Therapeutic hypothermia after cardiac arrest har shown to improve the rate of survival in a significant way. However hypothermia also causes leak of fluid into the surrounding tissue. This edema could lead to damage to the same tissue, not beneficial for the patients. We therefore try to evaluate if hyperosmolar, hyperoncotic fluid as an alternative to std. treatment (NaCl/RA)could affect the edema in a positive way, and result to a better outcome neurological for the patients.

After the patients are admitted to our hospital we randomise them to either std. fluid therapy (NaCl/RA) or HyperHAES. After PCI we state the rate of cerebral edema by carrying out a cerebral MRI before the cooling starts. We treat the patients with the different fluids for 24 hours. We then evaluate the edema after 24 and 72 hours by the same method. In addition we state the rate of peripheral capillary leak by Wick'S method. The capillary leak is calculated every 8.th hour for the 1. day the patients are treated in our ICU. AFter 1 year, those who survive are invited to a follow-up where we test the patient using Mini MEntal Status, SF-36, in addition to neurophysiological tests as EEG and the P300-test. We then relate the results to the fluid given initially after the cardiac arrest.

Inclusion Criteria:

• Witnessed cardiac arrest,
• ALS started within 15 min.
• ROSC within 60 min.
• Still unconscious,
• Age 18-80

Exclusion Criteria:

• Other malignancies,
• Persons who wake up,
• Pregnancy