Read the time capnogram — phases I–III, the alveolar plateau and the end-tidal CO₂. Load a pathology (obstruction shark-fin, rebreathing baseline, curare cleft, oesophageal intubation) and interpret the change in shape and ETCO₂ value.
CAPNOGRAPHYNORMAL
CO₂--mmHg
ETCO₂
--mmHg
RESP RATE
--/min
INSPIRED CO₂ (FiCO₂)
--mmHg
PATTERN
—
Pathology
Adjustments
Normal capnogram — phases
I — inspiratory / dead-space baseline (≈0) · II — expiratory upstroke · III — alveolar plateau → ETCO₂ · 0 — inspiratory downstroke.
The α angle (II→III) widens toward a slurred shark-fin in obstruction.