULTS: Compared to neutral scripts, increased blood oxygen level-dependent signal during irritability scripts was detected in the left subgenual anterior cingulate cortex, and in the left medial, anterolateral and posterolateral dorsal prefrontal cortex (cluster-wise p-value < 0.05). While the involvement of the subgenual cingulate and dorsal anterolateral prefrontal cortices was unique to the irritability state, increased blood oxygen level-dependent signal in dorsomedial and dorsal posterolateral prefrontal regions were also present during happiness induction. CONCLUSION: Irritability induction is associated with functional changes in a limited set of brain regions previously implicated in the mediation of emotional states. Changes in prefrontal and cingulate areas may be related to effortful cognitive control aspects that gain salience during the emergence of irritability.