RESUMEN
BACKGROUND: Muscle metabolism in horses has been studied mainly by analysis of substances in blood or plasma and muscle biopsy specimens. By using microdialysis, real-time monitoring of the metabolic events in local tissue with a minimum of trauma is possible. There is limited information about muscle metabolism in the early recovery period after anaesthesia in horses and especially in the colic horse. The aims were to evaluate the microdialysis technique as a complement to plasma analysis and to study the concentration changes in lactate, pyruvate, glucose, glycerol, and urea during anaesthesia and in the recovery period in colic horses undergoing abdominal surgery and in healthy horses not subjected to surgery. METHODS: Ten healthy university-owned horses given anaesthesia alone and ten client-owned colic horses subjected to emergency abdominal surgery were anaesthetised for a mean (range) of 230 min (193-273) and 208 min (145-300) respectively. Venous blood samples were taken before anaesthesia. Venous blood sampling and microdialysis in the gluteal muscle were performed during anaesthesia and until 24 h after anaesthesia. Temporal changes and differences between groups were analysed with an ANOVA for repeated measures followed by Tukey Post Hoc test or Planned Comparisons. RESULTS: Lactate, glucose and urea, in both dialysate and plasma, were higher in the colic horses than in the healthy horses for several hours after recovery to standing. In the colic horses, lactate, glucose, and urea in dialysate, and lactate in plasma increased during the attempts to stand. The lactate-to-pyruvate ratio was initially high in sampled colic horses but decreased over time. In the colic horses, dialysate glycerol concentrations varied considerably whereas in the healthy horses, dialysate glycerol was elevated during anaesthesia but decreased after standing. In both groups, lactate concentration was higher in dialysate than in plasma. The correspondence between dialysate and plasma concentrations of glucose, urea and glycerol varied. CONCLUSION: Microdialysis proved to be suitable in the clinical setting for monitoring of the metabolic events during anaesthesia and recovery. It was possible with this technique to show greater muscle metabolic alterations in the colic horses compared to the healthy horses in response to regaining the standing position.
Asunto(s)
Anestesia/veterinaria , Cólico/veterinaria , Enfermedades de los Caballos/metabolismo , Microdiálisis/veterinaria , Animales , Cólico/metabolismo , Cólico/cirugía , Femenino , Enfermedades de los Caballos/sangre , Enfermedades de los Caballos/cirugía , Caballos , Masculino , Microdiálisis/métodosRESUMEN
OBJECTIVE: To assess physiologic responses and plasma endothelin (ET)-1 concentrations associated with abrupt cessation of nitric oxide (NO) inhalation in isoflurane-anesthetized horses. ANIMALS: 6 healthy adult Standardbreds. PROCEDURES: Horses were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. Nitric oxide was pulsed into the respiratory tract for 2.5 hours, and then administration was abruptly discontinued. Just prior to commencement and at cessation of NO administration, and at intervals during a 30-minute period following cessation of NO inhalation, several variables including PaO(2), mean pulmonary artery pressure, venous admixture or pulmonary shunt fraction (Qs/Qt), and plasma ET-1 concentration were recorded or calculated. RESULTS: After cessation of NO inhalation, PaO(2) decreased slowly but significantly (172.7 +/- 29.8 mm Hg to 84.6 +/- 10.9 mm Hg) and Qs/Qt increased slowly but significantly (25 +/- 2% to 40 +/- 3%) over a 30-minute period. Mean pulmonary artery pressure increased slightly (14.0 +/- 1.3 mm Hg to 16.8 +/- 1 mm Hg) over the same time period. No change in serum ET-1 concentration was detected, and other variables did not change or underwent minor changes. CONCLUSIONS AND CLINICAL RELEVANCE: The improvement in arterial oxygenation during pulsed inhalation of NO to healthy isoflurane-anesthetized horses decreased only gradually during a 30-minute period following cessation of NO inhalation, and serum ET-1 concentration was not affected. Because a rapid rebound response did not develop, inhalation of NO might be clinically useful in the treatment of hypoxemia in healthy isoflurane-anesthetized horses.
Asunto(s)
Anestesia por Inhalación/veterinaria , Broncodilatadores/administración & dosificación , Endotelina-1/sangre , Caballos/fisiología , Óxido Nítrico/administración & dosificación , Administración por Inhalación , Animales , Análisis de los Gases de la Sangre/veterinaria , Presión Sanguínea/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Caballos/sangre , Masculino , Respiración/efectos de los fármacosRESUMEN
BACKGROUND: Many colic horses are compromised due to the disease state and from hours of starvation and sometimes long trailer rides. This could influence their muscle energy reserves and affect the horses' ability to recover. The principal aim was to follow metabolic parameter before, during, and up to 7 days after anaesthesia in healthy horses and in horses undergoing abdominal surgery due to colic. METHODS: 20 healthy horses given anaesthesia alone and 20 colic horses subjected to emergency abdominal surgery were anaesthetised for a mean of 228 minutes and 183 minutes respectively. Blood for analysis of haematology, electrolytes, cortisol, creatine kinase (CK), free fatty acids (FFA), glycerol, glucose and lactate was sampled before, during, and up to 7 days after anaesthesia. Arterial and venous blood gases were obtained before, during and up to 8 hours after recovery. Gluteal muscle biopsy specimens for biochemical analysis of muscle metabolites were obtained at start and end of anaesthesia and 1 h and 1 day after recovery. RESULTS: Plasma cortisol, FFA, glycerol, glucose, lactate and CK were elevated and serum phosphate and potassium were lower in colic horses before anaesthesia. Muscle adenosine triphosphate (ATP) content was low in several colic horses. Anaesthesia and surgery resulted in a decrease in plasma FFA and glycerol in colic horses whereas levels increased in healthy horses. During anaesthesia muscle and plasma lactate and plasma phosphate increased in both groups. In the colic horses plasma lactate increased further after recovery. Plasma FFA and glycerol increased 8 h after standing in the colic horses. In both groups, plasma concentrations of CK increased and serum phosphate decreased post-anaesthesia. On Day 7 most parameters were not different between groups. Colic horses lost on average 8% of their initial weight. Eleven colic horses completed the study. CONCLUSION: Colic horses entered anaesthesia with altered metabolism and in a negative oxygen balance. Muscle oxygenation was insufficient during anaesthesia in both groups, although to a lesser extent in the healthy horses. The post-anaesthetic period was associated with increased lipolysis and weight loss in the colic horses, indicating a negative energy balance during the first week post-operatively.
Asunto(s)
Anestesia/veterinaria , Cólico/veterinaria , Enfermedades de los Caballos/metabolismo , Caballos/fisiología , Músculo Esquelético/metabolismo , Animales , Análisis Químico de la Sangre/veterinaria , Análisis de los Gases de la Sangre/veterinaria , Cólico/metabolismo , Cólico/cirugía , Femenino , Enfermedades de los Caballos/cirugía , Masculino , Oxígeno/metabolismo , Estudios ProspectivosRESUMEN
OBJECTIVE: To investigate effects of carprofen on indices of renal function and results of serum bio-chemical analyses and effects on cardiovascular variables during medetomidine-propofol-isoflurane anesthesia in dogs. ANIMALS: 8 healthy male Beagles. PROCEDURES: A randomized crossover study was conducted with treatments including saline (0.9% NaCl) solution (0.08 mL/kg) and carprofen (4 mg/kg) administered IV. Saline solution or carprofen was administered 30 minutes before induction of anesthesia and immediately before administration of medetomidine (20 microg/kg, IM). Anesthesia was induced with propofol and maintained with inspired isoflurane in oxygen. Blood gas concentrations and ventilation were measured. Cardiovascular variables were continuously monitored via pulse contour cardiac output (CO) measurement. Renal function was assessed via glomerular filtration rate (GFR), renal blood flow (RBF), scintigraphy, serum biochemical analyses, urinalysis, and continuous CO measurements. Hematologic analysis was performed. RESULTS: Values did not differ significantly between the carprofen and saline solution groups. For both treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses; a transient, significant increase in urine alkaline phosphatase activity; and blood flow diversion to the kidneys. The GFR increased significantly in both groups despite decreased CO, mean arterial pressure, and absolute RBF variables during anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen administered IV before anesthesia did not cause detectable, significant adverse effects on renal function during medetomidine-propofol-isoflurane anesthesia in healthy Beagles.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Carbazoles/farmacología , Perros/fisiología , Riñón/efectos de los fármacos , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/farmacología , Anestésicos por Inhalación/administración & dosificación , Anestésicos por Inhalación/farmacología , Anestésicos Intravenosos/administración & dosificación , Anestésicos Intravenosos/farmacología , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Análisis de los Gases de la Sangre/veterinaria , Carbazoles/administración & dosificación , Sistema Cardiovascular/efectos de los fármacos , Creatinina/sangre , Creatinina/orina , Estudios Cruzados , Tasa de Filtración Glomerular/efectos de los fármacos , Isoflurano/administración & dosificación , Isoflurano/farmacología , Riñón/fisiología , Masculino , Medetomidina/administración & dosificación , Medetomidina/farmacología , Propofol/administración & dosificación , Propofol/farmacología , Respiración/efectos de los fármacos , Factores de TiempoRESUMEN
OBJECTIVE: To investigate effects of IV administered carprofen on indices of renal function and results of serum biochemical and hematologic analyses in dogs anesthetized with acepromazine-thiopentone-isoflurane that had low blood pressure during anesthesia. ANIMALS: 6 healthy Beagles. PROCEDURE: A randomized crossover study was conducted, using the following treatments: saline (0.9% NaCl solution)-saline, saline-carprofen, and carprofen-saline. Saline (0.08 ml/kg) and carprofen (4 mg/kg) were administered IV. The first treatment was administered 30 minutes before induction of anesthesia and immediately before administration of acepromazine (0.1 mg/kg, IM). Anesthesia was induced with thiopentone (25 mg/ml, IV) and maintained with inspired isoflurane (2% in oxygen). The second treatment was administered 30 minutes after onset of inhalation anesthesia. Blood gases, circulation, and ventilation were monitored. Renal function was assessed by glomerular filtration rate (GFR), using scintigraphy, serum biochemical analyses, and urinalysis. Hematologic analysis was performed. Statistical analysis was conducted, using ANOVA or Friedman ANOVA. RESULTS: Values did not differ significantly among the 3 treatments. For all treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses, a decrease in mean arterial blood pressure to 65 mm Hg, an increase of 115 pmol/L in angiotensin II concentration, and an increase of 100 seconds in time required to reach maximum activity counts during scintigraphy. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen administered IV before or during anesthesia did not cause detectable significant adverse effects on renal function or results of serum biochemical and hematologic analyses in healthy Beagles with low blood pressure during anesthesia.