Objective: To assess plasma iron status in critically ill patients with septic shock.
Design: Observational, prospective study.
Setting: Adult intensive care units in teaching and tertiary referral hospitals.
Patients and participants: Fifteen adult patients with established septic shock. Normal control subjects (n = 10) were also investigated. Data from patients and controls were compared with previously published iron values in critical care patients.
Measurements and results: The indices investigated and correlated with clinical scores of illness severity included bleomycin-detectable iron, non-haem iron; transferrin and its percentage iron saturation, and the iron binding (anti-oxidant) activity of transferrin. Bleomycin-detectable iron was not present in the plasma of patients with septic shock whilst the plasma transferrin remained unsaturated with iron. One patient in multi-organ failure displayed bleomycin-detectable iron in plasma (1.16 mumol/l) and had 100% iron-saturation of transferrin. The plasma non-haem iron levels (7.84 +/- 1.82 mumol/l) were the lowest of all critical care patient groups studied by us. The plasma transferrin levels were also low but resulted in a near normal percentage saturation of transferrin with iron (34.6 +/- 6.5%). The scores of clinical severity correlated with changes in plasma iron chemistry.
Conclusions: Patients with septic shock rarely have iron saturated transferrin in their plasma leading to the presence of bleomycin-detectable iron.