Follow (The Capnoman) Bhavani Shankar Kodali  Facebook  Twitter  

A Comprehensive Educational Website

Designed, Produced, and maintained (updated March 2019) by 

Bhavani Shankar Kodali MD


Time Capnogram/Respiratory Flow/Voume Capnogram /RQ Monitor - All-in-One


Almost 20 years ago, I envisioned a capnograph that would enable respiratory flow rates over a time capnogram. This would clearly demarcate the inspiratory and expiratory phases of a time capnogram.  The interpretation of capnograms becomes easier as any deformity of the wave form can be identified as inspiratory or expiratory.  This would also enable detection of expiratory phase artifacts caused by the dilution of end tidal gases with forward flow from the breathing circuit. Furthermore, rebreathing can be detected expeditiously as the wave form abnormality is identifiable in the expiratory phase. 

The following capnograph goes further in simultaneously displaying a volume capnogram and physiological dead space breath-by-breath. The respiratory quotient and energy expenditure is also calculated. These options are of great value in intensive care patients. Since the tidal volumes can be measured to as low as 2 ml per breath, it seems advantageous in newborns and neonates. 


Respiratory flow rates over time capnogram

Respiratory flow rates over time capnogram