Smith C M, Anderson S D
Dept of Thoracic Medicine, Royal Prince Alfred Hospital, Camperdown NSW, Australia.
Eur Respir J. 1990 Feb;3(2):144-51.
Non-isotonic aerosols are being used increasingly for bronchial provocation testing in patients with asthma. We investigated changes in forced expiratory volume in one second (FEV1) in response to inhaling ultrasonically nebulized 4.5% saline in 10 normal subjects and 68 subjects with asthma. A comparison of the sensitivity to this challenge was made with sensitivity to challenge with methacholine, water, exercise and eucapnic voluntary hyperventilation (EVH). In normal subjects the FEV1 was reduced by 6 +/- 2% (mean +/- SD) after inhalation of 33 ml of aerosol. Eighty four percent of the asthmatic subjects exhibited a fall in FEV1 of greater than 20% after inhaling 4.5% saline. The provoking dose (geometric mean +/- 95% confidence limits) of saline to induce a 20% fall (PD20) was 2.05 ml (1.34-4.48). The sensitivity to inhaled 4.5% saline was significantly related (p less than 0.001) with responsiveness to methacholine, exercise and EVH, but not to water. Those patients recording a PD20 to 4.5% saline had a PD20 to methacholine less than 2 mumol which is a response consistent with moderate to severe bronchial hyperresponsiveness.
非等渗气雾剂越来越多地用于哮喘患者的支气管激发试验。我们研究了10名正常受试者和68名哮喘患者吸入超声雾化4.5%盐水后一秒用力呼气量（FEV1）的变化。将该激发试验的敏感性与对乙酰甲胆碱、水、运动和等碳酸自主过度通气（EVH）激发试验的敏感性进行了比较。在正常受试者中，吸入33毫升气雾剂后FEV1降低了6±2%（平均值±标准差）。84%的哮喘患者吸入4.5%盐水后FEV1下降超过20%。诱导20%下降的盐水激发剂量（几何平均值±95%置信区间）为2.05毫升（1.34 - 4.48）。对吸入4.5%盐水的敏感性与对乙酰甲胆碱、运动和EVH的反应性显著相关（p < 0.001），但与对水的反应性无关。那些对4.5%盐水记录到PD20的患者对乙酰甲胆碱的PD20小于2微摩尔，这是一种与中度至重度支气管高反应性一致的反应。
