Effect of furosemide, bumetanide and mannitol on intracranial pressure in experimental brain edema of the rat.

Loop diuretics interfere with NaCl-KCl cotransport, which operates not only in the kidney but as well in a variety of nonepithelial cells including neuronal and glial cells. In these cells loop diuretics are able to reduce cellular volume. The present study has been performed to establish, whether furosemide or bumetanide directly modify intracranial pressure in cytotoxic brain edema. To this end, water intoxication was induced in animals acutely nephrectomized, to exclude any consequences of renal effects. Neither furosemide nor bumetanide proved effective in reducing intracranial pressure. In contrast, infusion of hypertonic mannitol solution leads to a marked, rapid reduction of intracranial pressure. The observations rule out a direct action of loop diuretics on intracranial cells to reduce intracranial pressure in water intoxicated animals.