Critical Illness Related Cardiac Arrest (CIRCA): a prospective investigation of the incidence and outcome of cardiac arrest within intensive care units in the United Kingdom.

Abstract

BACKGROUND: Cardiac arrest is frequently categorised by the event location, capturing differences in epidemiology, response and outcome. In the United Kingdom (UK) the National Cardiac Arrest Audit excludes arrests not attended by the resuscitation team, such as in many Intensive Care Units (ICU). Differences in staffing and skill mix within ICUs mean the risk of cardiac arrest occurring, the involvement (or not) of the resuscitation team, and the probability of return of spontaneous circulation (ROSC) are all likely to differ from other locations. This study aimed to determine the incidence proportion, risk factors and outcomes of in-hospital cardiac arrest (IHCA) in the ICU. METHODS: This was a 12-month prospective observational study of in-hospital cardiac arrest within 93 adult ICUs in the UK with data linkage to two national clinical audits. The recruitment period was adapted to accommodate the first two waves of the COVID-19 pandemic. RESULTS: In a 53,620 patient cohort, 726 experienced IHCA in ICU [Incidence proportion = 1.4 % (95 % CI 1.3-1.5 %)]. Of these, 35.4 % and 29.6 % survived to ICU and hospital discharge and 18.7 % survived to 12 months. Logistic regression revealed male sex, non-white or not stated ethnicity, CPR within 24 h before ICU admission and source of/reason for ICU admission were associated with increased risk of IHCA in ICU. For those with ROSC, increasing age, COVID-19 and increasing duration of resuscitation attempt were associated with a lower probability of survival to hospital discharge. Survivors had a reduced quality of life. CONCLUSION: Cardiac arrest is common in ICUs and carries high mortality, although pandemic-related study disruption reduces the certainty in our results. We highlight the role of ethnicity, existence of sub-phenotypes, and trials specific to cardiac arrest in the critically ill as areas for further research to reduce incidence and improve outcomes. TRIAL REGISTRATION: The CIRCA Study was registered at ClinicalTrials.gov on 7th January 2020 (NCT04219384).