Human Atrial Natriuretic Peptide Prevents the Increase in Pulmonary Artery Pressure Associated With Aortic Unclamping During Abdominal Aortic Aneurysmectomy

Objective: To assess the effect of human atrial natriuretic peptide (HANP) on the pulmonary and systemic circulations during infrarenal abdominal aortic aneurysmectomy.Design: A prospective, randomized study.Setting: A university hospital.Participants: Forty-five patients undergoing infrarenal abdominal aortic aneurysmectomy.Interventions: Abdominal aortic aneurysmectomy patients were randomly assigned to 1 of 3 groups (n = 15 for each group). They were infused with normal saline solution (SA), 0.02 μg/kg/min of HANP (LH), or 0.05 μg/kg/min of HANP (HH), starting 5 minutes after clamping. Hemodynamic variables were measured before/after clamping and unclamping.Measurements and Main Results: Both mean pulmonary arterial pressure (MPAP) and the pulmonary vascular resistance index (PVRI) increased (v baseline) in the SA group. HANP attenuated the rises in MPAP and PVRI dose dependently (LH and HH groups v SA). Mean arterial pressure and systemic vascular resistance index were not significantly different among the 3 groups.Conclusion: HANP, infused during aortic clamping and abdominal aortic aneurysmectomy, attenuates the rises in pulmonary artery pressure and vascular resistance without severe systemic hypotension. This may result from direct and/or indirect pulmonary vascular effects of HANP because no HANP-induced changes in endothelin-1, angiotensin-II, and thromboxane B2 were detected.