DePaso W J, Winterbauer R H, Lusk J A, Dreis D F, Springmeyer S C
Section of Pulmonary and Critical Care Medicine, Virginia Mason Medical Center, Seattle, Washington.
Chest. 1991 Nov;100(5):1293-9. doi: 10.1378/chest.100.5.1293.
The purpose of this article is to describe the spectrum and frequency of diseases presenting as unexplained dyspnea and to develop a logical diagnostic approach to such patients. Seventy-two consecutive physician-referred patients had dyspnea greater than one-month duration unexplained by the initial history, physical examination, chest roentgenogram, and spirometry. Patients underwent a standard diagnostic evaluation. A definite cause for dyspnea was recognized in 58 patients, and no answer was found in 14. Twenty-two diseases were recognized in the patient group. Dyspnea was due to pulmonary disease in 26 (36 percent) patients, cardiac disease in ten (14 percent) patients, hyperventilation in 14 (19 percent) patients, and only 3 patients had extrathoracic disease causing dyspnea. Age younger than 40 years, intermittent dyspnea, and normal alveolar-arterial oxygen pressure difference (P[A-a]O2) at rest breathing room air was strongly predictive of bronchial hyperreactivity or hyperventilation. No patient diagnosed as having disease of the lung parenchyma or vasculature had a P(A-a)O2 less than or equal to 20 mm Hg. The differential diagnosis to explain dyspnea in patients with nondirective histories, normal findings from physical examinations, normal chest roentgenograms, and normal spirograms is extensive. The patient's age and measurement of gas exchange at rest help to formulate a diagnostic approach.
本文旨在描述以不明原因呼吸困难为表现的疾病谱及发病频率，并为这类患者制定合理的诊断方法。连续72例由医生转诊的患者存在呼吸困难，且最初的病史、体格检查、胸部X线片及肺功能测定均无法解释其超过1个月的病程。患者接受了标准的诊断评估。58例患者明确了呼吸困难的病因，14例未找到病因。在患者组中识别出22种疾病。26例（36%）患者的呼吸困难归因于肺部疾病，10例（14%）归因于心脏疾病，14例（19%）归因于通气过度，仅3例患者存在引起呼吸困难的胸外疾病。年龄小于40岁、间歇性呼吸困难以及静息呼吸室内空气时肺泡-动脉氧分压差（P[A-a]O2）正常强烈提示支气管高反应性或通气过度。诊断为肺实质或血管疾病的患者，其P(A-a)O2均大于20 mmHg。对于病史无特异性、体格检查正常、胸部X线片正常及肺功能正常的患者，呼吸困难的鉴别诊断范围广泛。患者的年龄及静息时气体交换的测定有助于制定诊断方法。
