Infection and Drug Resistance (Mar 2018)
Prediction of imipenem-resistant microorganisms among the nosocomial critically ill patients with Gram-negative bacilli septicemia: a simple risk score
Abstract
I-Ling Chen,1,2 Chen-Hsiang Lee,2–4 Shih-Wen Ting,2,3 Lily Yu-Chin Wang1 1Department of Pharmacy, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; 2Infection Control Team, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; 3Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; 4College of Medicine, Chang Gung University, Kaohsiung, Taiwan Objectives: The increasing number of reports on infections due to carbapenem-resistant Gram-negative bacilli (GNB) has raised concerns, because they have complicated empiric or guided antibiotic therapy for critically ill patients. We aimed to develop a scoring system to predict nosocomial imipenem-resistant GNB (IR-GNB) septicemia among the critically ill patients.Materials and methods: The study included critically ill adult patients with nosocomial GNB septicemia at Kaohsiung Chang Gung Memorial Hospital (CGMH) in 2013–2015, and the scoring system for predicting IR-GNB septicemia was developed, followed by prospective validation conducted among patients at Linkou CGMH and Kaohsiung CGMH between January and June, 2016.Results: In the development of the scoring system, 748 patients were included. The independent factors associated with IR-GNB septicemia were prior exposure (days) to carbapenems (adjusted odds ratio [aOR] per 1-day increase, 1.1; 1–3 days: 2 points, 4–6 days: 5 points, 7–9 days: 8 points, and ≥10 days: 13 points), use of mechanical ventilation (aOR 3.7; 5 points), prior colonization with IR-GNB strains (aOR 3.5; 5 points) within 30 days before the onset of GNB septicemia, and comorbid condition with chronic kidney disease (aOR 2.1; 3 points). The internal validation showed an area under the receiver operating characteristic curve (ROC) of 0.75; and an external validation among 314 patients showed similarly good performance (ROC 0.77). Youden’s index indicated the score of ≥6 as the best cutoff value with sensitivity of 75% and specificity of 79%.Conclusion: This scoring system might help clinicians stratify the risk for developing IR-GNB septicemia among critically ill patients and combined antibiotics may be used until antimicrobial de-escalation/adjustment is clearly indicated by the subsequently identified GNB and its susceptibility profile. Keywords: antimicrobial resistance, carbapenem, bacteremia, nosocomial infection, scoring system, outcome
