Multi-Drug Resistant Gram-Negative Infections Among Critically Ill Patients: Analysis of Baseline Characteristics and Factors Associated with Mortality

Abstract BackgroundBacterial infections are a frequent cause of hospitalization and a leading cause of death, particularly with the emergence of antibiotics resistance. The emergence of Carbapenem resistance among gram-negative bacteria (GNB) is one of the evolving alerts as its use is considered the last resort of treatment [1]. Therefore, this urged studying the risk factors for the development of multi-drug resistant [2] GNB, identify the clinical outcomes and factors associated with mortality, especially among critically ill patients who are expected to have the worst outcomes.Materials/methodsThis is a retrospective observational study of critically ill patients who had an infection with Carbapenem-resistant Enterobacteriaceae (CRE), or MDR Pseudomonas aeruginosa, or MDR Acinetobacter spp. between May 2016- Nov 2018. Baseline demographics, co-morbidities, and clinical outcomes were collected and were evaluated for association with 28 days mortality. ResultsA total of 255 patients with MDR Gram-negative cultures were screened, 77 patients met the inclusion criteria. Pseudomonas aeruginosa was the most common index organism (53% of patients), followed by Acinetobacter spp. and CRE, respectively. The mortality rate at 28 days was (59.7%). Non-survivors were significantly older (mean age 64 vs. 44 years, P= 0.0001), had significantly worse disease severity scores on ICU admission, higher incidence of chronic kidney disease (CKD) (43% vs. 16%, P= 0.010), required more continuous renal replacement therapy (CRRT) (54% vs. 13% P= 0.0001), had longer hospital length of stay prior to infection (median 34 vs. 13 days, P= 0.018), and required longer inotropic and vasopressors support (median 19 vs. 8 days, P = 0.0001). In multivariate logistic regression the following factors were significantly associated with mortality; requirement of inotropic support [OR 10.01 (95% CI 1.55-64.77); P= 0.015], age [OR 1.05 (95% CI 1.0-1.1); P=0.01], APACHE IV score on ICU admission [OR 1.03 (95% CI 1.0- 1.06); P= 0.04], and ICU length of stay [OR 1.03 (95% CI 1.0- 1.06); P= 0.035].ConclusionMDR Gram-negative infection is associated with significant in-hospital mortality among critically ill patients. Old age, high APACHE IV score, higher ICU length of stay, and higher hemodynamic support are associated with higher mortality.Trial registrationretrospectively registered.