Department of Emergency Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
Department of Emergency Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
PLoS One. 2020 Jan 28;15(1):e0228111. doi: 10.1371/journal.pone.0228111. eCollection 2020.
The aim of this study was to investigate whether 33% duty cycle increases end-tidal carbon dioxide (ETCO2) level, a surrogate measurement for cardiac output during cardiopulmonary resuscitation (CPR), compared with 50% duty cycle.
Six pigs were randomly assigned to the DC33 or DC50 group. After 3 min of induced ventricular fibrillation (VF), CPR was performed for 5 min with 33% duty cycle (DC33 group) or with 50% duty cycle (DC50 group) (phase I). Defibrillation was delivered until return of spontaneous circulation (ROSC) thereafter. After 30 min of stabilization, the animals were re-assigned to the opposite groups. VF was induced again, and CPR was performed (phase II). The primary outcome was ETCO2 during CPR, and the secondary outcomes were coronary perfusion pressure (CPP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and right atrial pressure (RAP).
Mean ETCO2 was higher in the DC33 group compared with the DC50 group (22.5 mmHg vs 21.5 mmHg, P = 0.018). In a linear mixed model, 33% duty cycle increased ETCO2 by 1.0 mmHg compared with 50% duty cycle (P < 0.001). ETCO2 increased over time in the DC33 group [0.6 mmHg/min] while ETCO2 decreased in the DC50 group [-0.6 mmHg/min] (P < 0.001). Duty cycle of 33% increased SAP (6.0 mmHg, P < 0.001), DAP (8.9 mmHg, P < 0.001) RAP (2.6 mmHg, P < 0.001) and CPP (4.7 mmHg, P < 0.001) compared with the duty cycle of 50%.
Duty cycle of 33% increased ETCO2, a surrogate measurement for cardiac output during CPR, compared with duty cycle of 50%. Moreover, ETCO2 increased over time during CPR with 33% duty cycle while ETCO2 decreased with 50% duty cycle.
本研究旨在探讨与 50% 占空比相比，33%占空比是否会增加心肺复苏（CPR）期间的潮气末二氧化碳（ETCO2）水平，ETCO2 是心输出量的替代测量指标。
将 6 头猪随机分为 DC33 或 DC50 组。在诱导性心室颤动（VF）3 分钟后，使用 33%占空比（DC33 组）或 50%占空比（DC50 组）进行 5 分钟的 CPR（第 I 阶段）。此后，进行除颤直至自主循环恢复（ROSC）。稳定 30 分钟后，动物重新分配到相反的组。再次诱导 VF，并进行 CPR（第 II 阶段）。主要结局是 CPR 期间的 ETCO2，次要结局是冠状动脉灌注压（CPP）、收缩压（SAP）、舒张压（DAP）和右心房压（RAP）。
与 DC50 组相比，DC33 组的平均 ETCO2 更高（22.5mmHg 比 21.5mmHg，P=0.018）。在线性混合模型中，与 50%占空比相比，33%占空比使 ETCO2 增加 1.0mmHg（P<0.001）。在 DC33 组中，ETCO2 随时间增加[0.6mmHg/min]，而在 DC50 组中，ETCO2 减少[0.6mmHg/min]（P<0.001）。与 50%占空比相比，33%占空比增加了 SAP（6.0mmHg，P<0.001）、DAP（8.9mmHg，P<0.001）、RAP（2.6mmHg，P<0.001）和 CPP（4.7mmHg，P<0.001）。
与 50%占空比相比，33%占空比增加了 CPR 期间的 ETCO2，这是心输出量的替代测量指标。此外，在 33%占空比的 CPR 期间，ETCO2 随时间增加，而在 50%占空比的 CPR 期间，ETCO2 减少。
