Characteristics and Outcome in Out-of-hospital Cardiac Arrest when Patients Are Found in a Non-shockable Rhythm

Aim: To define factors associated with an improved outcome among patients suffering out-of-hospital cardiac arrest (OHCA) who were found in a non-shockable rhythm.

Patients: All the patients included in the Swedish OHCA registry between 1990 and 2005 in whom resuscitation was attempted, who were found in a non-shockable rhythm and where either the OHCA was witnessed by a bystander or was not witnessed.

Results: In all, 22,465 patients fulfilled the inclusion criteria. Their mean age was 67 years, 32% were women, 57% were witnessed, 64% had a cardiac aetiology, 71% occurred at home and 34% received bystander cardiopulmonary resuscitation (CPR). Survival to 1 month was 1.3%. The following were independently associated with an increased chance of survival: 1/Decreasing age, 2/Witnessed arrest, 3/Bystander CPR, 4/Cardiac arrest outside home, 5/Shorter ambulance response time and 6/Need for defibrillatory shock. If these six criteria were fulfilled (age and ambulance response time below the median), survival to 1 month increased to 12.6%. If no criteria were fulfilled, survival was 0.15%.

Conclusion: The overall survival among patients with an OHCA found in a non-shockable rhythm is very low (1.3%). Six factors associated with survival can be defined. When they are taken into account, survival varies between 12.6 and 0.15%.