Bacterial Colonisation and Antibiotic Sensitivity Profile of Endotracheal Tubes in Mechanically Ventilated Patients

Abstract

Introduction: Infections are the most important and leading cause of morbidity and mortality among the patients admitted in Intensive Care Units (ICU). The formation of biofilm around the Endotracheal Tubes (ET) by the micro organisms and their subsequent dislodgement following ET suction and repeated incubations contributes to lung colonisation and may lead ultimately to ventilator-associated pneumonia. The study also analysed common micro organisms associated with these infections and their antibiotic sensitivity profile. Aim: To study the time/trends of bacterial colonisation and sensitivity profile in tracheal tubes, in mechanically ventilated patients, in a tertiary care hospital ICU. Materials and Methods: A total of 109 consecutive patients admitted in the intensive care unit who were on mechanical ventilation for more than seven days were chosen. The study period was for one year. The ET suction catheter tip was cultured at 24 hours and at 48 hours post-incubation and ET tube tip culture was done on 7th day of incubation. Sensitivity of bacterial isolates from ET tip and suction tip cultures to commonly used antibiotics was also tested. All data were recorded in a predesigned study proforma and entered in Microsoft Excel (Microsoft Corporation, Redmond). All entries were double checked for any possible errors. Categorical variables were summarised as percentages. Results: A total of 109 subjects were enrolled in the study. Fifteen patients were excluded from the study. Bacterial colonisation was present in 60 patients at 24 hours, in 76 patients at 48 hours, and in 82 patients on 7th day of incubation. Three most common colonising organisms isolated at 24 hours, 48 hours and on the 7th day of incubation were Non-Fermentative Gram Negative Bacilli (NFGNB) including Acinetobacter, Pseudomonas aeruginosa and Klebsiella pneumonia. At 24 hours of incubation, 47.06% of NFGNB including Acinetobacter and 87.5% of Pseudomonas were sensitive to Cephaperazone-Sulbactam and with Imipenem the sensitivity was 35.29% for NFGNB including Acinetobacter and 93.57% for Pseudomonas. Almost similar trends were found in 48 hours post incubation culture and on 7th day culture. Among ventilator-associated pneumonia patients, Klebsiella pneumonia was the most common isolate. Conclusion: Most commonly isolated organisms were NFGNB including Acinetobacter, Pseudomonas aeruginosa and Klebsiella pneumoniae. Most of isolated organisms were sensitive to Cefaperazone-sulbactam and Imipenem antibiotics.

Keywords

• pseudomonas aeruginosa
• tracheal incubation
• ventilator associated pneumonia