Evaluation of ventilator-associated lower respiratory tract infection and tracheobronchial aspiration of gastrointestinal contents.

ABSTRACT

STUDY OBJECTIVE: Ventilator-associated lower respiratory tract infection (LRTI) in a set up of respiratory intensive care unit was evaluated. Also the incidence of tracheobronchial aspiration of gastrointestinal contents was explored among these patients. DESIGN: Twenty eight patients admitted in the respiratory intensive care unit of referral teaching hospital were studied. All patients were evaluated for tracheobronchial aspiration of gastrointestinal contents in the initial 48 hours of initiating mechanical ventilation using methylene blue as marker and glucostix reagent strip. Protected endotracheal aspirate was secured after 48 hours of beginning of mechanical ventilation and was submitted for microbiological assay. RESULTS: Of the 28 mechanically ventilated patients, 82% were found to have developed LRTI. Aerobic gram-negative bacilli accounted for 79% of the infections, Klesiella responsible for 39% while Pseudomonas and Escherichia accounted for 18% each. The remaining 4% were caused by Acinetobacter. Gram-positive cocci were responsible for 21% of infection with Staphylococcus and enterococci 14% and 7% respectively. Tracheobronchial aspiration of GI contents was found to be present in 72% of the patients which was significantly correlated with the incidence of LRTI (p=0.014). Significant association was also found between the incidence of LRTI and mortality (p=0.05). CONCLUSION: The incidence of gastrointestinal aspiration was found to be high and correlation with LRTI was significant. Both glucostix reagent strip and methylene blue were observed to have same positivity rate.