For the last year I have been using capnography on all my intubated patients. A good capnography wave insures that the tube is in the trachea where its supposed to be and not in the esophagas which would produce a flat line, immediately on the capnography wave form and eventually on the heart monitor as well if the tube is not moved to the right place.
Part of the class covered capnography for the non-intubated patient. Instead of an attachment on an ET tube, a nasal cannula-like monitoring device was put on the patient. We were taught about the shape of the wave form changed depending on the problem. Asthmatics and COPDers had a characteristic shark fin shape, which indicated resistance to expiration.
Yesterday we had an eighty-year COPDer with Sats in the 80's, alert, but not moving too much air. We gave her two back to back combi-nebs and monitored her with capnography. It was the first time I used capnography on a COPDer.
Here are the wave forms. Keep in mind a slanted "shark fin" wave form shows the person is struggling to exhale through resistance. A more box like wave form shows no resistance. Here's a normal wave form and a bronchospastic wave form:
And here's our patient's wave forms, initially, during the first treatment(combi-vent, which bronchodilates) and after two treatments:
Way cool, I thought. It really shows how effective our treatment was. The woman felt much better and was breathing easier. The nurse at the ED asked what the funny looking cannula was for. She was impressed when we said capnography. We tried to show her the wave forms, but she just nodded, and it seemed to me the wave forms meant nothing to her. A couple weeks ago, they would have meant nothing to me, too.
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For more information on capnography:
Capnography
