Risk Factors for Carbapenem Resistance in Gram Negative Nosocomial Pneumonia: A Single Centre Prospective Cohort Study

Abstract

Introduction: Gram Negative Bacilli (GNB) account for about 70% of Hospital Acquired Pneumonia (HAP), Ventilator Acquired Pneumonia (VAP) and Healthcare Associated Pneumonia (HCAP). Increasing use of carbapenems lead to infections caused by GNBs with therapeutically challenging Extended-Spectrum Beta-Lactamases (ESBLs). Aim: To assess the risk factors and clinical outcomes associated with HAP, VAP and HCAP caused by Carbapenem Resistant (CR) GNB at a Tertiary Care Centre. Materials and Methods: The present study was a prospective cohort study which was conducted from February 2015 to September 2016 that included 66 patients with Broncho Alveolar Lavage (BAL) cultures for GNB. Clinical, demographic and microbiological data (including antibiotic sensitivity) along with overall mortality, occurrence of sepsis and length of stay were collected for each patient. Data were analysed using OpenStat 30.0 along with relevant descriptive statistics. Comparison of outcomes between CR and Carbapenem Sensitive (CS) group were studied along with the concordance between initial antibiotics and BAL culture sensitivity. Results: Overall prevalence of CR in the cohort was 54.54%. The most common organism to be ESBL positive was Klebsiella pneumoniae (45.45%). Exposure to previous antibiotics was a risk factor for CR (p=0.017). Mortality was higher (50%) in CR group than in CS group (23.3%; p=0.026). There were 45.8% of the cases having lack of concordance of initial antibiotics that died in comparison to 16.7% who had an appropriate initial antibiotic therapy (p=0.030). Conclusion: There is a high prevalence of CR in nosocomial pneumonia. Judicious use of antibiotics is the need of the hour and can be implemented by an Antibiotic Stewardship program.