Oxygen toxicity: simultaneous measure of pentane and malondialdehyde in humans exposed to hyperoxia

In order to estimate cell damage caused by free radicals during oxygenother apy, we investigated the time course of two markers of lipoperoxidation: pe ntane in breath and malondialdehyde (MDA) in blood during brief normobaric hyperoxia. Nine healthy subjects inhaled hydrocarbon-free air (HCFA) for 30 minutes, hydrocarbon-free 100% O-2 (HCFO2) for 125 minutes and then HCFA f or 70 minutes. After 15 minutes of washout with HCFA, ambient pentane was eliminated. Afte r HCFO2, at T175 versus T30 (i.e., 145 min from the start of 100% HCFO2), p entane production increased (P < 0.05). MDA rose significantly at T155 min (i.e,, 125 min from the start of HCFO2), versus T30 (P < 0.01). These results suggest that acute hyperoxia causes a moderate increase in li pid peroxidation in healthy subjects. The increase of pentane and MDA confi rms that acute hyperoxia induces lipid peroxidation in healthy subjects. (C ) 2001 Editions scientifiques et medicales Elsevier SAS.