Mechanism of inappropriate polyuria in septic patients
A. Cortez, J. Zito, C. E. Lucas and S. J. Gerrick
Inappropriate polyuria leading to hypovolemia and hypotension occurs
frequently in severely septic patients. It's etiology was studied in three
patients with polyuria and systolic hypotension. Glomerular filtration rate
and renal blood flow were measured by the standard renal clearance
techniques. Renal blood flow distribution to the outer cortex, inner
cortex-outer medulla, and the inner medulla were measured by radioactive
xenon. The glomerular filtration rate, renal blood flow, and renal blood
flow distribution were normal. Polyuria does not result from a
maldistribution of renal blood flow. Antidiuretic hormone did not alter the
polyuric syndrome. These data suggest that sepsis produces a blockade at
either the distal tubule or the collecting duct, thereby preventing salt
and water conservation. This blockade may be due to either a toxin or a
toxic metabolic breakdown product of sepsis.
