摘要目的:评价高危肺血栓栓塞症患者在机械通气下的动脉血二氧化碳分压（PaCO 2）变化。 方法:回顾性分析2012年1月1日至2022年5月1日北京协和医院行静脉溶栓治疗的高危肺栓塞患者49例，其中男19例，女30例，年龄（57.8±14.5）岁。根据是否行有创机械通气分为机械通气组22例及自主呼吸组27例，比较两组患者自主呼吸状态下PaCO 2水平，比较机械通气组患者插管前、后及溶栓后PaCO 2变化，比较两组患者的14 d全因病死率。 结果:两组患者插管前PaCO 2均低于正常，差异无统计学意义。溶栓后两组患者PaCO 2均恢复至正常范围。机械通气组患者插管后11~147 min出现PaCO 2升高，溶栓后PaCO 2基本恢复正常，插管前、后及溶栓前、后PaCO 2差异有统计学意义。机械通气组患者14 d病死率为54.5%（12/22），而自主呼吸组患者全部存活。 结论:机械控制通气情况下，急性高危肺栓塞患者可表现为高碳酸血症，溶栓治疗成功后PaCO 2恢复正常。对于机械通气患者，若出现突发低氧血症伴高碳酸血症，应警惕高危肺栓塞的可能性。

abstractsObjective:To evaluate the variation of arterial partial pressure of carbon dioxide (PaCO 2) in patients with high-risk pulmonary embolism under mechanical ventilation. Methods:We retrospectively analyzed the cases of high-risk pulmonary embolism who underwent intravenous thrombolysis in Peking Union Medical College Hospital from January 1, 2012, to May 1, 2022. The enrolled patients were divided into a mechanical-ventilated group and an active-breathing group according to whether they received invasive mechanical ventilation or not. The level of PaCO 2 under active breathing between the two groups, the changes in PaCO 2 before intubation, after intubation and after thrombolysis in the mechanical-ventilated group were compared. The 14-day all-cause mortality of the two groups was calculated and compared. Results:A total of 49 patients with high-risk pulmonary embolism were enrolled, including 22 patients in the mechanical-ventilated group and 27 patients in the active-breathing group. Before intubation, PaCO 2 in both groups was lower than normal without statistically significant difference between the two groups. After effective thrombolysis therapy, PaCO 2 in both groups recovered to the normal range. In the mechanical-ventilated group, PaCO 2 significantly increased 11-147 min after intubation and returned to the normal range after thrombolysis therapy. The 14-day mortality in the mechanical-ventilated group was 54.5%, while all patients in the active-breathing group survived. Conclusions:Under mechanical controlled ventilation, patients with high-risk pulmonary embolism could represent hypercapnia which resolved after effective thrombolytic therapy. In mechanical ventilated patients with sudden-onset hypoxemia and hypercapnia, the possibility of high-risk pulmonary embolism should be considered.