Simons Jeroen C P, Pierce Eric, Diaz-Gil Daniel, Malviya Sanjana A, Meyer Matthew J, Timm Fanny P, Stokholm Janne B, Rosow Carl E, Kacmarek Robert M, Eikermann Matthias
From the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (J.C.P.S., E.P., D.D.-.G., S.A.M., M.J.M., F.P.T., J.B.S., C.E.R., R.M.K., M.E.); Department of Orthopaedic and Trauma Surgery, University of Cologne, Cologne, Germany (J.C.P.S.); Department of Anesthesiology, University of Copenhagen, Herlev Hospital, Copenhagen, Denmark (J.B.S.); Department of Respiratory Care, Harvard Medical School, Boston, Massachusetts (R.M.K.); and Department of Anesthesia and Critical Care, University of Essen, Essen, Germany (M.E.).
Anesthesiology. 2016 Sep;125(3):525-34. doi: 10.1097/ALN.0000000000001225.
Volatile anesthetics and propofol impair upper airway stability and possibly respiratory upper airway dilator muscle activity. The magnitudes of these effects have not been compared at equivalent anesthetic doses. We hypothesized that upper airway closing pressure is less negative and genioglossus activity is lower during deep compared with shallow anesthesia.
In a randomized controlled crossover study of 12 volunteers, anesthesia with propofol or sevoflurane was titrated using a pain stimulus to identify the threshold for suppression of motor response to electrical stimulation. Measurements included bispectral index, genioglossus electromyography, ventilation, hypopharyngeal pressure, upper airway closing pressure, and change in end-expiratory lung volume during mask pressure drops.
A total of 393 attempted breaths during occlusion maneuvers were analyzed. Upper airway closing pressure was significantly less negative at deep versus shallow anesthesia (-10.8 ± 4.5 vs. -11.3 ± 4.4 cm H2O, respectively [mean ± SD]) and correlated with the bispectral index (P < 0.001), indicating a more collapsible airway at deep anesthesia. Respiratory genioglossus activity during airway occlusion was significantly lower at deep compared with light anesthesia (26 ± 21 vs. 35 ± 24% of maximal genioglossus activation, respectively; P < 0.001) and correlated with bispectral index (P < 0.001). Upper airway closing pressure and genioglossus activity during airway occlusion did not differ between sevoflurane and propofol anesthesia.
Propofol and sevoflurane anesthesia increased upper airway collapsibility in a dose-dependent fashion with no difference at equivalent anesthetic concentrations. These effects can in part be explained by a dose-dependent inhibiting effect of anesthetics on respiratory genioglossus activity.
挥发性麻醉剂和丙泊酚会损害上呼吸道稳定性，并可能影响呼吸道上气道扩张肌的活动。尚未在等效麻醉剂量下比较这些效应的大小。我们假设，与浅麻醉相比，深麻醉期间上气道闭合压的负值更小，颏舌肌活动更低。
在一项针对12名志愿者的随机对照交叉研究中，使用疼痛刺激来滴定丙泊酚或七氟烷麻醉，以确定抑制对电刺激的运动反应的阈值。测量指标包括脑电双频指数、颏舌肌肌电图、通气、下咽压力、上气道闭合压以及面罩压力下降期间呼气末肺容积的变化。
共分析了阻塞操作期间的393次尝试呼吸。深麻醉时上气道闭合压的负值明显小于浅麻醉时（分别为-10.8±4.5与-11.3±4.4 cm H₂O[均值±标准差]），且与脑电双频指数相关（P<0.001），表明深麻醉时气道更易塌陷。气道阻塞期间，深麻醉时呼吸颏舌肌活动明显低于浅麻醉时（分别为最大颏舌肌激活的26±21%与35±24%；P<0.001），且与脑电双频指数相关（P<0.001）。七氟烷和丙泊酚麻醉期间，气道阻塞时的上气道闭合压和颏舌肌活动无差异。
丙泊酚和七氟烷麻醉以剂量依赖方式增加上气道塌陷性，在等效麻醉浓度下无差异。这些效应部分可由麻醉剂对呼吸颏舌肌活动的剂量依赖性抑制作用来解释。
