Zhang X-J, Yu G, Wen X-H, Lin Z-C, Yang F-Q, Zheng Z-G, Chen R-C, Zhong N-S
Department of Anaesthesiology, First Affiliated Hospital of Guangzhou Medical College, No. 151 Yanjiangxi Road, Guangzhou 510120, China.
Br J Anaesth. 2009 Jan;102(1):61-4. doi: 10.1093/bja/aen327. Epub 2008 Nov 19.
Several studies have demonstrated the inhibitory effect of propofol on diaphragmatic contractility in laboratory animals, but there have been few studies in humans. We have investigated the effect of a single bolus injection of propofol on twitch diaphragmatic pressure (TwPdi) evoked by cervical supramaximal magnetic stimulation, and its impact on diaphragmatic contractility.
In 16 patients scheduled for elective operation, TwPdi was evoked bilaterally at the cervical phrenic nerves with supramaximal magnetic stimulations using a 140 mm diameter magnetic coil. Changes of TwPdi were monitored dynamically before and during general anaesthesia induced by single bolus of propofol 2 mg kg (-1). During the study, all patients breathed 100% oxygen by a face mask, maintaining Sp(O(2)) > or = 99% and PE'(CO(2)) 4.6-5.2 kPa.
TwPdi declined after administration of propofol with gradual recovery. Compared with baseline [20.6 (6.0) cm H(2)O], TwPdi decreased by 23.3% (P<0.001) to [15.8 (6.4) cm H(2)O]. When the patients regained awareness, TwPdi returned to [19.1 (6.1) cm H(2)O], close to baseline (P=0.063). The time from starting the propofol infusion to the lowest TwPdi was [240 (86) s]. Total time course of stimulation lasted [363 (89) s].
A single bolus propofol depressed TwPdi evoked by cervical magnetic stimulation, demonstrating inhibitory effects of propofol on diaphragmatic contractility in patients during general anaesthesia.
多项研究已证实丙泊酚对实验动物膈肌收缩力有抑制作用，但针对人类的研究较少。我们研究了单次静脉推注丙泊酚对颈段超强磁刺激诱发的膈肌抽搐压力（TwPdi）的影响及其对膈肌收缩力的作用。
16例择期手术患者，使用直径140mm的磁线圈经颈段膈神经进行双侧超强磁刺激诱发TwPdi。在单次静脉推注2mg/kg丙泊酚诱导全身麻醉前及麻醉期间动态监测TwPdi的变化。研究期间，所有患者通过面罩吸入100%氧气，维持脉搏血氧饱和度（Sp(O₂)）≥99%，呼气末二氧化碳分压（PE'(CO₂)）4.6 - 5.2kPa。
丙泊酚给药后TwPdi下降并逐渐恢复。与基线值[20.6(6.0)cmH₂O]相比，TwPdi下降了23.3%（P<0.001）至[15.8(6.4)cmH₂O]。患者意识恢复时，TwPdi恢复至[19.1(6.1)cmH₂O]，接近基线值（P = 0.063）。从开始输注丙泊酚至TwPdi最低值的时间为[240(86)s]。刺激的总时长为[363(89)s]。
单次静脉推注丙泊酚可降低颈段磁刺激诱发的TwPdi，表明丙泊酚在全身麻醉期间对患者膈肌收缩力有抑制作用。
