Aspects on the increase in bystander CPR in Sweden and its association with outcome

To describe changes in the proportion of bystanders performing cardiopulmonary resuscitation (CPR) in out of hospital cardiac arrest (OHCA) in Sweden and to study the impact of bystander CPR on ventricular fibrillation and on survival during various times.

All patients who suffered from OHCA in Sweden in whom CPR was attempted and who were included in the Swedish cardiac arrest register (SCAR) between 1992 and 2005. Crew witnessed cases were excluded.

In all 34,125 patients were included in the survey. Among witnessed OHCA the proportion of patients receiving bystander CPR increased from 40% in 1992 to 55% in 2005 (p<0.0001). In non-witnessed OHCA the corresponding proportion increased from 22% to 44% (p<0.0001). There was a significant increase in bystander CPR regardless of age, sex and place. The increase was only found when CPR was performed by lay persons (21% in 1992 to 40% in 2005; p<0.0001). Bystander CPR was associated with an increased proportion of patients found in a shockable rhythm and a lower number of shocks to receive return of spontaneous circulation. Bystander CPR was associated with a similar increase in survival early and late in the evaluation.

There was a marked increase in bystander CPR in OHCA, when performed by lay persons, during the last 14 years in Sweden. Bystander CPR was associated with positive effects both on ventricular fibrillation and survival.