How often should rhythm checks occur during CPR?

• A. Every 3 minutes
• B. Every 1 minute
• C. Every 2 minutes
• D. Only when there is time

Answer: (C)

Rhythm checks during CPR are done at regular intervals to balance keeping blood flowing with the need to reassess the heart rhythm for possible shocks. The recommended interval is every two minutes, which roughly equals five cycles of CPR (for an adult, 30 compressions followed by 2 breaths). This timing ensures a timely update if the rhythm changes to a shockable one, without causing frequent pauses that would cut perfusion. Checking more often, such as every minute, would create unnecessary interruptions, while checking less often, like every three minutes, could delay recognizing a change that warrants a shock. So the best practice is to perform rhythm checks every two minutes.