The lowering of cerebral spinal fluid and brain interstitial pressure of preterm and term rabbits by furosemide.

CSF, brain interstitial, and arterial or venous pressures were measured in preterm and term rabbits. Ten to sixty minutes after the infusion of furosemide, in concentrations reported to inhibit CSF production, CSF and brain interstitial pressures fell an average of 1.4 and 1.8 cm H2O, respectively. No changes were observed in plasma osmolality, arterial or venous pressures. Histopathological examination of coronal brain sections showed the presence of germinal matrix and/or choroid plexus haemorrhages in four of eight brains examined. These results indicate that CSF and brain interstitial pressures of anaesthetised, restrained rabbits can be reduced to subatmospheric levels without altering serum osmolality. It remains to be established whether diminution of intracranial pressure by this method will increase the incidence of IVH in the awake, unrestrained preterm animal.