Non invasive direct writing recorder of Larynageal, central and peripheral airway hypersensitivity.

同时测定6例正常人和13例哮喘患者的呼吸阻力（Rrs）和解剖死亡间隙（Vdan），观察其对甲胆碱的剂量-反应曲线。在潮汐呼吸时，持续吸入浓度逐步增加的甲胆碱，直到观察到呼吸阻力（Rrs）增加近两倍。大气道反应由Voan测定，气道总反应由Rrs测定。当Vdan下降轻微时，从Rrs推断气道反应较小。呼吸阻力采用5hz振荡法测量，呼吸阻力采用兰利法测量（14），呼吸阻力采用CO_2和测试气体同时测量。在正常受试者中，Vdan下降了28(+-)7%（平均（+-）SD）， Rrs同时增加了100%，提示气道反应大。5例哮喘患者的大气道反应与正常人相似，但8例哮喘患者的Vdan下降了100%或更少，而Rrs增加了100%，提示Rrs的增加是由于小气道阻力（小气道反应）的增加。在哮喘患者中，小气道应答者的超敏反应高于大气道应答者（P<0.01）。这些结果提示气道反应部位是支气管超敏反应的决定因素之一

We examined the dose-response curves to methacholine in 6 normal subjects and 13 asthmatics by simultaneous assessment of respiratory resistance (Rrs) and anatomic dead space (Vdan). Methacholine was continuously inhaled in stepwise inctemented concentrations furing tidal breathing until a nearly twofoldincrease in respitatory resistance (Rrs) was observed. Largeairway response was determined by Voan,and overall airway response was determined by Rrs. Small air-ways response was inferred from Rrs when the decrease Vdan was slight. Respiratory resistance was measured with the 5-Hz oscillation technique, and the Dan was measured by langley's method (14) With CO_2 ad the testgas, andboth were recorded simultaneously breath by breath. Im the normal subject Vdan decreased by 28 (+-)7%7Mean (+-)SD) and Rrs increased simultaneously by 100%, suggesting a large airways responder. Five asthmatics were large large airway responders in a manner similar to that of the notmal subjects, but in 8 asthmatics, Vdan decresed by 100% orless,whereas Rrs increased by 100%,suggesting that the increase in Rrs was due to an increase in small sirways resistance(small airways responder). In the asthmatic subjects, small airways responders showed more hypersensitivity than did large airways responders (P<0.01). These results suggest thet the site of airway response is one of the determining factors in bronchial hypersensitibity