Polymyxin B-immobilised fibre column treatment for acute exacerbation of idiopathic pulmonary fibrosis patients with mechanical ventilation: a nationwide observational study.

Background: The prognosis for acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is poor, and there is no established treatment. Hence, we aimed to investigate the effectiveness of a polymyxin B-immobilised fibre column (PMX) for the treatment of AE-IPF.

Methods: Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from 1 July 2010 to 31 March 2018. We identified adult patients with idiopathic pulmonary fibrosis who received high-dose methylprednisolone (mPSL) therapy and mechanical ventilation upon admission. Eligible patients (n = 5616) were divided into those receiving PMX treatment combined with high-dose mPSL (PMX group, n = 199) and high-dose mPSL alone (mPSL alone group, n = 5417). To compare outcomes between the two groups, we applied a stabilised inverse probability of treatment weighting (IPTW) using propensity scores. The primary outcome was in-hospital mortality, and the secondary outcomes were 14- and 28-day mortality and length of hospital stay.

Results: The in-hospital mortality rates of the PMX and mPSL alone groups were 79.9% and 76.4%, respectively. The results did not significantly differ between the two groups after performing a stabilised IPTW. The odds ratio of the PMX group compared with the mPSL alone group was 1.56 (95% confidence interval 0.80-3.06; p = 0.19). The 14- and 28-day mortality and length of hospital stay (secondary outcomes) also did not significantly differ between the two groups.

Conclusions: In AE-IPF patients using mechanical ventilation, the treatment outcome was not significantly better for PMX combined with high-dose mPSL than for high-dose mPSL alone.