Gain a deep understanding of what ETCO₂ truly measures and why it reflects the real-time balance between ventilation, perfusion, and metabolism. Learn how capnography provides a more accurate picture of patient physiology than traditional vital signs alone.

Meet the key physiologic systems — the lungs, the bloodstream, and cellular metabolism — and discover how each contributes to producing the ETCO₂ value and waveform. This chapter builds the foundation for interpreting what “normal” truly looks like.

Explore the major conditions that disrupt ventilation, perfusion, or metabolism, and learn how each creates a predictable change in ETCO₂. You’ll be able to rapidly identify patterns that signal shock, sepsis, respiratory failure, and metabolic derangements.

Learn how to read the waveform like a narrative, using shape, angle, and pattern to diagnose airway obstruction, bronchospasm, hypoventilation, hyperventilation, rebreathing, and equipment issues. This chapter unlocks the ability to “see” physiology at a glance.

Apply ETCO₂ in cardiac arrest to guide compressions, predict outcomes, identify ROSC, and drive real-time decision-making. You’ll learn how capnography transforms resuscitation from guesswork into precision performance.