Plasma level of malondialdehyde in the cases of acute paraquat intoxication

Background, material, and methods. To assess plasma malondialdehyde (MDA) level as a clinical marker in acute paraquat (PQ) intoxication, we sequentially investigated 74 patients (40 males and 34 females, aged 49.9 +/- 16.2 years), all of whom ingested PQ as a means of suicide from July to December 2008. Results. The baseline level of MDA (10.8 +/- 3.5 mu M) had no correlation with plasma PQ levels of 22.1 +/- 48.7 mu g/mL (median: 1.9, range < 0.01-228.5) or with volume of PQ ingested. However, the following parameters were significantly different between survivors and nonsurvivors: the amount of PQ ingestion, plasma PQ levels, basal MDA levels, WBC, hemoglobin, hematocrit, platelet counts, albumin, BUN, creatinine, potassium, amylase, and arterial blood gas analysis (pH, pCO(2),). The nonsurvivors' baseline MDA (11.4 +/- 3.8 vs. 9.8 +/- 2.8, p = 0.040) was higher than the survivors. However, the baseline level was not a predictor of mortality in the univariate and the multivariate binary logistic analyses. Among the patients whose MDA levels were measured sequentially, 58.3% of the patients (35 out of 60) showed fluctuating MDA levels, 25% (n = 15) showed steady decreases, with only 16.6% (n = 10) showing steady increases in MDA levels during the observation period. These findings imply the presence of active MDA metabolism and/or that the half-life of MDA is very short in the human body. Conclusion. Both cross-sectional and sequential measurements of plasma MDA do not provide reliable information on outcome in patients with acute PQ intoxication.