Duke Tanya, Filzek Ulrike, Read Matthew R, Read Emma K, Ferguson James G
Department of Small Animal Clinical Studies, Western College of Veterinary Medicine, University of Saskatchewan, Saskatchewan, Canada.
Vet Anaesth Analg. 2006 Mar;33(2):122-7. doi: 10.1111/j.1467-2995.2005.00189.x.
During an 8-year period of clinic improvements, an increased incidence of postanesthetic myopathy (PAM) was observed in horses undergoing anesthesia. A request was made for an independent anesthesiologist to examine possible reasons for this increase. Routine methods used for anesthesia were then compared with new methods introduced by the anesthesiologist.
Investigative observations were conducted from October 1999 to April 2000. Following premedication with xylazine or detomidine, anesthesia was induced with diazepam or guiaifenesin followed by ketamine. Maintenance of anesthesia was with halothane/O(2) with mechanical ventilation. Information was gathered from observing routine anesthetics. Seventeen horses were designated group A (October-December 1999) for which hypotension was defined as mean arterial pressure (MAP) <60 mmHg and managed using low-volume crystalloid fluid therapy, etilefrine, or dopamine. In the next 18 horses (group B), hypotension was redefined as MAP <70 mmHg, and was managed using high-volume fluid therapy and dobutamine (January-April 2000). No other changes were made. In both groups, creatine kinase (CK) and aspartate transaminase (AST) concentrations were measured before induction, 1 and 25 hours after standing. Occurrence of PAM was defined as CK and/or AST concentrations above 1000 IU L(-1) and analyzed with Fisher's exact test between groups. Muscle enzymes increased in five horses in group A (two with clinical signs) and in one horse in group B (difference between groups: p = 0.088).
Maintaining MAP >70 mmHg with high-volume fluid therapy and dobutamine may help to reduce the severity of myopathy.
在为期8年的临床改进期间，观察到接受麻醉的马匹术后麻醉性肌病（PAM）的发病率有所增加。因此，邀请了一位独立的麻醉师来研究发病率增加的可能原因。随后，将常规麻醉方法与该麻醉师引入的新方法进行了比较。
研究观察于1999年10月至2000年4月进行。在使用赛拉嗪或地托咪定进行术前用药后，用安定或愈创甘油醚诱导麻醉，随后使用氯胺酮。使用氟烷/O₂并进行机械通气维持麻醉。通过观察常规麻醉收集信息。17匹马被指定为A组（1999年10月至12月），低血压定义为平均动脉压（MAP）<60 mmHg，并使用小容量晶体液疗法、依替福林或多巴胺进行处理。在接下来的18匹马（B组）中，低血压重新定义为MAP <70 mmHg，并使用大容量液体疗法和多巴酚丁胺进行处理（2000年1月至4月）。未进行其他更改。在两组中，分别在诱导前、站立后1小时和25小时测量肌酸激酶（CK）和天冬氨酸转氨酶（AST）浓度。PAM的发生定义为CK和/或AST浓度高于1000 IU L⁻¹，并在组间进行Fisher精确检验分析。A组有5匹马（2匹有临床症状）的肌肉酶升高，B组有1匹马的肌肉酶升高（两组间差异：p = 0.088）。
使用大容量液体疗法和多巴酚丁胺维持MAP >70 mmHg可能有助于降低肌病的严重程度。
