EtCO2 in acute resp events

[VentMedic]

It is a good tool only if you have the capability of monitoring the waveforms and the knowledge to understand them. Numbers alone will not give you a good diagnostic picture. The patient, of course, and the deadspace ventilation must be considered. It should be used to confirm what you may already suspect. Some get fooled when a COPD patient in respiratory distress appears with a low PetCO2 number but not considered is the PaCO2-PetCO2 gradient of that patient. The PaCO2 may actually be very high. A low PetCO2 can be accompanied with a wide PaCO2-PetCO2 gradient which could be atelectacis, over distention of the alveoli, PNA, pulmonary edema or pulmonary emboli. Also, the cardiac output must be considered as many patients are not just one single disorder especially if they have a chronic lung or a chronic cardiac condition. Long term steroid dependent patients may also present another factor with their glucose that must be examined. For the patient that is spontaneously breathing, these factors may not be a major issue with the chance of correcting something based on a numeric value. Thus, trending of the number and waveforms may be of use in the treatment. However, if you have a patient on a ventilator and since the tricked out demand valves or ATVs are gaining in popularity, it could be very easy to over or under correct if you do not understand the waveforms, numeric valves and clinical correlation of both chronic and acute.

There are a couple of things to be aware of with Physio-Control's model on the LP12. The monitor shows the maximum CO2 value over the last 20 seconds. If the EtCO2 values are increasing, the change can be seen with every breath. However, if the values are continually decreasing, it will take up to 20 seconds for a lower numerical value to be displayed in the CO2 area. As such, the EtCO2 value may not always match the CO2 waveform.

Edited November 28, 2009 by VentMedic

[Arctickat]

There are a couple of things to be aware of with Physio-Control's model on the LP12. The monitor shows the maximum CO2 value over the last 20 seconds. If the EtCO2 values are increasing, the change can be seen with every breath. However, if the values are continually decreasing, it will take up to 20 seconds for a lower numerical value to be displayed in the CO2 area. As such, the EtCO2 value may not always match the CO2 waveform.

What was the other thing? You said there were a couple.

[VentMedic]

What was the other thing? You said there were a couple.

There are a couple of things to be aware of with Physio-Control's model on the LP12.

1. The monitor shows the maximum CO2 value over the last 20 seconds.

a. If the EtCO2 values are increasing, the change can be seen with every breath.

b. However, if the values are continually decreasing, it will take up to 20 seconds for a lower numerical value to be displayed in the CO2 area.

2.As such, the EtCO2 value may not always match the CO2 waveform.

Or, one is understanding the numbers do not always match the waveform. Two is knowing there is a 20 second delay and why or how the numbers are obtained.

[kevkei]

Hey Mobey, how are ya?

I'm curious, are you aware of any services in Alberta that use ETC02 in non-intubated pts?

I believe most services that have the LP12 with EtCO2 capability do (can't speak for the individual practitioner though). For sure Edmonton, Strathcona and St. Albert are.

It's a great tool if you understand it's use and can interperate the capnography.

Or, one is understanding the numbers do not always match the waveform. Two is knowing there is a 20 second delay and why or how the numbers are obtained.

Good point that I was unaware of, if your values are dropping there would be up to a 20 second delay. Do you know if this is standard with all LP12's, or maybe an issue with older or non-updated models?

I guess the bonus is I tend to default two of the screens each to SpO2 and EtCO2 to monitor waveforms (quantitatvie and qualitative). Like you said with EtCO2, it is good for trending as well. I don't know how many times I've seen someone get an SpO2 of 96% on a cold or red nail polished finger but there is nothing for a waveform. On a side note, it's also a good way to assess distal perfusion on fingers or toes in trauma, splinting, etc.

[CBEMT]

I've been told by physio control that application of high flow O2 via a NRB over the nasal sensor would not result in inaccurate readings.

Excellent. Thanks for that!

www.capnography.com has great info.

That and medicscribe.com/capnography/ is where I got a lot of my initial information from, years back. ETCO2 is not currently taught at the level of care I'm at, so most of what I know has come from self-study or CME.