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

用呼吸阻力(RRS)和解剖死腔(VDAN)同时测定6例正常人和13例哮喘患者的乙酰甲胆碱的剂量-反应曲线。在潮气呼吸中持续吸入浓度递增的乙酰甲胆碱，直到观察到呼吸阻力(RRS)增加近两倍。大气道反应用VOAN测定，总气道反应用RRS测定。当Vdan下降较轻时，从RRS可推断出小气道反应。呼吸阻力测定采用5-HZ振荡技术，DAN测定采用兰利法(14)，分别用CO_2和试验气体，同时记录呼吸。在正常受试者中，Vdan下降28(+-)7%，RRS同时增加100%，提示有较大的呼吸道反应者。5例哮喘患者为大气道反应者，与正常对照组相似，但8例哮喘患者Vdan下降或减少100%，而RRS增加100%，提示RRS增加是由于小气道阻力(小气道反应者)增加。在哮喘受试者中，小气道反应者比大气道反应者表现出更多的过敏反应(P&lt；0.01)。这些结果提示，气道反应的部位是支气管过敏的决定因素之一。

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