Ms Abode conceptualized and drafted the initial manuscript, developed clinical protocols and quality metrics, and carried out data collection and initial analysis; Drs Drake, Zdanski, and Retsch-Bogart developed clinical protocols and quality metrics, and reviewed and revised the manuscript; Ms Gee carried out data collection and reviewed and revised the manuscript; Dr Noah developed clinical protocols and quality metrics, carried out data analysis, and critically reviewed and revised the manuscript; and all authors approved the fi nal manuscript as submitted.

In clinically stable children with CF, systemic antibiotics result in greater short-term reduction in lower airways inflammation than inhaled antibiotics.

OBJECTIVE To understand: (1) how endoscopic airway measurements compare to three-dimensional (3D) CT derived measurements; (2) where each technique is potentially useful; and (3) where each has limitations. STUDY DESIGN Compare airway diameters and cross-sectional areas from endoscopic images and CT derived 3D reconstructions. METHODS Videobronchoscopy was performed and recorded on an adult-sized commercially available airway mannequin. At various levels, cross sectional areas were measured from still video frames using a referent placed via the biopsy port. A 3D reconstruction was generated from a high resolution CT of the mannequin, planar sections were cut at similar cross-sectional levels and cross-sectional areas were obtained. RESULTS At three levels of mechanically generated tracheal stricture, the differences between the endoscopic measurement and CT derived cross sectional area were 1%, 0%, and 7% (1.8, 0.8, and 14 mm2). At the vocal folds, the difference was 9% (7.8 mm2). The tip of the epiglottis and width of the epiglottis differed by 27% and 10% (18.73 mm2, 0.40mm). The airway measurements at the base of tongue, minimal cross sectional area of the pharynx, and choana differed by 26%, 36%, and 30% (101.40 mm2, 36.67 mm2, 122.71 mm2). CONCLUSION Endoscopy is an effective tool for obtaining airway measurements compared with 3D reconstructions derived from CT. Concordance is best in geometrically simple areas where the entire cross-section measured is visible within one field of view (trachea, round; vocal folds, triangular) versus geometrically complex areas that encompass more than one field of view (i.e. pharynx, choana).

Objective Assess the feasibility of using serial bronchoalveolar lavage fluids (BALF) to characterize the course of cell damage and inflammation in airways of pediatric patients with acute burn or inhalation injury. Design Prospective, longitudinal descriptive pilot study. Setting Burn and Pediatric Intensive Care Units in a tertiary-care medical center. Subjects Six consecutive intubated, mechanically ventilated pediatric patients with acute inhalational injuries were studied. Interventions Serial BALF specimens from clinically-indicated bronchoscopies were used to measure DNA and cytokine levels. Measurements and Main Results BALF DNA levels for the 6 pediatric burn subjects were highest within the first 72 hours after burn injury and declined thereafter. At the early stages after injury, BALF DNA levels (median [min, max] 3789 [1170,11917] ng/ml) were similar to those in adult burn patients and pediatric cystic fibrosis or bronchiectasis patients, and higher than those in pediatric recurrent pneumonia patients. BALF DNA levels in children and adults with inhalation injury correlated significantly with BALF IL-6, IL-8, and TGF-β1 levels. The patient with the most severe early visible airway mucosal damage and soot pattern at bronchoscopy, as well as the most extensive burns, also had the highest average early BALF DNA level (11917ng/ml) and the longest ventilator course and hospital stay. Procedures were well tolerated. Conclusions In children with acute burn and inhalational injury, airway cellular damage and inflammation (reflected in high BALF DNA levels) appear to peak during the first 72 hours after burns or inhalation injury followed by a slow decline. Serial analysis of factors in airway secretions is feasible and has the potential to reveal important pathophyisiologic pathways and therapeutic targets for treatment of acute inhalational injuries.