Capnography and oesophageal intubation — FRCA Primary MCQ

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EasyPhysics and Clinical MeasurementCapnography and oesophageal intubationFRCA Primary

After emergency intubation, chest movement is poor and the capnograph shows no sustained expired CO2 after several ventilations. What is the most likely explanation?

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Correct answer: C — Oesophageal intubation

Absent sustained expired CO2 after ventilation strongly suggests oesophageal intubation, although profound cardiac arrest can reduce CO2 delivery to the lungs. Endobronchial intubation usually still produces a capnogram. Malignant hyperthermia and raised metabolic rate increase CO2 production. Continuous waveform capnography is the key confirmation of tracheal placement.

Reference: Association of Anaesthetists monitoring standards; Dorsch and Dorsch Understanding Anesthesia Equipment