Effects of norepinephrine on renal function in septic patients with normal and elevated serum lactate levels

Effects of iv norepinephrine (NE) on renal function were investigated retrospectively in 15 patients with hyperdynamic septic shock. All patients had either a low systolic BP less than 80 mm Hg, and/or oliguria less than 0.5 ml/kg-h. We examined their serum creatinine level (SCr), daily urine flow (UF), 24-h creatinine clearance (Ccr), and hemodynamic indices before and during NE infusion. Before NE administration, the patients were divided into those with with a serum lactate level (Lac) less than 20 mg/dl (group A, n = 9) and greater than 20 mg/dl (group B, n = 6). NE was infused continuously at rates between 0.05 and 0.24 microgram/kg.min which increased systolic BP by greater than or equal to 20 mm Hg. Cardiac index was not significantly changed in either group. In group A, NE increased both UF (p less than .05), and systemic vascular resistance index (SVRI) (p less than .01), but did not affect Ccr. In group B, NE did not increase UF nor SVRI, and decreased Ccr significantly (p less than .05). It is concluded that NE increased UF and SVRI only when Lac was in normal range; otherwise, NE reduced renal function. Thus, when administering NE to increase UF, both Lac and renal function should be monitored carefully.