Ma D, Sapsed-Byrne S M, Chakrabarti M K, Whitwam J G
Department of Anaesthesia, Royal Postgraduate Medical School, Hammersmith Hospital, London.
Br J Anaesth. 1998 Jan;80(1):68-72. doi: 10.1093/bja/80.1.68.
Sevoflurane causes a decrease in mean arterial pressure (MAP). We have studied in anaesthetized rabbits its interactive effects on MAP, the autonomic nervous system and baroreflexes. During sevoflurane administration changes in renal sympathetic nerve activity (RSNA) and heart rate (HR) were observed: (1) when the normal decrease in MAP occurred; (2) when this was prevented by angiotensin II; (3) during a similar decrease in MAP induced by infusion of sodium nitroprusside (SNP) without sevoflurane administration; and (4) during pressor and depressor responses to phenylephrine and SNP. There was a reduction in MAP from 80 to 40 mm Hg after 1-4% sevoflurane without changes in HR, while RSNA remained unchanged only up to concentrations of 3% and was depressed by 37% (P < 0.05) with 4% sevoflurane. When MAP was maintained constant with angiotensin II, both HR and RSNA decreased, by 12% and 69%, respectively, after 4% sevoflurane (P < 0.05). A decrease in MAP of 40 mm Hg during infusion of SNP increased HR and RSNA by 22% (P < 0.05) and 150% (P < 0.01), respectively. At 2% sevoflurane, baroreflex sensitivity (i.e. delta RSNA/delta MAP and delta HR/delta MAP) was depressed by 36% and 57%, respectively, for the pressor effects of pherylephrine, and by 89% and 81%, respectively, for the depressor effects of SNP. We conclude that the baroreflexes continued to compensate for the effects of sevoflurane on sympathetic and cardiomotor activity with concentrations up to 3% and 4%, respectively.
七氟醚可导致平均动脉压（MAP）降低。我们在麻醉兔身上研究了其对MAP、自主神经系统和压力反射的相互作用。在给予七氟醚期间，观察到肾交感神经活动（RSNA）和心率（HR）的变化：（1）当MAP出现正常下降时；（2）当用血管紧张素II阻止这种下降时；（3）在输注硝普钠（SNP）诱导MAP出现类似下降且未给予七氟醚时；（4）在对去氧肾上腺素和SNP的升压和降压反应期间。给予1 - 4%七氟醚后，MAP从80降至40 mmHg，HR无变化，而RSNA仅在浓度达3%时保持不变，4%七氟醚时降低37%（P < 0.05）。当用血管紧张素II使MAP保持恒定时，给予4%七氟醚后，HR和RSNA分别下降12%和69%（P < 0.05）。输注SNP期间MAP下降40 mmHg时，HR和RSNA分别增加22%（P < 0.05）和150%（P < 0.01）。在2%七氟醚时，对于去氧肾上腺素的升压作用，压力反射敏感性（即ΔRSNA/ΔMAP和ΔHR/ΔMAP）分别降低36%和57%，对于SNP的降压作用分别降低89%和81%。我们得出结论，分别在浓度达3%和4%时，压力反射继续补偿七氟醚对交感神经和心脏运动活动的影响。
