Apnoea Test PaCO2 Target — FRCA Final MCQ

Instant feedback + full explanation. One question, done properly.

HardMedicolegal & EthicsApnoea Test PaCO2 TargetFRCA Final

A patient in ICU is being assessed for brain death. During the apnoea test, what is the target PaCO2 that must be reached to confirm absent respiratory drive?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Any rise in PaCO2 above baseline

According to the Academy of Medical Royal Colleges (2008) code of practice, the apnoea test requires the PaCO2 to reach >6.65 kPa (50 mmHg) AND to have risen by at least 0.5 kPa above the pre-test baseline. The patient is pre-oxygenated, disconnected from the ventilator (with O2 insufflation via a catheter in the trachea), and observed for any respiratory effort. An ABG is taken after 5 minutes (or when SpO2 falls to 90%). Absence of any respiratory effort at a PaCO2 >6.65 kPa confirms absent brainstem respiratory centre function.

Reference: Academy of Medical Royal Colleges – 2008 – Code of practice for diagnosis and confirmation of death