Waveform Capnography | ACLS-Algorithms.com

Comments

  1. Andy says

    Excellent article and comments. A special population to consider on this topic: LVAD patients. Most LVAD patients will not have a palpable pulse, even with adequate perfusion + A&O x3. (The continuous flow pump drowns out the weak heart function). We rely on auscultating for the “hum” sound of the pump and a doppler blood pressure greater than 50. Trouble for EMS is I do not know of any rigs that carry dopplers. Maybe this is something that will change in the future. Without a doppler we rely on cap refill to assess for adequate perfusion. If a LVAD patient has pump sounds and good cap refill, they don’t need chest compressions. But when in doubt, start chest compressions.

    • Marc says

      Chest compressions with an LVAD are contraindicated given they can cause dislodgement of the LVAD from the major vessels and the heart. It’s recommended to compress the abdomen instead or only do chest compressions as a very last resort in this scenario. If you disrupt the continuity of the circuit, the patient won’t make it regardless.

      • Danielle Hawke says

        We are a hospital-based EMS service with LVAD placement (Heartmate) at our home hospital. Per the surgeon, dead is dead. We will perform chest compressions on an LVAD patient who is unresponsive, apneic (or gasping), and the pump is not audibly running, per a specific LVAD protocol. He adds the risk of dislodging a VAD “I put in” is very low if compression depth is kept at about 2 inches or less in adults. We use ZOLL’s Stat-Padz to monitor depth during all arrests, so this is an achievable goal. Marc is correct in that tearing the vessels/dislodgement is certain death. So, we use kid gloves with these patients and monitor depth very closely, but if the pump is not running and the heart is not pumping, they are dead unless we do something about it.

  2. Karen Risley says

    Hi. As the only RRT( 40 yrs experience, only 3 here) at a small community hospital I am having trouble convincing our EMS that during resuscitation one will not get the “normal” 35-45 ETCO2 during a cardiac arrest situation. While I am bagging the patient, they will routinely come over and say ” slow down” if the ETCO2 is in the twenties, bagging at a rate of 10 bpm While I will show them your column, any other advice?
    Another problem is, they will always expect me to place the CPR in progress patient on the vent which I politely decline. Has something changed in the last 3 yrs that I have missed ?
    Thank you.

    • Jeff with admin. says

      A patient should not be placed on a ventilator machine while CPR is in progress. Manuel use of bag mask ventilation is used for best practice and recommended by the AHA.

      If ROSC occurs the vent can be used.

      Kind regards,
      Jeff

      • Mike says

        The 2015 ECC guidelines for respiratory care post arrest recommends: “maintaining EtCO2 of 30-40 or PaCO2 of 35-45 may be reasonable.”

  3. clarissa says

    If the patient is being monitored for ETC02 during a code. Do you still stop chest compression to assess for pulse?

    • Jeff with admin. says

      At this time, the cardiac arrest algorithm does not replace the pulse check with any other form of assessment to determine ROSC.

      You would still stop chest compressions and assess for a pulse.

      Kind regards,
      Jeff

  4. Riviraj Warnakulasooriya says

    Hi Jeff
    Could cardiac arrest patients shows capnography over 40 with active CPR but still they are dead ?

    • Jeff with admin. says

      No. If a patient is clinically deceased then they cannot have a end tidal CO2 level greater than 40 mmHg. With high-quality CPR you can expect a end tidal CO2 level around 20 mmHg.

      Kind regards,
      Jeff

  5. brandon says

    What are the reasons that we would get a reading above 30 while doing cpr? We had a patient go into arrest, tubed and ventilated and were getting readings 35-60 during CPR but we felt no pulse. They were in PEA. we worked them for 30 minutes. Multiple people checked multiple locations for pulses because we couldn’t believe it. We checked heart tones and heard nothing. When we stopped doing CPR, the numbers fell below 10. we were always told we’d never get numbers above 25 if we were doing CPR. is this incorrect information? what’s your thoughts on this?

    Thanks so much

    • Jeff with admin. says

      This could have been caused by a heart that was in complete failure but a body system that still had and intact metabolism. In other words, everything was working except for the pump.

      Your patient’s metabolic processes were intact but his heart was not working. When you provided your patient with high-quality chest compressions and he was being adequately ventilated, this resulted in a close to normal ETCO2 unless chest compressions were stopped.

      I have seen this happen one time before. It sounds almost like the same scenario. We had a normal ETCO2 as long as we continue chest compressions. After 45 minutes of chest compressions, it was determined that this guy’s heart just was not going to start and the wife decided to stop efforts for resuscitation. This patient had complete heart failure, but it was just a bad heart. The rest of his body was still working relatively well. He had a long history of heart problems.

      Kind regards,
      Jeff

      • Troy says

        Thank you for this answer. The same thing happened during CPR in my ambulance yesterday. We were seeing ETCO2 between 50-80. We achieved ROSC 2 times, but the Pt’s heart finally gave out at the hospital. The ETCO2 was the topic of conversation last night, and it was driving us nuts.

    • Jason says

      I just got on an ambulance with portable ultrasound and twice in the last month have pulled it out on a pt that medics could not feel a pulse during PEA and sure enough there was cardiac activity. We got both pts to the hospital without feeling a pulse just relying on ultrasound and end tidal and both pts made it out of the ed and to the icu with stable ROSC. Point is take a gamble with end tidal and a strong PEA and get them to the hospital.

    • Kyle Lonesky says

      Our department has started using Dopamine in early PEA pts during a code. It may not have truly been PEA but only appeared to be because we were not able to feel the pulse due to low BP. We have also been using waveform capnography during our codes because along with normal range numbers or a significant spike in numbers, a true waveform can only occur when there is ventilation (autonomic or assisted) and cardiac output to cause gas exchange for the capnography to read.

    • Jeff with admin. says

      In the situation when there is no endotracheal tube in place, using ETCO2 monitoring is very difficult and has possibilities for being very in accurate. Until better monitoring treatments are available for ETCO2, endotracheal intubation provides the best method for monitoring.

      Kind regards, Jeff

  6. Mduduzi Mbuyisa says

    An ETCO2 above normal range (35 – 40), what would it mean? And if it is a problem, what should be done?

    • Jeff with admin. says

      An ETCO2 of 35-45 mmHg is normal. It means that the cells of the body are producing CO2, and that the CO2 is been exhaled with ventilation.

      It is a good thing and this should be maintained.

      During cardiac arrest, if this value is seen then it means that return of spontaneous circulation (ROSC) has occurred.

      Kind regards,
      Jeff

  7. Natalie L says

    Is the reason that CPR-generated EtCO2 (15-20mmHg odd) is lower than usual circulation EtCO2 (35-45mmHg) because the body is in anaerobic cellular respiration or because the venous content of CO2 is less or none of the above? Has it anything to do with VQ mismatching or increased dead space?

    • Jeff with admin. says

      It has everything to do with v/q. Cardiac output is only 25-50% of what it normally is with CPR. So we would anticipate a drop in CO2 production. The higher the co2 the better the cardiac output. Kind regards, Jeff

  8. Krysia says

    If you notice a spike in ETCO2 during arrest, should you stop to check for a pulse, then continue with ROSC care, or continue cpr until the next rhythm check?

    • Jeff with admin. says

      You will continue CPR until the next rhythm check. This ensures that the heart is given time to fully begin to perfuse blood again. I can take several minutes for the heart to fully recover and to achieve a sufficient ejection.

      Kind regards,
      Jeff

  9. Shaz says

    Is oxygen saturation a good indicator of adequate chest compressions , if you have a saturation of >94 can you assume you are doing effective CPR and therefore perusing peripherally?

    • Jeff with admin. says

      Oxygen saturation will not be an effective way to determine the effectiveness of chest compressions. This is because it is very unlikely that you will see an oxygen saturation any where near even 90%.

      I have helped with many codes, and I cannot recall a single person that was experiencing cardiac arrest and the oxygen saturation greater than 70%.

      If you do not have a way to monitor ETCO2 (waveform capnography) then having someone visually monitor the chest compressors while they perform CPR is probably the best way to gauge effectiveness.

      Kind regards,
      Jeff

  10. Michelle says

    If a patient with a trach goes into arrest and Co2 detector does not provide a reading does this confirm the pt has been dead for a while?

    • Jeff with admin. says

      This confirms one of 4 things. 1. The trach is obstructed and needs to be cleared. 2. The patient is not breathing. 3. If this lack of a CO2 reading is occurring with CPR and the trach is not obstructed, it means that there is no exchange of CO2 which would indicate complete cardiopulmonary failure (no gas exchange). or 4. The CO2 monitor is not functioning properly. It is not likely that you could accurately determine how long a patient had been in cardiopulmonary failure.
      Kind regards, Jeff

      • Brenda says

        Could it mean the intubation tube is in the esophagus instead of the airway if you don’t get a CO2 reading?

      • Jeff with admin. says

        yes, you’re absolutely correct. Thanks for pointing out that I did not include this reason in my reply. The reading probably would not be zero, but you definitely would not see a waveform and the reading with be extremely low.

        Kind regards,
        Jeff

    • Jeff with admin. says

      When return of spontaneous circulation (ROSC) occurs, the ETCO2 should return to normal within 0-120 SECONDS.

      This is why you finish a cycle of CPR before performing a pulse and rhythm check even if there is a change in ETCO2.

      It may take a few moments for the heart to reestablish effective cardiac output.

      Kind regards,
      Jeff

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