Monteiro Eduardo R, Teixeira-Neto Francisco J, Campagnol Daniela, Alvaides Renata K, Garofalo Natache A, Matsubara Lídia M
Faculdade de Medicina, UNESP -Universidade Estadual Paulista, Campus de Botucatu, Botucatu, SP, Brazil.
Am J Vet Res. 2010 Feb;71(2):150-6. doi: 10.2460/ajvr.71.2.150.
To evaluate the effects of remifentanil on isoflurane minimum alveolar concentration (ISO(MAC)) in dogs.
6 adult mixed-breed dogs.
Dogs were anesthetized with isoflurane on 2 occasions. During the first set of experiments, ISO(MAC) was determined before remifentanil infusion (baseline), during constant rate infusion (CRI) of remifentanil (0.15, 0.30, 0.60, and 0.90 microg/kg/min), and 80 minutes after remifentanil infusion. After a 1-week washout period, dogs received a CRI of remifentanil (0.15 microg/kg/min) and ISO(MAC) was redetermined 2, 4, and 6 hours after commencing the infusion.
Mean +/- SD baseline ISO(MAC) was 1.24 +/- 0.18%. Remifentanil infusion (0.15, 0.30, 0.60, and 0.90 microg/kg/min) decreased ISO(MAC) by 43 +/- 10%, 59 +/- 10%, 66 +/- 9%, and 71 +/- 9%, respectively. The ISO(MAC) values determined during the 0.30, 0.60, and 0.90 microg/kg/min infusion rates did not differ from each other, but these values were significantly lower, compared with the 0.15 microg/kg/min infusion rate. The ISO(MAC) recorded after remifentanil infusion (1.09 +/- 0.18%) did not differ from baseline ISO(MAC). There was no change in ISO(MAC) throughout the 6-hour period of a CRI of remifentanil.
Remifentanil decreased ISO(MAC) in a dose-related fashion; the reduction in ISO(MAC) was stable over the course of a prolonged CRI (6 hours). A dose of 0.30 microg of remifentanil/kg/min resulted in nearly maximal isoflurane-sparing effect in dogs; a ceiling effect was observed at higher infusion rates.
评估瑞芬太尼对犬异氟烷最低肺泡有效浓度（ISO(MAC)）的影响。
6只成年杂种犬。
犬只接受两次异氟烷麻醉。在第一组实验中，在输注瑞芬太尼前（基线）、瑞芬太尼恒速输注期间（0.15、0.30、0.60和0.90微克/千克/分钟）以及瑞芬太尼输注后80分钟测定ISO(MAC)。经过1周的洗脱期后，犬只接受瑞芬太尼恒速输注（0.15微克/千克/分钟），并在开始输注后2、4和6小时重新测定ISO(MAC)。
平均±标准差基线ISO(MAC)为1.24±0.18%。瑞芬太尼输注（0.15、0.30、0.60和0.90微克/千克/分钟）分别使ISO(MAC)降低43±10%、59±10%、66±9%和71±9%。在0.30、0.60和0.90微克/千克/分钟输注速率期间测定的ISO(MAC)值彼此无差异，但与0.15微克/千克/分钟输注速率相比，这些值显著更低。瑞芬太尼输注后记录的ISO(MAC)（1.09±0.18%）与基线ISO(MAC)无差异。在瑞芬太尼恒速输注的6小时期间，ISO(MAC)没有变化。
瑞芬太尼以剂量相关方式降低ISO(MAC)；在延长的恒速输注（6小时）过程中，ISO(MAC)的降低是稳定的。瑞芬太尼剂量为0.30微克/千克/分钟时，犬只异氟烷节省效应接近最大；在更高输注速率下观察到封顶效应。
