Elevated serum bleomycin-detectable iron concentrations in patients with sepsis syndrome

To determine serum bleomycin-detectable ¿free' iron in patients with septic shock and to relate these findings to both outcome and a marker of free radical damage.

A prospective observational study.

A nine-bed intensive care unit in a university teaching hospital.

Sixteen consecutive patients with septic shock, defined as: (1) Clinical evidence of acute infection; (2) hypo- or hyperthermia ( < 35.6 degrees or > 38.3 degrees C); (3) tachypnoea ( > 20 breaths/min or ventilated); (4) tachycardia ( > 90 beats min); (5) shock (systolic pressure < 90mmHg) or on inotropes. Fourteen patients also had secondary organ dysfunction.

Bleomycin-detectable iron concentrations were elevated in all patients (37.2 +/- 11.0 mumols/l vs 5.1 +/- 3.3 mumols/l in healthy subjects, P < 0.0001), but there was no difference between patients who died and those who survived (39.2 +/- 9.3 and 36.2 +/- 12.3 mumols/l, respectively). Thiobarbituric acid reactive substances (an index of lipid peroxidation) were higher in those who died (3.33 +/- 2.29 mumols/l) than in the surviving patients (0.99 +/- 0.14 mumols/l, P < 0.01) or healthy subjects (0.92 +/- 0.39 mumols/l, P < 0.01). Free iron did not correlate with thiobarbituric acid-reactive substances. However, a significant correlation was found between lipid peroxidation and clinical severity (APACHE II) score (r = 0.54, P < 0.05).

The present study provides evidence of lipid peroxidation in patients who die with septic shock. The data suggest that iron-catalysed hydroxyl radical generation does not form an important contribution to this lipid peroxidation in patients with sepsis.