a randomized, parallel, non-blinded trial in a single Emergency Mdeical Service in Poland within a group of 34 ground ambulances crews, comparing time and first pass success (FPS) for endotracheal intubation (ETI) in DL using the IntuBrite® (INT) and Macintosh laryngoscope (MCL) during cardiopulmonary resuscitation (CPR). intubations will be performed using INT and MCL based on an intention-to-treat analysis. The FPS time of the ETI attempt will be analysed. First attempt success will be counted.

Investigators designed a prospective observational study to compare INT (IntuBrite®, LLC; Vista, CA, USA) and MCL for ETI performed by paramedics in OHCA without an emergency physician on the scene. The main goal was to determine whether INT is superior to using an MCL laryngoscope during a tracheal intubation attempt in nontraumatic OHCA, in terms of time and effectiveness.

The time of intubation was measured using an electronic stopwatch. Time measurement began when the paramedic held the selected laryngoscope and declared their readiness to perform the procedure.

The effectiveness of the first ETI attempt for instrumental airway management for nontraumatic adult OHCA and end-tidal carbon dioxide monitoring was used to confirm correct device placement in all patients.

The degree difficulty of intubation attempts for all of the patients included in the study. A long-term survival and a cost-effectiveness analysis were not included within this trial.

The investigators will collect case report forms (CRFs) from patients after OHCA within a 40-month period.

The average professional experience of the paramedics in instrumental airway management will be noted (DL and LMA). The primary outcome is the FPS time of the ETI attempt performed by the paramedics.

The success rate on the first intubation attempt will be counted.

Inclusion Criteria:

• patients in cardiac arrest , requiring cardiopulmonary resuscitation

Exclusion Criteria:

• suspected difficult intubation