RESUMEN
This communication reports a partially reversible chemical immobilization protocol used for translocation and veterinary care in giant otter (Pteronura brasiliensis; GO). Six GOs (three males and three females) weighing 24.8 +/- 4.0 kg (mean +/- SD) and ranging in age from 16 to 42 mo old were anesthetized with an i.m. combination of medetomidine (29 +/- 3 microg/kg) and ketamine (3.9 +/- 0.4 mg/kg). To perform all procedures, two otters required an additional dose of ketamine (1.5 mg/kg). Anesthesia was reversed with atipamezole i.m. (147 +/- 14 mg/kg). The mean induction time and recovery times were 12 +/- 5 and 4 min (range, 0-9 min), respectively, with an anesthesia time of 47 +/- 16 min. According to these results, the combination of medetomidine (30 microg/kg i.m.) and ketamine (4 mg/kg i.m.) is a reasonable choice for inducing anesthesia in GOs.
Asunto(s)
Imidazoles/farmacología , Inmovilización/veterinaria , Ketamina/farmacología , Medetomidina/farmacología , Nutrias , Antagonistas Adrenérgicos alfa/administración & dosificación , Antagonistas Adrenérgicos alfa/farmacología , Anestesia/veterinaria , Anestésicos Disociativos/administración & dosificación , Anestésicos Disociativos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/farmacología , Imidazoles/administración & dosificación , Ketamina/administración & dosificación , Ketamina/efectos adversos , Masculino , Medetomidina/administración & dosificaciónRESUMEN
OBJECTIVE: To demonstrate the effect of anesthesia and surgery on serum ionized magnesium and ionized calcium concentrations in clinical canine and feline patients. ANIMALS: 37 client-owned dogs, ASA PS I-III and 10 client-owned cats, ASA PS I, all receiving anesthesia for elective or emergent surgery at a Veterinary Teaching Hospital. MATERIALS AND METHODS: Plasma ionized and serum total magnesium, and plasma ionized calcium were measured prior to and after a group-standardized anesthetic protocol. RESULTS: Regardless of pre-operative medication (hydromorphone or butorphanol), anesthetic induction (thiopental or lidocaine/hydromorphone/diazepam (LHD) and propofol combination), or type of surgical procedure (peripheral surgery or laparotomy), post-operative plasma ionized calcium concentration decreased in all groups of dogs, while post-operative plasma ionized magnesium increased in all groups, although the changes were not always significant. The dogs who were induced with an LHD and propofol technique had a greater increase in ionized magnesium (0.36 +/- 0.07 to 0.42 +/- 0.07 mmol L(-1)) than the group in which anesthesia was induced with thiopental (0.41 +/- 0.07 to 0.42 +/- 0.07 mmol L(-1), p = 0.009). The cats showed similar changes in ionized magnesium and ionized calcium, and also had a significant increase in serum total magnesium (2.17 +/- 0.20 to 2.31 +/- 0.25 mg dL(-1), p = 0.009) CONCLUSIONS, CLINICAL RELEVANCE: A post-operative decrease in ionized calcium was demonstrated in healthy animals, as well as an increase in ionized or total magnesium after various anesthetic protocols and surgeries. These changes, while statistically significant, do not appear to be clinically significant, as values remained within reference ranges at all times.
Asunto(s)
Anestesia General/veterinaria , Anestésicos Intravenosos/administración & dosificación , Calcio/sangre , Gatos/fisiología , Perros/fisiología , Magnesio/sangre , Animales , Gatos/sangre , Gatos/cirugía , Diazepam/administración & dosificación , Perros/sangre , Perros/cirugía , Femenino , Hidromorfona/administración & dosificación , Lidocaína/administración & dosificación , Masculino , Orquiectomía/veterinaria , Ovariectomía/veterinaria , Periodo Posoperatorio , Propofol/administración & dosificación , Tiopental/administración & dosificaciónRESUMEN
BACKGROUND: Resiniferatoxin is a potent capsaicin analog. Intrathecal administration leads to selective, prolonged opening of the transient receptor potential V1 ion channel, which is localized mainly to C-fiber primary afferent nociceptive sensory neurons. Following work in laboratory animals, the authors explored the use of intrathecal resiniferatoxin to control spontaneous bone cancer pain in companion (pet) dogs. METHODS: Normal canine population: Behavioral testing was performed to establish baseline paw withdrawal latency; subsequently, general anesthesia was induced and resiniferatoxin was administered intrathecally while hemodynamic parameters were recorded. Behavior testing was repeated for 12 days after administration of resiniferatoxin. Clinical canine population: Twenty companion dogs with bone cancer pain were recruited. The animal's baseline level of discomfort and analgesic use were recorded. Resiniferatoxin was administered intrathecally and hemodynamic parameters were monitored while the dogs were under general anesthesia. Dogs were reevaluated up to 14 weeks after resiniferatoxin administration. RESULTS: Normal canine population: In the first minutes after resiniferatoxin injection, there were significant (P < 0.05) increases in mean arterial blood pressure and heart rate from baseline. Two days after injection, limb withdrawal latencies increased to the point of cutoff in the dogs that received at least 1.2 microg/kg resiniferatoxin. Clinical canine population: From baseline, there were significant (P < 0.05) increases in mean arterial blood pressure and heart rate after resiniferatoxin injection. Comfort scores were significantly improved at 2, 6, 10, and 14 weeks after resiniferatoxin administration (P < 0.0001). There was decreased or discontinued use of supplemental analgesics in 67% of the dogs 2 weeks after resiniferatoxin administration. CONCLUSIONS: Intrathecal resiniferatoxin elicits transient hemodynamic effects. In controls, a profound and sustained blockade of thermal stimuli is produced in a dose-dependent fashion. Similar administration in dogs with bone cancer produces a prolonged antinociceptive response.
Asunto(s)
Analgésicos , Neoplasias Óseas/complicaciones , Neoplasias Óseas/veterinaria , Diterpenos/farmacología , Enfermedades de los Perros/patología , Dolor/tratamiento farmacológico , Dolor/veterinaria , Animales , Conducta Animal/efectos de los fármacos , Neoplasias Óseas/patología , Cateterismo , Estudios de Cohortes , Diterpenos/efectos adversos , Perros , Relación Dosis-Respuesta a Droga , Hemodinámica/efectos de los fármacos , Inyecciones Espinales , Dimensión del Dolor/efectos de los fármacosRESUMEN
OBJECTIVE: To determine frequency and severity of postanesthetic hypoxemia and hypercarbia in healthy dogs undergoing elective ovariohysterectomy or castration and given butorphanol or hydromorphone for analgesia. DESIGN: Prospective trial. ANIMALS: 0 healthy dogs weighing > 10 kg (22 lb). PROCEDURE: Dogs were anesthestized with acepromazine, glycopyrrolate, thiopental, and isoflurane, and butorphanol (n = 10) or hydromorphone (10) was used for perioperative analgesia. Arterial blood gas analyses were performed 10 and 30 minutes and 1, 2, 3, and 4 hours after extubation. RESULTS: In dogs that received hydromorphone, mean PaCO2 was significantly higher, compared with the preoperative value, 10 and 30 minutes and 1, 2, and 3 hours after extubation. Mean PaCO2 was significantly higher in dogs given hydromorphone rather than butorphanol 10 and 30 minutes and 1 and 2 hours after extubation. Mean PaO2 was significantly lower, compared with preoperative values, 30 minutes and 1 and 2 hours after extubation in dogs given hydromorphone and 30 minutes after extubation in dogs given butorphanol. Mean PaO2 was significantly lower in dogs given hydromorphone rather than butorphanol 1 hour after extubation. Four dogs had PaO2 < 80 mm Hg 1 or more times after extubation. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of hydromorphone to healthy dogs undergoing elective ovariohysterectomy or castration may result in transient increases in PaCO2 postoperatively and that administration of hydromorphone or butorphanol may result in transient decreases in PaO2. However, increases in PaCO2 and decreases in PaO2 were mild, and mean PaCO2 and PaO2 remained within reference limits.
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Analgésicos Opioides/efectos adversos , Butorfanol/efectos adversos , Enfermedades de los Perros/inducido químicamente , Hidromorfona/efectos adversos , Hipercapnia/veterinaria , Hipoxia/veterinaria , Complicaciones Posoperatorias/veterinaria , Animales , Análisis de los Gases de la Sangre/veterinaria , Dióxido de Carbono/sangre , Perros , Femenino , Hipercapnia/inducido químicamente , Hipoxia/inducido químicamente , Histerectomía/veterinaria , Masculino , Orquiectomía/veterinaria , Ovariectomía/veterinaria , Oxígeno/sangre , Presión ParcialRESUMEN
OBJECTIVE: To determine whether changes in amplitude of the reflex-evoked muscle action potential (REMP) elicited by noninvasive dental dolorimetry (electrical stimulation of the tooth pulp) in anesthetized dogs may be used to objectively evaluate the effectiveness of IV and intrathecal (IT) administration of morphine. ANIMALS: 6 male Beagles that were 2 to 6 years old. PROCEDURE: Dogs were used in a crossover design with at least a 5-day washout period between treatments. Each dog received morphine, saline (0.9% NaCl) solution, and oxytocin via the IV and IT routes of administration; however, only results for morphine and saline treatments were reported here. Dogs were anesthetized and prepared for noninvasive dental dolorimetry. After IV or IT administration, electrical stimulation was applied to a tooth, and REMPs of the digastricus muscle were recorded at 5-minute intervals for 60 minutes. To determine differences in REMP amplitude between treatments, a linear regression line was fitted for each dog-treatment combination. RESULTS: The IV administration of morphine significantly inhibited REMP amplitude, compared with IV administration of saline solution. Intrathecal administration of morphine significantly inhibited REMP amplitude, compared with IT administration of saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Noninvasive dental dolorimetry in anesthetized dogs has promise as a technique for use in evaluating the analgesic potential of drugs administered IV and IT through evaluation of their effect on REMP amplitude recorded for the digastricus muscle.
Asunto(s)
Enfermedades de los Perros/tratamiento farmacológico , Morfina/administración & dosificación , Morfina/uso terapéutico , Dimensión del Dolor/métodos , Dolor/tratamiento farmacológico , Dolor/veterinaria , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/uso terapéutico , Anestesia , Animales , Pulpa Dental , Enfermedades de los Perros/prevención & control , Perros , Potenciales Evocados , Inyecciones Intravenosas , Inyecciones Espinales , Masculino , Dolor/prevención & control , Factores de TiempoRESUMEN
OBJECTIVE: To determine whether intrathecal (IT) or IV administration of oxytocin will diminish amplitude of the reflex-evoked muscle action potential (REMP) in the digastricus muscle during electrical stimulation of the tooth pulp in anesthetized dogs, thus suggesting an analgesic effect for oxytocin. ANIMALS: 6 male Beagles that were 2 to 6 years old. PROCEDURE: Dogs were used in a crossover design with at least a 5-day washout period between treatments. Each dog received morphine, saline (0.9% NaCl) solution, and oxytocin by both the IT and IV routes of administration. Noninvasive dental dolorimetry was used to assess changes in pain threshold following administration of treatments. Effectiveness of analgesia was determined on the basis of change in REMP amplitude in the digastricus muscle. RESULTS: Morphine administered IV significantly inhibited REMP amplitude, compared with IV administration of saline solution or oxytocin. There was not a significant change in REMP amplitude between saline solution and oxytocin administered IV. Intrathecal administration of morphine significantly inhibited REMP amplitude, compared with IT administration of saline solution or oxytocin. Intrathecal administration of oxytocin significantly increased REMP amplitude, compared with IT administration of saline solution or morphine. CONCLUSIONS AND CLINICAL RELEVANCE: Although IV administration of oxytocin did not have an effect on REMP amplitude, compared with IV administration of saline solution, IT administration of oxytocin had the opposite effect of morphine and increased REMP amplitude of the digastricus muscle. These data do not support the use of oxytocin as an analgesic agent in dogs.
Asunto(s)
Potenciales de Acción/efectos de los fármacos , Analgésicos/administración & dosificación , Analgésicos/farmacología , Pulpa Dental/efectos de los fármacos , Pulpa Dental/fisiología , Oxitocina/administración & dosificación , Oxitocina/farmacología , Analgésicos/uso terapéutico , Animales , Perros , Estimulación Eléctrica , Potenciales Evocados/efectos de los fármacos , Inyecciones Intravenosas , Inyecciones Espinales , Masculino , Morfina/administración & dosificación , Morfina/farmacología , Morfina/uso terapéutico , Oxitocina/uso terapéutico , Dolor/tratamiento farmacológico , Dolor/prevención & control , Dimensión del Dolor , Factores de TiempoRESUMEN
A sensitive and simple high-performance liquid chromatographic (HPLC) assay was developed for the quantification of resiniferatoxin (RTX) in canine cerebrospinal fluid (CSF). A reversed-phase C(18) column and acetonitrile in 0.02 M NaH(2)PO(4) as mobile phase provided satisfactory resolution for RTX analysis. Direct HPLC analysis of the CSF samples without sample extraction or preparation improves the accuracy and detection limits of this assay. This assay was applied to measure CSF RTX content to test this method for research and clinical applications related to studies examining its analgesia effects.