Osmotic Diuretics

Abstract
FOLLOWING a burn, there is altered capillary permeability which results in loss of sodium, chloride, protein, and water from the vascular compartment to the burned area. This results in hypovolemia, decreased renal blood flow, and decreased glomerular filtration rate which predisposes to precipitation of casts within the renal tubules. Although the precipitation of casts within the renal tubules is nonspecific and its significance is not fully understood, the development of these casts is observed as one of the sequelae of inadequate renal perfusion. Matter and others1 have demonstrated that urea is effective in improving oliguria in experimental burns. Haynes2 feels that the maintenance of an adequate urinary flow using dextran produces a beneficial flushing in the renal tubules and is helpful in preventing the precipitation of casts. When osmotic diuretics such as mannitol or urea are used, water excretion is obligatory and, in excessive quantities, these agents can