Rodrigo G J, Rodrigo C
Departamento de Emergencia, Hospital Central de las FF.AA, Montevideo, Uruguay.
Chest. 2000 Dec;118(6):1547-52. doi: 10.1378/chest.118.6.1547.
(1) To determine the frequency of rapid-onset asthma attacks (ROAAs) and slow-onset asthma attacks (SOAAs) in adult patients with acute, severe disease (18 to 50 years old), who presented to an emergency department (ED); and (2) to establish whether ROAA patients differ from SOAA patients in terms of clinical and spirometric characteristics; and (3) in terms of the response of treatment.
Four hundred three patients (with peak expiratory flow [PEF] or FEV(1) of < 50% of predicted value) with acute exacerbations of asthma were enrolled in the trial using a prospective cohort study. Asthma attacks were classified as an ROAA (< 6 h of symptoms) or an SOAA (> or = 6 h). All patients were treated with albuterol, four puffs at 10-min intervals (100 microg per actuation), delivered by metered-dose inhaler with a spacer device during 3 h.
On the basis of previously determined criteria, 11.3% of patients were classified as having a ROAA. Male patients comprised 53.6% of the ROAA group (p = 0.03). In ROAA patients, the exacerbation was less likely to be attributed to respiratory tract infection (p = 0.001) and more likely to have no identifiable cause (p = 0.0001). Also, ROAA patients had lower pulmonary function (FEV(1)) at presentation (mean difference, - 0. 13; 95% confidence interval [CI], - 0.22 to - 0.04 L; p = 0.04) than SOAA patients. At the end of treatment, ROAA patients had an overall 48.0 L/min (95% CI, 14.1 to 81.8 L/min) greater improvement in PEF and a 0.31 L (95% CI, 0.08 to 0.54 L) greater improvement in FEV(1) than SOAA patients. Also, ROAA patients presented with less accessory muscle use (p < 0.05) and higher oxygen saturation (p = 0. 005). Finally, SOAA patients showed an increased incidence of hospital admission (relative risk, 3.89; 95% CI, 1.01 to 15.0).
Data from this study support the notion that ROAAs constitute a distinct but uncommon acute asthma ED presentation, with a predominance of male patients. Upper respiratory tract infection was not believed to be a significant trigger factor in these patients, and ROAA patients had rapid deterioration of their conditions followed by a more rapid response to treatment and a lower hospital admission rate than SOAA patients. Thus, we have identified a subgroup of patients who appear to have common characteristics with patients with sudden-onset near-fatal/fatal asthma.
（1）确定就诊于急诊科的急性重症成年患者（18至50岁）中速发型哮喘发作（ROAA）和缓发型哮喘发作（SOAA）的发生率；（2）确定ROAA患者与SOAA患者在临床和肺功能特征方面是否存在差异；（3）确定在治疗反应方面是否存在差异。
采用前瞻性队列研究，纳入403例哮喘急性加重患者（呼气峰值流速[PEF]或第1秒用力呼气容积[FEV₁]低于预测值的50%）。哮喘发作分为ROAA（症状持续时间<6小时）或SOAA（症状持续时间≥6小时）。所有患者均使用定量吸入器加储雾罐，每隔10分钟吸入4喷沙丁胺醇（每次喷药100μg），持续3小时。
根据先前确定的标准，11.3%的患者被归类为ROAA。男性患者占ROAA组的53.6%（p = 0.03）。在ROAA患者中，病情加重不太可能归因于呼吸道感染（p = 0.001），更可能无明确病因（p = 0.0001）。此外，ROAA患者就诊时的肺功能（FEV₁）低于SOAA患者（平均差异为-0.13；95%置信区间[CI]为-0.22至-0.04L；p = 0.04）。治疗结束时，ROAA患者的PEF总体改善幅度比SOAA患者大48.0L/min（95%CI为14.1至81.8L/min），FEV₁改善幅度比SOAA患者大0.31L（95%CI为0.08至0.54L）。此外，ROAA患者使用辅助呼吸肌的情况较少（p < 0.05），血氧饱和度较高（p = 0.005）。最后，SOAA患者的住院率增加（相对风险为3.89；95%CI为1.01至15.0）。
本研究数据支持以下观点，即ROAA是一种独特但不常见的急性哮喘急诊科表现，以男性患者为主。上呼吸道感染在这些患者中不被认为是重要的触发因素，ROAA患者病情迅速恶化，但对治疗反应更快，住院率低于SOAA患者。因此，我们确定了一组患者，他们似乎与突发濒死/致死性哮喘患者具有共同特征。
