Capno-Quiz-Clip arts 

Bhavani Shankar Kodali MD

Do you understand capnography? Check yourself


This section can be used in two ways. If you saw a capnogram in the operating room today and you want to know what it is,  identify the shape of the capnogram below and place the cursor over it to know the details. You can double click for a separate window showing details.


Take a quiz and see if you are right. For the answer take the cursor to the capnogram. You can double click for a separate window showing details.


This is a normal capnogram

Capnogram seen during spontaneous ventilation


This is a curare cleft capnogram

This is a dual waveform capnogram seen during sampling leaks. Can also occur due to differential lung emtying.


Hyperventilation capnogram. Progressive decrease in the height of the capnogram. Progressive depression in cardiac output and metabolism can also result in a decrease in the height of the capnograms

Sudden rise in the base line and height may occur due to contamination of the monitor


Progressive decreases in cardiac output resulting in decreasing CO2 output. Following cardiac arrest, there is successful resuscitation leading to progressively increasing CO2.

Base line remains at zero. There is a progressive increase in the height of the capnogram


The slope of the phase III is increased. This is a physiological variation. Pathologically, it can result from airway obstruction

Phase II is prolonged and slope of phase III is increased as in airway obstruction / Bronchospasm


Signature capnogram of Bain anesthetic system / Mapelson D



IMV breaths interposed during spontaneous ventilation

Inspiratory valve malfunction.



Inspiratory valve incompetency resulting in the prolongation of the plateau. Red indicates inspiration.

Ripple effect- Cardiogenic oscillations



Phase 4 recorded during anesthesia for cesarean section. Terminal upswing.

Side stream sensor capnographs in infants and children can produce distortion of waveforms due to dispersion of gases in the sampling lines.


Capno-Quiz page 2