Introduction

Sympathetic crashing acute pulmonary edema (SCAPE) is a subset of hypertensive heart failure which develops

rapidly due to an abrupt increase in catecholamine release, subsequently leading to increased pulmonary capillary

permeability and flooding of alveolar space. Preload and afterload reduction is key and is managed with non-invasive

ventilation (NIV) and pharmacologic agents such as nitroglycerin. However, nitroglycerin has dose-dependent

afterload reduction that requires doses >50-150 mcg/min.

Clinical Detail

ParameterDetails
MechanismOrganic nitrate vasodilator; reduces vascular smooth-muscle tension, dilating peripheral veins and (at higher doses) arteries — lowering preload and afterload.
Dose
  • Chest pain: 5–400 mcg/min (start 5 mcg/min)
  • Pulmonary edema / afterload reduction: 50–400 mcg/min
  • Titrate to symptom improvement and tolerated blood pressure
Administration
  • IV infusion: 50–400 mcg/min until symptom resolution
  • IV bolus: 400–2000 mcg over 2–5 min (per hospital policy)
  • Sublingual: 400 mcg tab, 2–4 tablets
  • Ointment: slow onset 30–60 min
PK / PD
  • Onset: IV 1–5 min; SL 1–3 min
  • Peak: 3–15 min
  • Duration: IV 5–10 min; SL 10–60 min
  • Elimination: ~22% renal
Adverse effectsHeadache, hypotension, syncope, rebound hypertension, tolerance with prolonged use (~24 hr).
Warnings / interactionsPDE-5 inhibitors; aortic stenosis, preload-dependent / hypertrophic obstructive cardiomyopathy, or hypotension.
CompatibilityIncompatible with levofloxacin, sulfamethoxazole-trimethoprim, daptomycin, and phenytoin.

Clinical pearl: higher-dose IV or bolus nitroglycerin may reduce ICU admissions and intubation in SCAPE.

Evidence

Author, yearDesign (n)Intervention & comparisonKey findings
Patrick, 2020Observational (n=48)IV NTG 1 mg bolus by EMS
  • ↓SBP ~31 mmHg, ↓HR ~10 bpm, ↑O₂ sat 86% → 98%
  • Symptomatic hypotension ~2% (1/48), transient, resolved without intervention
Hsieh, 2018Case series (n=3)SL NTG 0.6 mg ×3; IV bolus 1 mg q2 min then 40 mcg/min infusionNormalized respiratory status; avoided intubation and ICU admission.
Paone, 2018Case report (n=1)IV NTG 400 mcg/min titratedSymptom resolution at ~6 minutes.
Wilson, 2017Observational (n=395)IV NTG bolus (500–2000 mcg) q3–5 min vs infusion vs bothBolus had the lowest ICU-admission rate (48.4% vs 68.7% vs 83%) and shortest length of stay, without a significant increase in intubation.
Levy, 2007Observational (n=29)IV NTG bolus 2 mg q3 minReduced intubation and BiPAP/ICU admission.
Sharon, 2000RCT (n=40)High-dose IV isosorbide bolus 4 mg q4 min vs low-dose infusion + BiPAPHigh-dose nitrate reduced intubation, MI, and mortality; improved oxygenation.
Cotter, 1998RCT (n=104 analyzed / 110 randomized)High-dose IV isosorbide bolus 3 mg q5 min + low-dose furosemide vs high-dose furosemide + low-dose nitrateHigh-dose nitrate reduced mechanical ventilation and MI and improved oxygenation.
Recent Evidence
Pramudyo / Kamarullah, 2025Systematic review & meta-analysis (185 pts)High-dose vs low-dose NTG for SCAPE
  • ↓Mechanical ventilation (RR 0.31)
  • ↑6-hour symptom resolution (RR 3.88)
  • Shorter length of stay; 0% hypotension
Long / Brady / Gottlieb, 2025Narrative EM reviewEvidence-based ED approach to SCAPESupports NIPPV plus high-dose bolus NTG transitioning to an infusion.
Houseman / Martinelli, 2023
(HI-DOSE SCAPE)		Retrospective cohort (n=67)High-dose NTG infusion (largest cohort to date)Supports the safety and feasibility of high-dose NTG infusion in SCAPE.
Mathew / Aggarwal, 2021Prospective bolus pilot (n=25)High-dose NTG bolus strategyNo post-bolus hypotension observed.

Conclusions

  • High-dose nitroglycerin (bolus and/or infusion) rapidly reduces preload and afterload in SCAPE.
  • Doses of ≥400 mcg/min (or an equivalent bolus) are supported by case series, observational studies, and a 2025 meta-analysis.
  • High-dose IV or sublingual NTG is associated with improved respiratory status, fewer ICU admissions, and reduced intubation.
  • Symptomatic hypotension is uncommon but monitoring is essential, especially with bolus regimens.
  • Bolus dosing strategies may outperform continuous infusion in acute SCAPE decompensation, though most evidence is observational.

References

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  • Recent evidence added on review (2020–2025)
  • Pramudyo M, Kamarullah W, et al. Low versus high-dose intravenous nitroglycerin in sympathetic crashing acute pulmonary edema: a systematic review and meta-analysis. BMJ Open. 2025;15(6):e099142. doi:10.1136/bmjopen-2025-099142
  • Long B, Brady WJ, Gottlieb M. Emergency medicine updates: sympathetic crashing acute pulmonary edema. Am J Emerg Med. 2025;90:35-40. doi:10.1016/j.ajem.2024.12.061
  • Houseman BS, Martinelli AN, et al. High-dose nitroglycerin infusion for the treatment of sympathetic crashing acute pulmonary edema (HI-DOSE SCAPE). Am J Emerg Med. 2023;63:74-78. doi:10.1016/j.ajem.2022.10.018
  • Mathew R, Aggarwal P, et al. High-dose nitroglycerin bolus for sympathetic crashing acute pulmonary edema: a prospective observational pilot study. J Emerg Med. 2021;61(3):271-277. doi:10.1016/j.jemermed.2021.05.011
  • Stemple K, DeWitt KM, et al. High-dose nitroglycerin infusion for the management of sympathetic crashing acute pulmonary edema: a case series. Am J Emerg Med. 2021;44:262-266.
  • Siddiqua N, et al. Ultra-high-dose nitroglycerin in sympathetic crashing acute pulmonary edema. Am J Emerg Med. 2023;67:194.e1-194.e5.
  • Wang Z, Samai K. Role of high-dose intravenous nitrates in hypertensive acute heart failure. Am J Emerg Med. 2020;38(1):132-137.
Tags:SCAPE nitroglycerin non-invasive ventilation preload and afterload

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High Dose Nitroglycerin for SCAPE Handout. pharmacy friday Pearls 2.0-KW, ACS. jlp2.pdf