Trends and variation in use of end-tidal carbon dioxide during in-hospital cardiac arrest: an observational cohort study

The study examined the use of end-tidal carbon dioxide (ETCO2) during in-hospital cardiac arrest based on registry data collected from 2000 to 2023. Among 257,057 cardiac arrest cases with a newly placed airway, 92.6% were confirmed using ETCO2 during 2019–2023. Of the total 554,693 cardiac arrest cases with a new or existing airway, only 35.3% were monitored with ETCO2 to assess cardiopulmonary resuscitation during the same period. Variation among hospitals in confirming airway placement was minimal with a median of 94.0%, but high variation was observed in resuscitation monitoring. The results show that ETCO2 is widely used to confirm airway placement, but gaps remain in adherence to guideline recommendations for monitoring resuscitation with ETCO2.