β-endorphin immunoreactivity during anaesthesia in equidae

Objective To determine the effects of surgery, hypoxia, hypercapnia and flunixin administration on plasma β‐endorphin immunoreactivity (BEI) in anaesthetized horses. Study design Prospective crossover study. Animals Six healthy adult Welsh Mountain ponies and seven healthy adult Thoroughbreds. Methods Ponies were anaesthetized with thiopentone and halothane or with pentobarbitone and the horses with guaiphenesin, thiopentone and halothane. Ponies were anaesthetized for 2 hours and on separate occasions underwent a period of hypoxia, hypercapnia, anaesthesia only, or were given flunixin at induction. The horses were anaesthetized for 2 hours and on separate occasions underwent surgery to relocate one carotid artery subcutaneously or anaesthesia only. Plasma samples were taken pre‐anaesthesia, at 20 minute intervals during, and after anaesthesia for BEI assay using radio‐immunoassay. Analysis of variance of the concentration‐time curve was used for statistical analysis. Results Pre‐anaesthetic β‐endorphin immunoreactivity (BEI) values ranged between 5.7 and 20.4 pmol L^?1. Induction of anaesthesia caused a five to 10 fold increase in mean plasma BEI in all cases except the hypercapnia group. Halothane anaesthesia increased BEI in ponies and horses but there were no significant changes during pentobarbitone anaesthesia. The increase in BEI in the hypoxic group was greater (peak value 136.8 ± 32.2 pmol L^?1) and sustained for a longer period compared with levels in those given halothane alone or in those which became hypercapnic. There was marked individual variation in the flunixin group and changes were not significant. Surgery in the horses resulted in the highest peak values in the study (182.5 ± 153.0 pmol L^?1) but the AUC was not significantly higher than in the same animals without surgery, where the peak value was 102.9 ± 42.1 pmol L^?1. Conclusions Beta‐endorphin appeared to be a sensitive marker of an endocrine stress response but its physiological role during equine anaesthesia is unknown. Clinical relevance Unknown.     

Propofol and fentanyl infusions in dogs of various breeds undergoing surgery

ObjectiveTo report the cardiovascular variables, anaesthetic effects and recovery quality of an anaesthesia technique using variable rate infusion propofol combined with constant rate infusion fentanyl in dogs undergoing elective surgery.Study designProspective clinical trial.AnimalsA total of 27 dogs, aged 2.7 ± 2.65 years and weighing 24 ± 11 kg.MethodsFollowing intramuscular acepromazine (0.03 or 0.05 mg kg^?1) and subcutaneous carprofen (4 mg kg^?1) pre-medication, anaesthesia was induced with propofol (4.0 ± 0.5 mg kg^?1) intravenously (IV). All dogs were ventilated with 100% oxygen to maintain normocapnia. Propofol was infused at 0.4 mg kg^?1 minute^?1 for 20 minutes and then at 0.3 mg kg^?1minute^?1. If mean arterial blood pressure (MAP) decreased below 70 mmHg, propofol infusion was reduced by 0.1 mg kg^?1 minute^?1. Five minutes after induction of anaesthesia, fentanyl was administered (2 μg kg^?1) IV followed by the infusion at 0.5 μg kg^?1 minute^?1 and atropine (40 μg kg^?1) IV. Heart rate, MAP, respiratory rate, tidal volume, end-tidal carbon dioxide, presence of reflexes, movements and recovery times and quality were recorded.ResultsMean anaesthetic duration was 131 ± 38.5 minutes. Mean heart rate peaked 10 minutes after atropine injection and gradually declined, reaching pre-anaesthetic values at 55 minutes. MAP easily was maintained above 70 mmHg. Mean times to return of spontaneous ventilation, extubation, head lift and sternal recumbency were 21 ± 10.1, 33 ± 14.6, 43 ± 19.7 and 65 ± 23.4 minutes, respectively. Recovery was smooth and quiet. The time to sternal recumbency was significantly correlated with the duration of anaesthesia and total dose of propofol; time to extubation was correlated to total dose of propofol.Conclusion and clinical relevancePropofol and fentanyl infusions provided stable cardiovascular function and satisfactory conditions for surgery. Some modifications of infusion rates are required to improve the long-recovery times.     

Isoflurane Anesthesia for Equine Colic Surgery Comparison with Halothane Anesthesia

Isoflurane was compared with halothane as an anesthetic agent for emergency colic surgery in a series of 38 juvenile and adult horses. After presurgical stabilization with fluids and supportive medications, anesthesia was induced by intravenous xylazine and/or diazepam followed by ketamine. Anesthesia was maintained with isoflurane or halothane in oxygen with controlled ventilation. Heart rates (HR), arterial blood gases, mean arterial pressures (MAP), rate pressure products (RPP), requirements for cardiovascular support medications, and recovery times to standing were compared using nonparametric methods. Cardiopulmonary responses to isoflurane and halothane anesthesia were generally comparable although some temporal differences were observed. Higher HR (p less than 0.02) and lower PaCO2 levels (p less than 0.01) were identified during the course of isoflurane anesthesia. Recovery times to standing were significantly shorter (0.02 less than p less than 0.05) after isoflurane than halothane anesthesia.     

Candida albicans peritonitis in a dog

Objective – To describe the clinical management of a case of Candida albicans peritonitis in a dog and discuss the pathogenicity of Candida peritonitis along with treatment using the fungistatic agent, fluconazole.
Case Summary – A 15-week-old Papillon developed peritonitis secondary to enterectomy site dehiscence. A pure growth of Candida albicans was obtained from the abdominal fluid. Surgical repair of the dehiscence was performed and antifungal therapy instituted with fluconazole postoperatively. A marked exudative process was noted postoperatively with production of large volumes of fluid from the abdominal drain. Fresh frozen plasma and pentastarch were provided for oncotic support. Recovery was complicated by megaesophagus, however, the patient gradually improved and was discharged 11 days after surgery.
New or Unique Information Provided – To our knowledge, this is the first case report of successful treatment of Candida albicans peritonitis in a dog. A marked exudative process was noted during therapy requiring significant oncotic support. Resolution of the disease process was achieved with surgical intervention and antifungal therapy.