OBJECTIVETo investigate the effects of secondary dust exposure after whole-lung lavage (WLL) on the clinical symptoms, arterial blood gas parameters, and pulmonary function in subjects with pneumoconiosis and patients with stage I coal workers' pneumoconiosis (CWP).

METHODSThe subjects with pneumoconiosis and patients with stage I CWP who underwent WLL in our hospital during the study period were selected. All patients were divided into postoperative dust exposure group (n = 86) and lavage control group (n = 86) according to whether they were exposed to dust after conventional operation. In addition, their workmates with similar age, history of dust exposure, and type of dust exposure were selected as non-lavage control group (n = 86). Follow-up was performed before and at one month and one year after WLL to evaluate clinical symptoms, arterial blood gas parameters, and pulmonary function.

RESULTSOne month after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non-lavage control group (P < 0.01). One year after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non?lavage control group (P < 0.01), and the lavage control group had a significantly lower clinical score than the postoperative dust exposure group (P < 0.01). One month after operation, the arterial partial pressure of oxygen (PaO2) of the postoperative dust-exposure group and lavage control group were significantly higher than their preoperative values and the arterial PaO2 of the non-lavage control group (P < 0.01). One year after operation, the lavage control group had significantly higher arterial PaO2 than the postoperative dust exposure group and the arterial PaO2 of the non-lavage control group was significantly lower than its preoperative value and the arterial PaO2 of the postoperative dust exposure group and lavage control group (P < 0.05 or P < 0.01); the postoperative dust exposure group showed a significant decrease in arterial PaO2 (P < 0.01), while the lavage control group showed a significant increase in arterial PaO2 (P < 0.01). The partial pressure of carbon dioxide showed no significant differences between the three groups before and at one month and one year after operation (P > 0.05).

CONCLUSIONDust exposure should be avoided after WLL to ensure the treatment outcome.