Phase 1 in this normal capnograph represent which pa of expiration:-
Cellular metabolism produces carbon dioxide, while the lungs work to eliminate it from the body. The balance between production and elimination can be followed in the rise and fall of EtCO2 as displayed by the capnogram. More specifically, EtCO2waveforms provide clinicians with a tool for quick and reliable diagnoses of common pulmonary pathophysiology. Generally, EtCO2is displayed as a waveform with paial pressure of CO2on the y-axis and time on the x-axis (see the images below). Normal breathing. The capnogram has four phases, as follows: Phase I represents the end of inspiration, and early expiration of gas from dead space (circuit tubing, anatomic) Phase II represents gas from late anatomic and alveolar dead space, upsloping as alveolar gas mixes in and raises the CO 2 Phase III (plateau) represents the paial pressure of carbon dioxide exchanged at the alveoli; the amplitude of the plateau is referred to as EtCO 2;phase III normally has a very slight upslope due to physiologic V/Q mismatch Phase IV signifies the sta of inspiration, and the capnogram reflects the transition at the sampler from alveolar air flow to fresh air flow, or "scrubbed" air, in a closed circuit Of note, the information captured by end-tidal capnography (paial pressure of CO2) is devoid of volumetric information. Therefore, capnography should be used with end-tidal volume measurements to fully assess ventilation parameters.
Dead space ventilation
Alveolar ventilation
Both
None
Monitoring in Anesthesia