A Retrospective Study of Microbiological Profile and Resistance Pattern in Early- and Late-onset Ventilator-associated Pneumonia Among COVID-19 Patients of a Tertiary Care ICU

ABSTRACT

Aim and objectives: To compare the microbiological profile, resistance pattern, and outcome in early- and late-onset ventilatorassociated pneumonia (VAP) among severe COVID-19 patients in a tertiary care ICU. Materials and methods: It is a retrospective study conducted in the Department of Critical Care Medicine, Fortis Hospitals Pvt ltd, Bangalore over a period of 15 months (April 2020 to June 2021). It included all patients who had a first episode of VAP confirmed by positive tracheal aspirate culture. Patients on mechanical ventilation for <4 days (48-96 hours) were included in the early-onset VAP group and 5 days or more were included in the late-onset VAP group. Data collected from case records including demographic and clinical characteristics of the patients at ICU admission, data related to the disease course, ICU treatments (prior antibiotic exposure and immunomodulatory therapy), mortality and, finally, data related to each VAP episode (date of sampling, implicated germs and their detailed biochemical testing identified any significant growth, and antibiotic sensitivity testing report). Results: We analysed a total of 404 patients, out of which 149 patients had VAP. The incidence of VAP was found to be 36.8%, out of which 59 (39.5%) had early-onset VAP and 90 (60.5%) had late-onset VAP. The most common organisms isolated from early- and late-onset VAP was Klebsiella pneumoniae. Among earlyonset VAP, 42% of Klebsiella pneumoniae were extended-spectrum beta-lactamase (ESBL) with carbapenemase-producing strains and in late-onset VAP 85% of Klebsiella pneumoniae strains were ESBL with carbapenemase-producing strains. The overall mortality in our study was 65.7%. Conclusion: VAP is one of the most common complications in critically ill mechanically ventilated COVID-19 patients. The underlying immune nature of the virus and the various immunomodulating therapies used for the same has contributed towards a high incidence of VAP in COVID-19 pneumonia patients. Knowledge of your local microbial flora can help in initiating the appropriate therapy at the correct time and hence improve clinical outcomes.