Interpret capnography waveform changes during tube dislodgement, bronchospasm, and pulmonary embolism.

Interpret capnography waveform changes during tube dislodgement, bronchospasm, and pulmonary embolism.

• A. Disconnection yields abrupt ETCO2 drop to zero; bronchospasm shows a prolonged expiratory upstroke and decreased ETCO2; PE may show sudden ETCO2 drop with impaired pulmonary perfusion and increased dead space.
• B. Disconnection: abrupt ETCO2 spike to high; bronchospasm: flat line; PE: increased ETCO2.
• C. Disconnection: normal ETCO2; bronchospasm: prolonged rise; PE: no change.
• D. Disconnection: gradual rise in ETCO2; bronchospasm: ETCO2 disappears; PE: no change.

Answer: (A)