The effects of atrial natriuretic peptide infusion on hemodynamic, renal, and hormonal responses during gastrectomy

Atrial natriuretic peptide (ANP) antagonizes the reninangiotensin-aldosterone, adrenocorticotropic hormone-cortisol, vasopressin, and endothelin systems. Surgical injury stimulates these systems and causes vasoconstriction and antidiuresis. We assessed the hemodynamic, renal, and endocrine effects of continuous intravenous infusion of ANP in patients anesthetized with sevoflurane undergoing gastrectomy. ANP (0.1 microgram.kg-1.min-1; ANP group, n = 9) or saline (control group, n = 9) was infused continuously for 3 h from the start of the operation. The ANP group showed much higher urinary volume and sodium, potassium, and chloride excretion than the control group, although the former had lower arterial blood pressure. ANP infusion slightly inhibited aldosterone secretion and initially tended to inhibit renin secretion stimulated by surgery, but it did not affect surgery-induced increases in the plasma concentrations of vasopressin, adrenocorticotropic hormone, cortisol, or endothelin. Two patients in the ANP group experienced excessive hypotension, one experienced bradycardia, and two experienced mild hypoxemia, which required treatment but were resolved easily. These findings suggest that ANP infusion may be used with caution for controlling renal function and arterial blood pressure during surgery.

Continuous intravenous infusion of atrial natriuretic peptide, 0.1 microgram.kg-1.min-1, during gastrectomy was associated with higher water and sodium excretion and lower arterial blood pressure. It tended to inhibit the renin-angiotensin-aldosterone system compared with saline infusion, which suggests that atrial natriuretic peptide may be useful for intraoperative circulation control.