The primary objective is to show superiority in survival of the modified method with the LUCAS Chest Compression System, compared to the conventional manual resuscitation method in patients suffering from out of hospital sudden cardiac arrest.

Every year 300 000 to 400 000 people suffer from sudden cardiac arrest outside of the hospital in Europe. Only 5 - 7 % of these patients survive and are discharged from hospital. In spite of massive education, research and new methods the survival rate has not improved. In the latest international guidelines for CPR, published in 2005, there is a strong emphasis on chest compressions with as little interruptions as possible. Manual chest compressions during CPR result in only 20-30% of normal blood flow and are difficult to perform for a long period of time. Mechanical chest compressions with the LUCAS device have shown increased blood flow in experimental studies. Defibrillation during ongoing mechanical compressions is a new method of treatment that showed promising results in increased short time survival in out of hospital cardiac arrest in a recently completed pilot study.

The LINC trial is a prospective randomised multicenter study where LUCAS according to a concept will be used with simultaneous defibrillation compared to manual chest compressions according to 2005 guidelines for advanced CPR. The study will be conducted in first tier systems, where LUCAS always will be placed in the first arriving ambulance.

Inclusion Criteria:

• Unexpected adult out-of-hospital cardiac arrest where an attempt of resuscitation is considered appropriate.

Exclusion Criteria:

• Traumatic cardiac arrest, including hanging
• Age believed to be less than 18 years (no upper limit)
• Known pregnancy
• Defibrillated before LUCAS Chest Compressions System arrives at scene
• Patients body size not fitting the LUCAS Chest Compression System