Duration of CPR and impact on 30-day survival after ROSC for in-hospital cardiac arrest-A Swedish cohort study.

OBJECTIVES: Resuscitation on in-hospital cardiac arrest (IHCA) is estimated to occur in 200,000 hospitalised patients annually in the US. The duration of the resuscitation attempt, measured as minutes of cardiopulmonary resuscitation (CPR), and its impact on survival remains unknown.

AIM: Investigate if there is a difference in 30-day survival among IHCA who experience return of spontaneous circulation (ROSC) depending on the duration of CPR.

MATERIAL AND METHODS: All patients ≥18 years who experienced ROSC after an IHCA at Karolinska University Hospital between 2007 and 2017 were included. Data regarding the IHCA, patient characteristics, and death dates were obtained from medical records linked to Swedish national registries. Patients who experienced ROSC were stratified into quartiles depending on the length of CPR (in minutes). The difference in 30-day survival between the quartiles (Q) was assessed with adjusted logistic regression models and presented as odds ratios with 95% confidence intervals (OR 95% CI). Adjustments included sex, age, Charlson Comorbidity Index, first rhythm, ECG-surveillance, witnessed or not, time between CA and call, year of IHCA and location of the IHCA.

RESULTS: In all, 1639 patients suffered an IHCA, of whom 840 (51%) experienced ROSC and 471 (29% of the total, 56% of those with ROSC) survived for at least 30 days. Among the 840 patients with ROSC, 768 (91%) had a documented duration of their CPR in their medical file with a median of 5 min (interquartile range 2-12 min). Among those with ROSC, the adjusted OR for 30-day survival was OR 0.69 (0.37-1.29) for Q2 (3-5 min), 0.35 (0.19-0.65) for Q3 (6-12 min) and 0.10 (0.05-0.20) Q4. A cut-off time of 15 min, 20 min and 60 min, respectively, captures 90%, 95% and 99% of the 30-day survivors.

CONCLUSION: Resuscitation attempts on IHCA are often short and duration of CPR is associated with 30-day survival among those with ROSC. Still, the 30-day survival is high enough to question the use of CPR duration as a prognostic marker in post-resuscitation care, and ideal duration of resuscitation should remain a bedside decision taking into consideration the whole clinical picture.