Killian K J, Mahutte C K, Howell J B, Campbell E J
J Appl Physiol Respir Environ Exerc Physiol. 1980 Dec;49(6):958-63. doi: 10.1152/jappl.1980.49.6.958.
The acuity of resistive load detection (RLD) has been tested by comparing threshold detection (delta R50) under control conditions with that obtained when loads were applied at different times in inspiration, with different inspiratory flows, at different lung volumes, and with different background loads. For loads applied suddenly during established inspiratory flow, the mean delta R50 was 0.94 +/- 0.04 (+/- SEE) cmH2O . 1(-1) . s compared with 0.42 +/- 0.13 cmH2O . 1(-1) . s (P < 0.01) for loads applied before inspiration, suggesting that information generated early in the breath is important and the RLD is not subserved by a simple peripheral proprioceptive mechanism. Rapid voluntary inspiration through nonlinear resistances did not improve RLD (mean delta R50 0.86 cmH2O . 1(-1) . s compared with a control of 0.56 cmH2O . 1(-1) . s; P < 0.05) despite the much greater pressures and resistances at high flow rates, further suggesting that detection of a resistive load occurs early in inspiration. Alteration of the background load by breathing at increased lung volume (1 liter above FRC) or by breathing against a standing pressure of 1 or 3 cmH2O (i.e., pressure independent of volume or flow) did not significantly reduce RLD. This suggests that the change in pressure due to the added load, expressed as a fraction of the total driving pressure, cannot subserve RLD. Our results suggest that external resistive load detection is subserved by the relation between pressure and flow over the early part of inspiration.
通过比较对照条件下的阈值检测（δR50）与在吸气不同时间、不同吸气流速、不同肺容积以及不同背景负荷下施加负荷时获得的阈值检测，对电阻性负荷检测（RLD）的敏锐度进行了测试。对于在既定吸气流速期间突然施加的负荷，平均δR50为0.94±0.04（±标准误）cmH2O·L⁻¹·s，而对于在吸气前施加的负荷，平均δR50为0.42±0.13 cmH2O·L⁻¹·s（P<0.01），这表明呼吸早期产生的信息很重要，并且RLD不是由简单的外周本体感受机制所支持。通过非线性阻力进行快速自主吸气并没有改善RLD（平均δR50为0.86 cmH2O·L⁻¹·s，而对照为0.56 cmH2O·L⁻¹·s；P<0.05），尽管在高流速时压力和阻力要大得多，这进一步表明对电阻性负荷的检测发生在吸气早期。通过在增加的肺容积（高于功能残气量1升）下呼吸或通过对抗1或3 cmH2O的恒定压力（即与容积或流量无关的压力）呼吸来改变背景负荷，并没有显著降低RLD。这表明由于附加负荷导致的压力变化，以总驱动压力的分数表示，不能支持RLD。我们的结果表明，外部电阻性负荷检测是由吸气早期压力与流量之间的关系所支持的。
