Bhavani Shankar Kodali MD
Analysis of CO2 waveforms:
The descending limb can be prolonged or slanted, when the inspiratory valve of a closed circuit system is incompetent.1-3 or because of the use of side-stream sensor capnographs, with a prolonged response time.4 The capnograph with a prolonged response time also results in the prolongation of phase II and is observed commonly in children.4,5
Ripple effect: At slow respiratory rates it is common to see a ripple effect, referred to as cardiogenic oscillations, superimposed on the expiratory plateau and the descending limb of the capnogram. This arises from small gas movements created largely by the pulsations of the aorta and heart.6-8
|Inspiratory valve malfunction resulting in prolongation of descending inspiratory limb in addition to prolongation of alveolar plateau|
|Normal||Prolonged inspiratory descending limb due to dispersion gases in the sampling line or as well as prolonged response time of the analyzer. Seen in children who have faster respiratory rates.|
|Cardiogenic oscillations. Ripple effect, superimposed on the plateau and the descending limb, resulting from small gas movements produced by pulsations of the aorta and heart.|
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