Ghanei Mostafa, Aliannejad Rasoul, Mazloumi Mahdi, Saburi Amin
Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Ann Card Anaesth. 2015 Oct-Dec;18(4):479-85. doi: 10.4103/0971-9784.166443.
Exertional-induced bronchoconstriction is a condition in which the physical activity causes constriction of airways in patients with airway hyper- responsiveness. In this study, we tried to study and evaluate any relationship between the findings of cardiopulmonary exercise testing (CPET) and the response to methacholine challenge test (MCT) in patients with dyspnea after activity.
Thirty patients with complaints of dyspnea following activity referred to "Lung Clinic" of Baqiyatallah Hospital but not suffering from asthma were entered into the study. The subjects were excluded from the study if: Suffering from any other pulmonary diseases, smoking more than 1 cigarette a week in the last year, having a history of smoking more than 10 packets of cigarettes/year, having respiratory infection in the past 4 weeks, having abnormal chest X-ray or electrocardiogram, and cannot discontinue the use of medicines interfering with bronchial provocation. Baseline spirometry was performed for all the patients, and the values of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV/FVC were recorded. The MCT and then the CPET were performed on all patients.
The mean VO 2 (volume oxygen) in patients with positive methacholine test (20.45 mL/kg/min) was significantly lower than patients with negative MCT (28.69 mL/kg/min) (P = 0.000). Respiratory rates per minute (RR) and minute ventilation in the group with positive MCT (38.85 and 1.636 L) were significantly lower than the group with negative methacholine test (46.78 and 2.114 L) (P < 0.05). Also, the O 2 pulse rate in the group with negative methacholine test (116.27 mL/beat) was significantly higher than the group with positive methacholine test (84.26 mL/beat) (P < 0.001).
Pulmonary response to exercise in patients with positive methacholine test is insufficient. The dead space ventilation in these patients has increased. Also, dynamic hyperinflation in patients with positive methacholine test causes the reduced stroke volume and O 2 pulse in these patients.
运动诱发性支气管收缩是一种身体活动导致气道高反应性患者气道收缩的病症。在本研究中，我们试图研究和评估活动后出现呼吸困难的患者心肺运动试验（CPET）结果与对乙酰甲胆碱激发试验（MCT）反应之间的任何关系。
30名活动后出现呼吸困难且未患哮喘的患者被转诊至巴基耶塔拉医院的“肺部诊所”并纳入研究。若受试者存在以下情况，则被排除在研究之外：患有任何其他肺部疾病；过去一年每周吸烟超过1支；有每年吸烟超过10包的病史；过去4周内有呼吸道感染；胸部X线或心电图异常；以及不能停用干扰支气管激发的药物。对所有患者进行基线肺功能测定，并记录一秒用力呼气容积（FEV1）、用力肺活量（FVC）和FEV/FVC值。对所有患者进行MCT，然后进行CPET。
乙酰甲胆碱试验阳性患者的平均VO₂（氧含量）（20.45 mL/kg/min）显著低于MCT阴性患者（28.69 mL/kg/min）（P = 0.000）。MCT阳性组的每分钟呼吸频率（RR）和分钟通气量（分别为38.85和1.636 L）显著低于乙酰甲胆碱试验阴性组（46.78和2.114 L）（P < 0.05）。此外，乙酰甲胆碱试验阴性组的氧脉搏率（116.27 mL/次搏动）显著高于阳性组（84.26 mL/次搏动）（P < 0.001）。
乙酰甲胆碱试验阳性患者的肺部运动反应不足。这些患者的死腔通气增加。此外，乙酰甲胆碱试验阳性患者的动态肺过度充气导致这些患者的心搏量和氧脉搏降低。
