Association between renal and sympathetic responses to nonhypotensive systemic sepsis

We investigated the association between plasma catecholamines and the renal response to nonhypotensive sepsis. Arterial plasma catecholamines were measured in 16 sheep, before and 24 h after surgical induction of peritonitis. Animals were volume loaded with lactated Ringer's solution (8 L/24 h) before and after surgery; non became hypotensive. For analysis, animals were retrospectively divided into those with increased serum creatinine after 24 h of sepsis (group 1, n = 8) and those without (group 2, n = 8). Group 1 showed increased cardiac index and decreased systemic vascular resistance typical of severe sepsis, with decreased glomerular filtration rate (GFR), oliguria, sodium retention, increased plasma renin activity (PRA), decreased urinary kallikrein excretion, and increased urinary 6-keto-prostaglandin-F1 alpha excretion. Group 2 showed insignificant hemodynamic disturbance, and no significant renal response. Plasma catecholamines were equal in both groups at baseline. In group 1, there were uniform increases after 24 h in plasma norepinephrine (474 +/- 115 to 1183 +/- 158 [SEM] pg/ml; p less than .01) and plasma epinephrine (108 +/- 8 to 309 +/- 70 pg/ml; p less than .05). In group 2, neither plasma norepinephrine (343 +/- 59 to 330 +/- 56 pg/ml) nor plasma epinephrine (116 +/- 16 to 116 +/- 13 pg/ml) changed significantly. Plasma norepinephrine correlated inversely with GFR; plasma epinephrine correlated with PRA. The sympathetic nervous system may be involved in the renal response to nonhypotensive sepsis, both directly and via effects on other vasoactive hormone systems.