High-dose versus low-dose intravenous nitroglycerine for sympathetic crashing acute pulmonary edema: a randomised controlled trial

Objectives Sympathetic crashing acute pulmonary edema (SCAPE) is a subset of heart failure with a dramatic presentation. The unique physiology of this condition requires a different management strategy from the conventional practice. The trial objective was to compare the efficacy of high-dose and low-dose GTN in patients with SCAPE.Methods This was an open-label randomised control trial conducted in a tertiary care teaching hospital in India from 11 November 2021 to 30 November 2022. Consenting participants were randomised to high-dose GTN or conventional low-dose GTN. The primary outcome was symptom resolution at 6 hours and 12 hours. Secondary outcomes included intubation rates, admission rates, length of hospital stay, and any short-term adverse effects of GTN and major adverse cardiac events (MACE) at 30 days.Results Fifty-four participants were included (26 high-dose GTN, 26 low-dose GTN). At 6 hours, symptom resolution was seen in 17 patients (65.4%) in the 'high-dose' group, compared with 3 (11.5%) in the 'low-dose' group (p<0.001). At 12 hours, 88.5% of patients had a clinical resolution in the 'high-dose' arm versus 19.5% in 'low-dose' arm . The low-dose group had longer median hospital stay (12 hours vs 72 hours), more frequent MACE (3.8% vs 26.9%, p=0.02) and a higher intubation rate (3.8% vs 19.2%, p=0.08). The only short-term adverse effect seen was a headache in both the groups.Conclusion In SCAPE, patients receiving high-dose GTN (>100 mcg/min) had earlier symptom resolution compared with the conventional 'low dose' GTN without any significant adverse effects.