Overnight oximetry as a screening tool for moderate to severe obstructive sleep apnoea in South African children

Background. Obstructive sleep apnoea (OSA) is common in children yet  often overlooked, as symptom-based screening is unreliable. Polysomnography is regarded as the gold standard for the diagnosis of OSA, but is not widely available in South Africa (SA). Overnight oximetry is a validated screening tool for OSA.Objectives. To describe the impact and utility of overnight oximetry at a tertiary children’s hospital in SA.Methods. A retrospective descriptive study was conducted of patients screened for OSA by overnight oximetry at a paediatric referral hospital from December 2012 to December 2014. Clinical data were retrieved from the oximetry database and medical records. Recordings of ≥6 hours were considered adequate and included in the study. OSA severity was  determined using the McGill score. Details on management and outcome were documented.Results. Oximetry studies in 137 of 153 patients were suitable for analysis (88 males (64.2%), median age 31.4 months (interquartile range (IQR) 15.8 - 65.8). Adenotonsillar hypertrophy was common (n=97, 70.8%), and 65 children (47.4%) had two or more underlying OSA risk factors. McGill’s score classified patients as follows: no/mild OSA n=55 (40.1%), moderate OSA n=23 (16.8%), severe OSA n=23 (16.8%) and very severe OSA n=36 (26.3%). Male gender, adenotonsillar hypertrophy and a lower weight-for-age z-score (–1.3 v. –0.7; p=0.038) were associated with severe to very severe OSA. Seventy-eight children (56.9%) were referred for surgery, 33 (24.1%) receiving urgent surgery within a median of 6 days (IQR 4 - 12). In contrast, 59 children (43.1%) with suspected OSA did not require surgical intervention.Conclusions. Overnight oximetry is a simple low-cost tool to assess severity of OSA and prioritise appropriate OSA management in resource-constrained settings such as SA

Reconstruction of round voids in the elastic half-space: Antiplane problem

We study the reconstruction of geometry (position and size) of round voids located in the elastic half-space, in frames of antiplane two-dimensional problem. We assume that a known point force is applied to the boundary surface of the half-space, and we can measure the shape of the surface over a certain finite-length interval. Then, if the geometry of the defect is unknown, we construct an algorithm to restore its position and size. Some numerical examples demonstrate a good stability of the proposed algorithm

Impact of fibrinolytics on the outcome of empyema in South African children

Background. Childhood pneumonia is common in all countries, and empyema is one of the commonest complications. The role of routine intrapleural fibrinolytics in the management of childhood empyema is not well established in low- and middle-income countries.Methods. We did a prospective observational study of children sequentially hospitalised with empyema between December 2006 and December 2011 in South Africa (SA). Intrapleural tissue plasminogen activator (TPA), administered according to a standard protocol, was introduced in September 2009. Outcomes in children treated with TPA after 2009 were compared with the historical cohort not treated with TPA who met the treatment criteria.Results. One hundred and forty-two children with empyema, median age 17 months (interquartile range 8 - 43), were admitted during the study period. Excluding children who did not have a chest tube inserted and those in whom fibrinolysis was contraindicated, there were 99 patients, 52 of whom received fibrinolytics. Clinical characteristics and empyema aetiology were similar in those who received fibrinolysis and those who did not. Eighteen children (38.3%) not treated with TPA required surgery v. 5 (9.6%) treated with TPA (relative risk 0.25; 95% confidence interval 0.1 - 0.6). The median duration of hospitalisation was similar in both groups. Complications occurred rarely and with a similar incidence in both groups. In-hospital mortality was low, with two deaths in each group.Conclusion. Intrapleural TPA resulted in a four-fold reduction in surgery. Fibrinolytics should be used for management of empyema in children in SA

Overnight oximetry as a screening tool for moderate to severe obstructive sleep apnoea in South African children

Background. Obstructive sleep apnoea (OSA) is common in children yet often overlooked, as symptom-based screening is unreliable. Polysomnography is regarded as the gold standard for the diagnosis of OSA, but is not widely available in South Africa (SA). Overnight oximetry is a validated screening tool for OSA.Objectives. To describe the impact and utility of overnight oximetry at a tertiary children’s hospital in SA.Methods. A retrospective descriptive study was conducted of patients screened for OSA by overnight oximetry at a paediatric referral hospital from December 2012 to December 2014. Clinical data were retrieved from the oximetry database and medical records. Recordings of ≥6 hours were considered adequate and included in the study. OSA severity was determined using the McGill score. Details on management and outcome were documented.Results. Oximetry studies in 137 of 153 patients were suitable for analysis (88 males (64.2%), median age 31.4 months (interquartile range (IQR) 15.8 - 65.8). Adenotonsillar hypertrophy was common (n=97, 70.8%), and 65 children (47.4%) had two or more underlying OSA risk factors. McGill’s score classified patients as follows: no/mild OSA n=55 (40.1%), moderate OSA n=23 (16.8%), severe OSA n=23 (16.8%) and very severe OSA n=36 (26.3%). Male gender, adenotonsillar hypertrophy and a lower weight-for-age z-score (–1.3 v. –0.7; p=0.038) were associated with severe to very severe OSA. Seventy-eight children (56.9%) were referred for surgery, 33 (24.1%) receiving urgent surgery within a median of 6 days (IQR 4 - 12). In contrast, 59 children (43.1%) with suspected OSA did not require surgical intervention.Conclusions. Overnight oximetry is a simple low-cost tool to assess severity of OSA and prioritise appropriate OSA management in resource-constrained settings such as SA.

Clinical and Experimental Determination of Protection Afforded by BCG Vaccination against Infection with Non-Tuberculous Mycobacteria: A Role in Cystic Fibrosis?

Mycobacterium abscessus is a nontuberculous mycobacterium (NTM) of particular concern in individuals with obstructive lung diseases such as cystic fibrosis (CF). Treatment requires multiple drugs and is characterised by high rates of relapse; thus, new strategies to limit infection are urgently required. This study sought to determine how Bacille Calmette-Guérin (BCG) vaccination may impact NTM infection, using a murine model of Mycobacterium abscessus infection and observational data from a non-BCG vaccinated CF cohort in Sydney, Australia and a BCG-vaccinated CF cohort in Cape Town, South Africa. In mice, BCG vaccination induced multifunctional antigen-specific CD up sup T cells circulating in the blood and was protective against dissemination of bacteria to the spleen. Prior infection with M. abscessus afforded the highest level of protection against M. abscessus challenge in the lung, and immunity was characterised by a greater frequency of pulmonary cytokine-secreting CD4 T cells compared to BCG vaccination. In the clinical CF cohorts, the overall rates of NTM sampling during a three-year period were equivalent; however, rates of NTM colonisation were significantly lower in the BCG-vaccinated (Cape Town) cohort, which was most apparent for M. abscessus. This study provides evidence that routine BCG vaccination may reduce M. abscessus colonisation in individuals with CF, which correlates with the ability of BCG to induce multifunctional CD4T cells recognising M. abscessus in a murine model. Further research is needed to determine the optimal strategies for limiting NTM infections in individuals with CF

Modular versus monoblock stem in revision total hip arthroplasty: a systematic review and meta-analysis

Background: Total hip arthroplasty (THA) is estimated to grow in the following decades with a consequent increase of THA revisions (rTHA). This systematic review and meta-analysis aims to compare modular and monoblock stem in rTHA surgery, focusing on clinical and radiological outcomes and complication rates. Methods: A literature search was performed using the following search strategy: ((Modular stem) OR (monolithic stem)) AND (hip review) on PubMed, Scopus, and Cochrane. Randomized controlled trials (RCTs) and observational studies (OS) compared clinical and radiological outcomes, and complication rates for monoblock and modular revision femoral stem were included. The risk of bias was assessed through the Methodological Index for Non-Randomized Studies (MINORS) score. The Review Manager (RevMan) software was used for the meta-analysis. The rate of complications was assessed using odds ratio (OR) with 95% confidence intervals (CIs). Results: The authors included 11 OS and one RCT with 3,671 participants (mean age: 68.4 years old). The mean follow-up was 46.9 months. There was no prevalence of subsidence for one type of stem. Mean subsidence was from 0.92 to 10 mm for modular stem and from 1 to 15 mm for monoblock stem. Postoperative Harris Hip Score (HHS) showed better results with modular stems without statistical significance [mean difference (MD) =1.32; 95% CI: −1.62 to 4.27; P=0.38]. No statistically significant difference was found for dislocations (OR =2.48; 95% CI: 0.67 to 9.14; P=0.17), infections (OR =1.07; 95% CI: 0.51 to 2.23; P=0.86), intraoperative fractures (OR =1.62; 95% CI: 0.42 to 6.21; P=0.48), and postoperative fractures (OR =1.60; 95% CI: 0.55 to 4.64; P=0.39). Conclusions: Modular and monoblock stems show comparable and satisfactory clinical and radiological outcomes for rTHA. Both stems are valid and effective options for managing femoral bone deficit in hip revision surgery. The main limitation of this study is the small number and low quality of enclosed studies that compared the two stems. Moreover, the modular stem is usually used for more complex cases with lower quality femoral bone stock

Uniqueness, continuous dependence, and spatial behavior of the solution in linear porous thermoelasticity with two relaxation times

This work aims to contribute to the verification of the well-posedness question, as for the uniqueness and continuous dependence issues, for a linear thermoelastic model with two main features: (i) a porous material matrix modeled on the basis of the Cowin-Nunziato theory; (ii) a heat transfer process obeying a time-differential constitutive equation with two relaxation times, derived from the dual-phase lag theory with an appropriate selection of the Taylor series expansion orders. Imagining to deal with very small spatial scales (in the order of the micro or nanometer), we assume it is reasonable to accept that the deformations caused by temperature variations are small enough to be realistically modeled under hypotheses of linearity, thus making the mathematical theory under investigation particularly meaningful, e.g. in the study of miniaturized devices in very fast transients. The work is concluded by proving a domain of influence theorem, and with a reference to the future research activities to carry out starting from it

Flow-induced vortex field generated by a thin oscillating plate in an aeroacoustics framework

The authors study the structure of the vortex sheet generated by a thin rectangular plate harmonically oscillating in a flow of non-viscous fluid. In frames of the Lighthill-Curle and Powell aeroacoustic theories, it is shown that the shedding vortices determine the magnitude of the generated sound. The problem is reduced to a dual integral equation which is solved numerically. The solution defines the sound of the load, as well as the components of the vortex vector over the sheet. Some examples of the numerical treatment are shown for various combinations of physical parameters