BACKGROUND The aim of the present study was to investigate pulmonary stretch receptor activity (PSR) under different peak inspiratory pressures (PIPs) and inspiratory pressure waveforms during partial liquid (PLV) and gas ventilation (GV). METHODS PSR instantaneous impulse frequency (PSRfimp) was recorded from single fibers in the vagal nerve during PLV and GV in young cats. PIPs were set at 1.2/1.8/2.2/2.7 kPa, and square and sinusoidal pressure waveforms were applied. RESULTS PSRfimp at the start of inspiration increased with increasing PIPs, and was steeper and higher with square than with sinusoidal waveforms (p < 0.05). Total number of impulses, peak and mean PSRfimp were lower during PLV than GV at the lowest and highest PIPs (p < 0.025). Time to peak PSRfimp was shorter with square than with sinusoidal waveforms at all pressures and ventilations (p < 0.005). Irrespective of waveform, lower PIPs yielded lower ventilation during PLV. CONCLUSION As assessed by PSRfimp, increased PIPs do not expose the lungs to more stretching during PLV than during GV, with only minor differences between square and sinusoidal waveforms.

中文翻译：

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不同压力波形的部分液体通气过程中肺牵张感受器的活动。

背景本研究的目的是研究在部分液体 (PLV) 和气体通气 (GV) 期间不同吸气峰压 (PIP) 和吸气压力波形下的肺牵张受体活性 (PSR)。方法 在幼猫的 PLV 和 GV 期间，从迷走神经中的单纤维记录 PSR 瞬时脉冲频率 (PSRfimp)。PIP 设置为 1.2/1.8/2.2/2.7 kPa，并应​​用方波和正弦压力波形。结果 吸气开始时的 PSRfimp 随着 PIP 的增加而增加，并且比正弦波形更陡峭和更高（p < 0.05）。PLV 期间脉冲总数、峰值和平均 PSRfimp 低于最低和最高 PIP 的 GV（p < 0.025）。在所有压力和通气条件下，方波 PSRfimp 达到峰值的时间比正弦波形短（p < 0.005）。不管波形如何，在 PLV 期间，较低的 PIP 会产生较低的通气量。结论 正如 PSRfimp 评估的那样，与 GV 相比，在 PLV 期间增加的 PIP 不会使肺部受到更多的拉伸，方波和正弦波形之间只有很小的差异。