Prehospital Treatment of Acute Pulmonary Edema with Intravenous Bolus and Infusion Nitroglycerin

Abstract

Objective: The study describes the implementation of a prehospital treatment algorithm that included intravenous (IV) bolus (IVB) nitroglycerin (NTG) followed by maintenance infusion for the treatment of acute pulmonary edema (APE) in a single, high-volume Emergency Medical Services (EMS) system. Methods: This is a retrospective chart review of patients who received IVB NTG for APE in a large EMS system in Minnesota and Wisconsin (USA). Inclusion criteria for treatment included a diagnosis of APE, systolic blood pressure ≥120mmHg, and oxygen saturation (SpO2) ≤93% following 800mcg of sublingual NTG. Patients received a 400mcg IVB of NTG, repeated every two minutes as needed, and subsequent infusion at 80mcg/min for transport times ≥10 minutes. Results: Forty-four patients were treated with IVB NTG. The median total bolus dose was 400mcg. Twenty patients were treated with NTG infusion following IVB NTG. The median infusion rate was 80mcg/min. For all patients, the initial median blood pressure was 191/113mmHg. Five minutes following IVB NTG, it was 160/94mmHg, and on arrival to the emergency department (ED) it was 152/90mmHg. Five minutes after the initial dose of IVB NTG, median SpO2 increased to 92% from an initial reading of 88% and was 94% at hospital arrival. One episode of transient hypotension occurred during EMS transport. Conclusion: Patients treated with IVB NTG for APE had reduction in blood pressure and improvement in SpO2 compared to their original presentation. Prehospital treatment of APE with IVB appears to be feasible and safe. A randomized trial is needed to confirm these findings.

Safety of prehospital intravenous bolus dose nitroglycerin in patients with acute pulmonary edema: A 4‐year review

“…This study supports the favorable safety profile of prehospital highdose intravenous NTG use for treating AHFS with APE. The frequency of hypotension (1.3%) is similar to values documented in prior prehospital 21,22 and hospital- 10,11,23,24 based studies. Furthermore, this hypotension was transient, with no documented associated arrhythmia or altered mentation.…”

“…Our system cost for a single intravenous NTG bottle was approximately $20. Two‐thirds of the patients required only a single 1 mg dose, consistent with prior hospital and EMS studies 11,21,22 …”

“…26,27 However, more recently published data suggest that paramedics can accurately identify decompensated APE and that prehospital high-dose intravenous NTG use is feasible. 21,22 We believe that our prior success may Additional potential benefits of bolus dose intravenous NTG are its relatively low cost and simplicity of dosing and administration. We used a 100 mcg/mL concentration with a final volume of 10 mL.…”

“…Twothirds of the patients required only a single 1 mg dose, consistent with prior hospital and EMS studies. 11,21,22 Although there is no current prehospital comparison of sublingual to intravenous NTG, prior EMS evidence suggests a minimal hemodynamic impact of sublingual NTG on blood pressure when used to treat pain in ST-elevation myocardial infarction 28 or when treating prehospital CHF. 17 ED and ICU studies have found that intravenous NTG improves morbidity by reducing the incidence of intubation and mechanical ventilation, and the beneficial effects are more pronounced with high-dose bolus administration and less so with continuous NTG drip.…”

Evaluation of the effect of intravenous nitroglycerine on short-term survival of patients with acute heart failure according to congestion and perfusion status at emergency department arrival

“…Our subgroups analyses extensively failed in detecting any clinical setting with a more favourable setting for IV-NTG use in patients with AHF. Despite many authors have suggested that prompt initiation of IV-NTG in patients with severe pulmonary congestion (presenting in the form of acute pulmonary oedema) could be beneficial especially if it is quickly provided in the prehospital arena [8,[23][24][25], our subgroup analysis considering signs/symptoms of congestion separately according to whether they correspond to pulmonary or systemic congestion did not support this hypothesis, at least with respect to an improvement in patient survival. Similarly, age, sex, CAD as comorbidity and SBP did not have a different impact on the effects of NTG on patient survival.…”