Linked from
The 10 pages that link to Capnography, each with the reason it gives.
Respiratory depressionRelated: It can detect inadequate ventilation before oxygen saturation falls.
SedationRelated: It can reveal hypoventilation before oxygen saturation falls.
HyperventilationRelated: End-tidal carbon dioxide often falls when ventilation is excessive.
General anaestheticRelated: It helps detect ventilation problems during general anaesthesia.