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TOF Ratio Recovery — FRCA Primary MCQ

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HardPhysics & Clinical MeasurementTOF Ratio RecoveryFRCA Primary

After rocuronium, acceleromyography at the corrugator supercilii shows a train-of-four ratio of 0.92, but no adductor-pollicis measurement has been obtained. What is the safest interpretation before tracheal extubation?

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Correct answer: B — Confirm adductor-pollicis recovery at a quantitative ratio above 0.90

The best answer is “Confirm adductor-pollicis recovery at a quantitative ratio above 0.90”. Facial muscles recover earlier and are less sensitive than the adductor pollicis, so a facial value can falsely reassure about pharyngeal recovery. Quantitative monitoring at the adductor pollicis with a ratio at least 0.9 is the appropriate endpoint. A count of four or clinical strength tests cannot exclude residual block.

Reference: Association of Anaesthetists, Recommendations for standards of monitoring during anaesthesia and recovery 2021: https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/full/10.1111/anae.15501