Comparison of the effects of DMSO and pentobarbitone on experimental brain oedema.

The purpose of this report is to compare the effect of acute therapy with dimethyl sulphoxide (DMSO) and pentobarbitone on experimental brain oedema produced by a cryogenic lesion over the left hemisphere in albino rabbits. A group of animals received DMSO (1 mg/kg-10% solution) by intravenous bolus, and another group received a pentobarbitone intravenous 30-minute infusion (40 mg/kg). Intracranial pressure (ICP), systolic arterial pressure (SAP), central venous pressure (CVP), and EEG were studied. Brain water and electrolyte content were analyzed at one hour following the initiation of therapy. ICP was promptly reduced with both forms of therapy. A 66% reduction from control values was reached at 50 +/- 12 minutes with pentobarbitone, and a 45% reduction from control values was reached at 30 minutes with DMSO. There was no significant reduction in the water content of the brain with either form of therapy. A significant elevation in brain potassium content was noted following DMSO when compared to untreated controls. CVP was essentially unchanged in both groups. Pentobarbitone produced a reduction of SAP with a mean value of 20.3 torr at 45 minutes from infusion. DMSO produced no reduction of SAP. It is concluded that DMSO and pentobarbitone are just as effective in reducing ICP. DMSO has the capacity to maintain SAP which pentobarbitone does not have, thus assuring a better cerebral perfusion pressure.

Acute therapeutic modalities for experimental vasogenic edema.

Experimental vasogenic cerebral edema was created in rabbits with a cold-induced left occipital cortical lesions. Intracranial pressure (ICP), intracranial elastance (Em), water content, hemispheric brain tissue volume, electrolytes, electroencephalograms, behavior, and gross pathology were studied. Various therapeutic modalities were employed alone or in combination to reduce ICP acutely: acetazolamide, furosemide, mannitol, pentobarbital, lorazepam, and dexamethasone. All therapies except dexamethasone were effective in reducing ICP. Peak ICP reduction occurred at 27 +/- 9.8 (SD) minutes with mannitol and at 71.4 +/- 15.5 minutes with acetazolamide, with the remaining agents and combinations falling between these two extreme values. Em improved by 31.7 +/- 17.02% in all therapuetic trials except those employing acetazolamide and lorazepam. With therapy, there was a reduction in the water content of the hemispheres, but the difference from that in the untreated, lesioned animals was not statistically significant. In the lesioned left hemisphere, sodium content was increased by acetazolamide (p less than 0.005), furosemide (p less than 0.025), pentobarbital (p less than 0.05), and the combination of dexamethasone, pentobarbital, and mannitol (p less than 0.005). Significant reduction was noted in the lesioned group for the potassium content of the left hemisphere in the dexamethasone (p less than 0.05), pentobarbital (p less than 0.025), and combination groups containing these agents (p less than 0.005 to 0.025). (Neurosurgery, 5: 656--665, 1979).