During surgery under cisatracurium infusion, the peripheral nerve stimulator shows NO response at all to train-of-four stimulation. To further quantify the depth of this block, the next appropriate monitoring manoeuvre is:

• A Double-burst stimulation at the orbicularis oculi
• B Tetanic stimulation at 50 Hz for 5 seconds
• C Post-tetanic count following a 50 Hz tetanus for 5 seconds ✓
• D Single twitch at 0.1 Hz and record percentage depression

Explanation

When the block is so deep that no TOF response is detectable, the post-tetanic count is used: a 5-second 50 Hz tetanus is applied and the twitches elicited in the following seconds are counted. Each counted response predicts the number of twitches that will return on TOF. Single twitch and double-burst stimulation require some existing response to be interpretable.

Reference: Miller's Anesthesia, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.