This investigation was a 2lA year prospective observational cohort study from September 1, 1993, until February 28, 1996, in children requiring long-term mechanical ventilation, initially transtracheally and subsequently via tracheotomy, in the PICU.
Twenty-two patients, 17 male and 5 female, were enrolled in the study. Median age was 7.5 months with a range between 0.5 and 180 months. The mean age was 47 months (SD=65 months) at the time of tracheotomy (Table 1). Eight of the children suffered neurologic underlying disease, including five children with cerebral palsy and three patients each with status epilepti-cus, central apnea syndrome, and Guillain-Barre syndrome, respectively. Six of them received tracheotomies that were expected to be permanent. Three patients underwent tracheotomies for purely pulmonary problems and two were likely to be permanent. Airway obstruction was the indication for tracheotomy in nine patients. Of these, three were for upper airway obstructions, three for subglottic stenosis, one for vocal cord palsy, one for extratracheal compression, and one for tracheomalacia. In none of these patients was the tracheotomy regarded as being permanent. One patient had a myopathic disorder requiring a permanent tracheotomy and one patient had difficulties being weaned off the ventilator following a spinal operation for the correction of kyphoscoliosis.
Surveillance Samples: Surveillance samples from the oropharynx were obtained immediately on admission to the PICU and twice weekly afterwards, during both periods of artificial ventilation. The reason for taking these samples is to detect the carrier state of potential pathogens.
Diagnostic Samples: Diagnostic samples of lower airway secretions were taken once weekly, and on clinical indication, ie, in cases in which the tracheal aspirates were turbid. These samples allow the distinction between colonization and infection of the lower airways.
Surveillance Samples: Throat swabs were processed qualitatively and semiquantitatively using three solid media and enrichment broth to detect both overgrowth and low-grade carriage.
Diagnostic Samples: Endotracheal aspirates were processed in a qualitative and quantitative way, using standard microbiological methods. For all types of sample, macroscopically distinct colonies were isolated in pure culture. Standard methods for identification, typing, and sensitivity patterns were used for all microorganisms.
Table 1—Patient Demographics for 22 Study Subjects
|Age at time of tracheotomy|
|Median (range)||7.5 mo|
|Mean (SD)||47 mo (65 mo)|
|Neurologic disorder||8||5 cerebral palsy, 1 central apnea syndrome, 1 status epilepticus, 1 Guillain-Barre syndrome.|
|Pulmonary disorder||3||2 respiratory failure, 1 bronchopulmonary dysplasia.|
|Airway obstruction||9||4 supralaryngeal obstruction, 3 subglottic stenosis, 1 thoracic inlet obstruction, 1 bilateral vocal cord palsy|
|Myopathic disorder||1||Congenital myotonic dystrophy|
|Skeletal disorder||1||Kyphoscoliosis surgical correction|
|Term of tracheotomy||9/13|
|Total no. of ventilation days||435||829|
Tags: children, colonization, infection, pathogenesis, tracheotomy, transtracheal intubation