Urinary biomarker of oxidative stress correlating with outcome in critically septic patients

To determine whether urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), an in vivo parameter of oxidative stress, is correlated with the outcome of critically septic patients.

Clinical outcome study in an adult medical intensive care unit (ICU).

85 consecutive septic patients (59 men, 26 women).

Patient characteristics and the clinical course were examined. Urinary 8-OHdG was analyzed using isotope-dilution liquid chromatography with tandem mass spectrometry (LC/MS/MS). ICU mortality was 25.9% (22/85) and hospital mortality 38.8% (33/85). Survivors' APACHEII scores on days 1 and 3 and the difference between them differed significantly from those of nonsurvivors (day 1, 21.0+/-7.1 vs. 25.9+/-8.0; day 3, 15.0+/-5.8 vs. 23.2+/-8.3; difference, 6.0+/-5.5 vs. 1.7+/-6.6). Urinary 8-OHdG was significantly lower in survivors than in nonsurvivors on day 1 (1.8+/-2.4 vs. 3.0+/-2.4). The area under receiver operating characteristic curve analysis for the association between day 1 urinary 8-OHdG and ICU mortality was 0.71. The comparison performed upon discharge from hospital revealed similar results.

This is a preliminary study. Excretion of urinary 8-OHdG, as measured using isotope-dilution LC/MS/MS, and the APACHE II score were correlated with the outcome of critically septic patients in medical ICU.