Clinicoradiological correlation of Endotracheal secretion culture in each case of suspected VAP: a need of the present to combat drug-resistance

Abstract

Background: Ventilator-associated pneumonia (VAP) in intensive care unit (ICU)-admitted patients is a life-threatening event, caused by a diverse range of microbes having varied susceptibility to different classes of antibiotics. Materials and Methods: We enrolled patients admitted in trauma ICU on mechanical ventilation for >48 h. Modified clinical pulmonary infection score (≥6) having a significant bacterial count (≥105 cfu/ml) in endotracheal (ET) secretions was used to diagnose VAP. Subsequently, we did antibiotic susceptibility testing by the modified Kirby–Bauer method, and the results were interpreted per Clinical and Laboratory Standards Institute guidelines. Results: We enrolled 389 patients in this study. Amongst these, we noted VAP events in 87 patients with an incidence of 15.62/1000 days of ventilators. Gram-negative rods were the predominant microbes causing VAP. Acinetobacter baumannii-calcoaceticus complex (n = 30) followed by Klebsiella pneumoniae (n = 27) and Pseudomonas aeruginosa (n = 19) was the predominant isolate. All nine isolated Staphylococcus aureus strains were methicillin-resistant S. aureus (MRSA). About 48.72% (38/78) of the Gram-negative microbes were meropenem sensitive. All strains of A. baumanii and P. aeruginosa were sensitive to polymyxin B, whereas all isolated MRSA strains were sensitive to vancomycin and linezolid. In addition, drug-resistant epidemiological important bacterial pathogens were also isolated from ET secretions. Conclusion: VAP is caused by a diverse group of multidrug-resistant microorganisms; however, drug-resistant microbes also colonise the in situ ET tubes. Therefore, accurate diagnosis of VAP and its differentiation from ET tube colonisation is a need of present times as appropriate treatment of actual VAP cases will reduce the burden of drug-resistant microbes in ICU settings.