EFFECT OF AN ORAL OSMOTIC AGENT ON VENTRICULAR FLUID PRESSURE OF HYDROCEPHALIC CHILDREN

Abstract

To quantitatively measure the effect of oral isosorbide on ventricular fluid pressure in hydrocephalic children, a method for continuous direct pressure recording with a closed isometric system was utilized. A baseline pressure pattern could be established for each patient, and the effect of drug could be observed with follow-through for reestablishment of baseline pressure after the last dose of drug. Fourteen hydrocephalic children have been given oral isosorbide in doses varying from 1 to 3 gm per kilogram. Significant (average 50%) reduction in ventricular fluid pressure was measured in 13 of the 14 children following a single dose of isosorbide. Rebound pressure greater than baseline was measured in 5 of the 10 children given multiple doses of isosorbide. No toxic side effects were observed during the single dose studies. Clinically significant dehydration and hypernatremia began to occur after 72 hours of continuous drug administration. Serum-CSF gradient curves for drug level and osmolarity are included to show the correlation of these gradients to the ventricular fluid pressure. Pressure curves comparing the effects of intravenous urea, intravenous mannitol, and oral acetazolamide show the quantitative differences in pressure response which can be observed when the pressures are being recorded continuously with a closed system.