Physical and psychological problems reported by cardiac arrest survivors and interventions to treat these problems

The number of people surviving a cardiac arrest is increasing due to improvements in pre-and postresuscitation care. However, survival can come with a range of physical and psychological problems due to hypoxic brain injury, trauma of the event or ongoing cardiac disease. Severe brain injury is rare with most survivors returning home but fatigue, anxiety, depression, cognitive deficits and disability may all be present leading to reduced health related quality of life and participation in society. To date, the majority of studies investigating these problems have focused on the short-term, <12 months after the event while less is known about whether these problems resolve in the longterm.

To treat post-cardiac arrest problems, international guidelines recommend cardiac arrest survivors receive information, support and referral to specialist rehabilitation. However, there is a lack of knowledge on the effectiveness of rehabilitation interventions for cardiac arrest survivors and there are currently no specialist interventions for cardiac arrest survivors in Denmark.

This thesis aimed to meet these gaps in the current evidence base via three studies. Study 1 investigated the physical and psychological problems suffered by cardiac arrest survivors in the longterm via the DANCAS (DANish Cardiac Arrest Survivorship) survey. Study 2 assessed the existing evidence for the effectiveness of rehabilitation interventions for survivors via a systematic review. Study 3 tested the feasibility of a new rehabilitation intervention for cardiac arrest survivors in Denmark: SCARF (Survivors of Cardiac ARest focused on Fatigue.

In the first study, we found up to a third of survivors, 1-5 years after out-of-hospital cardiac arrest, report fatigue, anxiety, depression, reduced mental function and disability and this proportion does not appear to change with time. Hence, our findings support the current guidelines that advocate information provision, screening for problems and referral to tailored interventions to help survivors adapt to their new situation. Future studies, using the DANCAS survey data, will investigate survivors’ unmet information and rehabilitation needs, their cognitive status, and the self-reported needs of survivors’ relatives.

The systematic review identified fourteen studies involving rehabilitation interventions for CA survivors. However, as overall quality of evidence was low, no conclusions can be drawn on the 54 effectiveness of these interventions. We recommend existing guidelines on post-cardiac arrest management are followed while we await further high-quality studies.

In the third study, the new rehabilitation intervention, SCARF, was found to be feasible with high participant and clinician satisfaction and with the prospect to change important emotional and life activity related self-reported outcomes. However, study recruitment procedures and methods for collecting final outcome measures need to be amended before a full effect study can be conducted.

There are several challenges in undertaking research with cardiac arrest survivors. These include the wide range of potential problems suffered by survivors, the relative rarity of survivors and the lack of a common language to describe the post-cardiac arrest phase. In the short term, while we await more research evidence, improvements to current healthcare pathways and training for clinical staff on post-cardiac arrest problems may well reduce the long term impact of CA for this growing patient population.