The technique of taking capnograms.

• mainstream c. — uses an in-line infrared CO₂ sensor connected directly to the airway, between the endotracheal tube and the breathing circuit.
• sidestream c. — airway gas samples are collected from the breathing circuit; the infrared sensor is located in a remote monitor.

Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.