Emergency Department Lariboisière Hospital, AP-HP, University Paris VII René Diderot.
Emergency Department Pitié-Salpêtrière, APHP.
Eur J Emerg Med. 2019 Dec;26(6):412-416. doi: 10.1097/MEJ.0000000000000581.
The peak expiratory flow rate (PEFR) is the gold standard for monitoring asthmatic patients. However, its measurement requires understanding and active participation. End tidal carbon dioxide (EtCO2) may be considered an accurate surrogate for PaCO2, a severity marker in acute asthma. We studied the use of EtCO2 as a monitoring tool in acute asthma.
This was a prospective study that included consecutive patients admitted to our emergency department for acute asthma exacerbation. Data were collected at first medical contact (T0) and after 1 h of treatment (T60). The primary endpoint was the change in EtCO2; the secondary endpoints included changes in the EtCO2 Q angle value, plateau T time, and change in EtCO2 values for the patients with a PEFR ratio less than 50% after treatment.
Fifty-five patients were included and 36 waveforms were analysed. The mean age was 37 years and 26 (47%) were women. The median initial PEFR was 200 [interquartile range (IQR): 150-240]; the median EtCO2 at T0 and T60 was 35 (IQR: 30-38) and 34 (IQR: 29-37). There was no significant change in EtCO2 after treatment. There was no significant change in the Q angle and the T time after treatment. At T60, 20 (36%) patients had a PEFR ratio less than 50%. Change in EtCO2 from T60 to T0 was associated with a PEFR ratio less than 50%.
After 1 h of treatment, there was no significant change in EtCO2. A decrease in EtCO2 seems to be associated with a higher risk of PEFR ratio less than 50% after treatment.
呼气峰流速（PEFR）是监测哮喘患者的金标准。然而，其测量需要理解和积极参与。潮气末二氧化碳（EtCO2）可被视为 PaCO2 的准确替代物，后者是急性哮喘的严重程度标志物。我们研究了 EtCO2 在急性哮喘中的监测作用。
这是一项前瞻性研究，纳入了因急性哮喘加重而连续收入我院急诊科的患者。数据在首次就诊时（T0）和治疗后 1 小时（T60）收集。主要终点是 EtCO2 的变化；次要终点包括 EtCO2 Q 角值、平台 T 时间的变化，以及治疗后 PEFR 比值小于 50%的患者 EtCO2 值的变化。
共纳入 55 例患者，分析了 36 个波型。患者平均年龄为 37 岁，26 例（47%）为女性。初始 PEFR 中位数为 200[四分位距（IQR）：150-240]；T0 和 T60 时的 EtCO2 中位数分别为 35（IQR：30-38）和 34（IQR：29-37）。治疗后 EtCO2 无显著变化。治疗后 Q 角和 T 时间无显著变化。T60 时，20 例（36%）患者的 PEFR 比值小于 50%。从 T60 到 T0 的 EtCO2 变化与 PEFR 比值小于 50%相关。
治疗 1 小时后，EtCO2 无显著变化。EtCO2 下降似乎与治疗后 PEFR 比值小于 50%的风险增加相关。
