Ventilator associated pneumonia in a tertiary care hospital in India: Incidence, etiology, risk factors, role of multidrug resistant pathogens

Abstract

Background: Ventilator associated pneumonia (VAP), a hospital acquired infection (HAI) is seen among critically ill patients on mechanical ventilation (MV) due to various causes, in intensive care units (ICUs). VAP increases morbidity, mortality, as well as the cost of healthcare. Materials and Methods: A prospective study was done over a period of 10 months in a tertiary care hospital in India to determine the incidence, etiological agents, their sensitivity profiles, and risk factors associated with VAP. Combination disc method, ethylenediaminetetraacetic acid (EDTA) disc synergy (EDS) tests, and AmpC disc tests were performed for detection of extended-spectrum beta-lactamases (ESBL), metallo-beta-lactamases (MBL), and AmpC beta-lactamases, respectively. Results: One hundred and forty adult patients, on MV for 48 h and more, were included and 28 (20%) developed VAP. The incidence density rate of VAP was 21.875 per 1,000 ventilator days. Most of the patients had late onset VAP (60.7%) with average number of days for onset around 8 days. Pseudomonas spp. and Acinetobacter spp. were significantly associated with late onset VAP, whereas Enterobacteriaceae, Staphylococcus aureus , Haemophilus influenzae , Streptococcus pneumoniae , Burkholderia cepacia, and Candida species were commonly isolated from early onset VAP. Polymicrobial infections occurred in 14 cases, so overall 43 VAP pathogens were isolated. Thirty (69.7%) of them were multidrug resistant (MDR), among which ESBL contributed 23.25%, MBL 30.23%, AmpC beta-lactamases 9.30%, and to methicillin resistant S. aureus (MRSA) contributed 6.97%. Prior antibiotic therapy ( P P P P P = 0.0012), and impaired consciousness ( P = 0.0191) were significant risk factors for VAP. Conclusions: Proper knowledge of risk factors can help identify high risk groups for VAP, among the critically ill patients on MV. MDR pathogens, with production of ESBL, MBL, AmpC beta-lactamases, and MRSA were commonly associated with VAP. So, judicious use of antibiotic is recommended.