- 學位論文
評估經鼻腔給予Dexmedetomidine作為犬 CT及 MRI檢查麻醉前給藥的實用性
Evaluation the Practicality of Intranasal Administration of Dexmedetomidine for Premedication before CT and MRI Examination
摘要
動物在進行磁振造影掃描(MRI)與電腦斷層掃描(CT)檢查時大多需要在麻醉下進行，若動物有腦部疾病、高腦壓、低體溫或是低血壓時，會增加麻醉的風險。文獻指出經鼻腔給予Dexmedetomidine時，可降低對心血管的影響，並改善低體溫或血壓過低的情況。因此本實驗目的為評估經鼻腔給予Dexmedetomidine作為MRI與CT檢查前鎮靜投藥的實用性。研究分成三部分：第一部分為評估經鼻給予125 µg/m2、375 µg/m2的Dexmedetomidine對犬隻的影響，並確認作為後續實驗的適合劑量；第二部分為比較臨床上進行CT檢查時，經鼻腔給予Dexmedetomidine作為麻醉前給藥時，對生理數值的影響；第三部分，評估患有腦部及脊髓疾患的犬隻進行MRI檢查時，經鼻腔給予Dexmedetomidine作為麻醉前給藥對生理數值的影響。結果顯示Dexmedetomidine以125 µg/m2和375 µg/m2投予時的鎮靜效果類似，但較少的藥物體積在操作上較為方便；經鼻腔給予Dexmedetomidine作為麻醉前給藥的犬隻，進行CT、MRI檢查時血壓較穩定，可減少心跳過低的發生率，且可減少對腦部疾患的犬隻在進行MRI拍攝時的體溫下降。本研究認為鼻腔注射125 µg/m2的Dexmedetomidine適合作為進行CT及MRI檢查時的麻醉前給藥。
並列摘要
Anesthesia is commonly required for companion animals during examination of magnetic resonance imaging (MRI) and computed tomography (CT). However, the intracranial disease, higher intracranial pressure, hypotension and hypothermia may increase the risk of anesthesia. Previous studies showed the intranasal administration of dexmedetomidine could improve hypothermia, hypotension and reduce adverse effects on cardiovascular function. The aim of this study is to evaluate the practicality of intranasal administration of Dexmedetomidine as premedication before MRI and CT examination. First, evaluating the effects by intranasal administration of dexmedetomidine at 125 µg/m2 or 375 µg/m2 on dogs. Then, the optimal dose for the following studies was decided. Second, the variation of physiological parameters by using intranasal administration of dexmedetomidine as sole premedication agent was evaluated on dogs during CT examination. Third, the dogs with symptoms which were associated to brain or spinal abnormalities and undergone MRI examination were enrolled and grouped. The variation of physiological parameters by using intranasal administration of dexmedetomidine as sole premedication agent during the procedure was also evaluated. The results indicated that the dose at 125 µg/m2 could provide similar sedative effects as 375 µg/m2 , and the less volume for injection brought the advantages in consistent results and restraint of dogs. Moreover, intranasal 125 µg/m2 dexmedetomidine produced more stable blood pressure with less bradycardia episodes during CT/MRI examination. It also reduced the decline of body temperature in dogs with symptoms of brain during MRI examination. In conclusion, the intranasal administration of dexmedetomidine at 125 µg/m2 is practical for premedication before CT and MRI examination.