Effect of haemodilution on experimental cerebral oedema in cats.

The effect of haemodilution with Dextran 60 on experimental cerebral oedema produced by the modified method of Ishii, Hayner, Kelly & Evans (1959) is described. The intracranial pressure was measured from the cisterna magna or epidurally in the parieto-occipital region. In the group of cats subjected to haemodilution, with a haematocrit of 27.20 +/- 1.48%, the intracranial pressure first increased by 500% and, after 1.5 h, began to fall gradually so that at the end of the experiment it was only 160% of initial value. In the other experimental group in which haemodilution with a haematocrit of 27.40 +/- 1.14% was started after 6 h of the experiment, the intracranial pressure gradually fell for the next 6 h from 350% of initial value of 200% of initial value after 12 h. It was concluded that haemodilution slows down the development of cerebral oedema, and can be employed in the treatment of fully developed oedema.