Do medications affect vital signs in the prehospital treatment of acute decompensated heart failure?

INTRODUCTION: Prehospital treatment of patients with acute decompensated heart failure (ADHF) has been shown to decrease mortality and morbidity. Vital sign changes have been proposed as clinical endpoints in the evaluation of prehospital treatment for this condition.

OBJECTIVE: To examine the effect of prehospital treatments on vital signs among patients with ADHF.

METHODS: Records of an urban emergency medical services system from September 1, 2002, through September 1, 2003, were queried for patients who had a paramedic impression of shortness of breath or respiratory distress and had received nitroglycerin and/or furosemide. Demographics, initial and repeat vital signs (blood pressure, heart rate, respiratory rate, and oxygen saturation), and medications and doses were collected.

RESULTS: Three hundred nineteen patients were included; the average age was 77 (+/-12) years and 47% were male. Treatments administered to these patients included nitroglycerin, 296 (93%); furosemide, 194 (61%); albuterol, 189 (59%); aspirin, 57 (18%); morphine, 20 (6%); and prehospital intubation, 15 (5%). Patients were initially hypertensive [mean +/- standard deviation of systolic blood pressure (SBP) was 167 +/-37 mm Hg], tachycardic (heart rate 106 +/- 24 beats/min), tachypneic (respiratory rate 33 +/- 7 breaths/min), and hypoxic (pulse oximetry 88% +/- 9.5%). After treatment, mean changes included decreases (95% confidence interval) in (SBP), -10.6 mm Hg (-14.1 to -7.1), heart rate, -2.3 beats/min (-4.0 to -0.7), and respiratory rate, -3.0 (-3.6 to -2.3), and an increase in oxygen saturation, +8.2 (7.1 to 9.3). Changes in blood pressure and oxygen saturation after treatment correlated with initial values. There was no independent association of either nitroglycerin, furosemide, albuterol, or morphine with improvement in vital signs.

CONCLUSION: Prehospital patients with ADHF are a heterogeneous group of patients with significant variability in vital signs. The change in systolic blood pressure or oxygen saturation after treatment depends greatly on the patient's starting point. There was no association of either nitroglycerin or other medications with the improvement in vital signs.