McFadden E R
J Allergy Clin Immunol. 1986 Jan;77(1 Pt 1):1-5.
Although asthma is a disease of airways, it affects all aspects of lung function, and in acute severe episodes even cardiac performance is influenced. The typical exacerbation is characterized by symptoms of wheezing, dyspnea, and cough associated with the signs of tachycardia, tachypnea, hyperinflation of the thorax, and stridulous breathing. Usually, the pulse rate is 100 bpm or more, and the respiratory frequency varies between 25 to 28 breaths per minute. Use of accessory muscles and pulsus paradoxicus occur in 30% to 40% of episodes. From a functional standpoint, the FEV1, peak flow, and residual volume tend to average approximately 30%, 20%, and 40% of expected values, respectively. Neither the presenting signs, symptoms, or functional abnormalities can be used to predict a relapse or the need for hospitalization because these variables do not necessarily determine the subsequent response to therapy. Furthermore, these signs and symptoms imperfectly reflect the physiologic abnormalities, and their loss can not be relied on as indicating a return to functional normalcy.
尽管哮喘是一种气道疾病，但它会影响肺功能的各个方面，在急性重症发作时甚至会影响心脏功能。典型的加重期表现为喘息、呼吸困难和咳嗽症状，伴有心动过速、呼吸急促、胸廓过度充气和喘鸣呼吸等体征。通常，脉搏率为100次/分钟或更高，呼吸频率在每分钟25至28次呼吸之间变化。30%至40%的发作会出现辅助肌使用和奇脉。从功能角度来看，第一秒用力呼气量（FEV1）、峰值流速和残气量往往分别平均约为预期值的30%、20%和40%。现有的体征、症状或功能异常均不能用于预测复发或住院需求，因为这些变量不一定能决定后续对治疗的反应。此外，这些体征和症状并不能完美反映生理异常情况，不能仅仅依靠它们的消失就认定功能已恢复正常。
