Measures of total free radical activity in critically ill patients.
OBJECTIVE
To examine the role played by free radicals during the initial phase of critical illness in patients on an Intensive Care Unit (ICU).


METHODS
Serum total antioxidant status (TAS) and uric acid (UA) levels were measured in 50 patients over 18 hours to represent the initial stage of critical illness. Clinical scoring systems (APACHE II and multiple organ dysfunction scores) were used to assess the degree of organ dysfunction. Outcome was assessed according to patient survival (survivors, n = 36; non-survivors, n = 14).


RESULTS
Serum TAS was higher in non-survivors; a similar finding was demonstrated for serum UA. Levels of both biochemical markers were associated with the degree of organ function and with higher antioxidant and UA levels present in patients with more severe organ dysfunction. In addition, serum UA was significantly correlated to serum TAS and probably accounted for much of the antioxidant activity observed.


CONCLUSIONS
The increased TAS and UA levels observed may simply be a response to the degree of renal dysfunction observed as those patients with worse renal function had higher TAS and UA levels. In conclusion, measurement of serum TAS appears to be a reflection of UA concentration and results should be interpreted with caution particularly in patients who have renal dysfunction.
MacKinnon
K L
KL
Department of Clinical Biochemistry, University Hospital Aintree, Liverpool, United Kingdom.
Molnar
Z
Z
Lowe
D
D
Watson
I D
ID
Shearer
E
E
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D016638:Critical Illness / Q000401:mortality; D005609:Free Radicals / Q000097:blood*; D006801:Humans; D007362:Intensive Care Units; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D051437:Renal Insufficiency / Q000378:metabolism / Q000401:mortality; D016019:Survival Analysis; D014527:Uric Acid / Q000097:blood
D000975:Antioxidants; D005609:Free Radicals; D014527:Uric Acid