Multimodal Handheld Probe for Characterizing Otitis Media - Integrating Raman Spectroscopy and Optical Coherence Tomography.

Otitis media (OM) is a common disease of the middle ear, affecting 80% of children before the age of three. The otoscope, a simple illuminated magnifier, is the standard clinical diagnostic tool to observe the middle ear. However, it has limited contrast to detect signs of infection, such as clearly identifying and characterizing middle ear fluid or biofilms that accumulate within the middle ear. Likewise, invasive sampling of every subject is not clinically indicated nor practical. Thus, collecting accurate noninvasive diagnostic factors is vital for clinicians to deliver a precise diagnosis and effective treatment regimen. To address this need, a combined benchtop Raman spectroscopy (RS) and optical coherence tomography (OCT) system was developed. Together, RS-OCT can non-invasively interrogate the structural and biochemical signatures of the middle ear under normal and infected conditions.In this paper, in vivo RS scans from pediatric clinical human subjects presenting with OM were evaluated in parallel with RS-OCT data of physiologically relevant in vitro ear models. Component-level characterization of a healthy tympanic membrane and malleus bone, as well as OM-related middle ear fluid, identified the optimal position within the ear for RS-OCT data collection. To address the design challenges in developing a system specific to clinical use, a prototype non-contact multimodal handheld probe was built and successfully tested in vitro. Design criteria have been developed to successfully address imaging constraints imposed by physiological characteristics of the ear and optical safety limits. Here, we present the pathway for translation of RS-OCT for non-invasive detection of OM.

Cost-effectiveness of polysomnography in the management of pediatric obstructive sleep apnea.

OBJECTIVES: At our institution, younger children require polysomnography (PSG) testing to confirm obstructive sleep apnea (OSA hereafter) before surgical intervention by adenotonsillectomy (T&A). Given that sleep studies can be costly, we investigated the cost-effectiveness of PSG as well as the possible role for symptom documentation in evaluation for T&A. METHODS: Pediatric patients age 1-3 years who received PSG testing between Jan. 2015 and Jan. 2016 who had not previously had T&A were identified for retrospective cost analysis. Cost data were obtained from institutional accountants. We defined a positive PSG as obstructive apnea-hypopnea index ≥1. Logistic regression analysis was used, and statistical significance was set a priori at p < 0.05. Sensitivities and specificities of symptom documentation screen for OSA were compared to gold standard, or PSG testing. RESULTS: Of the 176 children who received polysomnography testing, 140 (80%) had a positive PSG indicative of OSA. Seventy-one (51%) children with OSA underwent T&A within 1 year of PSG, and 10 (7%) eventually received T&A after 1 year from PSG date. Of the children whose PSG results were negative (n = 36), 14 (39%) still underwent T&A within 1 year (n = 7, 19%) or later (n = 7, 19%). Children with positive sleep studies were significantly more likely to receive T&A within one year of PSG (p = 0.0006) and at any time after PSG (p = 0.04). Hospital costs for T&A varied widely while PSG costs were fairly consistent. Using average institutional costs of T&A and PSG, the total cost of a T&A was 17.7× the cost of PSG testing. Using number of recorded symptoms to diagnose OSA instead of PSG testing yielded low specificities. CONCLUSION: Fifty-eight percent of patients with OSA and 39% of patients without OSA had a T&A within 1 year or later, although positive PSG was significantly associated with a higher likelihood of receiving T&A. Given costs at this institution and current decision-making practices, 147 PSGs would need to be done to account for the cost of one T&A, which in our cohort would occur after approximately 305 days.

Single cell analysis of human tissues and solid tumors with mass cytometry.

BACKGROUND: Mass cytometry measures 36 or more markers per cell and is an appealing platform for comprehensive phenotyping of cells in human tissue and tumor biopsies. While tissue disaggregation and fluorescence cytometry protocols were pioneered decades ago, it is not known whether established protocols will be effective for mass cytometry and maintain cancer and stromal cell diversity. METHODS: Tissue preparation techniques were systematically compared for gliomas and melanomas, patient derived xenografts of small cell lung cancer, and tonsil tissue as a control. Enzymes assessed included DNase, HyQTase, TrypLE, collagenase (Col) II, Col IV, Col V, and Col XI. Fluorescence and mass cytometry were used to track cell subset abundance following different enzyme combinations and treatment times. RESULTS: Mechanical disaggregation paired with enzymatic dissociation by Col II, Col IV, Col V, or Col XI plus DNase for 1 h produced the highest yield of viable cells per gram of tissue. Longer dissociation times led to increasing cell death and disproportionate loss of cell subsets. Key markers for establishing cell identity included CD45, CD3, CD4, CD8, CD19, CD64, HLA-DR, CD11c, CD56, CD44, GFAP, S100B, SOX2, nestin, vimentin, cytokeratin, and CD31. Mass and fluorescence cytometry identified comparable frequencies of cancer cell subsets, leukocytes, and endothelial cells in glioma (R = 0.97), and tonsil (R = 0.98). CONCLUSIONS: This investigation establishes standard procedures for preparing viable single cell suspensions that preserve the cellular diversity of human tissue microenvironments. © 2016 International Clinical Cytometry Society.

Prevention of pressure ulcers after pediatric tracheotomy using a Mepilex Ag dressing.

OBJECTIVES/HYPOTHESIS: Skin irritation and ulceration beneath the tracheostomy tube or ties secondary to pressure and shearing forces on the skin frequently complicate pediatric tracheotomy in the immediate postoperative period. The aim of this study is to determine the effectiveness of Mepilex Ag dressings in reducing posttracheotomy wound complications. STUDY DESIGN: Retrospective study. METHODS: We identified 134 pediatric tracheotomies performed between June 2005 and June 2011 at a tertiary care academic pediatric hospital. Peristomal skin breakdown was documented at the time of the first tracheostomy tube change. Starting in February 2010, the application of Mepilex Ag, a silver-impregnated foam dressing, underneath the tracheostomy tube and twill ties became standard practice. The rates of wound breakdown before and after the introduction of Mepilex Ag were compared. Age, indication for tracheotomy, comorbidities, and severity of wound breakdown were also compared. RESULTS: Patients undergoing tracheotomies prior to February 2010 had no dressing applied under the tracheotomy at the end of the procedure (n = 93). Beginning in February 2010, Mepilex Ag barrier was applied beneath the tracheostomy and ties in all subjects undergoing tracheotomy (n = 41). In the cohort without Mepilex Ag, 11.8% developed skin breakdown by the time of first tracheostomy tube change. When Mepilex Ag was used to pad the tracheotomy site, no peristomal skin breakdown occurred (P = 0.02). No comorbidities were associated with postoperative ulcer formation in either cohort. CONCLUSIONS: The use of Mepilex Ag after pediatric tracheotomy reduces the occurrence of postoperative peristomal pressure ulcers.

Detection of viruses in human adenoid tissues by use of multiplex PCR.

By PCR, we detected a high frequency of viruses in adenoids obtained from children without acute respiratory symptoms. Our results suggest that persistent/latent viral infection in the respiratory tract confounds interpretation of the association of pathogen detection by PCR with acute respiratory infection in these sources.

Tracheotomy in the preschool population: indications and outcomes.

OBJECTIVE: Although more tracheotomy procedures are performed within the first year of life than in any other age group, preschool-aged children requiring tracheotomy remain understudied. We characterize the indications and outcomes for patients between the ages of 3 and 6 years undergoing tracheotomy. METHODS: Out of 480 pediatric tracheotomy procedures performed at a tertiary-care hospital between 1988 and 2004, 15 patients underwent primary tracheotomy between 3 and 6 years of age. RESULTS: Most (60%) procedures were performed for pulmonary toilet. Upper-airway obstruction represented the second most common indication (40%), and trauma necessitated tracheotomy procedures more often than had been predicted (40%). The decannulation rate was 40%; 2 patients died. CONCLUSION: Trauma contributed to both upper-airway obstruction as well as requirements for pulmonary toilet. These procedures performed secondary to trauma will likely continue to increase. SIGNIFICANCE: Tracheotomy procedures in the preschool population remain uncommon; however, nearly half of those studied were performed as a direct result of otherwise preventable trauma.

Tracheotomy in the first year of life: outcomes in term infants, the Vanderbilt experience.

OBJECTIVE: In an era emphasizing critical care of preterm infants, we characterize the indications and outcomes of tracheotomies performed in the first year of life in term infants compared to preterm infants. METHODS: Retrospective study of 127 tracheotomies performed in the first year of life at a tertiary-care children's hospital between 1988-2004. RESULTS: Mean gestational ages of the term and preterm groups were 38.97 and 29.71 weeks, respectively (P < 0.001). Indications for tracheotomy were upper airway abnormalities in 53% for the term group. The number of subsequent airway procedures required was 1.39 in the term group, achieving decannulation in 36.3%, with a 20.5% mortality rate. CONCLUSION: Compared to preterm infants, the term decannulation rate was favorable, as chronic lung disease was uncommon. However, non-tracheotomy-related mortalities remained high. SIGNIFICANCE: Tracheotomies are often performed for relief of upper airway obstruction, and congenital and acquired comorbidities not related to tracheotomy are associated with adverse outcomes in term infants. EBM RATING: C-4.

Use of AlloDerm in type I tympanoplasty: a comparison with native tissue grafts.

OBJECTIVES: AlloDerm, an acellular human dermis allograft, has been shown to be an effective option as a tympanic membrane (TM) graft in animals and humans and has several potential advantages, including eliminating donor site morbidity, reducing operative time, and preserving native tissues for later use. We compared AlloDerm and native tissue grafts in type I tympanoplasty with regard to operative time, graft success rate, and audiologic outcome. STUDY DESIGN: A retrospective chart review of tympanoplasties performed at a major tertiary referral hospital over a 31 month period, starting with the first use of AlloDerm for TM grafting at this institution. METHODS: The medical charts of all patients undergoing tympanoplasty were reviewed. Only those patients undergoing type I tympanoplasty without mastoidectomy or ossicular chain reconstruction were included. These 114 patients (25 AlloDerm, 56 fascia reconstruction, and 33 fascia plus cartilage reconstruction) were compared for operative time, success rate of the graft, and change in audiologic outcome. RESULTS: There was a statistically significant reduction in operative time in the AlloDerm group when controlled for surgeon and choice of approach. All groups showed no statistically significant difference in the success rate of the graft and closure of audiologic air-bone gap, regardless of graft material used. CONCLUSIONS: AlloDerm is an effective TM graft when used in type I tympanoplasty. It is as effective as native tissues in closing the air-bone gap on audiogram as well as in graft success rate. AlloDerm may also significantly reduce operative time, depending on the surgeon's technique.

Growth of respiratory syncytial virus in primary epithelial cells from the human respiratory tract.

Respiratory syncytial virus (RSV) is the most important cause of lower respiratory tract disease in infants and children. To study RSV replication, we have developed an in vitro model of human nasopharyngeal mucosa, human airway epithelium (HAE). RSV grows to moderate titers in HAE, though they are significantly lower than those in a continuous epithelial cell line, HEp-2. In HAE, RSV spreads over time to form focal collections of infected cells causing minimal cytopathic effect. Unlike HEp-2 cells, in which wild-type and live-attenuated vaccine candidate viruses grow equally well, the vaccine candidates exhibit growth in HAE that parallels their level of attenuation in children.

Microlaryngoscopy-airway management with anaesthetic techniques for CO(2) laser.

Carbon dioxide laser microlaryngoscopy requires planning and cooperation of both the anaesthesiologist and surgeon. While there are potentially significant complications, such as fire and difficulty ventilating the patient, laser microlaryngoscopy techniques provide the benefit of allowing for precise management of a wide range of upper airway conditions. Laryngoscopy and bronchoscopy require that the surgeon and anaesthesiologist cooperate in order to maximize exposure for the surgeon and allow for adequate ventilation of the patient. The type of airway the anaesthesiologist may use is dictated by whether access is needed to the hypopharynx, supraglottis, larynx, or subglottis. When the carbon dioxide laser is used for airway surgery, ventilation techniques that may be used include jet ventilation (subglottic or supraglottic) and intermittent or continuous endotracheal intubation, with a variety of tubes. The major complication to be avoided is airway fire. Each technique has advantages and disadvantages for avoiding fire and providing adequate ventilation. Fire is not a concern when the carbon dioxide laser bronchoscope is used, but the humidifier must be eliminated from the anaesthesia circuit to avoid vapour obstructing the bronchoscope coupler.