Management of the reversible causes in cardiac arrest is fundamental for successful treatment of out-of-hospital cardiac arrests. Point-of-care diagnostics as prehospital emergency ultrasound, blood gas analysis and toxicological screening support the diagnostic process of evaluating potential reversible causes. Digital tools provide support of a structured approach. This study aims to evaluate the frequency of reversible causes during OHCA as well as specific interventions due to these findings. Furthermore, CPR performance (hands-off, ROSC, 30-day mortality) and cognitive load of the prehospital emergency physician will be investigated. In total 100 patients with OHCA will be included in this study. Identification of reversible causes will be performed upon a structured protocol using an interactive checklist. Cognitive load of emergency physician as well as CPR parameter (frequency of reversible causes, hands-off, ROSC, 30-day mortality) will be analysed.

Inclusion Criteria:

• Patients with prehospital cardiac arrest, where POCUS, blood gas analysis as well as screening for intoxication can integrated in ALS rhythm without delay of life-saving treatment or transportation will be included.

Exclusion Criteria:

• Patients will be excluded under the age of 18, or if POCUS, blood gas analysis will lead to a delay of live-saving treatment or transportation. Furthermore, pregnant patients will be excluded.