Establishing the Ideal Conditions to Create an Airway Fire Using a Porcine Airway Model.

Objective: Airway fires are a rare but devastating complication of airway surgery. Although protocols for managing airway fires have been discussed, the ideal conditions for igniting airway fires remain unclear. This study examined the oxygen level required to ignite a fire during a tracheostomy. Study Design: Porcine Model. Setting: Laboratory. Methods: Porcine tracheas were intubated with a 7.5 air-filled polyvinyl endotracheal tube. A tracheostomy was performed. Monopolar and bipolar cautery were used in independent experiments to assess the ignition capacity. Seven trials were performed for each fraction of inspired oxygen (FiO2): 1.0, 0.9, 0.7, 0.6, 0.5, 0.4, and 0.3. The primary outcome was ignition of a fire. The time was started once the cautery function was turned on. The time was stopped when a flame was produced. Thirty seconds was used as the cut-off for "no fire." Results: The average time to ignition for monopolar cautery at FiO2 of 1.0, 0.9, 0.8, 0.7, and 0.6 was found to be 9.9, 6.6, 6.9, 9.6, and 8.4 s, respectively. FiO2 ≤ 0.5 did not produce a flame. No flame was created using the bipolar device. Dry tissue eschar shortened the time to ignition, whereas moisture in the tissue prolonged the time to ignition. However, these differences were not quantified. Conclusion: Dry tissue eschar, monopolar cautery, and FiO2 ≥ 0.6 are more likely to result in airway fires.

Management of pediatric aural foreign bodies: Towards a universal Otolaryngology referral algorithm.

OBJECTIVES: Children with aural foreign bodies (AFB) frequently present to the Emergency Department (ED). Our objective was to analyze patterns of pediatric AFB management at our center to characterize children who are commonly referred to Otolaryngology. METHODS: A retrospective chart review of all children (ages 0-18 years) presenting with AFB to the tertiary care Pediatric ED over a three-year period was performed. Demographics, symptoms, type of AFB, retrieval strategy, complications, need for Otolaryngology referral, and, use of sedation, were evaluated with respect to outcomes. Univariable logistic regression models were conducted to determine which patient characteristics were predictive of AFB removal success. RESULTS: One hundred and fifty-nine patients seen at the Pediatric ED met the inclusion criteria. Average age at presentation was 6 years (2-18 years). Otalgia was the most common presenting symptom (18.0%). However, only 27.0% of children were symptomatic. ED physicians primarily flushed AFBs out of the external auditory canal with water, whereas Otolaryngologists exclusively used direct visualization. Otolaryngology-Head & Neck Surgery (OHNS) was consulted for 29.6% of children. Of these, 68.1% had complications associated with prior retrieval attempts. Sedation was administered in 40.4% of referred children, with 21.2% in an operative setting. Patients experiencing multiple retrieval methods by ED, and, age less than 3 years, were more likely to be referred to OHNS. CONCLUSION: Patient's age should be strongly considered as a factor for early OHNS referral. By synthesizing our conclusions with previously published results, we propose a referral algorithm.

Thematic Analysis of Canadian Patient-Reported Outcomes in Facial Nerve Paralysis: A Combined Interpretive Description and Modified Delphi Approach.

Background: In facial nerve dysfunction literature, subjective reporting tools lack essential construct validity arising from a patient-driven design process. Objective: Elicit patient-identified themes of importance pertaining to disease course in facial nerve dysfunction from a variety of etiologies. Methods: Twenty participant interviews were conducted from a standardized script and analyzed using a thematic analysis framework. Subsequently, four participants participated in a modified Delphi focus group for consensus of relative theme and domain importance. Results: Upon thematic analysis of 315 codable phrases, 33 codes were sorted into six domains. In descending order: smiling, facial symmetry, surgical access, self-consciousness, eye care, eating, lip movement, eye closure, beverage consumption, speech, chewing, drooling, eyebrow raise, mouth closure, and ptotic vision limitations were identified as the most important aspects of disease course. Care experience, defined as areas of interaction with the health care system in which patients felt strongly about their care or outcome, was the most important domain to participants. Conclusion: Patients with facial nerve dysfunction identified care experience as the highest domain of importance, and value smiling, facial symmetry, and access to surgical treatments.

The Identification of Intraoperative Risk Factors Can Reduce, but Not Exclude, the Need for Completion Thyroidectomy in Low-Risk Papillary Thyroid Cancer Patients.

Background: The extent of initial surgical resection for low-risk papillary thyroid cancer (PTC) remains debatable. Since the 2015 American Thyroid Association (ATA) guidelines, several retrospective studies have reported that 40-60% of patients initially treated with lobectomy would require a completion thyroidectomy (CTx) due to high-risk pathological features (HRFs). These studies are limited by variable preoperative stratification and inability to quantify the value of intraoperative assessment. The study objectives were to determine whether diligent preoperative and intraoperative assessment improves the appropriateness of initial surgery for low-risk PTCs and whether varying the criteria for lobectomy reduces the need for CTx. Methods: A prospectively collected province-wide database was analyzed over a 10-year period (2008-2017) for patients who underwent a total thyroidectomy (TT) for PTC without preoperative HRFs. All patients had preoperative ultrasound and fine-needle aspirates. Unique to this database are mandatory synoptic operative fields that identify intraoperative risk factors such as positive lymph nodes and local invasion. Results: In total, 74% of patients (709/959) were deemed eligible for lobectomy. Of those eligible, 149 (21%) had intraoperative risk factors that would necessitate conversion to TT at the initial operation. A further 209 (30%) would require CTx due to HRFs on final pathology. Varying the preoperative criteria for lobectomy did not significantly affect intraoperative conversion or CTx rates. Conclusions: Although intraoperative assessment reduced the need for CTx in 21%, up to 30% of patients would still require a second operation. Altering the preoperative criteria does not influence this outcome. Patients deemed eligible for lobectomy should be informed that despite careful pre- and intraoperative assessment, there is up to a 30% risk of requiring CTx.

Conserved pharmacological rescue of hereditary spastic paraplegia-related phenotypes across model organisms.

Hereditary spastic paraplegias (HSPs) are a group of neurodegenerative diseases causing progressive gait dysfunction. Over 50 genes have now been associated with HSP. Despite the recent explosion in genetic knowledge, HSP remains without pharmacological treatment. Loss-of-function mutation of the SPAST gene, also known as SPG4, is the most common cause of HSP in patients. SPAST is conserved across animal species and regulates microtubule dynamics. Recent studies have shown that it also modulates endoplasmic reticulum (ER) stress. Here, utilizing null SPAST homologues in C. elegans, Drosophila and zebrafish, we tested FDA-approved compounds known to modulate ER stress in order to ameliorate locomotor phenotypes associated with HSP. We found that locomotor defects found in all of our spastin models could be partially rescued by phenazine, methylene blue, N-acetyl-cysteine, guanabenz and salubrinal. In addition, we show that established biomarkers of ER stress levels correlated with improved locomotor activity upon treatment across model organisms. Our results provide insights into biomarkers and novel therapeutic avenues for HSP.

Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders.

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and thus current therapeutic treatment strategies are not curative. Through the use of whole exome sequencing, an increasing number of genes have been identified to play a role in human locomotion. Despite identifying these genes, it is not known how these genes are crucial to normal locomotive functioning. Therefore, a reliable assay, which utilizes model organisms to elucidate the role of these genes in order to identify novel targets of therapeutic interest, is needed more than ever. We have designed a sensitized version of the negative geotaxis assay that allows for the detection of milder defects earlier and has the ability to evaluate these defects over time. The assay is performed in a glass graduated cylinder, which is sealed with a wax barrier film. By increasing the threshold distance to be climbed to 17.5 cm and increasing the experiment duration to 2 min we have observed a greater sensitivity in detecting mild mobility dysfunctions. The assay is cost effective and does not require extensive training to obtain highly reproducible results. This makes it an excellent technique for screening candidate drugs in Drosophila mutants with locomotion defects.

The non-motile phenotype of Salmonella hha ydgT mutants is mediated through PefI-SrgD.

BACKGROUND: Two ancestral nucleoid-associated proteins called Hha and YdgT contribute to the negative regulation of several virulence-associated genes in Salmonella enterica serovar Typhimurium. Our previous work showed that Hha and YdgT proteins are required for negative regulation of Salmonella Pathogenicity Island-2 and that hha ydgT double mutants are attenuated for murine infection. Interestingly, hha ydgT mutant bacteria exhibited a non-motile phenotype suggesting that Hha and YdgT have a role in flagellar regulation. RESULTS: In this study we show that the non-motile phenotype of hha ydgT mutants is due to decreased levels of the master transcriptional regulator FlhD4C2 resulting in down-regulation of class II/III and class III flagellar promoters and lack of surface flagella on these cells. The horizontally acquired pefI-srgD region was found to be partially responsible for this phenotype since deletion of pefI-srgD in a hha ydgT deletion background resulted in transient restoration of class II/III and III transcription, expression of surface flagella, and motility in the quadruple mutant. CONCLUSION: These data extend our current understanding of the mechanisms through which Hha and YdgT regulate flagellar biosynthesis and further describe how S. Typhimurium has integrated horizontal gene acquisitions into ancestral regulatory networks.