Effects of Medetomidine and Tramadol Administration on the Minimum Alveolar Concentration of Isoflurane in Dogs

Abstract

This study was to evaluate the effects of tramadol and medetomidine administration on minimum alveolar concentration (MAC) of isoflurane in dogs. MAC of isoflurane was determined in four occasions; 1 ml saline (Control), 2 μg/kg medetomidine (M2), 4 mg/kg tramadol (T4), 2 μg/kg medetomidine - 4 mg/kg tramadol combination(M2T4). Heart rate, blood pressure, respiratory rate, end-tidal carbon dioxide concentration, saturation of hemoglobin with oxygen and body temperature were recorded. After administration of M2 (0.81 ± 0.18%), T4 (0.81 ± 0.14%) and M2T4 (0.62 ± 0.12%), less isoflurane was required than the control value (1.13 ± 0.19%). Significantly lower heart rate than the control value was detected after treatment of M2, T4, and M2T4. When only M2T4 was administered, blood pressure was significantly higher than the control value. Administration of tramadol, medetomidine and medetomidine-tramadol combination decreased the MAC of isoflurane in dogs.

본 연구는 tramadol과 medetomidine이 개에서 isoflurane의 최소폐포농도에 미치는 영향에 대해 알아보고자 하였다. Isoflurane의 최소폐포농도는 1ml의 생리식염수(control), 2 μg/kg의 medetomidine (M2), 4 mg/kg의 tramadol (T4), 2 μg/kg medetomidine과 4 mg/kg tramadol (M2T4)의 투여 네 가지 경우에 따라 측정되었다. 실험 중 심박수, 혈압, 호흡수, 호기말 이산화탄소분압, 혈중산소포화도, 체온을 측정하였다. M2, T4, M2T4 투여 후 isoflurane의 최소폐포농도는 각각 0.81 ± 0.17%, 0.81 ± 0.14%, 0.62 ± 0.13%로 대조군1.13 ± 0.19% 에 비해서 낮았다. 심박수는 M2, T4, M2T4 투여 시 낮았고 혈압은 M2T4투여 시에만 유의적으로 높았다. Tramadol 과 medetomidine의 투여 및 두 약물의 혼합투여는 isoflurane의 최소폐포농도를 유의적으로 낮추었다.