A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Medicine. Johannesburg, July 2019 / Background: Cycloplegic refraction is a reliable procedure for obtaining an accurate refraction in children. Atropine is considered the gold standard, however, it does not have the properties of an ideal cycloplegic agent. Theoretically, cyclopentolate is the preferred agent and many have advocated it as an alternative. In the African population where dark irides are common there is insufficient information comparing the two agents, especially so in younger aged children. Objective: To establish if cyclopentolate is as effective as atropine in cycloplegic refraction in dark irides. Method: A prospective, sequential, paired study on patients requiring cycloplegic refraction was conducted. Each patient was refracted after the usage of cyclopentolate. Refraction was then repeated 2 weeks later after using atropine. Results: 40 patients (80 eyes) were refracted with both agents. The mean difference between the agents (atropine – cyclopentolate) was +0,14 DS (95% CI: +0.05 to +0.24; paired t-test; p=0.0027), however, the effect size was small (Cohen’s d=0.35) making it clinically insignificant. No adverse effects were reported with either of the cycloplegic agents. Conclusion: Cyclopentolate is as effective as atropine for cycloplegic refraction in dark irides and can be used as an alternative to atropine for cycloplegic refraction. / MT 2020

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Tuberculosis (TB) in children is a common infectious disease in the world affecting approximately 550 000 children annually and contributing to approximately 10-15% of the TB caseload. The estimate is that 75% of the children who have TB live in the 22 countries that have the highest burden of TB disease. In these 22 countries, the technology required to make the diagnosis and manage complicated cases is limited. The epidemiological data required to estimate the proportion of children with severe disease requiring intervention at a global level are lacking. Airway involvement is commonly seen in children with primary TB, but only in a small group of children the compression is severe, needing intervention. The incidence of children with airway obstruction requiring intervention due to primary TB in the chemotherapeutic era is not known. The incidence of complicated lymph node disease in two recent reports varied from 8-38% in children younger than 15 years of age. Flexible bronchoscopy (FB) is an invasive procedure performed under general anesthetic is used to assess the airways of children. Few studies have been published on the use of FB in the diagnosis of paediatric TB and most have concentrated on the use of bronchoscopy as an intervention for obtaining samples to diagnose pulmonary TB (PTB). All previous studies only examined broncho-alveolar lavage (BAL) for Ziehl Neelsen (ZN) positive organisms and mycobacterial culture. All the published studies are from developed countries with a very low incidence of PTB in children. It has been postulated that HIV positive children with TB are more likely to have airway obstruction, but this hypothesis has not been studied. The same is true for children infected with drug-resistant strains of tuberculosis. Similarly, there have been few reports on the correlation between the findings at bronchoscopy and those found on chest computer tomography (CT). The aim of this research project was to systematically determine airways involvement in childhood pulmonary TB and assess the role paediatric bronchoscopy plays in the diagnosis, sample collection and the management of severe airway obstruction. The first part of the thesis describes the bronchoscopic assessment of airway obstruction due to pulmonary TB in children, specifically concentrating on the areas of the airway involved and the severity of the obstruction. We investigated which factors determine the severity of airway obstruction and this included age, sex, HIV status and drug sensitivities. We have shown that there was no difference in airway obstruction in HIV positive children and in children with drug resistance TB. More severe airway obstruction was seen in the younger child. The second question that was analysed is the value of flexible bronchoscopy in collecting samples for TB culture and drug sensitivity testing. It has previously been reported that BAL culture was inferior to gastric lavage in isolating the bacilli. We set out to evaluate which factors determine if a child will be culture-positive on BAL. Most childhood pulmonary TB is postulated to have a low yield of ZN positive cases. We found a higher yield from BAL as was previously reported, and the yield was increased if segmental or lobar pneumonia was present on the chest radiography. We developed novel interventions of finding the organism and increasing the yield from BAL. About 80% of children with PTB have enlarged subcarinal lymph nodes. We performed a trans-bronchial needle aspiration (TBNA) biopsy of these lymph nodes for culture. This technique enables us to differentiate the cause of enlarged mediastinal lymph nodes. This is especially important in children who are HIV positive, as they are prone to have other causes of enlarged lymph nodes. We successfully performed TBNA, even in very young infants, which resulted in a diagnostic yield of 55%. The use of Xpert has been described on other tissue, but not on BAL. We wanted to test if the use of Xpert on BAL is feasible in children, and determine if it will increase the diagnostic yield by using BAL samples. The third aspect of this research was to compare flexible bronchoscopy findings with those of chest CT scan finding. Firstly, the aim was to describe the CT scan findings of mediastinal glands and lungs in children with significant airway obstruction due to PTB. The second aim was to investigate how these two investigations of airway obstruction compared, with particular emphasis on their advantages and disadvantages. The areas of airway obstruction as well as the severity of the obstruction as determined by CT scan were very similar to the findings with bronchoscopy. The final part under this aspect of the study was to analyze airway shape using a computer model to asses if this could predict TB. This was done by extracting components of the airway surface mesh and branch radius and orientation features. This method showed the potential of computer-assisted detection of TB and other airway pathology by using airway shape deformation analysis. The fourth aspect investigated was to determine which children with severe airway obstruction would benefit from a surgical intervention. Surgical enucleation is done via a lateral thoracotomy in children with severe airway obstruction. We investigated which factors determine the need for surgical enucleation, the optimal timing of this intervention, and – if surgical enucleation was done as an emergency intervention – which factors would predict for this. The combination of trachea, left main bronchus and bronchus intermedius involvement was the best predictor for children requiring surgical enucleation. Involvement of the smaller airway divisions did not play a significant role. Children needing enucleation were younger and had more severe airway obstruction. The fifth aspect of this thesis was to measure the outcome following surgical enucleation. Measurements used included clinical measurements, radiological measurements and bronchoscopy. The response in children treated surgically were compared to those treated medically by estimating airway size with flexible bronchoscopy. Both groups showed significant improvement with the magnitude of improvement greater in those surgically treated. We have demonstrated in this thesis that the site and severity of severe airway obstruction can be assessed by either bronchoscopy or chest CT scan. Approximately one third of children with severe airway compression due to TB lymph nodes can be successfully treated surgically with a low morbidity and mortality. / AFRIKAANSE OPSOMMING: Tuberkulose (TB) by kinders is wêreldwyd ’n algemene siekte wat jaarliks ongeveer 550 000 kinders raak en sowat 10-15% van die algehele TB-siektelas uitmaak. Na raming kom 75% van alle kinders met TB van die 22 lande met die hoogste TB-siektelas. Hierdie 22 lande beskik oor beperkte tegnologie om die siekte te diagnoseer en ingewikkelde gevalle te bestuur. Die vereiste epidemiologiese data om te raam watter persentasie kinders wêreldwyd ernstig siek is en intervensie vereis, ontbreek ook. Lugwegaantasting word algemeen by kinders met primêre TB aangetref. Tog is die kompressie by slegs ’n klein groepie kinders so erg dat dit intervensie vereis. Die voorkoms van kinders in die chemoterapeutiese era met primêre-TB-verwante obstruksie van die lugweë wat intervensie vereis, is onbekend. In twee onlangse verslae het die voorkoms van gekompliseerde limfkliersiekte by kinders jonger as 15 jaar van 8% tot 38% gewissel. Buigbare brongoskopie is ’n indringende prosedure wat onder algemene verdowing uitgevoer word om kinders se lugweë te ondersoek. ’n Paar studies is reeds gepubliseer oor die gebruik van buigbare brongoskopie om pediatriese TB te diagnoseer. Die meeste daarvan het gekonsentreer op die gebruik van brongoskopie as intervensie vir die insameling van monsters om pulmonêre TB (PTB) te diagnoseer. Alle vorige studies het uitsluitlik ondersoek ingestel na brongo-alveolêre spoeling (BAS) vir die opsporing van Ziehl Neelsen- (ZN-)positiewe materiaal en vir kweking. Geen ander diagnostiese tegnieke is tot dusver ondersoek nie, wat die waarde daarvan vir populasies met ’n hoë siektelas beperk. Boonop is alle gepubliseerde studies in ontwikkelde lande met ’n baie lae voorkoms van PTB by kinders onderneem. Daar word aangevoer dat MIV-positiewe kinders met TB meer waarskynlik aan obstruksie van die lugweë sal ly, hoewel hierdie hipotese nog nie bestudeer is nie. Dieselfde geld vir kinders wat aan middelweerstandige vorme van TB ly. Daar is ook weinig verslae oor die verband tussen die bevindinge van brongoskopie en dié van rekenaartomografie (RT) van die borskas. Die doel van hierdie navorsing was om stelselmatig vas te stel hoe pulmonêre TB by kinders die lugweë aantas, en watter rol pediatriese brongoskopie in diagnose, monsterinsameling en die hantering van ernstige obstruksie van die lugweë speel. Die eerste deel van die tesis beskryf die brongoskopiese voorkoms van PTB-verwante obstruksie van die lugweë, met bepaalde klem op die aangetaste dele van die lugweg en die erns van die obstruksie. Daar is ondersoek ingestel na watter faktore die erns van die obstruksie bepaal, onder meer ouderdom, geslag, MIV-status en middelsensitiwiteit. Die resultate toon geen verskil in obstruksie by MIV-positiewe kinders en kinders met middelweerstandige TB nie, hoewel ernstiger obstruksie van die lugweë by die jonger kind opgemerk is. Die tweede kwessie wat ontleed is, is die waarde van buigbare brongoskopie in die verkryging van monsters vir TB-kweking en toetse vir middelsensitiwiteit. Daar is voorheen aangemeld dat BAS-kweking minder doeltreffend is as gastriese spoeling om die basille te isoleer. Hierdie studie was daarop toegespits om te beoordeel watter faktore bepaal of ’n kind kwekingspositief met BAS sal wees. Die meeste PTB by kinders toon na bewering ’n lae opbrengs van ZN-positiewe gevalle. Tog het BAS in hierdie studie ’n hoër opbrengs gehad as wat voorheen aangemeld is, welke opbrengs hoër was met die aanwesigheid van segmentale of lobêre pneumonie op die borskasradiogram. Innoverende intervensies is ontwikkel om die organisme op te spoor en die opbrengs met BAS te verhoog. Sowat 80% van kinders met PTB het vergrote subkarinale limfkliere. ’n Transbrongiale naaldaspirasie- (TBNA-)biopsie is gevolglik vir die doeleinde van kweking op hierdie kliere uitgevoer. Hierdie tegniek het die navorser in staat gestel om tussen die verskillende oorsake vir vergrote mediastinale limfkliere te onderskei. Dít is veral belangrik by MIVpositiewe kinders, wat geneig is om ander oorsake vir vergrote limfkliere te toon. Die TBNA-biopsies is selfs by baie jong babas suksesvol uitgevoer, wat tot ’n diagnostiese opbrengs van 55% gelei het. Die gebruik van Xpert op ander weefsel as BAS is al voorheen beskryf. Die navorser wou dus vasstel of die gebruik van Xpert by BAS haalbaar is by kinders, en of dit die diagnostiese opbrengs deur die gebruik van BAS-monsters sal verhoog. Die derde aspek van hierdie navorsing was om die bevindinge van buigbare brongoskopie met dié van RT-skanderings van die borskas te vergelyk. Die doel was eerstens om die bevindinge van die RT-skanderings van mediastinale kliere en longe by kinders met beduidende PTB-verwante lugweg-obstruksie te beskryf. Tweedens wou die navorser vasstel wat die verskille tussen hierdie twee ondersoeke van lugweg-obstruksie is, met bepaalde klem op die voordele en nadele daarvan. Die RT-skandering en die bevindinge van brongoskopie lewer betreklik soortgelyke resultate op wat die aangetaste gedeeltes van die lugweg sowel as die erns van sodanige obstruksie betref. Die laaste doel onder hierdie studieaspek was om die vorm van die lugweg met behulp van ’n rekenaarmodel te ontleed om te bepaal of dit TB kan voorspel. Dít is gedoen deur komponente van die die erns van die obstruksie. Daar is ondersoek ingestel na watter faktore die erns van die obstruksie bepaal, onder meer ouderdom, geslag, MIV-status en middelsensitiwiteit. Die resultate toon geen verskil in obstruksie by MIV-positiewe kinders en kinders met middelweerstandige TB nie, hoewel ernstiger obstruksie van die lugweë by die jonger kind opgemerk is. Die tweede kwessie wat ontleed is, is die waarde van buigbare brongoskopie in die verkryging van monsters vir TB-kweking en toetse vir middelsensitiwiteit. Daar is voorheen aangemeld dat BAS-kweking minder doeltreffend is as gastriese spoeling om die basille te isoleer. Hierdie studie was daarop toegespits om te beoordeel watter faktore bepaal of ’n kind kwekingspositief met BAS sal wees. Die meeste PTB by kinders toon na bewering ’n lae opbrengs van ZN-positiewe gevalle. Tog het BAS in hierdie studie ’n hoër opbrengs gehad as wat voorheen aangemeld is, welke opbrengs hoër was met die aanwesigheid van segmentale of lobêre pneumonie op die borskasradiogram. Innoverende intervensies is ontwikkel om die organisme op te spoor en die opbrengs met BAS te verhoog. Sowat 80% van kinders met PTB het vergrote subkarinale limfkliere. ’n Transbrongiale naaldaspirasie- (TBNA-)biopsie is gevolglik vir die doeleinde van kweking op hierdie kliere uitgevoer. Hierdie tegniek het die navorser in staat gestel om tussen die verskillende oorsake vir vergrote mediastinale limfkliere te onderskei. Dít is veral belangrik by MIVpositiewe kinders, wat geneig is om ander oorsake vir vergrote limfkliere te toon. Die TBNA-biopsies is selfs by baie jong babas suksesvol uitgevoer, wat tot ’n diagnostiese opbrengs van 55% gelei het. Die gebruik van Xpert op ander weefsel as BAS is al voorheen beskryf. Die navorser wou dus vasstel of die gebruik van Xpert by BAS haalbaar is by kinders, en of dit die diagnostiese opbrengs deur die gebruik van BAS-monsters sal verhoog. Die derde aspek van hierdie navorsing was om die bevindinge van buigbare brongoskopie met dié van RT-skanderings van die borskas te vergelyk. Die doel was eerstens om die bevindinge van die RT-skanderings van mediastinale kliere en longe by kinders met beduidende PTB-verwante lugweg-obstruksie te beskryf. Tweedens wou die navorser vasstel wat die verskille tussen hierdie twee ondersoeke van lugweg-obstruksie is, met bepaalde klem op die voordele en nadele daarvan. Die RT-skandering en die bevindinge van brongoskopie lewer betreklik soortgelyke resultate op wat die aangetaste gedeeltes van die lugweg sowel as die erns van sodanige obstruksie betref. Die laaste doel onder hierdie studieaspek was om die vorm van die lugweg met behulp van ’n rekenaarmodel te ontleed om te bepaal of dit TB kan voorspel. Dít is gedoen deur komponente van die lugwegoppervlaknetwerk en vertakkingsradius- en oriëntasiekenmerke te onttrek. Hierdie metode het daarop gedui dat rekenaargesteunde opsporing van TB en ander lugwegpatologie deur middel van ’n ontleding van lugwegvervorming wél potensiaal toon. Die vierde aspek was om te bepaal watter kinders met ernstige obstruksie van die lugweë by intervensie sal baat vind. By sulke kinders word chirurgiese enukleëring deur ’n laterale torakotomie uitgevoer. Die studie het ondersoek ingestel na watter faktore die behoefte aan chirurgiese enukleëring bepaal, wat die optimale tyd vir sodanige intervensie sou wees, en – indien chirurgiese enukleëring as noodintervensie uitgevoer word – watter faktore so ’n noodintervensie sou vereis. Die kombinasie van aantasting van die tragea, linkerhoofbrongus en brongus intermedius was die beste voorspeller van kinders wat chirurgiese enukleëring benodig. Aantasting van die kleiner lugwegverdelings het nie ’n beduidende rol gespeel nie. Kinders wat enukleëring vereis, was jonger en het aan ernstiger obstruksie van die lugweë gely. Die vyfde aspek van hierdie tesis was om die uitkoms na afloop van chirurgiese enukleëring te meet. Kliniese metings, radiologiese metings en brongoskopie is hiervoor gebruik. Die reaksie by kinders wat chirurgies behandel is, is vergelyk met diegene wat medies behandel is deur lugweggrootte met behulp van buigbare brongoskopie te raam. Albei groepe het beduidende verbetering getoon. In die studie het ons getoon dat die ligging en die erns van ernstige lugwegobstruksie kan geassesseer word deur óf brongoskopie of rekenaartomografie van die borskas. Ongeveer een derde van kinders met 'n ernstige lugweg-obstruksie weens TB limfkliersiekte kan suksesvol chirurgies met 'n lae morbiditeit en mortaliteit behandel word.

by Ping-Fu Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 98-102). / Abstract also in Chinese. / Abstract --- p.iv / Acknowledgements --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Medical Visualization System --- p.4 / Chapter 1.1.1 --- Data Acquisition --- p.4 / Chapter 1.1.2 --- Computer-aided Medical Visualization --- p.5 / Chapter 1.1.3 --- Existing Systems --- p.6 / Chapter 1.2 --- Research Goal --- p.8 / Chapter 1.2.1 --- System Architecture --- p.9 / Chapter 1.3 --- Organization of this Thesis --- p.10 / Chapter 2 --- Volume Visualization --- p.11 / Chapter 2.1 --- Sampling Grid and Volume Representation --- p.11 / Chapter 2.2 --- Priori Work in Volume Rendering --- p.13 / Chapter 2.2.1 --- Surface VS Direct --- p.14 / Chapter 2.2.2 --- Image-order VS Object-order --- p.18 / Chapter 2.2.3 --- Orthogonal VS Perspective --- p.22 / Chapter 2.2.4 --- Hardware Acceleration VS Software Acceleration --- p.23 / Chapter 2.3 --- Chapter Summary --- p.29 / Chapter 3 --- IsoRegion Leaping Technique for Perspective Volume Rendering --- p.30 / Chapter 3.1 --- Compositing Projection in Direct Volume Rendering --- p.31 / Chapter 3.2 --- IsoRegion Leaping Acceleration --- p.34 / Chapter 3.2.1 --- IsoRegion Definition --- p.35 / Chapter 3.2.2 --- IsoRegion Construction --- p.37 / Chapter 3.2.3 --- IsoRegion Step Table --- p.38 / Chapter 3.2.4 --- Ray Traversal Scheme --- p.41 / Chapter 3.3 --- Experiment Result --- p.43 / Chapter 3.4 --- Improvement --- p.47 / Chapter 3.5 --- Chapter Summary --- p.48 / Chapter 4 --- Parallel Volume Rendering by Distributed Processing --- p.50 / Chapter 4.1 --- Multi-platform Loosely-coupled Parallel Environment Shell --- p.51 / Chapter 4.2 --- Distributed Rendering Pipeline (DRP) --- p.55 / Chapter 4.2.1 --- Network Architecture of a Loosely-Coupled System --- p.55 / Chapter 4.2.2 --- Data and Task Partitioning --- p.58 / Chapter 4.2.3 --- Communication Pattern and Analysis --- p.59 / Chapter 4.3 --- Load Balancing --- p.69 / Chapter 4.4 --- Heterogeneous Rendering --- p.72 / Chapter 4.5 --- Chapter Summary --- p.73 / Chapter 5 --- User Interface --- p.74 / Chapter 5.1 --- System Design --- p.75 / Chapter 5.2 --- 3D Pen Input Device --- p.76 / Chapter 5.3 --- Visualization Environment Integration --- p.77 / Chapter 5.4 --- User Interaction: Interactive Navigation --- p.78 / Chapter 5.4.1 --- Camera Model --- p.79 / Chapter 5.4.2 --- Zooming --- p.81 / Chapter 5.4.3 --- Image View --- p.82 / Chapter 5.4.4 --- User Control --- p.83 / Chapter 5.5 --- Chapter Summary --- p.87 / Chapter 6 --- Conclusion --- p.88 / Chapter 6.1 --- Final Summary --- p.88 / Chapter 6.2 --- Deficiency and Improvement --- p.89 / Chapter 6.3 --- Future Research Aspect --- p.91 / Appendix --- p.93 / Chapter A --- Common Error in Pre-multiplying Color and Opacity --- p.94 / Chapter B --- Binary Factorization of the Sample Composition Equation --- p.96

A traqueostomia percutânea é um procedimento realizado rotineiramente na Unidade de Terapia Intensiva (UTI), guiada por broncoscopia. Recentemente, a ultrassonografia tem surgido como uma ferramenta potencialmente útil para assistir à traqueostomia percutânea e reduzir as complicações relacionadas ao procedimento. Um ensaio clínico randomizado, aberto, paralelo, de não inferioridade, foi conduzido comparando a traqueostomia percutânea guiada por ultrassonografia com a traqueostomia percutânea guiada por broncoscopia, em pacientes sob ventilação mecânica na UTI. O desfecho primário, a falência do procedimento, foi definido como um desfecho composto, incluindo (1) a conversão para traqueostomia cirúrgica, (2) o uso associado e não planejado da broncoscopia ou da ultrassonografia, ou (3) a ocorrência de uma complicação maior. Um total de 4.965 pacientes foram avaliados quanto a elegibilidade. Desses, 171 pacientes foram elegíveis e 118 foram submetidos ao procedimento, com 60 pacientes randomizados para o grupo ultrassonografia e 58 pacientes randomizados para o grupo broncoscopia. A falência do procedimento ocorreu em um (1,7%) paciente no grupo ultrassonografia e um (1,7%) paciente no grupo broncoscopia, sem diferença no risco absoluto entre os grupos (intervalo de confiança de 90%, -5,57 a 5,85), na análise \"conforme tratados\", não incluindo a margem de não inferioridade pré-especificada de 6%. Nenhum outro paciente apresentou uma complicação maior em ambos os grupos. As complicações menores relacionadas ao procedimento ocorreram em 20 (33,3%) pacientes no grupo ultrassonografia e em 12 (20,7%) pacientes no grupo broncoscopia, (P = 0,122). A duração do procedimento foi de 11 [7-19] vs. 13 [8-20] minutos (P = 0,468), respectivamente, e os desfechos clínicos também não foram diferentes entre os grupos. Em conclusão, a traqueostomia percutânea guiada por ultrassonografia é eficiente, segura e associada com taxas de complicações semelhantes à traqueostomia percutânea guiada por broncoscopia, em pacientes sob ventilação mecânica na UTI / Percutaneous Dilational Tracheostomy (PDT) is routinely performed in the intensive care unit (ICU) with bronchoscopy guidance. Recently, ultrasound has emerged as a potentially useful tool in order to assist PDT and reduce procedure-related complications. An open-label, parallel, non-inferiority, randomized controlled trial was conducted comparing the ultrasound-guided PDT with the bronchoscopy-guided PDT in mechanically ventilated critically ill patients. The primary outcome was procedure failure, defined as a composite end-point of conversion to a surgical tracheostomy; unplanned associated use of bronchoscopy or ultrasound during PDT; or the occurrence of a major complication. A total of 4,965 patients were assessed for eligibility. Of these, 171 patients were eligible and 118 underwent the procedure, with 60 patients randomly assigned to the ultrasound group and 58 patients to the bronchoscopy group. Procedure failure occurred in one (1.7%) patient in the ultrasound group and one (1.7%) patient in the bronchoscopy group, with no absolute risk difference between the groups (90% confidence interval, -5.57 to 5.85), in the \'as treated\' analysis, not including the pre-specified margin of 6% for noninferiority. No other patient had any major complication in both of the groups. Procedure-related minor complications occurred in 20 (33.3%) patients in the ultrasound group and in 12 (20.7%) patients in the bronchoscopy group, (P=0.122). The median procedure length was 11 [7-19] vs. 13 [8-20] minutes (P=0.468), respectively, and the clinical outcomes were also not different between the groups. In conclusion, ultrasound-guided PDT is effective, safe and associated with similar complication rates and clinical outcomes compared with bronchoscopy-guided tracheostomy in mechanically ventilated critically ill patients

INTRODUCTION: The anesthetic management for pediatric patients undergoing direct laryngoscopy and/or bronchoscopy (DLB) is administered based on the anesthesiologist’s preference. Objectives: The preliminary analysis of this study aims to identify variables that decrease surgical end-to-transport (SET) time and directly impacts patient outcomes. SET time is defined as the time of surgery end to the time of patient exit from the operating room. METHODS: After IRB approval, all DLBs performed at Boston Children’s Hospital (Boston, MA) by the Otolaryngology Department from June 2012 to December 2014 (n= 2419) were obtained from the Anesthesia Information Management System. With a 0.05 level of significance, a multivariate logistic regression was performed in SAS v9.3 with SET time as the dependent variable and surgery duration, age, gender, ASA status, airway device and extubation status as the independent variables. Airway device and extubation status were found to be moderately predictable of each other, so separate models were conducted. Spearman correlation testing was performed to evaluate the relationship between SET time and post-anesthesia care unit (PACU) duration. RESULTS: We excluded cases having ASA classification >2, age >21 years, regional nerve blocks, tracheostomy, nasal cannula, or unknown airway or extubation status. Remaining cases (n = 967) were arranged by SET times and dichotomized by the median value (14 minutes) into two groups (≤14 minutes and >14 minutes). After adjusting for other variables, we found that patients with an endotracheal tube (ETT) were 4.85 times more likely to have a SET time higher than the median, as compared with to those having with a laryngeal mask airway (LMA) (p = 0.0023, 95% CI: 1.76, 13.33). We also found that patients with an ETT were 2.89 times more likely to have a SET time higher than the median compared with those having a mask airway device. (p < 0.0001, 95% CI: 2.09, 3.98). In addition, there was a weak positive correlation between SET time and PACU duration (r = 0.09406, p = 0.0069). DISCUSSION: Preliminary analysis indicates that airway management has a significant impact on SET time after adjusting for surgery duration, age, gender, and ASA status. The use of either a mask or an LMA resulted in a lower SET time than the use of an ETT. The correlation of SET time and PACU duration suggests that reducing SET time does not negatively impact post-operative outcomes and may even be positively, though weakly, correlated. This study is limited by its retrospective nature. Future analysis will include the evaluation of commonly used perioperative anesthetics with dosage and timing variables and their correlation with SET time and patient outcomes.

Background Particulate matter (PM) air pollution is associated with increased respiratory and cardiovascular morbidity and mortality. Diesel engine exhaust (DE) and wood combustion are major contributors to ambient air pollution and adverse health effects. The aim of this thesis was to investigate the fate of inhaled combustion-derived PM, the subsequent effects on pulmonary inflammation and symptomatology and to explore the potential for particle filters to improve public health. Additionally, it aimed at increasing the understanding of the pathophysiological mechanisms underlying the adverse vascular effects of PM inhalation in man. Methods In study I, lung deposition of wood smoke-derived particulates from incomplete combustion was determined in healthy and COPD subjects. In study II, airway inflammation was assessed in healthy subjects exposed to wood smoke and filtered air. In study III, vehicle cabin air inlet filters were evaluated regarding filtering capacity for DE and whether they affected the toxicological potential of the filtered PM. Healthy subjects were then exposed to filtered air and unfiltered DE, as well as DE filtered through two selected filters. In study IV, healthy subjects were exposed to filtered air and DE. Nitric oxide bioavailability was assessed by plethysmography in the presence of an NO clamp (NO synthase inhibitor NG-monomethyl locally and systemically administered) with measurements of arterial stiffness, cardiac output and blood pressure (BP). Results Study I: The total PM number deposition fraction of the wood smoke was 0.32 and 0.35 for healthy and COPD subjects respectively. Study II: Inhalation of wood smoke caused CD3+ and mast cell infiltration in the bronchial submucosa along with CD8+ cell recruitment to the epithelium. In bronchial wash, inflammatory cells, myeloperoxidase and matrix metalloproteinase 9 levels decreased. Study III: An efficient cabin air filter with an active charcoal component was most favourable in in-vitro tests and reduced symptoms in the human exposure study. Study IV: Local NO synthase inhibition caused similar vasoconstriction after exposure to DE and filtered air, along with an increase in plasma nitrate concentrations, suggesting an increase in the basal NO release due to oxidative stress. Systemic NO synthase inhibition increased arterial stiffness and blood pressure after DE exposure along with an increase in systemic vascular resistance and reduced cardiac output, implying that the increased basal NO release could not compensate for the reduced NO bioavailability in the conduit vessels. Conclusion Wood smoke particles from incomplete combustion tend to have a greater airway deposition than particles from better combustion. The airway inflammatory responses to the former particles differ from what have been shown for other PM pollutants, which may be of importance for subsequent health effects. The vasomotor dysfunction shown after DE exposure may largely be explained by reduced NO bioavailability. A vehicle cabin air inlet particle filter with active charcoal was effective to reduce DE exposure and subsequent symptoms. This may conceptually be of benefit when it comes to decreasing engine exhaust-related adverse health effects.

Respiratory infection remains a leading cause of morbidity and death in severely immunocompromised febrile neutropenic haematology patients, despite the introduction of numerous prophylactic strategies and advances in diagnosis and treatment. Prognosis is improved if an organism can be isolated and specific therapy commenced as soon as possible. Current practice in this population group is to commence empirical antibiotics and perform flexible bronchoscopy (FB) if temperature does not settle or after patients develop clinical or radiological features suggesting a respiratory source. This delay may result in a lower procedural diagnostic yield due to prior or prolonged anti-microbial treatment, and increased risk of respiratory compromise and procedural complications due to advanced respiratory infections. We hypothesised that proceeding to FB as early as possible after developing febrile neutropenia would improve treatment outcomes. With this randomised, prospective trial, we aim to further define the role of FB with reference to optimal timing of the procedure and its impact on diagnostic yield, future management and complication rate. We also aim to analyse the impact of proven infection on the cytokine profile of immunocompromised patients. Methods: Patients with acute leukaemia, allogeneic bone marrow transplantation or chronic lymphocytic leukaemia (CLL) being treated with Fludarabine/ Mabthera without an obvious non-respiratory source of infection were prospectively randomised into early bronchoscopy or conventional management groups at onset of febrile neutropenia. Bronchoalveolar lavage (BAL) fluid chemokine levels (IP-10, RANTES, MIG, IL-8, MCP-1) were measured using a human Chemokine cytometric bead array (CBA) kit. Results: Thirty-one episodes of febrile neutropenia in 29 patients were analysed; 17 conventional and 14 early. There was an increased yield in fungal growth in the early bronchoscopy group, which was not predicted by prior clinical or radiological changes. However, this had no impact on clinical management in the short-term due to the delayed growth. Overall diagnostic yield was not significantly different between the two groups. Procedural complication rate was negligible overall and there was no difference associated with either group. IP-10 and MIG were significantly lower in those patients who had a fungal pathogen isolated, compared with those study patients who did not (175.17 vs 1157.8, p=0.03, 30.33 vs 247.8, p=0.03 respectively). IP-10 levels were higher in the conventional than early group (1253.0 vs 261.14, p = 0.035) and the study population had higher MCP-1 (734 vs 2.83, p=0.006) and IL-8 levels (606.9 vs 14.25, p=0.00655) than normal controls. Those cases with fungal infection had higher mean MCP-1, RANTES and IL-8 levels than in normal controls (844.0 vs 2.83, p=0.007; 17.5 vs 2.1, p=0.03; 156.0 vs 14.25, p=0.004). Conclusions: Early bronchoscopy as a component of the septic screen in febrile neutropenic patients was feasible and safe. A significant difference in fungal yield was seen in the early bronchoscopy group compared to conventional methods, with a negligible complication rate, but this did not result in a change in immediate clinical management or outcomes. / Thesis (M.Clin.Sc.) - University of Adelaide, School of Medicine, 2009

A traqueostomia percutânea é um procedimento realizado rotineiramente na Unidade de Terapia Intensiva (UTI), guiada por broncoscopia. Recentemente, a ultrassonografia tem surgido como uma ferramenta potencialmente útil para assistir à traqueostomia percutânea e reduzir as complicações relacionadas ao procedimento. Um ensaio clínico randomizado, aberto, paralelo, de não inferioridade, foi conduzido comparando a traqueostomia percutânea guiada por ultrassonografia com a traqueostomia percutânea guiada por broncoscopia, em pacientes sob ventilação mecânica na UTI. O desfecho primário, a falência do procedimento, foi definido como um desfecho composto, incluindo (1) a conversão para traqueostomia cirúrgica, (2) o uso associado e não planejado da broncoscopia ou da ultrassonografia, ou (3) a ocorrência de uma complicação maior. Um total de 4.965 pacientes foram avaliados quanto a elegibilidade. Desses, 171 pacientes foram elegíveis e 118 foram submetidos ao procedimento, com 60 pacientes randomizados para o grupo ultrassonografia e 58 pacientes randomizados para o grupo broncoscopia. A falência do procedimento ocorreu em um (1,7%) paciente no grupo ultrassonografia e um (1,7%) paciente no grupo broncoscopia, sem diferença no risco absoluto entre os grupos (intervalo de confiança de 90%, -5,57 a 5,85), na análise \"conforme tratados\", não incluindo a margem de não inferioridade pré-especificada de 6%. Nenhum outro paciente apresentou uma complicação maior em ambos os grupos. As complicações menores relacionadas ao procedimento ocorreram em 20 (33,3%) pacientes no grupo ultrassonografia e em 12 (20,7%) pacientes no grupo broncoscopia, (P = 0,122). A duração do procedimento foi de 11 [7-19] vs. 13 [8-20] minutos (P = 0,468), respectivamente, e os desfechos clínicos também não foram diferentes entre os grupos. Em conclusão, a traqueostomia percutânea guiada por ultrassonografia é eficiente, segura e associada com taxas de complicações semelhantes à traqueostomia percutânea guiada por broncoscopia, em pacientes sob ventilação mecânica na UTI / Percutaneous Dilational Tracheostomy (PDT) is routinely performed in the intensive care unit (ICU) with bronchoscopy guidance. Recently, ultrasound has emerged as a potentially useful tool in order to assist PDT and reduce procedure-related complications. An open-label, parallel, non-inferiority, randomized controlled trial was conducted comparing the ultrasound-guided PDT with the bronchoscopy-guided PDT in mechanically ventilated critically ill patients. The primary outcome was procedure failure, defined as a composite end-point of conversion to a surgical tracheostomy; unplanned associated use of bronchoscopy or ultrasound during PDT; or the occurrence of a major complication. A total of 4,965 patients were assessed for eligibility. Of these, 171 patients were eligible and 118 underwent the procedure, with 60 patients randomly assigned to the ultrasound group and 58 patients to the bronchoscopy group. Procedure failure occurred in one (1.7%) patient in the ultrasound group and one (1.7%) patient in the bronchoscopy group, with no absolute risk difference between the groups (90% confidence interval, -5.57 to 5.85), in the \'as treated\' analysis, not including the pre-specified margin of 6% for noninferiority. No other patient had any major complication in both of the groups. Procedure-related minor complications occurred in 20 (33.3%) patients in the ultrasound group and in 12 (20.7%) patients in the bronchoscopy group, (P=0.122). The median procedure length was 11 [7-19] vs. 13 [8-20] minutes (P=0.468), respectively, and the clinical outcomes were also not different between the groups. In conclusion, ultrasound-guided PDT is effective, safe and associated with similar complication rates and clinical outcomes compared with bronchoscopy-guided tracheostomy in mechanically ventilated critically ill patients

Granular cell tumors (GCTs) are rare neoplasms of neuroectodermal origin characterized by large polygonal cells with abundant eosinophilic and granular cytoplasm. GCTs rarely affect the lungs, with only a few cases reported in the literature. The pathophysiology of this Schwann cell-derived condition is not well understood but is thought to be due to recurring genetic mutations. GCTs have been linked with Noonan syndrome. Here, we report the case of a 17-year-old caucasian male who presented with partial upper airway obstruction due to a GCT. This case promotes awareness among pathologists and clinicians for this condition in the workup of patients presenting with upper airway obstruction.

Law Tsui Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 64-70). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Structure of Bronchus --- p.3 / Chapter 1.2 --- Existing Systems --- p.4 / Chapter 1.2.1 --- Virtual Endoscope System (VES) --- p.4 / Chapter 1.2.2 --- Virtual Reality Surgical Simulator --- p.4 / Chapter 1.2.3 --- Automated Virtual Colonoscopy (AVC) --- p.5 / Chapter 1.2.4 --- QUICKSEE --- p.5 / Chapter 1.3 --- Organization of Thesis --- p.6 / Chapter 2 --- Three Dimensional Visualization in Medicine --- p.7 / Chapter 2.1 --- Acquisition --- p.8 / Chapter 2.1.1 --- Computed Tomography --- p.8 / Chapter 2.2 --- Resampling --- p.9 / Chapter 2.3 --- Segmentation and Classification --- p.9 / Chapter 2.3.1 --- Segmentation by Thresholding --- p.10 / Chapter 2.3.2 --- Segmentation by Texture Analysis --- p.10 / Chapter 2.3.3 --- Segmentation by Region Growing --- p.10 / Chapter 2.3.4 --- Segmentation by Edge Detection --- p.11 / Chapter 2.4 --- Rendering --- p.12 / Chapter 2.5 --- Display --- p.13 / Chapter 2.6 --- Hazards of Visualization --- p.13 / Chapter 2.6.1 --- Adding Visual Richness and Obscuring Important Detail --- p.14 / Chapter 2.6.2 --- Enhancing Details Incorrectly --- p.14 / Chapter 2.6.3 --- The Picture is not the Patient --- p.14 / Chapter 2.6.4 --- Pictures-'R'-Us --- p.14 / Chapter 3 --- Overview of Advanced Segmentation Methodologies --- p.15 / Chapter 3.1 --- Mathematical Morphology --- p.15 / Chapter 3.2 --- Recursive Region Search --- p.16 / Chapter 3.3 --- Active Region Models --- p.17 / Chapter 4 --- Overview of Centerline Methodologies --- p.18 / Chapter 4.1 --- Thinning Approach --- p.18 / Chapter 4.2 --- Volume Growing Approach --- p.21 / Chapter 4.3 --- Combination of Mathematical Morphology and Region Growing Schemes --- p.22 / Chapter 4.4 --- Simultaneous Borders Identification Approach --- p.23 / Chapter 4.5 --- Tracking Approach --- p.24 / Chapter 4.6 --- Distance Transform Approach --- p.25 / Chapter 5 --- Automated Extraction of Bronchus Area --- p.27 / Chapter 5.1 --- Basic Idea --- p.27 / Chapter 5.2 --- Outline of the Automated Extraction Algorithm --- p.28 / Chapter 5.2.1 --- Selection of a Start Point --- p.28 / Chapter 5.2.2 --- Three Dimensional Region Growing Method --- p.29 / Chapter 5.2.3 --- Optimization of the Threshold Value --- p.29 / Chapter 5.3 --- Retrieval of Start Point Algorithm Using Genetic Algorithm --- p.29 / Chapter 5.3.1 --- Introduction to Genetic Algorithm --- p.30 / Chapter 5.3.2 --- Problem Modeling --- p.31 / Chapter 5.3.3 --- Algorithm for Determining a Start Point --- p.33 / Chapter 5.3.4 --- Genetic Operators --- p.33 / Chapter 5.4 --- Three Dimensional Painting Algorithm --- p.34 / Chapter 5.4.1 --- Outline of the Three Dimensional Painting Algorithm --- p.34 / Chapter 5.5 --- Optimization of the Threshold Value --- p.36 / Chapter 6 --- Automatic Centerline Determination Algorithm --- p.38 / Chapter 6.1 --- Distance Transformations --- p.38 / Chapter 6.2 --- End Points Retrieval --- p.41 / Chapter 6.3 --- Graph Based Centerline Algorithm --- p.44 / Chapter 7 --- Experiments and Discussion --- p.48 / Chapter 7.1 --- Experiment of Automated Determination of Bronchus Algorithm --- p.48 / Chapter 7.2 --- Experiment of Automatic Centerline Determination Algorithm --- p.54 / Chapter 8 --- Conclusion --- p.62 / Bibliography --- p.63