ANTIOXIDANT ACTIVITY OF PROPOFOL IN BLOOD FROM ANESTHETIZED PATIENTS

The antioxidant capacity of plasma taken from 10 patients before and d uring prapofol anaesthesia was measured. Mean total plasma antioxidant activity fell from 1.73 to 1.64 mM L-1 trolox equivalents (p=0.047). This was caused by haemodilution since mean haemoglobin concentration fell from 13.0 to 12.5 g dL(-1) (P= 0.016). The time to 50%, haemolysi s (H-50) of 10% red blood cell suspensions induced by 2,2'azo-bis(2-am idinopropane) dihydrochloride (ABAP) was measured in blood from six pa tients. There was no change when red cells alone were studied, but whe n the patients' plasma was added to red cell suspensions (producing 10 % plasma and 10% red cell suspensions), mean H-50 increased from 291 t o 308 min (P=0.049). Despite there being no overall increase in plasma antioxidant activity, the lipid soluble component of blood antioxidan t activity appears to be increased by propofol.