Title:Capnography

题目：二氧化碳监护仪（及其在鉴定骤停原因的应用）

Author 作者: John Greenwood, MD

I. Review of capnography 二氧化碳监护仪现状

a.2010 European Resuscitation Council recommended using waveform

capnography during cardiac arrest to guide CPR

2010年欧洲复苏委员会建议在心脏骤停抢救中使用波形式二氧化碳监护仪指导CPR

b.2010 AHA guidelines made it a Class 2B recommendation

2010年美国心脏协会指南把它列为推荐类别2B

c.Uses for capnography 二氧化碳监护仪的使用

i.Has a specificity of 97 – 100% for confirming correct placement of endotracheal tube

在确定气管内插管正确位置方面的特异性式97－100％

ii.Useful for CPR 在CPR时非常有用

1.If < 10 mmHg, it may be that CPR is inadequate and providers

should maximize effectiveness of compressions by switching out

or pushing harder

如低于10mmHg，说明CPR效果差，需要通过换人或更有力的按压以达到最大的按压效果

2.Useful for alerting providers there is a return of spontaneous

circulation (ROSC) 在有自主循环恢复（ROSC）时可发出警示

a.If end-tidal CO2 (ETCO) is 30 – 40, has positive

correlation with ROSC 如呼吸末期CO2（ETCO2）30－40，与ROSC有明确的关系

b.If there is a sudden increase of 15 – 25 above the baseline

ETCO2, also has a positive correlation with ROSC

如果ETCO2突然比基线升高15－20，同样意示着ROSC

c.This can help minimize interruptions in compressions for

pulse check 它会有助于最大限度的限制因检查脉搏而中断按压

3.If ETCO2 is persistently < 10 mmHg for 20 minutes despite adequate CPR, chances of ROSC are slim

即使CPR有效，如ETCO2持续20分钟低于10mgHg标志着ROSC的机会非常小

II.Use of ETCO2 for determining the cause of arrest – Resuscitation article

用ETCO2确定心脏骤停的原因－复苏杂志的文章

a. Respiratory arrest patients had higher mean ETCO2 (in the mid 20’s mmHg) compared to other causes. Thought to be from retained CO2 from diminished ventilation.

与其它原因比较，呼吸性骤停的病人会有较高的ETCO2（20几的ETCO2）。可能是由低通气造成的CO2储留。

b. Pulmonary embolus patients had lower mean ETCO2 than cardiac arrest

and respiratory arrest. Thought to be due to decreased pulmonary blood flow and

increased alveolar dead space.

与心脏和呼吸骤停相比，肺动脉栓塞病人的ETCO2较低，可能是由减低的肺动脉血流和增加的肺泡死腔造成。

c. Patients who had eventual ROSC had higher initial ETCO2 compared to

patients who did not have ROSC .

最终ROSC病人的ETCO2要比没有ROSC的病人要高。

References 参考文献:
Heradstveit BE, Sunde K, et al. Factors complicating interpretation of capnography during advanced life support in cardiac arrest-a clinical retrospective study in 575 patients. Resuscitation. 2012 Jul; 83(7): 813-818.