2004, an early morning class at the EMS World expo; I unexpectedly found myself in a captivating class. A young physician by the Name of Dr. Krause enthusiastically expounded on a new assessment tool for EMS. In the case of this new tool EMS will be at the cornerstone of its use and education of the medical community he touted. The tail will wag the dog. Though our success with capnography in EMS, we will bring it to the rest of the medical community. Did we fail his vision? How do we pick up this mantel for the future?
Where we succeeded…
Just prior to capnography implementation intubation in the prehospital setting came under fire. Some studies gave way to the belief the skill was too risky and to much of a challenging skill for paramedics. As my favorite skill of my budding EMS career kicks off my favorite skill may have disappeared. Soon after in 2005 The American Heart Association picked up the mantle for use of checking exhaled co2 for ET tube confirmation. This move reinvigorated the continued skill of intubation in the prehospital setting. With all new tools, education and techniques this skill survived.
Moreover, even though Dr. Krause expounded on its use for cardiac arrest management in 2004 and research in the early 2001, it wouldn’t be until 2010 it would be implemented in ACLS. We get it change is slow, sometimes out of resistance to change.
Air goes in and out, blood goes round and round, any deviation of that is a problem.
Lets review the ancient term Vita. Latin for Life. The word vitals then means “signs of life.” We all know the top four vitals. Pulse, respiratory rate, blood pressure and temperature gives us a good picture of the basics of what’s going on.
In addition to the others, pulse oximetry became the 5th vital sign as a means of assessing perfusion. The brakes were pumped when on this one when we found its down falls. Pulse ox difficulty getting readings on patients with poor perfusion, painted fingernails and hypothermia to name a few. Pulse ox is slow to respond due to a patients oxygen reserve capacity. you may even see someone go several minutes without ventilation before a pulse ox changes. What pulse ox did well was simply give value to how much oxygen was getting to the red blood cells and carried to the prereferral tissues.
The 6th vital sign
Dr. Krause started explaining that morning simply, Kapnos in Greek means smoke. In ancient Greece there was a belief that the body had its own engine inside producing smoke. This belief isn’t all that far off if you think of it. The process of creating exhaled CO2 is very similar.
As a result, in order to produce exhaled co2 we need metabolism at the cellular level. The gas for those cells being glucose and oxygen as we know. Remember the wonderful Kreb (citric acid) cycle we were all taught long ago? Once metabolism occurs, that exhaust (exhaled co2) needs to make its way.
Capnography gives us a means to measure intake, combustion and exhaust of that organic engine. It used to be said all the time “Air goes in and out, blood goes round and round, any deviation of that’s a problem. What if we could measure if there is a deviation? In my opinion capnography the 6th vital sign.
Enter capnography
Capnography can be used for us to look deeper in a patient’s condition. Capnography gives us a breath by breath analysis of mechanical ventilation, cardiac output and cellular respiration. With that understanding we should be applying it in any time there is a something that is causing a potential variation. Capnography gives us a heads up before a potential crashing patient. Below is a list of patients I feel should be getting capnography.
- Difficulty breathing
- Shock of any type
- altered mental status
- trauma
- Chest pain
- Overdose
- anytime pain or sedation medications are administered
- With any advanced airway placement
Capnography is so tied to cardiac output that in a recent study trauma patients had a 100% mortality rate if their PETCO2 dropped below 20mmHg in surgery. ( Roman et al, Anesthesia & Analgesia 2017, July 10)
Getting back to his vision (teaching old dogs new tricks)
Raise your hands in the room, How many people spend 30 seconds assessing respiratory rate and rhythm… Well theirs always one. As much as we say treat your patient not the monitor, capnography provides another layer of assessment. In the fast paced emergency environment we tend to look at too fast, to slow or not breathing at all. Capnography gives us that exact number. With the capnography apnea alarm at 30 seconds, your a fool to sit in the captains seat caring for critical patient without it.
It helps educate us on how fast we are ventilating the patient. I have transferred care to respiratory techs while ventilating with a BVM. After leaving the capnography on I have observed many techs ventilating patients at rates above 40 a minute. I urge someone to due a study on respiratory rates during manual bag valve mask ventilations. I’m sure EMS ventilation rates are on par with this respiratory.
Overall, I wish I could figure out why exactly capnography use is so slow taking off. Even with the strong evidence in use with intubation, too many providers still don’t use it. Maybe because they are over confident in their skills. I remember a paramedic that was too confident to practice intubation during training. ” I do it all the time was her response. I’ve been a paramedic for 15 years.” The system implemented protocols which mandated capnography for every intubation and she “forgot.” At least that was her response when she brought in a patient with a esophageal intubation. Only through leading and education are we going to get past this blockade of arrogance, ignorance and complacency .
Check our https://www.capnography.com/ for further information on capnography. Also keep an eye out for more articles like these.