Atrial natriuretic peptide as a preload depressor in acute renal failure secondary to congestive heart failure

The present study was undertaken to verify the hypothesis that infusion of atrial natriuretic peptide (ANP) might lower preload and be beneficial in the treatment of pulmonary congestion even without a diuresis in patients with acute renal failure (ARF) secondary to severe congestive heart failure (CHF). We studied 22 patients with ARF secondary to CHF. The mean age of the patients (14 men and 8 women) was 72 years (range 36 to 85 years). Seven of the patients had dilated cardiomyopathy, ten had ischemic heart disease, and five had valvular heart disease. ANP was infused intravenously and the following data before and 1 hour after the start of ANP infusion were recorded; urinary output, systemic blood pressure (SBP), pulmonary blood pressure (PBP), right atrial pressure (RAP), cardiac index (CI), heart rate (HR), and arterial blood oxygen partial pressure. Diastolic PBP were employed as pulmonary capillary wedge pressure. Urinary output did not change. Mean SBP decreased from 92 to 85 mmHg (p < 0.05), and mean PBP decreased from 34 to 28 mmHg (p < 0.01). Mean RAP decreased from 11 to 9 mmHg (p < 0.01) and diastolic PBP decreased from 25 to 19 mmHg (p < 0.01). HR did not change significantly and CI increased 2.4 to 2.5 mi/min/m2 (p < 0.05). Arterial blood oxygen partial pressure increased significantly from 71 to 82 mmHg (p < 0.05). In conclusion, ANP decreased preload and improved arterial blood oxygen partial pressure, though diuretic response to ANP is attenuated in ARF secondary to CHE. Infusion of ANP will be very beneficial in cases in which dyspnea and pulmonary edema due to elevation of preload are the principal clinical problems.