Morning Report: 6/20/2013

Today’s Morning Report is courtesy of Dr. DiMare!

 

Color Change Capnography

 

How does it work?mr06202013p1

  • pH based
  • REVERSIBLY reacts with expired CO2
  • purple with ETCO2 < 3mmHg
  • yellow with ETCO2> 15mmHg

 

How good is it?

–       nearly 100% specific (97-100% different studies, different devices)

  • WHEN USED PROPERLY

–       sensitivity varies greatly with patient condition (20-100%)

 

False Positives & Solutions

–       copious bagging has forced CO2 into esophagus/stomach

  • observe color change back and forth 6 times

–       ETT is in hypopharynx

  • Capnography should only be used IN CONJUNCTION WITH visualization

–       Gastric contents, mucous, medication such as epinephrine and lidocaine

  • Will cause a permanent change, must observe back and forth color change

 

False Negatives

–       Cardiac arrest

  • Patient is not generating enough CO2 to cause color change

–       Massive PE

  • Gas exchange is limited

–       Large dose IV epi, such as during cardiac arrest

  • Theoretically can decrease ETCO2
    • Unclear when/if it will decrease it enough to prevent color change

 

References:

Srinivasa V, Kodali BS. Caution when using colorimetry to confirm endotracheal intubation. Anesth Analg 2007;104:738

Nagler, Joshua, and Baruch Krauss. “Capnography: a valuable tool for airway management.” Emergency medicine clinics of North America 26.4 (2008): 881-897.

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.
The following two tabs change content below.

Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital

Latest posts by Jay Khadpe MD (see all)