Pilot Study to Assess the Use of Ultrasound in Evaluating the Abnormal Pediatric Airway.

In this study, we sought to explore the feasibility of using ultrasonography to evaluate airway anomalies in awake children with previous airway reconstruction. For the month of December 2018, we reviewed the medical records of patients aged <18 years old with prior airway reconstruction who had an outpatient appointment and a microlaryngoscopy and bronchoscopy within 24 hours of each other. Four patients met inclusion criteria and were enrolled. Sonographic airway images and measurements were obtained during the outpatient appointment and compared with those obtained during endoscopy. Ultrasound identified extraluminal stents and glottic, subglottic, and tracheal pathology. Subglottic measurements obtained sonographically were within 0.1 to 0.5 mm of the outer diameter of the appropriate endotracheal tubes. Ultrasound did not visualize tracheotomy tubes or posterolateral pathology. Our findings lay the foundation for expanding the role of ultrasound in pediatric airway assessment, keeping in mind its apparent inability to visualize posterolateral airway pathology.

Practice Patterns and Projections for the US Pediatric Otolaryngology Workforce.

IMPORTANCE: This study represents up-to-date information on the current status of and future projections for the pediatric otolaryngology workforce. OBJECTIVE: To provide an update on the practice patterns of and projections for the US pediatric otolaryngology workforce. DESIGN, SETTING, AND PARTICIPANTS: An online survey was sent to all 172 members of the American Academy of Pediatrics Section on Otolaryngology-Head and Neck Surgery and fielded from May 29, 2014, to September 17, 2014. MAIN OUTCOMES AND MEASURES: Current status of and perceived trends in the pediatric otolaryngology workforce. RESULTS: Eighty-four (48.8%) of the 172 members responded to the survey. Not all respondents answered all questions, and so totals and percentages might not reflect a total of 84 for any given response. The demographics and practice characteristics of the responding pediatric otolaryngologists were similar to those noted in a 1997 workforce survey. Fifty-four percent of respondents (n = 38) planned to continue full-time work over the next 5 years, and 47% (n = 31) believed that the number of patients in their practice was increasing. The proportion of those who believed that the need for pediatric otolaryngologists in their community was increasing (31%; n = 21) or decreasing (13%; n = 9) remained relatively constant from the 1997 survey (34% and 12%, respectively). Forty-nine percent (n = 35) reported believing that the number of pediatric otolaryngologists being trained was appropriate and that the need in their community was stable. Eighty-three percent (n = 55) reported believing that employment opportunities for pediatric otolaryngologists in the United States would be plentiful in the near future. CONCLUSIONS AND RELEVANCE: The overall state of the pediatric otolaryngology workforce appears stable. The perceived current and future needs for pediatric otolaryngologists appear to be met by the current number of trainees. Employment opportunities appear promising for future pediatric otolaryngologists based on our respondents' opinions. This represents up-to-date information on the current status of and future projections for the pediatric otolaryngology workforce.

The Persistence of Tinnitus after Acoustic Neuroma Surgery.

OBJECTIVE: Examine possible prognostic factors for the persistence of tinnitus after acoustic neuroma resection. STUDY DESIGN: Case series with chart review. SETTING: Tertiary academic medical center. SUBJECTS AND METHODS: The records of 166 patients who underwent acoustic neuroma resection from 2009 to 2014 were reviewed. Patients were asked to complete a survey, including the Tinnitus Handicap Inventory, 1 to 6 years postoperatively. RESULTS: Of the 53 patients who completed the survey, 17% reported that their tinnitus resolved; 9% reported improvement; 23% reported no change; 43% reported that their tinnitus worsened; and 8% were unsure. Respondents ≥50 years old and those with nonserviceable hearing preoperatively were more likely to report that their tinnitus resolved or improved (P < .01 and P = .02, respectively). Respondents <50 years old and those with serviceable hearing preoperatively were more likely to report that their tinnitus was the same or worse (P < .001 and P = .036, respectively). Respondents with age <50 years, serviceable hearing preoperatively, and residual tumor had a higher average Tinnitus Handicap Inventory score (P = .016, P = .048, and P = .047, respectively). Sex, tumor size, surgical approach, hearing preservation, and cochlear nerve status did not correlate with the prognosis of tinnitus postoperatively. Respondents whose tinnitus resolved postoperatively were more likely to report being "very satisfied" with their care (P = .012). CONCLUSION: In this study, 83% of respondents had persistent tinnitus after acoustic neuroma resection. The prognosis of tinnitus was worse for younger respondents, those with serviceable hearing preoperatively, and those with residual tumor postoperatively. Respondents' satisfaction was higher if their tinnitus resolved.

Evaluating the role of single-photon emission computed tomography in the assessment of neurotologic complaints.

We conducted a retrospective study to reexamine the value of single-photon emission computed tomography (SPECT) in the evaluation of patients with neurotologic complaints, and to assess the intra- and inter-radiologist variability of SPECT readings. Our study population was made up of 63 patients--23 men and 40 women, aged 34 to 91 years (mean: 59)--who had presented to a tertiary care otolaryngology practice and university hospital for evaluation of head trauma, sensorineural hearing loss, tinnitus, and/or vertigo. All patients had undergone brain scanning with SPECT during their evaluation, and almost all had also undergone magnetic resonance imaging (MRI) and standard computed tomography (CT). We compared the findings of all three imaging modalities in terms of their ability to detect neurotologic abnormalities. We found that detection rates were very similar among the three modalities; abnormalities were found in 24% of SPECT scans, 26% of MRIs, and 23% of CTs. Nevertheless, we did find that among 60 patients who underwent all three types of imaging, 13 (22%) exhibited areas of cerebral hypoperfusion on SPECT while their MRIs and CTs were read as either normal or nonspecific. In all, 18 of these 60 patients (30%) exhibited normal or nonspecific findings on all three types of imaging. In addition, when SPECT scans were read by the same radiologist at different times, different results were reported for 17 of the 63 scans (27%). Likewise, when SPECT scans were read by different radiologists, different results were reported for 21 of 63 scans (33%). We conclude that SPECT may be a valuable complementary diagnostic modality for making a comprehensive neurotologic evaluation and that it may detect abnormalities in some patients whose other imaging is read as normal. However, we did not find that SPECT was the most sensitive of the three modalities in neurotologic evaluation, as we had previously found in a preliminary study that the senior author (R.T.S.) published in 1996. In addition, with respect to our radiologists, both their intra- and inter-reader reliability was low, and we recommend additional study on this matter.

Radiation stability of cations in ionic liquids. 3. Guanidinium cations.

Due to their superb structural versatility, guanidinium cations find increasing use as constituent ions in room temperature ionic liquids (ILs). This versatility allows fine-tuning of hydrophobicity, which is an important concern for the use of ILs as diluents for metal ion separations. However, the presence of six C-N bonds in such cations poses a question, whether the guanidinium based ILs can be considered as diluents for nuclear separations, given that the radiation emitted by the decaying radionuclides can break these relatively weak bonds over the use cycle of the solvent. As nothing is presently known about the radiolytic stability of the guanidinium cations, we addressed this question using 2-dialkylamino-1,3-dimethylimidazolidine based cations (R = Et, Pr, and Bu) as a representative model for the entire class of such cations, and assessed their stability in 2.5 MeV electron beam radiolysis. Electron paramagnetic resonance spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry have been used to establish chemical mechanisms for radiation damage in guanidinium cations. Our conclusion is that radiation stability of these cations is not significantly different from that of more familiar aliphatic and aromatic IL cations. In fact, these cations yield exceptionally stable radicals, and fragmentation occurs only in their radiolytically generated excited states. The predominant chemical pathway for the cation decomposition is the elimination of their aliphatic arms, with radiolytic yields of 0.65 to 1.06 to 1.46 per 100 eV from R = Et to R = Bu, respectively. The total loss of the parent cation was estimated as 2.62, 1.65, and 1.98 species per 100 eV. While this attrition is not negligible, it is comparable to other organic cations that have fewer fissile C-N bonds. Many of the products are either modified guanidinium ions or protonated bases that are not expected to interfere with radionuclide separations.

Radiation-induced fragmentation of diamide extraction agents in ionic liquid diluents.

N,N,N',N'-Tetraalkyldiglycolamides are extracting agents that are used for liquid-liquid extraction of trivalent metal ions in wet processing of spent nuclear fuel. This application places such agents in contact with the decaying radionuclides, causing radiolysis of the agent in the organic diluent. Recent research seeks to replace common molecular diluents (such as n-dodecane) with hydrophobic room-temperature ionic liquids (ILs), which have superior solvation properties. In alkane diluents, rapid radiolytic deterioration of diglycolamide agents can be inhibited by addition of an aromatic cosolvent that scavenges highly reactive alkane radical cations before these oxidize the extracting agent. Do aromatic ILs exhibit a similar radioprotective effect? To answer this question, we used electron paramagnetic resonance spectroscopy to study the fragmentation pathways in radiolysis of neat diglycolamides, their model compounds, and their solutions in the ILs. Our study indicates that aromatic ILs do not protect these types of solutes from extensive radiolytic damage. Previous research indicated a similar lack of protection for crown ethers, whereas the ILs readily protected di- and trialkyl phosphates (another large class of metal-extracting agents). Our analysis of these unanticipated failures suggests that new types of organic anions are required in order to formulate ILs capable of radioprotection for these classes of solutes. This study is a cautionary tale of the fallacy of analogical thinking when applied to an entirely new and insufficiently understood class of chemical materials.

Extraction separation of rare-earth ions via competitive ligand complexations between aqueous and ionic-liquid phases.

The extraction separation of rare earth elements is one of the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (trivalent actinide lanthanide separations by phosphorus-reagent extraction from aqueous komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([C(n)mim][NTf(2)] and [C(n)mim][BETI], n = 4,6,8,10) and one pyrrolidinium IL ([C(4)mPy][NTf(2)]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for the separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as a diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and of different anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper.