Bartter T C, Dubois J, Pratter M R
Department of Medicine, Cooper Hospital/University Medical Center, Camden, NJ.
Chest. 1993 Nov;104(5):1338-41. doi: 10.1378/chest.104.5.1338.
The purpose of this study was to look prospectively at the practice of prefacing methacholine bronchoprovocation challenge (BPC) with diluent challenge using physiologic saline solution (NaCl) as the diluent. We wished to determine whether NaCl challenge added to the safety or diagnostic accuracy of BPC. We studied 108 consecutive patients undergoing methacholine BPC. We determined (1) the FEV1 response of all patients to the inhalation of NaCl (the difference between the FEV1 before NaCl and the FEV1 after NaCl), and (2) the correlation between the response to saline solution and bronchial hyperresponsiveness (BHR) measured using methacholine. Paired Student's t testing demonstrated a small but significant difference between the values for FEV1 before and after NaCl for the group as a whole (n = 108; mean change, -0.9 +/- 4 percent [+/- SD]; p = 0.023). When the mean changes in the FEV1 after NaCl for the group with increased BHR (BHR+) (n = 62; mean, -1.1 +/- 4.9 percent) and the group with no increase in BHR (BHR-) (n = 46; mean, -0.6 +/- 2.4 percent) were contrasted, there was no significant difference between the two groups (p = 0.46). Only 4 of 108 patients had a drop in FEV1 of 10 percent or more after NaCl, with the greatest drop being 16 percent. All four patients were BHR+, but none had marked BHR. For the BHR+ group, there was no correlation between response to saline solution and subsequent response to methacholine (r = 0.02). We conclude that saline solution challenge adds time and expense to BPC without increasing the safety or yield of BPC. We suggest that NaCl challenge can be omitted from the standard performance of BPC.
本研究的目的是前瞻性观察以生理盐水（NaCl）作为稀释剂进行稀释剂激发试验作为乙酰甲胆碱支气管激发试验（BPC）的前置操作。我们希望确定NaCl激发试验是否能提高BPC的安全性或诊断准确性。我们研究了108例连续接受乙酰甲胆碱BPC的患者。我们测定了（1）所有患者吸入NaCl后的第一秒用力呼气容积（FEV1）反应（NaCl吸入前的FEV1与NaCl吸入后的FEV1之差），以及（2）使用乙酰甲胆碱测定的对盐溶液的反应与支气管高反应性（BHR）之间的相关性。配对学生t检验显示，整个组（n = 108；平均变化，-0.9±4%[±标准差]；p = 0.023）在NaCl吸入前后的FEV1值之间存在微小但显著的差异。当比较BHR增加组（BHR+）（n = 62；平均，-1.1±4.9%）和BHR未增加组（BHR-）（n = 46；平均，-0.6±2.4%）吸入NaCl后FEV1的平均变化时，两组之间无显著差异（p = 0.46）。108例患者中只有4例在吸入NaCl后FEV1下降10%或更多，最大下降为16%。所有4例患者均为BHR+，但均无明显BHR。对于BHR+组，对盐溶液的反应与随后对乙酰甲胆碱的反应之间无相关性（r = 0.02）。我们得出结论，盐溶液激发试验增加了BPC的时间和费用，而没有提高BPC的安全性或阳性率。我们建议在BPC的标准操作中可以省略NaCl激发试验。
