Study objective: To evaluate the efficacy, safety and tolerability of intravenous (i.v.) isosorbide dinitrate (ISDN) administered as a bolus in the treatment of cardiogenic acute pulmonary edema (CAPE).
Design: Clinical, prospective, open, noncontrolled trial.
Setting: Emergency room.
Patients and interventions: Twenty two patients (15 male and 7 female), aged 54 to 80 years (68.4 +/- 6.4) with severe respiratory distress consistent with CAPE were included. The cause of CAPE was chronic ischemic cardiopathy in 13 patients, acute myocardial infarction in four, hypertensive cardiopathy in three and mitral valve disease in two. Patients were excluded from the study because of shock or systolic blood pressure equal or lower than 100 mmHg, severe aortic stenosis, hypertrophic cardiomyopathy and non-cardiogenic pulmonary edema. All patients were placed in the sitting position and received oxygen. Initial therapy consisted of an i.v. bolus of 5 to 10 mg of ISDN. Clinical data were recorded at admission and after 5, 10, 15 and 30 minutes. A new i.v. bolus of ISDN and/or another drug was administered at 5 minutes, when necessary.
Results: Fifteen patients treated exclusively with ISDN (in three a second i.v. bolus was necessary) improved markedly. In the remaining seven patients that needed other drugs, the improvement was not so impressive. The mean total dose of i.v. ISDN was 10.34 +/- 3.48 mg. Although all data showed a trend towards improvement, just the following were statistically significant (p < 0.05): pH increased from 7.26 +/- 0.13 to 7.32 +/- 0.9, systolic blood pressure decreased from 192.7 +/- 34.8 mmHg to 155.0 +/- 24.4 mmHg (-19%) and diastolic blood pressure decreased 110.5 +/- 12.7 mmHg to 93.2 +/- 9.1 mmHg (-16%).
Conclusions: In this trial, iv ISDN administered as a bolus in doses ranging from 5 to 20 mg, was effective and safe as a first line agent in the treatment of CAPE. No serious adverse reaction were reported.