吸入麻醉药相对丙泊酚在自主呼吸下能更大程度地维持潮气量和每分通气量

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吸入麻醉药相对丙泊酚在自主呼吸下能更大程度地维持潮气量和每分通气量

贵州医科大学 麻醉与心脏电生理课题组

翻译：张中伟   编辑：潘志军   审校：曹莹

1   .   背景  

虽然已知全身麻醉可对自主呼吸产生抑制，但全身麻醉对呼吸功能的综合影响尚不清楚。本研究的目的是探讨不同类型和药物剂量的全麻方式对非插管小鼠自主呼吸的影响。

2   .   方法  

成年C57BL/ 6J小鼠分别给予丙泊酚、依托咪酯等静脉麻醉药和七氟烷、异氟烷等吸入麻醉药，吸入麻醉药剂量分别为最低肺泡有效浓度(MAC)/中位有效剂量(ED50)的0.5、1.0、2.0倍，以诱导小鼠复位反射消失(LORR)。采用全身体积描记系统(WBP)测量非插管小鼠的呼吸参数。同时测定了全身麻醉下小鼠的呼吸道对二氧化碳(CO2)的敏感性变化。在麻醉过程中连续记录以下呼吸参数:呼吸频率(FR)、潮气量(TV)、每分通气量(MV)、呼气时间(TE)、吸气时间(TI)、吸气-呼气时间比(I/E)和吸气峰值流量。

3   .   结果  

七氟烷或异氟烷在0.5 MAC下可使FR、TV和MV增加。在吸入异氟烷或七氟烷时，呼吸道对CO2的敏感性降低，FR、TV和MV的升高幅度降低。与吸入麻醉药相比，丙泊酚和依托咪酯更易引起呼吸抑制，影响FR、TV和MV。在100%氧气(O2)条件下，丙泊酚在1.0倍中位有效剂量（ED50）的FR为69.63±33.44次/min，依托咪酯组为155.68±64.42次/min。在3% CO2条件下，FR分别为88.72±34.51次/min和225.10±59.82次/min;在5% CO2条件下，FR分别为144.17±63.25次/min和197.70±41.93次/min。与丙泊酚处理的小鼠相比，依托咪酯处理的小鼠对二氧化碳的敏感性更高。此外，与依托咪酯、七氟烷和异氟烷相比，丙泊酚组小鼠的FR、MV和I/E均显著降低(P < 0.05)。

4   .   结论  

全身麻醉药在体内对自主呼吸有不同的调节作用。吸入麻醉药在较低浓度下增加FR、TV和MV，而在较高浓度下降低FR。丙泊酚比依托咪酯在更大程度上持续抑制呼吸。

原始文献来源

Xuechao Hao, Mengchan Ou, Cheng Zhou, et al. Volatile anesthetics maintain tidal volume and minute ventilation to a greater degree than propofol under spontaneous respiration.[J]. BMC Anesthesiol(2021) 21:238:1

  英文原文

Volatile anesthetics maintain tidal volume and minute ventilation to a greater degree than propofol under spontaneous respiration

Abstract

Background:Although general anesthetics depress spontaneous respiration, the comprehensive effect of general anesthetics on respiratory function remains unclear. We aimed to investigate the effects of general anesthetics on spontaneous respiration in non-intubated mice with different types and doses of general anesthetic.

Method:Adult C57BL/6 J mice were administered intravenous anesthetics, including propofol and etomidate, and inhalational anesthetics, including sevoflurane and isoflurane in vivo at doses of 0.5-, 1.0-, and 2.0-times the minimum alveolar concentration (MAC)/median effective dose  (ED50) to induce loss of the righting reflex (LORR). Whole-body plethysmography (WBP) was applied to measure parameters of respiration under unrestricted conditions without endotracheal intubation. The alteration in respiratory sensitivity to carbon dioxide  (CO2) under general anesthesia was also determined. The following respiratory parameters were continuously recorded during anesthesia or  CO2 exposure: respiratory frequency (FR), tidal volume (TV), minute ventilation (MV), expiratory time (TE), inspiratory time (TI), and inspiratory–expiratory time ratio (I/E), and peak inspiratory flow.

Results:Sub-anesthetic concentrations (0.5 MAC) of sevoflurane or isoflurane increased FR, TV, and MV. With isoflurane and sevoflurane exposure, the  CO2-evoked increases in FR, TV, and MV were decreased. Compared with

inhalational anesthetics, propofol and etomidate induced respiratory suppression, affecting FR, TV, and MV. In 100% oxygen  (O2), FR in the group that received propofol 1.0-times the ED50 was 69.63 ± 33.44 breaths/min compared with 155.68 ± 64.42 breaths/min in the etomidate-treated group. In the same groups, FR was 88.72 ± 34.51 breaths/min and 225.10 ± 59.82 breaths/min, respectively, in 3% CO2 and 144.17 ± 63.25 breaths/min and 197.70 ± 41.93 breaths/min, respectively, in 5% CO2. A higher CO2 sensitivity was found in etomidate-treated mice compared with propofol-treated mice. In addition, propofol induced a greater decrease in FR, MV, and I/E ratio compared with etomidate, sevoflurane, and isoflurane at equivalent doses (all P < 0.05).

Conclusion:General anesthetics differentially modulate spontaneous breathing in vivo. Volatile anesthetics increase FR, TV, and MV at sub-anesthetic concentrations, while they decrease FR at higher concentrations. Propofol consistently depressed respiratory parameters to a greater degree than etomidate.