Clinical Outcomes of High-dose Intravenous Nitroglycerin in Sympathetic Crashing Acute Pulmonary Edema

Abstract Introduction: Sympathetic Crashing Acute Pulmonary Edema (SCAPE) is a life-threatening form of acute heart failure requiring immediate management with noninvasive ventilation (NIV) and vasodilator therapy. Although nitroglycerin (NTG) is commonly used, optimal dosing remains uncertain. Emerging evidence suggests high-dose NTG may provide rapid clinical improvement. We aimed to evaluate the safety and efficacy of high-dose intravenous NTG in patients presenting with SCAPE to the emergency department (ED). Methods: We conducted a prospective observational study in a high-volume, busy ED, enrolling adults (>18 years) meeting established diagnostic criteria for SCAPE who received an initial intravenous NTG bolus ≥400 μg. Patients with acute coronary syndrome, trauma, recent phosphodiesterase V inhibitor use, or significant aortic stenosis were excluded. Clinical status and outcomes were assessed at 3, 6, and 12 h, and at ED disposition. The primary objective was clinical outcomes (symptom resolution, need for intubation, and ED disposition) of SCAPE patients. Results: Sixty-one patients were included. The mean NTG bolus dose was 830 μg. One patient (1.6%) developed hypotension requiring fluids and brief inotropic support. Headache occurred in five patients (8.2%). Symptom resolution was observed in 10 patients (16%) at 3 h, 32 (52.5%) at 6 h, and 55 (90%) at 12 h. Five patients (8.2%) required intubation. Overall, 41 patients (67.2%) were discharged directly from the ED. The mean ED length of stay was 14 h. Conclusion: High-dose intravenous NTG may improve clinical outcomes in the acute management of SCAPE, with rapid symptom resolution and reduced need for intubation. Larger studies are warranted to confirm these findings and to standardise dosing protocols.