The lower respiratory tract is considered to be sterile to bacteria in healthy humans. The insertion of a tracheostomy tube results in the lower respiratory tract becoming colonized with bacteria. Mechanical ventilation enhances the severity of these risk factors. The ability to predict the likely organism and initiate earlier appropriate empiric antibiotic therapy should improve the client’s outcome. To date there is no considered standard approach to attempting to predict specific organisms or to predicting a specific antibiotic choice for lower respiratory tract infections in patients with a tracheostomy who may or may not be mechanically ventilated.Our hypothesis is that regular tracheal swabs will detect the likely causative organism in lower respiratory tract infections in predisposed tracheotomized patients. This knowledge will improve antibiotic choice and reduce morbidity and mortality.
For this study, 17 patients with chronic tracheotomies, 9 of whom were mechanically ventilated were selected. Periodic tracheal aspirates were obtained for bacterial culture and resistance profile to standard antibiotics. Clinically, when a determination of a lower respiratory tract infection was made, an antibiotic was chosen based on physician preference. At the same time a tracheal aspirate was obtained prior to the initiation of antibiotics.
If Pseudomonas Aeruginosa was present as a colonizing orgainsm in the tracheal aspirate done when well, it was always present in heavy growth when the patient was ill. Thus making the choice of antibiotic one which would be effective against this organism.With respect to other gram negative and positive isolates, no apparent correlation could be found necessitating empiric coverage for these organisms at times of clinical infection.
Knowlege of colonizing tracheal organisms in patients compromised with a tracheostomy tube and/or mechanically ventilated is valuable in that Pseudomonas Aeruginosa, if present, should be empirically covered for when clinical infection occurs. Thereafter no other prediction of infecting organisms could be drawn.
At times of clinically documented infection, the prior knowledge of tracheal aspirate microbiology was of limited application for appropriate antibiotic choice.
Lily Yang, None.