Question

Three minutes after witnessing a cardiac arrest, one member of your team inserts an endotracheal tube while another performs continuous chest compressions. During subsequent ventilation, you notice the presence of a waveform on the capnography screen and a PETCO2 level of 8 mm Hg. What is the significance of this finding?

A. Chest compressions may not be effective.
B. The endotracheal tube is no longer in the trachea.
C. The patient meets the criteria for termination of efforts.
D. The team is ventilating the patient too often (hyperventilation).

Answer 1

The significance of a waveform on the capnography screen and a PETCO2 level of 8 mm Hg during subsequent ventilation after witnessing a cardiac arrest is that chest compressions may not be effective.

Step-by-step explanation:

The significance of a waveform on the capnography screen and a PETCO2 level of 8 mm Hg during subsequent ventilation after witnessing a cardiac arrest is that chest compressions may not be effective. The presence of a waveform indicates that there is some degree of airflow during ventilation, but a low PETCO2 level suggests that the ventilation is not sufficient to adequately remove carbon dioxide from the lungs and expel it from the body. This finding may indicate inadequate chest compressions or inadequate ventilation technique, and further assessment and adjustment of CPR techniques may be necessary.

Answer 2

A, Chest compressions may not be effective.

Step-by-step explanation:

The 2010-2015 AHA Guidelines for ACLS now recommend using quantitative waveform capnography in intubated patients during CPR. Waveform capnography allows providers to monitor CPR quality, optimize chest compressions, and detect Return Of Spontaneous Circulation (ROSC) during chest compressions.

Also, according to the AHA, continuous waveform capnography along with clinical assessment is the most reliable method of confirming and monitoring correct placement of an ET tube.

Quantitative waveform capnography is the continuous, noninvasive measurement and graphical display of end-tidal carbon dioxide/ETCO2 (also called PetCO2). It uses a sample chamber/sensor placed for optimum evaluation of expired CO2. The inhaled and exhaled carbon dioxide is graphically displayed as a waveform on the monitor along with its corresponding numerical measurement.

As an assessment tool during CPR, capnography can help the ACLS provider determine a number of things. It is a direct measurement of ventilation in the lungs, and it also indirectly measures metabolism and circulation. For instance, a decrease in cardiac output will lower the delivery of carbon dioxide to the lungs. This will cause a decrease in the ETCO2 (end-tidal CO2), and this can be observed on the waveform as well as with the numerical measurement.

The Normal range of ETCO2 in the adult patient should be 35-45 mmHg.

The two very practical uses of waveform capnography in CPR are: Evaluating the effectiveness of chest compressions.

And Identification of ROSC.

ETCO2 value (< 10 mmHg) during CPR in an intubated patient low indicates low quality of chest compressions while ETCO2 value (>10mmHG) would indicate normal or high quality of chest compressions.