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

To compare the clinical and microbiological outcomes of patients treated with beta-lactam monotherapy or combination therapy for Pseudomonas aeruginosa infections.MEDLINE, Google Scholar and the Cochrane Library.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.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 difference was observed between groups in terms of microbiological cure and clinical cure.This meta-analysis demonstrated no difference in mortality rate, clinical cure rate and microbiological cure rate in patients treated with beta-lactam monotherapy or combination therapy for P. aeruginosa infections.