Therapy of hemorrhagic shock using small volumes of hypertonic-hyperoncotic NaCl-dextran solution--effects on the brain

Abstract

Infusion of small volumes of hypertonic/hyperoncotic solution (HHL: 7.2% NaCl/10% dextran 60) is highly effective in haemorrhagic shock. Cardiovascular function is restored in a matter of minutes by rapid mobilisation of extravasal fluid. However, little experience has been collected to date on the side effects on the brain by this new form of shock therapy. The present studies on HHL were conducted with particular reference to cerebral blood flow, cerebral oxygen supply, and intracranial pressure. Haemorrhagic shock with a drop in arterial blood pressure to 40 mmHg over a period of 30 min was induced in rabbits under alpha-chloralose anaesthesia by means of bloodletting. Subsequently, the hypertonic/hyperoncotic solution (HHL) was infused into the experimental animals within two minutes. The regional cerebral blood flow (H2-clearance) and the cerebral O2 supply were studied by determining the pO2 of the cerebral cortex in experimental animals without haemorrhagic shock but with infusion of HHL. Finally, separate single tests were conducted to analyse the effect of the infusion of HHL on the intracranial pressure after induction of a focal cold lesion of the brain in combination with the implantation of a rubber balloon in the epidural space as an intracranial space-occupying growth. Infusion of HHL during shock produced rapid normalisation of cardiac output, whereas in normovolaemic animals without shock it produced a temporary increase of this parameter.(ABSTRACT TRUNCATED AT 250 WORDS)