March Log

Medtronic VHS Capnography Tape

I watched the Medtronic VHS Capnography tape today. It is about 8 minutes long and features Tim Phalen and Baruch Krauss. It is an introduction to nonintubated capnography for the person unfamiliar with it. Not a lot of information, but a clear start for novices.

More on CHF/COPD

I recieved the following comment on the CHF/COPD question. I think it is an excellent explanation:

I haven't been using capnography long, but here is my interpretation of the CHF waveform. I have only seen upright waveforms, even with wheezing. The wave form, as we have been told, is due to uneven alveolar emptying caused by constriction of the bronchioles. This constriction is obviously not the same thoughout the lungs, which leads to the uneveness. In CHF, the bronchioles "stiffen" up to protect against the fluid. This causes the wheezing (not constriction). Since the bronchioles are relatively the same size, alveolar emptying is rather even-therefore a decent waveform. I know what you are thinking........what about the fluid. You maybe thinking the fluid may cause uneven emptying. I disagree. If fluid is in the bronchioles, then it has collapsed the distal alveoli and no gas exchange will be taking place- therefore no uneven emptying.

This is just my thoughts. Mike S.

Hyperventilation

We got called to a treatment facility for a just admitted patient who couldn't feel her legs. We found a twenty-two year old breathing eighty times a minute. We tried to get her to slow her breathing down, but that wouldn't work. She was up on the third floor of a residential setting, but the elevator was broken, so we tried to help her walk, but she said she couldn't. We made it down on flight, and then I just said to a first responder, we need to carry her. I took her upper half and he took the lower half and we carried her the rest of the way. I leaned against the wall as I went down the stairs for support. The other medics thought I was too nice to be carrying her. In the ambulance, I put her on the capnography and her ETCO2 was 20 and her RR was 50-80. For experiments on myself, I know if you can even get your ETCO2 down to 20 and are breathing that fast, you probably will be dizzy and unable to feel your legs.

I patched the call in as hyperventilation. When we wheeled the patient in, the nurse (one who is always sarcastic) shouted across the ER -- "You have her on an oxygen cannula! Do you need a mask?" She said it in a belittling way like she's just hyperventilating, she doesn't need oxygen. After I unloaded the patient I went up to her and said, "For your education, this is not oxygen. It is capnography. It measures her respitratory rate and her ETCO2, which is 20. It provides objective proof of hyperventilation." "Oh, oh, I didn't know," she said.

Patient with Trach

I had a patient today with a trach, fever of 103 and history of respiratory failure. I popped an ET capnofilter on her trach, even though she could breath on her own (she had blow by 02), and it gave an excellent reading and wave form. No need to attach an ambubag.


State Conference

I taught a class at the state conference on capnography. I saw a couple people nodding off. I advertised the class as Capnography for Paramedics and EMTs, but I think I might have been over the heads of some of the EMTs. It takes me awhile to understand concepts, but then once I have them, they seem easy. I need to show the same patience when I teach. Teaching is also always harder than I imagine it. I try to tell them everything I know in an hour and a half and I think I end up rushing. But each time I teach, I figure out a better way to do it. It is also hard when I compare myself to Bob Page's presentation. I can do better than I did, but will have a hard time matching his class.

Sleep Apnea

I did an interesting call written about in A Nap. The bottom line was a barely responsive patient with an ETCO2 of 64-70. She had a history of sleep apnea, and was in fact, just sleeping deeply. Patients with sleep apnea are at risk for hypoventilation because they stopped breathing until they wake themselves up.

March 9, 2007 - Capnography Vendors at JEMS

I walked about the EXPO hall looking specifically for capnography and was disappointed to see it displayed so poorly.

The Physio-Control booth had a table with some literature/handouts on capnography, which was good. I talked briefly there with a person from Oridion, which manufactures the capnofilters that Physio uses.

Phillps Medical Systems also had some Oridion filters out, but not much promotion of the capnography in their monitors. I did have a very pleasant talk with one of their salespeople about capnography.

The Respironics booth had CPAP and a small capnography monitor, but every time I walked by they were demonstrating CPAP.

Zoll, which in Las Vegas sponsored Bob Page’s half hour class on capnography in their demo theatre, had nothing visible.

I did encounter a new product from a company called Nonin, which had a product called Lifesense Capnograph, which had a interesting capnography screen. They also advertised their product as having first breath capability.

I also queried the booksellers about capnography books.

Brady Books actually had Bob Page there at the time I stopped by and he said his book will be out late next year. The Mosby salesperson had no books they knew about. Jones and Bartlett Publishers said they were in discussion with some people about writing one, but had nothing definite.


Jems Conference - Bob Page "Slap the Cap!

Highlights from Bob Page’s Slap the Cap Cagnography Presentation

I attended Bob Page’s hour and a half version of his famous capnography class. Last year in Las Vegas I saw the half hour condensed version. I envy anyone who has been able to attend his half day course. He is a phenomenal educator/entertainer.

People filtered into the classroom before show time to see Queen and then Billy Joel performing on the big screens set up in the front of the room. When Bob Page appeared to start the class, he humbly thanked his opening acts...Queen and Billy Joel.

Page calls capnography an “upgrade,” and to illustrate this he describes his first airline upgrade to first class and how he found out the drinks were unlimited, you could be served before the plane took off, you got peanuts, cashews and pistachios in a bowl rather than a tiny bag of salted peanuts and you also got warm moist lemon scented towels. Like first class on an airplane, capnography gives you stuff that you can’t get in coach.

Before getting into what that stuff is, he does a great demonstration of a blood cell carrying carbon dioxide in which he plays the blood cell running through the body. He simulates what happens to him during cardiac arrest, during a PE, and during a hemorrhage how he is thrown out of the body, and describes the effect of that all on the end tidal C02.

I’m not going to go through his entire class, but I will point out the key points from his presentation that I found personnaly found valuable or helped clarify my own thinking on the issue.

1. While most people use the definition of hyperventilation and hypoventilation to describe low and high ETCO2 numbers, he uses the terms hypocapnia and hypercapnia, which may be a more accurate was of describing it.

2. He does a killer job of trashing colorimetric capnography devices and the turkey baster/bulb syringe by reading their instructions and then applying them to real situations. For instance, the colorimetric says you must give six breaths to determine the reading to make certain all of the carbon dioxide is out of the stomach. Well six bags into the stomach is going to visually tell you there is a problem before the device does.

3. He takes about the wave form you will get from an intubated patient who is coming out of sedation before they start bucking the tube, so you can get out more sedation before they actually buck the tube. It is another example of how capnography makes you proactive as opposed to reactive.

4. He talks about asthma and makes the point you can’t fake a broncospasm/shark fin wave form. Anyone who says they are having an asthma attack and is trying to make a wheezing sound deliberately will have a straight up wave form unless they are actually having an asthma attack.

5. He calls wave form capnography a “one stop tube confirmation stop.” Technically, it is a two stop shop, because you still have to listen to lung sounds to make certain you don’t have a right mainstem intubation, which won’t show up on capnography. Still a desciptive phrase, meaning you don't have to go through all the step you might otherwise have to use if you didn't hve capnography.

6. He suggests hitting record on your intubated patients right before you move them to the ED’s stretcher and then immediately after you have moved them over to time stamp your intubation in case the ED says your tube is no good.

7. On the issue of ventilation rate, while the new AHA guidelines specify the rate as 8-10 for a patient in arrest and 10-12 for an intubated patient, you should instead use the capnography as your guide. If their ETCO2 is 70, you might want to increase your ventilation rate to blow some of that CO2 off.

8. Finally, before I could ask, he addressed the COPD/CHF question and his take is if the wave form is upright, there is no obstruction, so the wheezing is caused by the CHF, not the COPD, so you might want to withhold the neb treatment.

There is obviously much more to the class than this. As I have said before, if you ever get a chance to attend one of his courses, do it, he is great.

In the meantime, you can download his 35-page handout for the course at the following link:

Bob Page's Download Page

Click on "capnography."

While there also visit his Capnography Waveforms

***

I saw Bob Page later at the Brady books booth. I asked him about the CHF/COPD and he said definately an upright waveform is CHF. The wheezing is from the rales in the bases, but it is not widespread like with COPD, which will cause the extended uneven emptying and the shark fin shape.