Spiral CT scanning technique in the detection of aspiration of LEGO foreign bodies.

BACKGROUND: Radiolucent foreign bodies (FBs) such as plastic objects and toys remain difficult to identify on conventional radiographs of the neck and chest. Children may present with a variety of respiratory complaints, which may or may not be due to a FB. OBJECTIVE: To determine whether radiolucent FBs such as plastic LEGOs and peanuts can be seen in the tracheobronchial tree or esophagus using low-dose spiral CT, and, if visible, to determine the optimal CT imaging technique. MATERIALS AND METHODS: Multiple spiral sequences were performed while varying the CT parameters and the presence and location of FBs in either the trachea or the esophagus first on a neck phantom and then a cadaver. Sequences were rated by three radiologists blinded to the presence of a FB using a single scoring system. RESULTS: The LEGO was well visualized in the trachea by all three readers (both lung and soft-tissue windowing: combined sensitivity 89 %, combined specificity 89 %) and to a lesser extent in the esophagus (combined sensitivity 31 %, combined specificity 100 %). The peanut was not well visualized (combined sensitivity < 35 %). The optimal technique for visualizing the LEGO was 120 kV, 90 mA, 3-mm collimation, 0.75 s/revolution, and 2.0 pitch. This allowed for coverage of the cadaver tracheobronchial tree (approximately 11 cm) in about 18 s. Although statistical power was low for detecting significant differences, all three readers noted higher average confidence ratings with lung windowing among 18 LEGO-in-trachea scans. CONCLUSION: Rapid, low-dose spiral CT may be used to visualize LEGO FBs in the airway or esophagus. Peanuts were not well visualized.

Contribution of routine pulse oximetry to evaluation and management of patients with respiratory illness in a pediatric emergency department.

STUDY OBJECTIVE: To determine whether routine pulse oximetry in a pediatric emergency department can be used to identify patients with a low oxygen saturation (SaO2) that is unexpected on the basis of clinical evaluation. DESIGN: Prospective comparison of blinded, clinical evaluation by physicians with subsequent pulse oximetry readings. SETTING: Pediatric ED in an urban, university medical center. PARTICIPANTS: A convenience sample of 368 patients presenting to the pediatric ED with respiratory illnesses. METHODS: The history, physical examination, pediatric ED management, and therapy were recorded. Based on clinical assessment, the physician was asked whether the patient had a low SaO2 (< or = 92%). Room-air pulse oximetry was then obtained, with subsequent treatment and management plans recorded. RESULTS: Clinical assessment had a sensitivity of 33%, specificity of 86%, negative predictive value of 85%, and positive predictive value of 35% for detecting children with low SaO2. Unexpected low SaO2 usually led to a change in patient management or disposition. CONCLUSION: Clinical evaluation in a pediatric ED does not screen adequately for the detection of hypoxemia and should be supplemented by routine pulse oximetry in all patients with respiratory findings.