Safety and efficacy of a prehospital initiated protocol of nitrates plus non-invasive ventilation on prehospital and Emergency Department outcomes for acute cardiogenic pulmonary oedema

Background Acute heart failure is a common presentation to Emergency Departments (ED) the world over. Amongst the most common presenting signs and symptoms is dyspnoea due to acute pulmonary oedema, a life threatening emergency that if left untreated or poorly managed. There is increasing evidence demonstrating improved outcomes following the use of vasodilators or non invasive ventilation for these patients in the emergency setting. Consequently, the potential exists that initiating these therapies in the prehospital setting will similarly improve outcomes. Methods A historical cohort study was conducted to assess the effect of a prehospital initiated treatment protocol of nitrates plus non invasive ventilation (NIV) versus regular therapy for severe cardiogenic APO on all-cause in-hospital mortality at 7 days, 30 days, and in total. Secondary outcomes included changes in EMS respiratory and haemodynamic parameters; admission status; length of stay; and emergency endotracheal intubation. Results The intervention led to an approximate 85% reduction in adjusted odds of mortality at 7 days compared to the regular therapy (AOR 0.15, 95% CI: 0.05 to 0.46, p = 0.001); approximate 80% reduction in odds of mortality at 30 days (AOR 0.19, 95% CI: 0.07 to 48, p < 0.0001); and Approximate 60% reduction in odds of total mortality (AOR 0.25, 95% CI: 0.12 to 0.56, p = 0.001). Conclusion The results of this analysis provide strong evidence of the potential synergistic benefits that can be achieved with the early implementation of a simple treatment protocol of prehospital administered nitrates and initiation of NIV for cardiogenic APO.