Short versus prolonged courses of antimicrobial therapy for patients with uncomplicated Pseudomonas aeruginosa bloodstream infection: a retrospective study.

Background The optimal duration of antimicrobial therapy for uncomplicated Pseudomonas aeruginosa bloodstream infection (BSI) is unknown. We compared the outcomes of short and prolonged courses of antimicrobial therapy in adults with uncomplicated pseudomonal BSI. Methods All patients with uncomplicated P. aeruginosa BSI admitted at a tertiary-care hospital from April 2010 to April 2020 were included. We compared the primary outcome (a composite of the rate of recurrent P. aeruginosa infection and mortality within 30 days after discontinuing antimicrobial therapy) among patients who underwent short (7‒11 days) and prolonged (12‒21 days) courses of antimicrobial therapy using propensity score analysis with the inverse probability of treatment weighting (IPTW) method. Results We evaluated 1477 patients with P. aeruginosa BSI; of them, 290 met the eligibility criteria who received antimicrobial agents with in vitro activity, including 97 (33%) who underwent short-course therapy [median of 9 (IQR = 8‒11) days] and 193 (67%) who underwent prolonged-course therapy [median of 15 (IQR = 14‒18) days]. We found no significant difference in the risk of recurrence or 30 day mortality between the prolonged-course and short-course groups [n = 30 (16%) versus n = 11 (11%); IPTW-adjusted HR = 0.68, 95% CI = 0.34 - 1.36, P = 0.28]. The prolonged-course therapy did not significantly reduce the risk of the recurrence of P. aeruginosa infection within 180 days compared with short-course therapy [n = 37 (19%) versus n = 12 (12%); IPTW-adjusted HR = 0.57, 95% CI = 0.29 - 1.10, P = 0.09]. Conclusions Short-course antimicrobial therapy could be as effective as prolonged-course therapy for uncomplicated P. aeruginosa BSI.