Methicillin-Resistant Staphylococcus aureus Nasal Screening With Polymerase Chain Reaction for Early De-escalation of Empiric Vancomycin in the Treatment of Suspected/Confirmed Respiratory Infection in Critically Ill Patients.

Abstract

Background: Vancomycin empirically for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia coverage often is prolonged. With high negative predictive value for MRSA pneumonia, we evaluated the efficacy of MRSA nasal screening with polymerase chain reaction for early de-escalation of empiric vancomycin for treatment of respiratory infections in patients admitted to the intensive care units.

Study question: The impact of MRSA nasal screening on early de-escalation of vancomycin for respiratory infections.

Study design: A retrospective, single-center cohort study was conducted to evaluate the outcomes of vancomycin therapy in patients admitted to the intensive care units with diagnosis of pneumonia before (control group) and after (study group) implementation of MRSA nasal screening.

Measures and outcomes: The primary end point was the difference in duration of vancomycin drug therapy in patients with suspected/confirmed pneumonia between the control and study groups. Secondary end points included the number of vancomycin trough levels obtained, discordance between polymerase chain reaction and sputum culture results, and clinical outcomes.

Results: In total, 123 patients (control: n = 76; study: n = 47) were included. The median vancomycin duration in the control group and the study group was 73.3 hours (54.3-110.6) and 30.2 hours (20.3-39.7), respectively, P < 0.0001. The control group had 2.73 times (95% CI: 2.15-3.45, P < 0.0001) longer vancomycin duration than the study group. There was a significant difference in the number of trough levels obtained between the 2 groups. The median in the control and study groups were 1 (1-3) and 1 (0-1), respectively, P < 0.0001. There was no difference between groups for length of stay, 30-day readmission for MRSA infection, reinitiation of anti-MRSA therapy for infection, vancomycin-resistant enterococci infection within 30 days, acute kidney injury, and in-hospital all-cause mortality.

Conclusion: The implementation of a MRSA nasal screening for critically ill patients treated with vancomycin for pneumonia resulted in a significantly shorter duration of vancomycin treatment without negatively affecting patient outcomes.