对重症SARS预警因子和高危因素的探讨

目的 对2003年12月前广东省严重急性呼吸综合征（SARS）临床数据库采用决策树方法重新评价重症诊断标准，探讨预警因子并筛选高危因素。方法 首先选取按国家卫生部SARS诊断标准确诊的患者402例，其中358例符合重症标准。358例中，再选取进行有创机械通气、无创机械通气、或死亡者作为明确重症患者，余44例作为明确非重症患者。将氧合指数（OI）按病程中的最差值划分为3个等级，≤200mmHg（1mmHg=0．133kPa）为1；200～300mmHg为2；〉300mmHg为3，初步评价OI等级划分对重症SARS患者的预测作用，并进一步筛选临床的高危因素。结果 利用OI≤300mmHg作为判别规则对明确重症患者和明确非重症患者进行分类，错判率只有6．800%，由OI≤300mmHg所筛选的重症患者与按国家卫生部重症诊断标准（剔除OI≤300mmHg的部分）所筛选的患者以Logistic回归比较了病死概率和并发症，提示以OI≤300mmHg为标准划分的重症患者临床风险更高、预后更差。结论OI≤300mmHg即急性肺损伤的诊断标准更符合现行重症SARS的诊断要求，可作为重症SARS的预警指标之一。

Retrospective discriminant analysis of the clinical diagnostic criteria for serious contagious severe acute respiratory syndrome

OBJECTIVE: To analyze the clinical diagnostic criteria for serious severe acute respiratory syndrome (SARS) in Guangdong retrospectively discriminant with SARS database, and to screen out the sensitive warning factors in predicting the outcome. METHODS: Four hundred and two SARS patients were selected based on the diagnostic criteria for SARS from Ministry of Health, China. Of them, 358 SARS patients were selected as their clinical manifestations conformed to the diagnostic criteria of serious SARS. The study subjects were divided into two groups. One group consisted of the patients with serious SARS (358 patients), and they either underwent invasive or non-invasive mechanical ventilation or died of the disease. The remaining 44 SARS patients constituted the non-serious SARS group. Taking the lowest value of oxygen index (OI) as the main index, the OI was categorized into 3 classes, namely< or =200 mm Hg (1 mm Hg=0.133 kPa) as 1,200-300 mm Hg as 2, and >300 mm Hg as 3. According to this index, the seriousness and the prognosis were analyzed. RESULTS: OI less than 300 mm Hg were identified as the unequivocal serious SARS patients, and the mistake judgement rate was 6.800%. Furthermore mortality and complications were compared with Logistic regression, and questionable SARS patients were excluded. The results showed that the patients identified with OI less than 300 mm Hg had worse outcome than the original ones diagnosed with criteria of Ministry of Health. CONCLUSION: OI less than 300 mm Hg in patients with ALI meet the diagnostic criteria of serious SARS better, and it can be taken as a prognostic criterion in clinic.