Every procedural facilitation or a change in available equipment in treatment of out-of-hospital arrest (OHCA) by two-person teams may significantly enhance their performance quality. The aim of this study was to assess the impact of adrenaline in prefilled syringes on improving the adherence to Advanced Life Support protocol by understaffed teams. The research was based on a randomized cross-over high-fidelity simulation study. Two-person teams took part in two 10-minute simulation scenarios featuring sudden cardiac arrest in ventricular fibrillation (VF). The control group (group C) had at its disposal standard ampoules, whereas the experimental group (group E) prefilled syringes. The execution times of CPR start, defibrillation shocks, intravenous (IV) access, epinephrine and amiodarone doses were measured. Additionally, the chest compression fraction (CCF) was calculated. The designed two-minute loops were considerably prolonged in group C. Nineteen teams (31.1%) in group C but 49 (80.3%) in group E carried out the fifth defibrillation (P < 0.001). After two minutes of CPR nobody in group C switched to perform chest compressions. IV access was obtained significantly earlier in group E (114.7 ± 52.2 sec) than in group C (150.2 ± 68.6 sec)(P = 0.002). Two doses of adrenaline were administered in group E, whereas its second dose only by 12 teams in group C. The simulation study has proved that for understaffed teams a use of prefilled syringes not only did enhance the flow of ALS procedure, but it also improved the quality of cardiopulmonary resuscitation.