In SCAPE—a hypertensive, rapidly progressive form of cardiogenic pulmonary edema—the two immediate, evidence-supported cornerstones are noninvasive ventilation (NIV) and aggressive afterload reduction with high-dose nitroglycerin (NTG). Loop diuretics are adjuncts, typically given after blood pressure and work of breathing are controlled. Avoid delays, avoid morphine, and reassess frequently. (1–7, 10)
What is SCAPE?
A rapidly evolving, sympathetically driven pulmonary edema characterized by sudden severe dyspnea, marked hypertension (often SBP ≥160 mmHg/MAP ≥120), flash alveolar edema, and intense afterload excess. The pathophysiology is dominated by afterload and sympathetic surge, not primary fluid overload—hence the primacy of vasodilation and NIV. (9, 10)
ED protocol (step-wise)
1) Immediate actions (time zero)
Position upright; place monitors, obtain IV access.
NIV without delay (CPAP or BiPAP). Start CPAP ~10 cm H₂O (or BiPAP e.g., IPAP 12–15/EPAP 8–10), titrate to relieve dyspnea and improve oxygenation. NIV reduces intubation and mortality in cardiogenic pulmonary edema. (5, 6)
Avoid morphine; not beneficial and may worsen outcomes in acute heart failure. (7)
2) Rapid afterload reduction (first minutes)
High-dose IV nitroglycerin (preferred):
Bolus: 600–1000 mcg IV over 1–2 minutes (alternatively, 2–3 SL sprays/tablets while setting up IV).
Infusion: start 100–200 mcg/min, titrate up (e.g., by 20–40 mcg/min every few minutes) to relieve distress while maintaining MAP ≥65 and avoiding abrupt hypotension. (1–4, 9)
Rationale & evidence: RCT and observational data in SCAPE favor high-dose over traditional low-dose NTG for faster symptom resolution and lower intubation/admission, though studies are small and mostly single-center; a 2025 systematic review suggests benefit but calls for larger trials. (1–4)
3) If still hypertensive/distressed despite NTG + NIV
Consider nitroprusside with arterial line monitoring when available/experienced, or escalate NTG further if tolerated. (7, 9)
4) Diuretics—adjunct, not first-line
Once afterload and work of breathing improve (often within 15–30 minutes), give IV loop diuretic (e.g., furosemide 40–80 mg, higher if diuretic-tolerant chronically). The goal is decongestion after the acute sympathetic storm is controlled. (7, 9, 10)
5) Search for and treat precipitants
Hypertensive emergency, ACS, tachyarrhythmia, medication non-adherence, renal failure, high-salt load, etc. Start ACS pathway if suspected; NTG is compatible. (7, 9)
6) Monitoring, reassessment, and targets
Reassess every few minutes: dyspnea, RR, SpO₂, BP/MAP, mental status.
Point-of-care ultrasound: B-lines, lung sliding, IVC, and focused cardiac views (LV function, gross valvular disease). (9)
Targets (first hour): visible relief of distress, SpO₂ ≥92% on decreasing support, gradual SBP reduction (~20–25%) without hypotension. (7, 9)
7) Special cautions & contraindications
Do not give NTG if recent PDE-5 inhibitor use (sildenafil <24 h; tadalafil <48 h).
Use extreme caution or avoid potent vasodilators in moderate–severe aortic stenosis or hypertrophic cardiomyopathy. (1, 7, 9)
If shock or right-sided failure suspected, reassess diagnosis—SCAPE is typically hypertensive, not hypotensive. (9)
8) Disposition
ICU/step-down if on NIV, continuous vasodilators, or persistent instability.
Consider monitored floor only after off NIV/infusions, symptoms controlled, and triggers addressed. (7)
Practical medication summary (for bedside use)
Nitroglycerin (first-line):
Bolus: 600–1000 mcg IV (or 2–3 SL sprays/tablets while IV being prepared).
Infusion: start 100–200 mcg/min; titrate rapidly to response; decrease if MAP <65 or symptomatic hypotension. (1–4, 9)
NIV: CPAP 10–12 cm H₂O (or BiPAP, e.g., 14/8), titrate based on comfort and gas exchange. (5, 6)
Loop diuretic: after stabilization, furosemide 40–80 mg IV (adjust for chronic dose/renal function). (7, 9)
Consider: nitroprusside when NTG insufficient and expertise/monitoring available. (7)
Evidence summary
NIV consistently reduces intubation and mortality in acute cardiogenic pulmonary edema. (5, 6)
High-dose NTG in SCAPE shows faster symptom resolution and favorable secondary outcomes vs low-dose in a 2024 RCT, with supportive observational data and a 2025 systematic review/meta-analysis—quality moderate-to-low and mostly single-center, but physiologically compelling. (1–4)
Contemporary heart-failure guidance and ED reviews prioritize vasodilators and NIV up front in hypertensive pulmonary edema; morphine is discouraged. (7)
References
(1) Siddiqua N, Mathew R, Sahu AK, et al. High-dose versus low-dose intravenous nitroglycerin for SCAPE: randomized controlled trial. Emerg Med J. 2024;41(2):96–102.
emergencymed.org.il
(2) Houseman BS, Martinelli AN, Oliver WD, et al. HI-DOSE SCAPE: high-dose nitroglycerin infusion—safety and efficacy. Am J Emerg Med. 2023;63:74–78.
(3) Mathew R, Kumar A, Sahu A, et al. High-dose nitroglycerin bolus for SCAPE: prospective pilot. J Emerg Med. 2021;61(3):271–277.
(4) Pramudyo M, Kamarullah W, Pranata R, et al. Low- vs high-dose nitroglycerin in SCAPE: systematic review & meta-analysis. BMJ Open. 2025;15(6):e099142.
(5) Gray A, Goodacre S, Newby DE, et al. Noninvasive ventilation in acute cardiogenic pulmonary edema. N Engl J Med. 2008;359:142–151.
(6) Masip J, Roque M, Sánchez B, et al. Noninvasive ventilation in acute cardiogenic pulmonary edema: meta-analysis. JAMA. 2005;294:3124–3130.
(7) ESC Guidelines (2021) and 2023 Focused Update for acute/chronic heart failure—acute pulmonary edema management (NIV, vasodilators; avoid morphine). Eur Heart J. 2021 & 2023 Updates.
(8) Emergency medicine update on SCAPE. Am J Emerg Med. 2025 (narrative review).
(9) EMCrit IBCC: SCAPE (expert synthesis of diagnosis and treatment, updated 2025).
(10) Cotter G, et al. Treatment of acute pulmonary oedema: diuresis or vasodilatation? Lancet. 1998;351: (classic discussion supporting vasodilators).
