achieve a target effect site (brain) concentration of propofol. However, patients may lose consciousness at variable effect site concentrations (Ce), with a higher Ce being associated with higher upper airway critical closing pressure.6,7 Most DISE procedures are started shortly after the patients lose consciousness. Objective:To evaluate the effect of sedation depth on druginduced sleep endoscopy (DISE). Methods: Ninety patients with obstructive sleep apnea (OSA) and 18 snorers underwent polysomnography and DISE under bispectral index (BIS)-guided propofol infusion at two different sedation levels: BIS 65-75 (light sedation) and 50-60 (deep sedation). Results: For the patients with OSA, the percentages of velopharynx, oropharynx, hypopharynx, and larynx obstructions under light sedation were 77.8%, 63.3%, 30%, and 33.3%, respectively. Sedation depth was associated with the severity of velopharynx and oropharynx obstruction, oropharynx obstruction pattern, tongue base obstruction, epiglottis anteroposterior prolapse and folding, and arytenoid prolapse. In comparison, OSA severity was associated with the severity of velopharynx obstruction, severity of oropharynx obstruction, and arytenoid prolapse (odds ratio (95% confi dence interval); 14.3 (4.7-43.4), 11.7 (4.2-32.9), and 13.2 (2.8-62.3), respectively). A good agreement was noted between similar DISE fi ndings at different times and different observers (kappa value 0.6 to 1, respectively 1 Drug-induced sleep endoscopy (DISE) has been used for decades to directly examine the upper airways in sedative-induced sleep and improve treatment outcomes by acting as an adjuvant tool to assess surgical or nonsurgical treatment options. 2-4Various sedation methods have been used to allow for the performance of DISE. Roblin introduced target-controlled infusion (TCI) of propofol to DISE to allow for better control of the sedation level.5 TCI of propofol uses computer-based pharmacokinetic and pharmacodynamic models to predict and Bispectral Index in Evaluating Effects of Sedation Depth on Drug-Induced Sleep EndoscopyYu-Lun Lo, MD BRIEF SUMMARYCurrent Knowledge/Study Rationale: Drug-induced sleep endoscopy (DISE) were performed under different sedative conditions and might affect upper airway obstructions. We aimed to evaluate the affects of sedation depth and obstructive sleep apnea severity on different upper airway obstruction patterns. Study Impact: Under DISE, sedation depth affected velopharynx and oropharynx obstruction severity, oropharynx obstruction pattern, tongue base obstruction, epiglottis anteroposterior prolapse and folding, and arytenoid prolapse; however, OSA severity was associated with velopharynx and oropharynx obstruction severity as well as arytenoid prolapse. Bispectral index guided DISE offers an objective and reproducible method to evaluate upper airway collapsibility.

Obstructive sleep apnea (OSA) is a known risk factor for atherosclerosis. We investigated the association of common carotid artery intima-media thickness (CCA-IMT) with snoring sounds in OSA patients. A total of 30 newly diagnosed OSA patients with no history of cardiovascular diseases were prospectively enrolled for measuring mean CCA-IMT with B-mode ultrasonography, body mass index, metabolic syndrome, 10-year cardiovascular disease risk score, high-sensitivity C-reactive protein, and homocysteine. Good-quality signals of full-night snoring sounds in an ordinary sleep condition obtained from 15 participants were further acoustically analyzed (Included group). All variables of interest were not significantly different (all p > 0.05) between the included and non-included groups except for diastolic blood pressure (p = 0.037). In the included group, CCA-IMT was significantly correlated with snoring sound energies of 0–20 Hz (r = 0.608, p = 0.036) and 652–1500 Hz (r = 0.632, p = 0.027) and was not significantly associated with that of 20–652 Hz (r = 0.366, p = 0.242) after adjustment for age and sex. Our findings suggest that underlying snoring sounds may cause carotid wall thickening and support the large-scale evaluation of snoring sound characters as markers of surveillance and for risk stratification at diagnosis.

Laryngeal cysts are uncommon in infants, who usually have stridor, dyspnea, and feeding difficulties. Supraglottic cyst at tongue base and vallecular cyst are the most common laryngeal cysts in children, l Although these cysts are benign, they may cause serious airway obstruction and even death if not treated appropriately. A mortality rate of about 40% in children with laryngeal cysts was reported. 2-5 However, most of the tongue base cysts improve symptomatically after surgical removal. 5~' In this article we report two young infants with valiecular cysts associated with laryngomalacia presenting symptoms of feeding difficulties and stridor. After excision of the vallecular cyst, stridor persisted despite improvement of feeding difficulties. Because vallecular cyst in combination with laryngomalacia is an extremely rare clinical finding, we herein report two such cases diagnosed by flexible bronchoscopy. CASE REPORTSCase t. A 1-month-old male infant was referred by a pediatrician with a 2-week history of decreased appetite, choking episodes during milk feeding, and noisy respiration. Physical examination showed a stridulous child with suprasternal retraction. Chest x-ray film was normal, and soft-tissue x-ray film of the neck showed a globular lesion at the tongue base (Fig. 1). Flexible bronchoscopy revealed a 2.5-cm cystic mass at the vallecular space and an epiglottis that was flaccid and sucked into the laryngeal introitus during inspiration. The trachea and bilateral mainstem bronchi were normal. A thyroid scan was normal with no ectopic uptake. Excision of the cyst was done after needle aspiration. After surgery stridor persisted, and poor feeding and respiratory distress improved. One From Division of Pediatric Pulmonology (Dr. Wong), Chang Gung Children's Hospital; and the Department of Otolaryngology (Drs. Li and Huang), Chang Gung Memorial Hospital.