Sequential antimicrobial therapy in mediastinitis after cardiac surgery: An observational study of 81 cases

Abstract

Introduction: Mediastinitis is an infrequent but serious complication of cardiac surgery. Antimicrobial treatment guidelines are not well established. The aim was to describe the efficacy of sequential intravenous to oral therapy in selected post-surgical mediastinitis patients.

Methods: A retrospective observational study including cases of mediastinitis after cardiac surgery, defined according to CDC criteria, at a third-level university hospital between January 2002 and December 2016. Sequential antimicrobial therapy was proposed in clinically stable patients. Rates of cure, relapse, and hospital stay were compared between patients who received sequential intravenous to oral therapy and those who received therapy exclusively by the intravenous route.

Results: Eighty-one cases were included. Sequential intravenous to oral therapy was performed in 48 (59.3%) patients on median day 15. No differences in baseline characteristics or causal microorganisms were found between the two cohorts. The average duration of antibiotic therapy was 41.2±10.09 days. The most commonly used drugs in sequential therapy were quinolones in 31 (64.6%) cases and rifampicin, always in association with another antibiotic, in 25 (52.1%). Hospital stay was shorter in the sequential therapy group (57.57±34.03 vs. 84.35±45.67; P=0.007). Cure was achieved in 77 (92.8%) patients. Overall in-hospital mortality was less frequent in the group that received sequential therapy (2.1% vs. 15.2%; P=0.039). There were no differences in relapse between the two cohorts (4.2% vs 9.1%; P=0.366).

Conclusion: Sequential antimicrobial treatment in selected patients with post-surgical mediastinitis may be as effective as exclusively intravenous treatment, reducing risks, hospital stay and associated costs.

Keywords: Cardiac surgery; Cirugía cardiaca; Infección de la herida quirúrgica; Mediastinitis; Sequential antimicrobial therapy; Surgical wound infection; Tratamiento antimicrobiano secuencial.