Beta-lactam monotherapy or combination therapy for bloodstream infections or pneumonia due to Pseudomonas aeruginosa: a meta-analysis

Objectives: To compare the clinical and microbiological outcomes of patients treated with beta-lactam monotherapy or combination therapy for Pseudomonas aeruginosa infections. Data sources: MEDLINE, Google Scholar and the Cochrane Library.Study eligibility criteria and interventions: Experimental and observational studies published as full papers up to December 2020 that compared the efficacy of beta-lactams used as monotherapy or in combination with other active agents as empirical or targeted therapy for bloodstream infections or hospital-acquired pneumonia/ventilator-associated pneumonia due to P. aeruginosa were included in this meta-analysis. The outcomes evaluated were in-hospital mortality rate, 14 -day-or 30-day-mortality rate, microbiological cure rate and clinical cure rate.Results: Of 8363 citations screened, six randomized controlled trials, six prospective cohort studies and 21 retrospective cohort studies were included in the analysis, accounting for a total of 3861 subjects. Considering the 14 studies evaluating empirical therapy, no significant difference in mortality rate was observed between the two groups [relative risk (RR) 1.06, 95% confidence interval (CI) 0.86-1.30; P = 0.6]. Similar findings were obtained among the 18 studies analysing targeted therapy (RR 1.04, 95% CI 0.83- 1.31; P = 0.708); however, grouping the studies by design, higher mortality was observed among patients receiving monotherapy in five prospective studies (RR 1.37, 95% CI 1.06-1.79; P = 0.018). Finally, no differ-ence was observed between groups in terms of microbiological cure and clinical cure.Conclusions: This meta-analysis demonstrated no difference in mortality rate, clinical cure rate and mi-crobiological cure rate in patients treated with beta-lactam monotherapy or combination therapy for P. aeruginosa infections.(c) 2021 Elsevier Ltd and International Society of Antimicrobial Chemotherapy. All rights reserved.