Comparação da contenção farmacológica com cetamina e xilazina, administradas pela via intramuscular no membro torácico ou pélvico, em jacarés-do-papo-amarelo juvenis / Comparison of pharmacological restraint with ketamine and xylazine, administered intramuscularly in the forelimb or hindlimb, in broad-snouted caiman juveniles

Os répteis possuem um sistema porta-renal, o qual pode desviar parte do sangue proveniente das porções caudais do corpo aos rins antes que a mesma atinja a circulação sistêmica. Em vista disto, vem sendo aconselhada a administração de medicamentos injetáveis nos membros torácicos, para que se evite a filtração imediata pelo parênquima renal, causando redução do efeito esperado. O objetivo do presente estudo foi comparar aspectos qualitativos e quantitativos da associação de cetamina (30 mg/kg) e xilazina (1 mg/kg), injetada no membro torácico ou pélvico, em jacarés-do-papo-amarelo (Caiman latirostris) juvenis. Oito animais machos com peso médio (±DP) de 1,3 (±0,3) kg e, aproximadamente, dois anos de idade foram anestesiados em duas ocasiões distintas com intervalo de sete dias. Em cada ocasião, os animais receberam, de forma aleatória, a associação anestésica por via intramuscular em membro torácico (tratamento MT) ou pélvico (tratamento MP). Foram avaliados os intervalos de tempo entre a administração do tratamento e a perda do reflexo de endireitamento (período de indução), entre a perda e o retorno desse reflexo (duração do efeito clínico importante) e entre o retorno do reflexo de endireitamento e os primeiros movimentos de deambulação (duração do efeito residual), as frequências cardíaca e respiratória e as temperaturas ambiental e cloacal. Os escores de sedação/anestesia foram avaliados através de uma escala com variação de 0 (alerta/consciente) a 10 (anestesia profunda/sobredosagem). No tratamento MP, dois animais não apresentaram perda de reflexo de endireitamento. Considerando somente aqueles que apresentaram a perda desse reflexo, o tempo de indução (21±9 e 17±5 minutos) e a duração do efeito clínico importante (35±19 e 43±21 minutos) e residual (28±31 e 12±11 minutos) foram similares entre os tratamentos MT e MP (média±desvio padrão)...

Reptiles possess a renal portal system which can divert part of the blood from the caudal portions of the body to the kidney before it reaches the systemic circulation. In view of this, it has been recommended the administration of injectable medications in the forelimbs, in order to avoid immediate glomerular filtration, which might result in a reduction of the expected effect. The aim of this study was to compare qualitative and quantitative aspects of the pharmacological restraint provided by the combination of ketamine (30mg/kg) and xylazine (1mg/kg), injected into the forelimb or hindlimb, in broad-snouted caiman juveniles (Caiman latirostris). Eight male animals, with a mean weight (±SD) of 1.3 (±0.3) kg, and aged about 2 years old, were anesthetized on two separate occasions with an interval of 7 days. On each occasion, the animals were randomly assigned to receive the anesthetic combination intramuscularly into the forelimb (FL treatment) or hindlimb (HL treatment). The time intervals between administration of treatment and loss of the righting reflex (induction time), between the loss and return of this reflex (duration of important clinical effect), and between the return of the righting reflex and first movements of ambulation (duration of residual effect) were measured as well as heart and respiratory rates and cloacal and environmental temperatures. Sedation/anesthesia scores were evaluated using a scale ranging from 0 (alert/conscious) to 10 (deep anesthesia/overdose). In the HL treatment, loss of righting reflex was not observed in two animals. Considering only those animals whose loss of righting reflex was observed, the induction time (21±9 and 17±5 minutes), the duration of important clinical effect (35±19 and 43±21 minutes), and the duration of residual effect (28±31 and 12±11 minutes) were similar between the FL and HL treatments, respectively (mean±SD). Sedation/anesthesia scores were significantly higher than at baseline...

Sympathetic activity of S-(+)-ketamine low doses in the epidural space / Atividade simpática de cetamina S-(+) em doses baixas no espaço epidural / Actividad simpática de la ketamina S(+)-en dosis bajas en el espacio epidural

BACKGROUND AND OBJECTIVES: S-(+)-ketamine is an intravenous anaesthetic and sympathomimetic with properties of local anaesthetic. It has an effect of an analgetic and local anaesthetic when administered epidurally, but there are no data whether low doses of S-(+)-ketamine have sympathomimetic effects. The aim of this study was to determine whether low doses of S-(+)-ketamine, given epidurally together with local anaesthetic, have any effect on sympathetic nervous system, both systemic and below the level of anaesthetic block. METHODS: The study was conducted on two groups of patients to whom epidural anaesthesia was administered to. Local anaesthesia (0.5% bupivacaine) was given to one group (control group) while local anaesthesia and S-(+)-ketamine were given to other group. Age, height, weight, systolic, diastolic and mean arterial blood pressure were measured. Non-competitive enzyme immunochemistry method (Cat Combi ELISA) was used to determine the concentrations of catecholamines (adrenaline and noradrenaline). Immunoenzymometric determination with luminescent substrate on a machine called Vitros Eci was used to determine the concentration of cortisol. Pulse transit time was measured using photoplethysmography. Mann-Whitney U-test, Wilcoxon test and Friedman ANOVA were the statistical tests. Blood pressure, pulse, adrenaline, noradrenaline and cortisol concentrations were measured in order to estimate systemic sympathetic effects. RESULTS: 40 patients in the control group were given 0.5% bupivacaine and 40 patients in the test group were given 0.5% bupivacaine with S-(+)-ketamine. Value p < 0.05 has been taken as a limit of statistical significance. CONCLUSIONS: Low dose of S-(+)-ketamine administered epidurally had no sympathomimetic effects; it did not change blood pressure, pulse, serum hormones or pulse transit time. Low dose of S-(+)-ketamine administered epidurally did not deepen sympathetic block. Adding 25 ...

JUSTIFICATIVA E OBJETIVOS: cetamina S-(+) é um anestésico intravenoso e simpaticomimético com propriedades de anestésico local. Tem efeito analgésico e de anestésico local quando administrada por via epidural, mas não há dados que relatem se cetamina S-(+) em doses baixas tem efeitos simpaticomiméticos. O objetivo deste estudo foi determinar se cetamina S-(+) em doses baixas, administrada por via epidural em combinação com anestésico local, tem algum efeito sobre o sistema nervoso simpático, tanto sistêmico quanto abaixo do nível do bloqueio anestésico. MÉTODOS: o estudo foi conduzido com dois grupos de pacientes submetidos à anestesia epidural. Anestesia local (bupivacaína a 0,5) foi administrada a um grupo (controle), enquanto anestesia local em combinação com cetamina S-(+) foi administrada ao outro grupo (teste). Idade, altura, peso, pressão arterial sistólica e diastólica e pressão arterial média foram medidos. O método imunoquímico de inibição enzimática não competitiva (Cat Combi Elisa) foi usado para determinar as concentrações de catecolaminas (adrenalina e noradrenalina). O ensaio imunoenzimométrico com substrato luminescente em uma máquina chamada Vitros Eci foi usado para determinar a concentração de cortisol. O tempo de transição do pulso foi medido com fotopletismografia. Para análise estatística, os testes de Wilcoxon, U de Mann-Whitney e Anova de Friedman foram usados. Pressão arterial, pulso e concentrações de adrenalina, noradrenalina e cortisol foram medidos para estimar os efeitos simpáticos sistêmicos. RESULTADOS: receberam bupivacaína a 5% 40 pacientes do grupo controle e 40 do grupo teste receberam bupivacaína a 0,5% com cetamina S-(+). Um valor de p < 0,05 foi ...

JUSTIFICACIÓN Y OBJETIVOS: la ketamina S(+) es un anestésico intravenoso y simpaticomimético con propiedades de anestésico local. Posee un efecto analgésico y de anestésico local cuando se administra por vía epidural, pero no existen datos que informen si la ketamina S(+) en bajas dosis tiene efectos simpaticomiméticos. El objetivo de este estudio fue determinar si la ketamina S(+) en bajas dosis y administrada por vía epidural en combinación con el anestésico local tiene algún efecto sobre el sistema nervioso simpático, tanto sistémico como por debajo del nivel del bloqueo anestésico. MÉTODOS: el estudio fue realizado con 2 grupos de pacientes sometidos a anestesia epidural. A un grupo (grupo control) se le administró la anestesia local (bupivacaína al 0,5), mientras que a otro se le administró la anestesia local en combinación con la ketamina S(+). La edad, altura, peso, presión arterial sistólica y diastólica y la presión arterial media se midieron. El método inmunoquímico de inhibición enzimática no competitiva (Cat Combi ELISA) se usó para determinar las concentraciones de catecolaminas (adrenalina y noradrenalina). El ensayo inmunoenzimométrico con sustrato lumínico en una máquina llamada Vitros Eci fue usado para determinar la concentración de cortisol. El tiempo de transición del pulso fue medido usando la fotopletismografía. Para el análisis estadístico se usaron los test de Wilcoxon, U de Mann-Whitney y ANOVA de Friedman. La presión arterial, pulso y concentraciones de adrenalina, noradrenalina y cortisol fueron medidos para estimar los efectos simpáticos sistémicos. RESULTADOS: cuarenta pacientes del grupo control recibieron bupivacaína al 5% y 40 pacientes del grupo test recibieron bupivacaína al 0,5% con ketamina ...

Club drugs: review of the ‘rave’ with a note of concern for the Indian scenario.

'Club drugs’ which include Ecstasy, gamma-hydroxybutyrate (GHB), ketamine, and Rohypnol (flunitrazepam) have become popular with participants in ‘raves’, because they are perceived to enhance energy, endurance, sociability and sexual arousal. These drugs vary in their pharmacologic properties, physiological and psychological effects, and potential consequences. The use of club drugs by young people has increased in the last decade, and continue to get modified and evolve, making them very difficult to monitor. Further, these drugs are not picked up by routine drugs screening procedures, thereby making these popular with the criminals. India, which is in a phase of social transition, also faces this rising menace. Despite the nature and extent of this problem, this area has been under-researched. Data from India are sparse barring a few newspaper and police reports. Keeping abreast of current trends in club drug use prepares the clinician to recognize the clinical effects of club drug use, to manage club drug related emergencies, and to generate social awareness.

Efeitos cardiovasculares da anestesia dissociativa na reposição volêmica com colóide e solução hipertônica em cães: avaliação biotelemétrica / Cardiovascular effects of dissociative anesthesia in the volemic expansion with colloid and hypertonic solution in dogs: biotelemetric evaluation

Avaliaram-se os efeitos cardiovasculares por um período de 24 horas, após a administração de solução salina hipertônica (NaCl) 7,5 por cento ou em associação ao hidroxietilamido 130/0,4 (HES), em cães com hipovolemia induzida e tratados com cetamina levógira ou racêmica. Após a indução da hipovolemia, administrou-se NaCl 7,5 por cento (4mL/kg) no grupo hipertônica levógira (GHL) e no grupo hipertônica racêmica (GHR) ou HES 130/0,4 na mesma proporção de sangue retirado, associado a NaCl 7,5 por cento (4mL/kg) no grupo hipertônica colóide levógira (GHCL) e no grupo hipertônica colóide racêmica (GHCR). Após 30 minutos, administrou-se por via intravenosa, cetamina levógira (CL; 5mg/kg) no GHL e GHCL ou cetamina racêmica (CR; 10mg/kg) no GHR e GHCR. A frequência cardíaca (FC) e a pressão arterial sistólica (PAS) foram menores após a hipovolemia e após a CR. A pressão arterial média (PAM) e a pressão arterial diastólica (PAD) foram menores após a hipovolemia e após a administração de CL e CR. Não foram observadas diferenças significativas entre os grupos em relação à FC, PAS, PAM e PAD durante o período de mensuração por biotelemetria desde T210 até T1440. A administração de HES associado ao NaCl 7,5 por cento propiciou restabelecimento imediato da PAM, a administração de NaCl 7,5 por cento não restaurou a PAM em pacientes hipovolêmicos, a administração de CR ou CL produziu efeitos semelhantes e todos os tratamentos mantiveram estáveis as pressões arteriais e a FC por um período de até 24 horas.

The cardiovascular effects were evaluated for a 24-hour period, after the administration of hypertonic solution (NaCl 7.5 percent) or in association with hidroxyethyl starch 130/0.4 (HES) in dogs under induced experimental hypovolemia and treated with racemic ketamine (RK) or S(+) ketamine (SK). After the hypovolemia induction, administration of NaCl 7.5 percent (4mL.kg-1) was performed in two groups named hypertonic S(+) (HSG) and hypertonic racemic (HRG), or NaCl 7.5 percent (4mL.kg-1) in association with HES, in the same ratio of removed blood, in two groups named hypertonic colloid S(+) (HCSG) and hypertonic colloid racemic (HCRG). After 30 minutes, SK (5mg.kg-1) was administered by intravenous injection in HSG and HCSG groups, or RK (10mg.kg-1) in HRG and HCRG groups. The heart rate (HR) and systolic arterial pressure (SAP) were lower after hypovolemia and RK. Mean (MAP) and diastolic arterial pressure (DAP) were reduced after hypovolemia and either SK or RK administration. Significant differences were not observed among the groups to HR, SAP, MAP, and DAP during the biotelemetry mensuration period, from T210 to T1440. HES associated with NaCl 7.5 percent administration propitiated immediate re-establishment of MAP. NaCl 7.5 percent administration did not restore MAP in hypovolemic patients. Either RK or SK administrations produced similar effects and all of the treatments maintained stable blood pressure and heart rate for a 24-hour period.

Advances in research of ketamine addiction mechanism / 法医学杂志

Ketamine is a phencyclidine derivative acting primarily as a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) excitatory glutamate receptors. As a common intravenous anaesthetic in clinic, it is also increasingly abused because of its hallucination and addiction effects. Based on the pharmacological and toxicologic characteristics of ketamine and the acknowledged addiction mechanism of other abused drugs, this article reviews the possible addiction mechanism of the ketamine in the aspects of its enhanced effects and reward systems, the anatomic structures, the related receptors and the individual differences.

Parametric evaluation of methotrimeprazine-midazolam-ketamine and methotrimeprazine-midazolam-ketamine-xylazine combination in dogs / Avaliação paramétrica das associações levomepromazinamidazolam-cetamina e levomepromazinamidazolamcetamina-xilazina em cães

PURPOSE: To evaluate the parameters of dogs anesthetized by different dissociative drugs protocols through continuous intravenous infusion. METHODS: Thirty healthy dogs of both sexes were assigned randomly to three groups (G1, G2, and G3). G1 was administered with methotrimeprazine as a pre-anesthetic medication, intravenously midazolam-ketamine as bolus for induction and midazolam-ketamine by continuous intravenous infusion for a 60 minute-period of maintenance. G2: the same as for G1. plus an increase in the midazolam dose during maintenance. G3: the same treatment as for G2, plus the addition of xylazine during maintenance. Immediately after induction the anesthetic maintenance started, and measures were taken 15 minutes after pre-medication, at 10 minutes intervals, during maintenance (M0 to M7). RESULTS: Bradycardia, atrioventricular blockage, bradypnea and hypoxemia were shown in G3. G1 and G2 showed a slight hypotension only. CONCLUSION: There were some advantages by using the continuous intravenous via: no parameters oscillation and reduction in the anesthetic recovery period. The increase in midazolam dose brought about little parametric variations which were greater when xylazine was used, with a consequent hypoxemia, bradyarrhytmia, and decrease in respiratory frequency and minute volume.

OBJETIVO: Avaliar os parâmetros de cães anestesiados com diferentes protocolos de fármacos dissociativos por infusão intravenosa contínua. MÉTODOS: Foram utilizados 30 cães, machos e fêmeas, clinicamente sadios, distribuídos aleatoriamente em três grupos (G1,G2 e G3) (*)). Em G1 utilizou-se levomepromazina como medicação pré-anestésica (MPA), midazolam-cetamina pela via intravenosa em bolus para indução e midazolam-cetamina em infusão intravenosa contínua por 60 minutos para manutenção. Em G2 procedeu-se da mesma forma que em G1 elevando-se, porém, a dose de midazolam durante a manutenção. Em G3 repetiu-se o tratamento empregado em G2, acrescentando-se a xilazina à manutenção. Após a indução, iniciou-se imediatamente a manutenção anestésica, realizando-se aferições, 15 minutos depois da MPA, em intervalos de 10 minutos, durante a manutenção (M0 a M7). RESULTADOS: Em G3 ocorreu bradicardia, bloqueio átrio-ventricular, bradipnéia e hipoxemia e em G1 e G2, discreta hipotensão. CONCLUSÃO: A via intravenosa contínua apresentou vantagens quanto a: não oscilação dos parâmetros e redução no período de recuperação anestésica. A elevação da dose de midazolam resultou em discretas variações paramétricas, estas, acentuadas pelo uso da xilazina, que causou hipoxemia, bradiarritmia, diminuição da freqüência respiratória e volume minuto.

Effect of intratesticular injection of xylazine/ketamine combination on canine castration

This study was performed to compare the effect of intratesticular (IT) injection of xylazine/ketamine combination for canine castration with those of intramuscular (IM) or intravenous (IV) injection. Xylazine and ketamine was administered simultaneously via intratesticularly (IT group), intramuscularly (IM group) or intravenously (IV group) at doses of 2 and 10 mg/kg, respectively. Pain response at the time of injection, mean induction time, mean arousal time, mean walking time and cardiopulmonary function during anesthesia were monitored after the xylazine and ketamine administration. In IV and IM groups, heart rates were significantly decreased 30 and 45 min after xylazine and ketamine administration, respectively (p < 0.05). Respiratory rates were significantly decreased in the IV group (p < 0.05). In the IT group, there was no significant changes in heart and respiratory rates. The occurrence of cardiac arrhythmias was less severe in IT group compared with those in IM and IV groups. The route of administration did not affect rectal temperature. Mean induction time was significantly (p < 0.05) longer in IT group than in IM and IV groups. On the contrary, mean arousal time and mean walking time were shortened in IT group. Clinical signs related to pain response at the time of injection and vomiting were less observed in IT group than in IM group, and head shaking was less shown in IT group than in IM and IV groups during recovery period. These results indicated that intratesticular injection of xylazine/ketamine for castration has several advantages such as less inhibition of cardiopulmonary function and fast recovery from anesthesia without severe complications, and would be an effective anesthetic method for castration in small animal practice.