Alterations in regional kidney oxygenation during expansion of extracellular fluid volume in conscious healthy sheep

Abstract

Expansion of extracellular fluid volume with crystalloid solutions is a common medical intervention, but its effects on renal cortical and medullary oxygenation are poorly understood. Therefore, we instrumented sheep under general anesthesia to enable continuous measurement of systemic and renal hemodynamics, global renal oxygen delivery and consumption, and intrarenal tissue perfusion and oxygen tension (Po2) in conscious animals ( n = 7). The effects of three sequential intermittent infusions of 500 ml of compound sodium lactate solution, administered at hourly intervals, were determined. Volume expansion induced transient increases in mean arterial pressure (+7 ± 2%), central venous press..