A STUDY OF BACTERIAL PATTERN OF VENTILATOR ASSOCIATED PNEUMONIA AT A TERTIARY CARE CENTRE OF WESTERN INDIA

Abstract

Background: Ventilator associated pneumonia (VAP) remains the commonest co-morbid infection in patients admitted to ICU leading to increased morbidity and mortality, despite the technological advancements in health care. Hence, a study of the local bacterial pattern of VAP along with antibiotic sensitivity is essential to frame institutional antibiograms to ensure appropriate empirical treatment of VAP. Aim:The present study aims to study the bacterial pattern of VAP in medical ICUs in a tertiary care center along with the antibiotic sensitivity of the isolates. Method: A descriptive, observational, cross-sectional study was conducted in combined 45 bedded, medical ICUs, at Sawai Man Singh Medical College and Hospital, from March 2020 to 2021. A total of 105 cases were enrolled after application of appropriate exclusion and inclusion criteria from patients on mechanical ventilation for > 48 hours without prior evidence of pneumonia or sepsis. Data regarding demographic and clinical features, laboratory parameters, culture and sensitivity and outcome in terms of death or discharge were collected in a pre-structured proforma and analyzed. Results: Out of the 105 patients evaluated in the study, 71(67.6%) were males. The mean age of the study population was 45.1 years (45.1 17.57) with a range of 18-85 years. Majority were below the age of 40 years (46.7%) followed by those above 60 years (26.7%). The incidence of VAP in the study was 49.5%. Most common co-morbidities underlying patients of VAP was chronic obstructive pulmonary disease (14.3%), coronary artery disease (13.3%), and chronic kidney disease (10.5%). Patients of VAP had a mean temperature of 101.1F (Mean ± SD; 101.1 0.99), along with leukocytosis (Mean ± SD;14399 5373), elevated serum creatinine (Mean ± SD; 1.9 5.9), alanine aminotransferase (Mean ± SD; 84.4 153.7), aspartate aminotransferase (Mean ± SD; 128.7 238.4), and LDH (Mean ± SD; 861.6 690.2), and decreased serum albumin(Mean ± SD; 3.0 0.5). The predominant isolate from endotracheal aspirate culture was Enterobacter species (17.2%), followed by Pseudomonas (15.2), Klebsiella (6.7%), Acinetobacter species (6.7%), and E. coli (4.9%). Those isolated from blood were Enterobacter species (17.2%), followed by Pseudomonas (6.7%), Klebsiella (6.7%), Enterococcus species (5.7%), and coagulase positive S.aureus (5.7%). The antibiotic sensitivity in the study revealed sensitivity predominantly to polymyxin (57.9%) and tigecycline (52.6%) followed by piperacillin-tazobactam (47.4%) and aztreonam (23.7%). The mortality observed in the study was 46.7%. Conclusion: The incidence of VAP in our study was 49.5% attributed to the use of microbiological definition to select cases of VAP and to lack of adequate nursing staff. Most of the isolated organisms isolated from endotracheal aspirate were multidrug resistant organisms sensitive to polymyxin and tigecycline. The mortality observed was also high due to prevalence of multi drug resistance and polymicrobial infection and delay in institution of appropriate antibiotics. Large multicentric studies with large sample size are needed to study the risk factors and their relation in causation of VAP.