A previous pearl has looked at serum HCO3 as a predictor of DKA (see pearl from 8/21/15). The article by Gilhotra looks at using end tidal CO2 (ETCO2) to exclude DKA. 58 pediatric patients were enrolled with 15 being in DKA. No patient with ETCO2 > 30 mmHg had DKA. Six patients with ETCO2 < 30 mmHg did not have DKA. Other studies done in children have shown similar results.
An article recently published by Chebl and colleagues examined patients older than 17 years with hyperglycemia. In this study, 71 patients were included with 32 having DKA. A ETCO2 >35 excluded DKA in this group while a level <22 was 100% specific for DKA.
Bottom line: ETCO2 >35 mmHg is a quick bedside test that can aid in the evaluation of hyperglycemic patients.
References
Gilhotra Y and Porter P. Predicting diabetic ketoacidosis in children by measuring end-tidal CO2 by non-invasive nasal capnography. J Paediatr Child Health 2007; 43 (10): 677-80.
Chebl BR, Madden B, Belsky J, Harmouche E, Yessayan L. Diagnostic value of end tidal capnography in patients with hyperglycemia in the emergency department. BCM Emerg Med 2016: 16 (1).
