A 70-year-old man with a dual-chamber permanent pacemaker implanted for complete heart block is posted for transurethral resection of the prostate. Monopolar electrocautery will be used. Which intraoperative measure is MOST appropriate to prevent device malfunction?

• A Place a magnet over the device and proceed without further checks
• B No precautions are needed because modern devices are immune to electromagnetic interference
• C Suspend pacing entirely whenever cautery is activated
• D Reprogram the pacemaker to an asynchronous mode (VOO/DOO) before surgery ✓

Explanation

Electromagnetic interference from monopolar cautery can be misinterpreted as intrinsic cardiac activity, causing inappropriate inhibition of output in demand mode. Reprogramming to asynchronous mode guarantees fixed-rate pacing independent of sensing and is the standard recommendation. The magnet response differs between manufacturers and may not ensure asynchronous behaviour throughout the case, so option A is unreliable. Suspending pacing risks asystole in a pacemaker-dependent patient, and modern devices remain susceptible to interference.

Reference: Morgan and Mikhail's Clinical Anesthesiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.