Factors Affecting Incidence of Ventilator-Associated Pneumonia With Multidrug-Resistant Microbes in Intensive Care Unit

Abstract

Ventilator-associated pneumonia (VAP) with multidrug-resistant (MDR) microbes is one of the leading causes of hospital mortality. In this study, the risk factors of pneumonia with MDR microbes are investigated. This work was a retrospective study conducted at 2 academic centers and 3 intensive care units (ICUs). All patients who were clinically suspected VAP and had a positive microbial culture have been included in this study from late March 2018 to mid-June 2019. Patients were divided into 2 groups: MDR and non-MDR. Clinical and paraclinical (CBC, microbial culture, CXR) findings of these patients were recorded and reviewed. Then, using the multivariate analysis, the factors affecting the incidence of VAP with MDR microbes were investigated. Out of the 1854 patients admitted to the ICU, 110 of them have been diagnosed with VAP using X-ray and microbiological findings, and MDR microbes were separated in the culture of 85 patients. The mean age range of the patients was 60 ± 20 years and 75% of them were male. In univariate analysis, the factors affecting the incidence of MDR VAP were as follows: length of stay in the ICU, length of stay in other wards, history of admission in ward before ICU, duration of mechanical ventilation, and diabetes. In multivariate analysis, diabetes (odds ratio, 2.66; 95% confidence interval, 0.9–7.8; P = 0.002), history of admission in ward before ICU (odds ratio, 10.25; 95% confidence interval, 3.17–33.1), and a combination of the 3 factors related to the length of exposuring health care environment which named FAC, were independent risk factors of infection with MDR microbes. Hence, the FAC variable includes the length of stay in ICU, duration of mechanical ventilation, and length of stay in other wards.