Percentage of Patients Colonized and/or Infected: This was calculated by obtaining the total number of patients who developed one or more episodes of colonization or infection during the two study episodes pretracheotomy and posttracheotomy, and dividing by the total number of patients enrolled in each episode X100.
Incidence of Infection Episodes per 1,000 Ventilation Days: The incidence was for episodes of both forms of artificial ventilation: transtraeheally and via tracheotomy.
Percentage of Type of Infection Episodes: This was calculated for the two different periods both pretracheotomy and posttracheotomy by obtaining the number of primary endogenous, secondary endogenous, and exogenous colonization or infection episodes, respectively, and dividing each of them by the total number of episodes of colonization or infection registered during both study periods X100.
A statistical package (Arcus Professional Version 2.0; Medical Computing; Lancashire, UK) was used for the analysis of the data. Pretracheotomy and posttracheotomy colonization and infection rates were compared with McNemar s test, including Yates’ continuity corrected x2- Wilcoxon’s signed rank test was used to compare the number of days required to manifest infection, pretracheotomy and posttracheotomy. Proportions analysis using a two-tailed exact method with 95% confidence intervals (CIs) was used in the following analysis: to compare number of episodes of colonization and infection, pretracheotomy and posttracheotomy, routes of pathogenesis of colonization and infection, and rates of infection per 1,000 days of infection pretracheotomy and posttracheotomy. X2 was used to compare the number of patients who were colonized and subsequently developed an infection pretracheotomy and posttracheotomy.
Before the tracheotomy, all patients had been intubated with orotracheal or nasotracheal tubes, and mechanically ventilated for a median of 22.5 days (range, 1 to 50 days; 95% Cl, 7 to 31 days) (Table 1). Following tracheotomy, mechanical ventilation continued for a median of 16.5 days (range, 1 to 220 days; 95% Cl, 2 to 45 days). Mechanical ventilation was expected to be permanent in two patients (patients 18 and 20 in Table 2). In four of the patients (patients 3, 13, 15, and 22), infection of the lower airways was present at enrollment into the trial. Patients 3 and 22 suffered culture-negative viral meningitis and croup, respectively. Patient 13 was admitted to the hospital with a pneumosepticemia due to S pneumoniae. The fourth patient had a bronchopneumonia caused by S aureus.
Tags: children, colonization, infection, pathogenesis, tracheotomy, transtracheal intubation