Hyperbaric oxygen therapy in resuscitation medicine

Individuals who suffer from cardiac arrest (CA) still show considerably low chances of being successfully resuscitated. However, also after return of spontaneous circulation (ROSC), neurological deficits are frequent (e.g., difficulties in movement or psychological problems). These ongoing problems can often only be treated up to a certain level, and many patients show a lifelong impairment of their daily activities. A method for treating these cerebral lesions that has so far only been scarcely investigated is hyperbaric oxygen therapy (treatment in a hyperbaric chamber with additionally breathing 100% oxygen, short HBOT). This treatment is currently used, for instance, after diving accidents. In animal studies and case series, it could be shown that HBOT might have a place in the treatment of cerebral impairment after CA: Effects range from anti-inflammatory properties or a reduction in brain swelling to new growth of blood vessels and neurons. The planned study aims at conducting HBOT after CA in a structured way in order to draw conclusions that can serve as a basis for future studies with several international centres. There will be three study groups: (1) Patients who are treated at an intensive care unit directly after their CA (assessing the effects of HBOT immediately after the episode); (2) patients who have already been discharged from hospital after their CA (assessing potential effects long after the CA); and (3) volunteers (assessing HBOT-effects on healthy individuals as a comparison). In each of these groups, it will also be distinguished in a randomized manner between patients receiving HBOT and those only serving as controls. In addition, various lengths of treatment will be investigated. In terms of measurements, primarily markers of inflammation in the patients blood will be assessed. Moreover, blood vessel function will be evaluated, and neuropsychological tests will be conducted. Thus, it will be determined if a noteworthy effect of HBOT in patients after CA is present, and if future larger studies should be planned.