目的:分析急诊气管插管（endotracheal intubation，ETI）后患者平均动脉压（mean arterial pressure, MAP）及呼气末二氧化碳（end tidal COn 2, ETCOn 2）的变化特点，探讨急诊ETI后监测MAP和ETCOn 2对早期预测严重循环崩溃（cardiovascular collapse, CVC）的价值。n 方法:前瞻性顺序收集2015年3月至2020年5月北京协和医院急诊科行急诊ETI成人患者的临床资料。观察并记录患者ETI后5、10、30、60和120 min MAP和ETCOn 2的数值。根据患者急诊ETI后是否发生严重CVC分为严重CVC组和无严重CVC组。对两组MAP和ETCOn 2的数值进行组间相同时间点和组内相邻时间点的比较，并将ETI后MAP与ETCOn 2的数值进行相关性分析。采用ROC曲线分析急诊ETI后5 min和10 min MAP及ETCOn 2对严重CVC的预测能力。n 结果:共纳入研究患者116例，其中75（64.7%）例患者ETI后发生严重CVC，严重CVC组中以男性和高龄患者居多。严重CVC组急诊ETI后5、10、30、60、120 min MAP和ETCOn 2的数值明显低于无严重CVC组。两组MAP和ETCOn 2在急诊ETI后5~30 min表现为同步下降，在ETI后30 min达最低值，其后至ETI后120 min表现为同步回升。ETI后MAP和ETCOn 2两者的变化具有相关性（n rs=0.653, n P<0.01）。ETI后5 min MAP可准确预测严重CVC（AUC=0.86, n P<0.01），最佳截断值为MAP≤72 mmHg（灵敏度为78.7%，特异度为87.8%）。ETCOn 2也可准确预测严重CVC（AUC=0.85, n P<0.01），最佳截断值为ETCOn 2≤35 mmHg（灵敏度为77.3%，特异度为85.4%）。ETI后10 min MAP可准确预测严重CVC（AUC=0.90, n P<0.01），最佳截断值为MAP≤67 mmHg（灵敏度为89.3%，特异度为85.4%）。ETI后10 min ETCOn 2也可准确预测严重CVC（AUC=0.87, n P0.05）。n 结论:急诊ETI后严重CVC患者早期即有MAP和ETCOn 2下降表现，但识别滞后和干预不足可能与CVC的发生发展有关。ETI后早期MAP和ETCOn 2对预测严重CVC均有较高效能。插管后5 min MAP≤72 mmHg、ETCOn 2≤35 mmHg、插管后10 min MAP≤67 mmHg及ETCOn 2≤33 mmHg均提示患者发生严重CVC的可能性大。n “,”Objective:To analyze the changes of mean arterial pressure (MAP) and end expiratory carbon dioxide (ETCOn 2) in patients after emergency endotracheal intubation (ETI). To explore the values of MAP and ETCOn 2 monitoring in early prediction of severe cardiovascular collapse (CVC) after emergency ETI.n Methods:The clinical data of adult patients who underwent ETI from March 2015 to May 2020 were collected consecutively in the emergency departments of Peking Union Medical College Hospital. The values of MAP and ETCOn 2 were observed and recorded at 5, 10, 30, 60 and 120 min after intubation. According to whether severe CVC occurred after ETI, the patients were divided into the severe CVC group and non-severe CVC group. The values of MAP and ETCOn 2 were compared at the same time points between the two groups and the adjacent time points within the groups. The correlation between MAP and ETCOn 2 after ETI was also analyzed. ROC curve was used to analyze the ability of MAP and ETCOn 2 at 5 min and 10 min after ETI to predict severe CVC.n Results:Totally 116 patients were enrolled in this study, among them 75 (64.7%) cases had severe CVC after ETI. The majority were male and elderly patients in the severe CVC group. The values of MAP and ETCOn 2 in 5, 10, 30, 60 and 120 min after ETI in severe CVC group were significantly lower than those in the non-severe CVC group. The values of MAP and ETCOn 2 in the two groups showed simultaneous decrease from 5 min to 30 min after ETI, reached the lowest value at 30 min after ETI, and appeared the synchronous recover from then to 120 min after ETI. After ETI, the changes of MAP was correlated with that of ETCOn 2 (n rs = 0.653, n P<0.01). At 5 min after ETI, MAP could predict severe CVC (AUC=0.86, n P<0.01), MAP≤72 mmHg was the best cutoff value (sensitivity 78.7%, specificity 87.8%); ETCOn 2 could also predict severe CVC (AUC=0.85, n P<0.01), and ETCOn 2≤35 mmHg was the best cutoff value (sensitivity 77.3%, specificity 85.4%). At 10 min after ETI, MAP could predict severe CVC (AUC = 0.90, n P<0.01), MAP≤67 mmHg was the best cutoff value (sensitivity 89.3%, specificity 85.4%), ETCOn 2 could also predict severe CVC (AUC=0.87, n P0.05).n Conclusions:Patients with severe CVC after ETI have early signs of decreased MAP and ETCOn 2, but the delayed recognition and insufficient intervention may be related to the occurrence and development of severe CVC. MAP and ETCOn 2 at the early stage after ETI have high accuracy in predicting severe CVC. MAP≤72 mmHg, ETCOn 2≤35 mmHg at 5 min after intubation, MAP≤67 mmHg and ETCOn 2≤33 mmHg at 10 minutes after intubation all suggest the possibility of severe CVC.n