CT imaging as a prognostic indicator for patients with pulmonary injury from acute paraquat poisoning

CT imaging may be an effective diagnostic method for assessing the extent and progression of pulmonary injury in patients with acute paraquat (PQ) poisoning.

A retrospective review of 78 patients with acute PQ poisoning (survivor group, n=42; non-survivor group, n=36) was conducted to examine the lung segment involvement and CT image characteristics from baseline (first CT scan at a mean of 2.4 days after poisoning) to treatment time (second CT scan 3 days after the first). We examined the association between prognosis and pulmonary lesions indicated by characteristic effusion, fibrosis and consolidation in CT images.

Significant differences were apparent in CT images at baseline and after 3 days between the survivor and the non-survivor groups, with higher levels of pulmonary segment involvement, effusion, consolidation and fibrosis observed in the non-survivor group at baseline (p<0.05). The non-survivor group also showed rapid lesion progression. The receiver operating characteristic curve indicated that the best prognostic value of baseline CT scanning was achieved when performed 2-3 days following the initial exposure.

Prognosis correlated with increasing lung segment involvement, extent of disease characteristics visualised using CT and speed of lesion progression from baseline. Prognostic evaluation using CT scanning can be used to effectively provide earlier treatment for patients at risk for severe complications associated with PQ toxicity, such as acidosis; leukocytosis; and renal, hepatic and pancreatic failures.

Chest CT scan can be used 2-3 days following acute PQ poisoning to determine prognosis.