Compliance with CPR quality guidelines and survival after 30 days following out-of-hospital cardiac arrest. A retrospective study.

Background: Our study assessed the quality of cardiopulmonary resuscitation (CPR) given by emergency medical services in Southern Ostrobothnia Finland, as is advised in the international guidelines. The goal was to evaluate the current quality of CPR given to patients who suffered an out-of-hospital cardiac arrest and to examine possible measures for improving emergency medical services.

Methods: A retrospective study was conducted on out-of-hospital cardiac arrest patients in Southern Ostrobothnia, Finland, during a three-year period. Confounding caused by each patient's individual medical history was addressed by calculating Charlson Comorbidity Index (CCI), a score describing individual's risk for death in 10 years. The Utstein analysis and the CPR metrics were acquired from the medical records hospital district in question and analysed in an orderly manner using SPSS. Descriptive statistics are presented as mean (SD) and median [IQR].

Results: We found that of the 349 patients, 144 (41%) received ROSC, 96 (28%) survived to the hospital and 51 (15%) survived for at least 30 days. CPR metrics data were available for 181 patients. CCIs were 3.0 versus 5.0 (p = .157) for the ones who did and those who did not survive at least 30 days. Correspondingly, following metrics were as follows: Mean compression depth was 5.1 (1.3) versus 5.6 (0.8) cm (p = .088), median 28 [18;40] versus 40 [26;54]% of the compressions were in target depth (p = .015) and median compression rate was 113 [109;119] versus 112 [108;120] min^-1 (p = .757). The median no-flow fraction was 5.1 [2.8;7.1] versus 3.7 [2.5;5.5] s (p = .073). Ventricular fibrillation (OR 8.74, 95% CI 2.89-26.43, p < .001), public location (OR 3.163, 95% CI 1.03-9.69, p = .044) and compression rate of 100-110/min (OR 7.923, 95% CI 2.11-29.82, p = .002) were related to survival.

Conclusion: Patients who suffered out-of-hospital cardiac arrest in Southern Ostrobothnia received CPR that met the international CPR quality target values. The proportion of unintentional pauses during CPR was low and the 30-day survival rate exceeded the international average.