Pattern of bacterial colonization and antimicrobial susceptibility of tracheal aspirates in tracheostomised patients at the Kenyatta National Hospital.

Abstract

Tracheostomy is an operative procedure that creates a surgical airway in the cervical trachea. Tracheostomy is vital in airway management in both emergency and elective situations. The airway in healthy non tracheotomised individuals is protected from colonization by bacteria through the filtering mechanism of the upper airway. This is bypassed in tracheostomy leading to colonization of the trachea predisposing one to lower respiratory tract infections. Indiscriminate use of antibiotics in treatment of the infections has led to emergence of antibiotic resistance. Study Objective: To determine the pattern of bacterial colonization and antimicrobial susceptibility in tracheal aspirates of tracheotomised patients at the Kenyatta National Hospital. Study Design: Cross sectional study Study Duration: 12 months Study setting: The Kenyatta National Hospital Operating Theatres, Intensive Care Unit & wards. Methodology: Eighty eight patients undergoing open tracheostomy were recruited using consecutive sampling technique after obtaining an informed consent/assent. An open surgical tracheostomy was done under strict aseptic conditions. A sterile suction catheter was introduced into the trachea through the tracheostomy tube and suction done to clear the secretions. The secretions within the suction catheter were emptied into a sterile container by pushing 5mls of normal saline and transported to laboratory within 1 hour for bacteriological analysis; the same procedure was repeated on day 7. Data Analysis and Results: Data analysis was done using SPSS version 22. 88 patients aged between 14-83 years with a mean age of 52.1years were studied. Mechanical obstruction was the commonest indication. The trachea was colonised on day zero in 11.36% and 61.36% in day 7, (P<0.001) using independent sample T-test. Gram negative bacteria predominated; Pseudomonas aeruginosa 28.6%, Acinetobacter baumanii17.9%, Enterobacterioceae 12.5%. The commonest gram positive bacterium isolated was Staphylococcal aureus at 8.9%. Both gram negative and gram positive bacteria were resistant to amoxicillin, Cefotaxime, Ceftriaxone and Amoxicillin Clavulinic acid. No Vancomycin resistance was found. Conclusion and Recommendation: Post tracheostomy colonization occurs early in the first week. There is an overwhelming resistance to commonly used antibiotics such as penicillins and cephalosporins at KNH. Serial tracheal aspirate cultures should be incorporated in the care of post tracheostomy patients.