IMPACT OF TRACHEOTOMY ON COLONIZATION AND INFECTION OF LOWER AIRWAYS IN CHILDREN REQUIRING LONG-TERM VENTILATION - A PROSPECTIVE OBSERVATIONAL COHORT STUDY

Study objectives: Determination of the following: (1) colonization and infection rates in children requiring long-term ventilation initially via a transtracheal tube and subsequently via a tracheotomy; (2) the number of infection episodes per 1,000 ventilation days, during both t ypes of artificial airways; and (3) routes of colonization/infection o f the lower airways, ie, whether the pathogenesis was endogenous (via the oropharynx) or exogenous (via the transtracheal tube or tracheotom y). Design: Observational, cohort, prospective study over 21/2 years. Setting: Pediatric ICU (PICU), Royal Liverpool Children's National Hea lth Service Trust of Alder Hey, a tertiary referral center. Patients: Twenty-two children requiring long-term mechanical ventilation initial ly transtracheally and subsequently tia a tracheotomy. Intervention: N il. Results: The lower airways were colonized in 71% of children durin g transtracheal ventilation; posttracheotomy, this was 95% (p=0.03). C hildren developed significantly fewer infections following colonizatio n with a microorganism posttracheotomy (8/15 pretracheotomy vs 6/21 po sttracheotomy; p=0.013). Throughout the study, there were a total of 1 7 episodes of infection, all of which were preceded by colonization. H aemophilus influenzae, Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa were the same four causative pathogens dur ing mechanical ventilation both transtracheally and via tracheotomy. F orty-nine episodes of colonization were observed, 15 pretracheotomy an d 34 posttracheotomy; of these, 12 (80%) and 19 episodes (56%), respec tively, were primary endogenous, ie, present in the oropharynx on hosp ital admission and subsequently at tracheotomy. Only one colonization episode (7%) of exogenous pathogenesis was observed during transtrache al intubation, while 12 (35%) (p=0.02) occurred after tracheotomy. An equal number of secondary endogenous colonization episodes two and thr ee, ie, acquired in the oropharynx after PICU admission and after trac heotomy, respectively, were recorded. Conclusions: (1) Despite a high level of hygiene, exogenous colonization without subsequent infection was common. (2) Although all patients were colonized, the infection ra te was lower after tracheotomy. This may be due to enhanced immunity ( medically stable) and improved tracheobronchial toilet. (3) Microorgan isms in children with tracheotomy differ from those in adults.