Anestesia epidural cranial com lidocaína e morfina para campanhas de castração em cães

A castração de machos e fêmeas tem sido preconizada como a principal técnica para redução do grande número de cães errantes. No entanto, vários são os entraves com relação à escolha do melhor protocolo anestésico, em relação à eficácia, segurança e redução de custos. Objetivou-se, com este trabalho, avaliar os efeitos cardiorrespiratórios, hemogasométricos e analgésicos da utilização de lidocaína em um volume maior, associada à morfina, pela via epidural em cadelas submetidas à ovariosalpingohisterectomia (OSH), com ou sem suplementação de oxigênio. Utilizaram-se 12 cadelas, com peso médio de 11,5±3,7kg e idade de um a quatro anos. Os animais receberam como medicação pré-anestésica (MPA) acepromazina (0,1mg kg-1) e meperidina (5mg kg-1), pela via intramuscular. Após 15 minutos, administrou-se tiopental (10mg kg-1), por via intravenosa, seguido de intubação endotraqueal. Nesse momento, os animais foram alocados em dois grupos: o grupo GCO (com oxigênio, n=06) recebeu suplementação de oxigênio 100% e o grupo GSO (sem oxigênio, n=06) permaneceu intubado sem suplementação de oxigênio. Após a intubação, foi administrada, pela via epidural, em ambos os grupos, morfina (0,1mg kg-1) em volume final ajustado para 1mL 3,0kg-1 de peso com lidocaína 2% sem vasoconstritor. Imediatamente após a anestesia epidural, os animais foram posicionados em decúbito dorsal com a cabeça no mesmo plano do corpo, e iniciou-se o procedimento cirúrgico, o qual foi padronizado em 30 minutos. em ambos os grupos, foi possível realizar a cirurgia sem a necessidade de complementação analgésica e sem resposta de dor. A pressão arterial média (PAM) foi menor no GSO em todos os momentos em comparação ao basal. No GCO, a PAM foi menor após MPA e após epidural. Houve redução da f de M1 até M6 no GSO. A SaO2 e PaO2 foram maiores no GCO em comparação ao GSO. O pH foi menor no GCO 15 minutos após MPA até 40 minutos após epidural, em comparação ao GSO. Conclui-se que a anestesia epidural lombossacra com morfina e lidocaína na dose e no volume propostos é efetiva para realização de OSH em cadelas, com mínimas alterações cardiovasculares e hemogasométricas, as quais são bem toleradas em animais hígidos. Essa prática é exequível em campanhas de castração em que não há possibilidade de oxigenação dos animais.

The pre-emptive effect of epidural ketamine on wound sensitivity in horses tested by using von Frey filaments

Objective To evaluate the pre-emptive analgesic effect of pre-incisional epidural ketamine.Study Design A blinded, randomized experimental study.Animals Sixteen mixed breed mares, 17.6 +/- 2.8 years old, weighing 352 +/- 32 kg.Methods In a pilot study, an incision was made on one lateral thigh using a lidocaine block and no further analgesics, and it was verified that the nociceptive threshold was lower on the incised side than nonincised side (p < 0.05), and that von Frey filaments evoked a pain response. The 16 animals were divided into group A (ketamine, n = 9) and B (saline, n = 7). An epidural catheter was inserted 24 hours before the trials, the thigh was shaved bilaterally, and the right side was blocked (incised side) using lidocaine. Twenty-five minutes later, ketamine (A) or saline (B) was administered epidurally. Five minutes later, a 10-cm. skin incision was made on the right side, and then sutured. Nociceptive threshold was determined with von Frey filaments at 1, 3, and 5 cm. around the incision at 15-minute intervals for 2 hours, then at 4, 6, and 8 hours. Behavioral alterations, heart and respiratory rates were recorded. Nociceptive thresholds from these points were averaged to obtain mean values at each time, converted to a logarithmic scale, and submitted to a nonparametric analysis (Mann-Whitney and one-way repeated measures anova test,p less than or equal to 0.05).Results After 8 hours, the global range score revealed reduced hyperalgesia (p < 0.01) around the incision in 92% (4.65-4.27) of evaluated intervals in group A (ketamine). There were no significant changes in behavior, heart and respiratory rates,Conclusions It was concluded that pre-emptive epidural ketamine reduced post-incisional pain in the horse, and that von Frey filaments were able to quantify cutaneous sensitivity after tissue damage.Clinical relevance Epidural ketamine injection can reduce post-incisional sensitivity in the horse.

Sympathetic hyperactivity, respiratory failure, pruritus, and anesthesia after unintentional epidural injection of potassium chloride: Case report

Background and Objectives. A combination of epidural and general anesthesia has been widely used to attenuate the surgical stress response and to provide postoperative analgesia. This case report illustrates the use of this anesthetic technique. Analgesia was induced with local anesthetic in the immediate postoperative period using unintentional 19.1% potassium chloride (KCI) as diluent. Methods. An ASA I male patient was scheduled for surgical correction of idiopathic megaesophagus under continuous epidural anesthesia combined with general anesthesia. In the postoperative period, while preparing 10 mt 0.125% bupivacaine to be administered through the epidural catheter for pain control, 5 mt 19.1% KCI was unintentionally used as diluent, resulting in a 9.55% potassium solution concentration. Results. The patient developed warmness of the lower limbs, tachycardia, hypertension, intense pruritus on the chest, agitation, exacerbation of sensory and motor blocks, and respiratory failure secondary to pulmonary edema, requiring ventilatory support. Total recovery was observed after 24 hours. Conclusions. Epidurally injected potassium leads to severe clinical manifestations caused by autonomic dysfunction, spinal cord irritation, and possible release of histamine. Despite continuous recommendations, ampule misidentification still happens in hospitals, frequently leading to serious accidents.

Analgesia of Epidural Tramadol in Dogs Submitted to Orchiectomy

Epidural tramadol in veterinary medicine has been studied in only a few instances. In this case, 36 dogs submitted to orchiectomy received 6.0 mg/kg of lidocaine combined with 1.0 mg/kg of tramadol, 0.1 mg/kg of morphine or 0.01 ml/kg of 0.9% NaCl by epidural route. Analgesia was assessed at 4, 8, 12, 18 and 24 hours after surgery. There were no differences between morphine and tramadol over the time of evaluation within these groups, and no complementary analgesia was necessary. In the NaCl group, analgesia was needed at 4, 8 and 12 hours. Epidural tramadol provides an analgesic effect comparable to that of morphine during the first 12 hours post-surgery.

Antinociceptive effects of epidural buprenorphine or medetomidine, or the combination, in conscious cats

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

Plasma concentrations of buprenorphine after epidural administration in conscious cats

Buprenorphine plasma concentrations were measured after administering buprenorphine (20 mu g/kg) into the lumbosacral epidural space of conscious cats chronically instrumented with an epidural catheter. Blood was collected from a jugular vein before injection and 15, 30, 45 and 60 min and 2, 3, 4, 5, 6, 8, 12 and 24 h after administration. Plasma buprenorphine concentrations were measured using ELISA. Background concentration (before injection) was 1.27 +/- 0.27 ng/mL (mean +/- SD). Including background concentration, the mean peak plasma concentration was obtained 15 min after injection (5.82 +/- 3.75 ng/mL), and ranged from 3.79 to 2.20 ng/mL (30 min-3 h), remaining between 1.93 and 1.77 ng/mL (412 h), and declined to 1.40 +/- 0.62 ng/mL at 24 h. Elimination half-life was 58.8 +/- 40.2 min and clearance 56.7 +/- 21.5 mL/min. Results indicate early rapid systemic uptake of buprenorphine from epidural administration with plasma concentrations similar to using buccal or IM routes by 15 min postinjection. (C) 2010 Elsevier Ltd. All rights reserved.

Comparative study of epidural xylazine or clonidine in horses

Objective To evaluate the cardiorespiratory and behavioural effects of epidural xylazine (XYL) or clonidine (CLO) in horses.Study design Blinded, randomized experimental study.Twelve healthy Arabian yearling horses weighing 117-204 kg were randomly allocated into two groups: XYL (n = 6) and CLO (n = 6).Methods An epidural catheter was inserted and a facial arterial catheter was placed and the next day the horses were restrained in stocks. Baseline values for heart (HR) and respiratory (RR) rates, arterial pressure and behavioural responses were evaluated before (TO) and 10, 20, 30, 45, 60, 90 and 120 minutes after epidural injection (T10-T120). The horses received 0.2 mg kg(-1) of XYL or 5 mu g kg(-1) CLO; adjusted to (3.4 + (body weight in kg x 0.013) mL with saline. Data were analysed by the Kolmogorov-Smirnov test, one-way ANOVA with repeated measures, and one-way ANOVA followed by a Student-Newman-Keuls test or Fisher's exact test, as necessary. Significance was set at p <= 0.05.Results Sedation and ataxia were seen at T10, persisting until T120 in four and three horses, respectively, in XYL and all horses in CLO respectively. Two XYL and one CLO horses became recumbent at T45 and T25 respectively. Penile prolapse occurred in four of five males at T30 and T45, in the XYL and CLO groups, respectively, resolving by T120. Tail relaxation was present from T10 to T120 in all horses in XYL and in four horses in CLO. Head drop was observed from T20 to T60 and from T10 to T120 in XYL and CLO respectively. Respiratory rate decreased significantly only at T45 in the CLO group. Heart rate and arterial blood pressure remained stable.Conclusions and clinical relevance Epidural CLO and XYL produce similar cardiorespiratory and behavioural changes but neither would be safe to use clinically at the doses used in this study.

Comparison of the effects of epidural or intravenous methadone on the minimum alveolar concentration of isoflurane in dogs

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

Anestesia epidural em cutias (Dasyprocta azarae) submetidas à ovariossalpingohisterectomia

In this research, the epidural anesthesia technique in nulliparous and non non-nulliparous submitted to ovarysalpingohysterectomy was studied. These are rodents belonging to the Missina Palmeira Zancaner municipal zoo of catanduva in São Paulo. The tranquilization was achieved using azaperone (4mg/kg) and meperidine (4mg/kg) followed by injection of cetamine (20mg/kg) and xylazine (0.4mg/kg), intramuscularly from the same syringe. Subsequently, lidocaine (5mg/kg) was injected into the lumbosacral space. The time of latency of the anesthesic association (4.0[plus or minus]1.51min), time of latency of epidural lidocaine (6.87[plus or minus]2.35min) and time of analgesia (115.0[plus or minus]12.49min) were analyzed, in addition to rectal temperature, which decreased 2.12[plus or minus]0.86[degree]C on average from the beginning of the anesthesia to the end of its effective time. All animals recovered satisfactorily without presenting signs of excitation or complications due to the epidural tecnique. It was concluded that the balanced anesthesia tecnique provided adequate analgesia during a time considered sufficient for several procedures, by means of low doses of xylazine and ketamine.

Injeção epidural de cetamina ou cetamina levógira no controle da dor pós-incisional, em eqüinos

The aim of this study was to evaluate the pre-emptive effect of epidural ketamine S (+) (SK) or racemic ketamine (RK) administration, in post-incisional pain in horses. Were used in a blinded, randomized experimental study, sixteen mixed breed mares, 6±2 years old, weighting 273.2±42.0 kg. An epidural catheter was inserted 24 hours before the trials. The thigh region was shaved bilaterally, and mechanical cutaneous sensibility was measured using von Frey filaments (T-30). Using the left side as the control one, local anesthesia was performed at the right side. Twenty-five minutes later, SK was injected in G1 or RK in G2 through the epidural catheter. Five minutes after the ketamine injection, a 10 cm skin incision was made on the right side, and then sutured. Mechanical post-incisional pain was measured using von Frey filaments, at 1, 3 and 5 cm around the incision at 15 minutes intervals, for 2 hours, then 4, 6 and 8 hours after suturing. No changes were observed in the heart and respiratory rate and rectal temperature among groups or times of each group. Hind limb ataxia was observed in 62.5% and 12.5% of G1 and G2 respectively. SK and RK reduced cutaneous sensibility in the right and the left sides to mechanical postincisional pain during all time of experiment. Epidural SK and RK produce similar post-incisional analgesic effects, did not interfere in the cardio-respiratory parameters. The SK induces more intense ataxia in mares and presents a larger analgesic potency in the first 60 minutes after the administration.

Uso da lidocaína isolada ou associada à quetamina ou ao butorfanol, em anestesia epidural em cães: avaliação cardiorrespiratória e analgésica

Pós-graduação em Anestesiologia - FMB

Efeitos da administração epidural de dexmedetomidina sobre a concentração alveolar mínima do isofluorano em cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da injeção epidural de cetamina ou da sua associação com ifenprodil na mediação nociceptiva somática e visceral em equinos

Pós-graduação em Cirurgia Veterinária - FCAV

Anatomia da coluna vertebral torácica em auxílio de ressonância nuclear magnética

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of epidural nalbuphine on intraoperative isoflurane and postoperative analgesic requirements in dogs

PURPOSE: To measure the change in the minimum alveolar concentration of isoflurane (EtISO) associated with epidural nalbuphine and the postoperative analgesic requirements in dogs after ovariohysterectomy.METHODS: Twenty four healthy female dogs were randomly assigned to receive saline or nalbuphine at 0.3 or 0.6 mg/kg (n=8 for each group) administered via lumbosacral epidural catheter introduced cranially into the epidural canal. Changes in heart and respiratory rates and arterial blood pressure during surgery were recorded along with the corresponding EtISO. Immediately after tracheal extubation, analgesia, sedation, heart rate, respiratory rate, and arterial blood pressure were measured at predetermined intervals and every 60 min thereafter until the first rescue analgesic.RESULTS: A significant decrease in EtISO was associated with epidural nalbuphine at 0.3 mg/kg (26.3%) and 0.6 mg/kg (38.4%) but not with saline in ovariohysterectomized dogs. In the postoperative period, VAS and Colorado analgesic scores were lower for the dogs that received the higher nalbuphine dose, which only required supplemental analgesia 10 h following its administration, compared with dogs that received the lower dose.CONCLUSION: Epidural nalbuphine significantly reduces the intra-operative isoflurane requirement and provides prolonged postoperative analgesia after ovariohysterectomy in dogs.