Postoperative polymyxin B hemoperfusion and mortality in patients with abdominal septic shock: a propensity-matched analysis.

To examine the effect of postoperative polymyxin B hemoperfusion on mortality in patients with abdominal septic shock triggered by lower gastrointestinal tract perforation, identifying subpopulations of patients who may benefit from this treatment. Propensity-matched analysis. We used a nationwide inpatient database in Japan. We included patients who are 18 years old or older hospitalized during a period of 34 months between July 2007 and October 2011, who had open abdominal surgery on the day of admission (day 0) for perforation of lower gastrointestinal tract, and who required noradrenaline and/or dopamine. We excluded patients who died on day 0 or 1 and patients starting polymyxin B hemoperfusion on day 2 or later. The main outcome was 28-day mortality. Of 2,925 eligible patients, 642 received one or two polymyxin B hemoperfusion sessions, starting the first one on day 0 or 1. Propensity score matching created a matched cohort of 1,180 patients (590 pairs with and without polymyxin B hemoperfusion). The 28-day mortality was 17.1% (101 of 590) in the polymyxin B hemoperfusion group and 16.3% (96 of 590) in the control group (p = 0.696). Subgroup analyses by number of polymyxin B hemoperfusion sessions (one or two), timing of polymyxin B hemoperfusion initiation (day 0 or 1), the use of noradrenaline, and number of dysfunctional organs (one to six) did not show any significant difference in 28-day mortality between the groups. Multiple logistic did not show a significant association between the use of polymyxin B hemoperfusion and 28-day mortality (adjusted odds ratio, 1.10; 95% CI, 0.80-1.51; p = 0.569). Age, end-stage renal disease requiring maintenance hemodialysis, the use of noradrenaline, and number of dysfunctional organs were positively associated with 28-day mortality. In this retrospective study, postoperative polymyxin B hemoperfusion did not show any survival benefit for the overall study population or any of the studied subgroups of patients with abdominal septic shock. A large multicentered prospective randomized trial is warranted to identify the true role of polymyxin B hemoperfusion in sepsis caused by Gram-negative bacteria.