Evaluation Of The Anesthetic Effects Of Fentanyl,Ketamine,xylazole As Induction Anesthesia Used In Combination With Intravenous Emulsified Sevoflurane In Ponies

Along with the development of the equine industry,china's equestrian sports have been receiving great attention while there has also been an increasing number of equines in local zoos.Toda y,the modern equine industry and the utilization of equine animals are surpassing that of traditional industry.Additionally,the life span of equine species is quite long and these animals are prone to developing various diseases.Veterinarians are often presented with a number of cases requiring surgical procedures in equine such as castration,wound management,alimentary tract conjunctiva and other traumas.Horses are quite susceptible to pain and in most cases local anesthesia may prove to be inadequa te therefore necessitating general anesthesia.Inhalation anesthesia is the most frequently used method however,it ma y not be suitable for use in horses and other large wild animals undergoing surgical procedures under field condition.Halothane,sevoflur ane,and isoflurane have been popular inhalation agents used in both human and veterinary medicine as these drugs are considered safe,reliable and has minimal inhibition on cardiopulmonary function.In large animal anesthesia access to expensive equipment for providing inhalational anesthesia may be a challenge therefore the development of a method of anesthesia which would enable for the administration of inhalational drugs directly in the bloodstream enabling for an adequate depth of anesthesia seem to b e innovative and realistic.Moreover,the anesthetic depth and time can be easily controlled.The intravenous delivery of emulsified inhalational agents may not only allow for more desirable control of anesthesia depth and time but can also be an ideal substitute for inhalational delivery.The aim of this experiment was to assess and select a suitable combination of anesthetic agents that would facilitate approaching and handling of ponies to further allow for administering intravenous delivery of emulsifie d sevoflurane.To select a safe and satisfactory method of anesthesia for ponies which could also be used as a reference for other equine and large animals including zebra and donkeys.Five ponies were injected intramuscularly with a combination of Fentanyl?0.2?g/kg,weishun Chemical Co.Ltd China?,Ketamine?5mg/kg,Shenyang veterinary pharmaceuticals,China?,and Xylazole?34?g/kg,Heng Rui Pharmaceutical Co.Ltd,Jiangsu,China?,as induction anesthesia using a blow pipe.Anesthesia was maintained with emulsified sevoflurane for 1.5 hrs.Results showed that following administration of fentanyl,ketamine,xylazole?FKX?ponies achieved recumbency in 2.70±0.84 min and maintenance with sevoflurane?2.1m L/kg/h?provided adequate depth of anesthesia,muscle relaxation and sedation.Parameters tested during anesthesia included cardiopulmonary function,blood oxygen saturation,blood gas analysis,and biochemistry.Respiration rate?RR?decreased from 19.40±0.89 to13.40±1.67 beats/min,heart rate decr eased from 56.20±3.03 to 35.60±16 beats/min Results were considered extremely significant?P<0.01?.Systolic blood pressure decreased from136.20±6.65t o 119.00±12.06 mm Hg,diastolic blood pressure decreased from 93.20±3.70 to72.80±7.12 mm Hg,a significant decrease was observed in mean arterial blood pressure showing a decrease from 107.20±1.79 to 88.20±8.50?P<0.01?.Blood oxygen saturation?Sp O₂?decreased from 98.80±0.84 to 90.60±0.55,temperature decreased from 38.66±0.59to 37.56±0.30?C.ECG results showed that P,QRS,and T waves were visible.Following induction anesthesia there was a one-time inversion of the P wave,and a double peak was also seen in the T wave during sevoflurane maintenance.There were no significant changes in biochemistry parameters?BUN,AST,ALT,ALT,CREA?.Blood gas parameters?PH,PCO₂,HCO₃-,Na+,K+,Cl-?were within normal clinical range.There was an increase in ACTH and CGRP in a time dependent manner with concentration being the highest at 90 mi n timepoint.The peak serum PGE₂concentration was at the 60 min timepoint.The average time for recovery in all ponies was 4.80±2.49.Statistically significant changes were observed in physiological parameters during anesthetic monitoring.Conclusion:Fentanyl Ketamine Xylazole used in combination with emulsified sevoflurane maintenance produced satisfactory sedation,muscle relaxation and analgesia.This anesthetic protocol can be suitable for surgical procedures in ponies with adequate control of anesthetic depth and time.Changes in clinical parameters were within acceptable physiological range.