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

Objective 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. Design and setting Clinical outcome study in an adult medical ICU. Patients Eighty-five consecutive septic patients: 59 men and 26 women. Measurements and results Urinary 8-OHdG was analyzed using isotope-dilution liquid chromatography with tandem mass spectrometry (LC/MS/MS). ICU mortality in these 85 septic patients was 25.9% (n = 22) and hospital mortality 38.8% (n = 33). APACHE II scores of survivors on day 1, on day 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. Conclusions This is a preliminary study. The excretion of the urinary 8-OHdG, as measured using isotope-dilution LC/MS/MS, as the APACHE II score, were correlated with the outcome of critically septic patients in medical ICU. An erratum to this article can be found at