Predictors of Multi-Drug Resistant Gram-Negative Bacterial Infection in Critically Ill Older Adults

Abstract

Background/Purpose: Multi-drug resistant Gram-negative bacterial (MDR-GNB) infection has a higher risk of morbidity and mortality. The study aims to identify the incidence and predictors of MDR-GNB infection in critically ill older adults. Methods: A prospective cohort study including 297 critically ill older adults. These patients were newly admitted to high dependency units (HDUs) in a tertiary care Geriatrics hospital, from April 1, 2019, to January 4, 2020. Collection of demographic, clinical, and laboratory data on index hospitalization was done through reviewing participant's medical records and direct questioning for each patient/proxy about potential risk factors. Followed by observation of the emergence of MDR-GNB infection during the HDUs stay. Results: Incidence of MDR-GNB infection was 41.1%. Univariate analysis showed variables significantly associated with MDR-GNB infection including Neutrophil-lymphocyte ratio, Lymphocytes% and Monocytes% on admission, presence of diabetes mellitus (DM), chronic respiratory disease and dementia in clinical history, recent hospitalizations within the last 3 months, length of stay (LOS) in recent hospitalizations and presence of pressure ulcers/wounds before admission. Multivariate analysis showed that dementia in clinical history and monocytes % on admission were independent predictors with an odds ratio of 3.86 (P =0.003, 95% CI: 1.60-9.31) and 1.16 (P =0.012, 95% CI: 1.03-1.31) respectively. A predictive nomogram was constructed with an area under the curve.70 (P =0.000, 95% CI: 0.60-0.79). Conclusion: The incidence of MDR-GNB infection in critically ill older adults was 41.1%. Dementia in clinical history and monocytes % on admission were predictors for MDR-GNB infection. A novel nomogram was formulated.