A Study of Post Extubation Endotracheal Tube Microbial Colonisation in Patients Undergoing Elective Postoperative Mechanical Ventilation

Introduction: Elective post operative ventilation facilitates recovery but also increases the risk of post-operative chest infection. An observational study was carried out in patients electively ventilated postoperatively, to study the microbial growth in the tracheal irrigate obtained after tracheal extubation. Objectives: Primary: To study the microbial colonisation of endotracheal tube in patients undergoing elective postoperative ventilation. Secondary: 1. To study the proportion of patients developing respiratory infections postoperatively.2. To analyze the antibiotic sensitivity of micro-organisms cultured.3. To correlate the microbial colonisation with duration of tracheal intubation and nature of respiratory infections. Methods: Post extubation, under aseptic conditions, the endotracheal tube was flushed with 5 ml of sterile isotonic saline and the irrigate subjected to culture sensitivity study. Results: Cultures were negative for microbial growth in patients extubated at 24 hrs. A positive microbial culture was obtained in all patients extubated at 72 hrs. Incidence of chest infection was 13 %. Acinetobacter, Klebsiella and Pseudomonas were the most common micro-organisms isolated. Acinetobacter and Klebsiella were found most sensitive to colistin. Conclusion: Risk of endotracheal microbial colonisation and chest infection is nil/negligible with elective post-op ventilation of 24 hrs. Incidence of endotracheal microbial colonization and chest infection increases with duration of mechanical ventilation. Acinetobacter and Klebsiella are the two most common micro-organisms isolated. Both are highly sensitivity to colistin.