september 2020 • JAMA Network Open

Association of Staphylococcus aureus Colonization and Pneumonia in the Intensive Care Unit

Paling F., et al.

DOI: 10.1001/jamanetworkopen.2020.12741

Content curated by:David Rodrigues

Key message

Estudo que procurou responder à pergunta “qual é a densidade de incidência de pneumonia em unidade de terapia intensiva por Staphylococcus aureus (SAIP) na Europa e quais fatores estão associados ao risco de SAIP?” Neste estudo de coorte de 1933 participantes, a densidade de incidência ponderada de SAIP foi de 4,9 eventos por 1000 pacientes-dia na unidade de terapia intensiva, e a colonização por S. aureus foi o único fator independentemente associado ao SAIP. As incidências de SAIP ponderadas foram de 11,7 eventos por 1000 pacientes-dia na UCI para pacientes colonizados por S aureus e 2,9 eventos por 1000 pacientes-dia na UCI para pacientes não colonizados (incidência geral, 4,9 eventos por 1000 pacientes-dia na UCI). A incidência de SAIP foi de 4,9 eventos por 1.000 pacientes-dia na UTI para pacientes submetidos à ventilação mecânica na admissão na UCI (ou logo depois). O risco diário de SAIP foi 3,6 vezes maior em pacientes colonizados com S. aureus na admissão na UTI em comparação com pacientes não colonizados. Esses resultados sugerem que a incidência de SAIP pode ser maior do que inicialmente percebida, e futuras intervenções para prevenir SAIP devem concentrar-se em pacientes colonizados com S. aureus para alcançar uma eficácia mais alta.

Abstract

Importance Carriage of Staphylococcus aureus is associated with S aureus infection. However, associations between S aureus carriage and the development of S aureus intensive care unit (ICU) pneumonia (SAIP) have not been quantified accurately, and interpretation of available data is hampered because of variations in definitions. Objective To quantify associations of patient-related and contextual factors, including S aureus colonization status, with the occurrence of SAIP. Design, Setting, and Participants This cohort study was conducted in ICUs of 30 hospitals in 11 European countries, geographically spread across 4 regions. Among patients with an anticipated length of stay 48 hours or longer who were undergoing mechanical ventilation at ICU admission, S aureus colonization was ascertained in the nose and lower respiratory tract. From this group, S aureus–colonized and noncolonized patients were enrolled into the study cohort in a 1:1 ratio. Data analysis was performed from May to November 2019. Main Outcomes and Measures SAIP was defined as any pneumonia during the ICU stay developing 48 hours or more after ICU admission with S aureus isolated from lower respiratory tract specimens or blood samples. The incidence of SAIP was derived in the study cohort and estimated on the weighted incidence calculation for the originating overarching population, while taking competing events into account. Weighted risk factor analysis was performed using Cox multivariable regression. Results The study cohort consisted of 1933 patients (mean [SD] age, 62.0 [16.0] years); 1252 patients (64.8%) were men, and 950 patients (49.1%) were S aureus carriers at ICU admission. In all, 304 patients (15.7%) developed ICU-acquired pneumonia, of whom 131 patients (6.8%) had SAIP. Weighted SAIP incidences were 11.7 events per 1000 patient-days in the ICU for S aureus–colonized patients and 2.9 events per 1000 patient-days in the ICU for noncolonized patients (overall incidence, 4.9 events per 1000 patient-days in the ICU). The only factor independently associated with SAIP was S aureus colonization status at ICU admission (cause-specific hazard ratio, 3.6; 95% CI, 2.2-6.0; P < .001). There were marked regional differences in SAIP incidence and cause-specific hazard ratios for colonization status. Conclusions and Relevance SAIP incidence was 4.9 events per 1000 ICU patient-days for patients undergoing mechanical ventilation at ICU admission (or shortly thereafter). The daily risk of SAIP was 3.6 times higher in patients colonized with S aureus at ICU admission compared with noncolonized patients.