Anesthetic considerations for microlaryngeal surgery

Introduction: Microlaryngeal surgery encompasses a wide range of laryngeal procedures. Patients presenting for microlaryngeal surgery frequently have a difficult airway. The chosen approach to this airway depends on the pathology and the patient’s symptoms. The Aim of the study is to determine the risk factors and anesthetic problems during microlaryngeal surgery.Materials and Methods: A prospective cohort study including 100 patients undergoing microlaryngeal surgery in the Department of Otorhinolaryngology at the University Hospital „Queen Giovanna“ – ISUL, Sofia, in the period 2020–2021; Medical University-Sofia. Preoperative examination of the larynx is performed in all patients by Storz 8402 ZX fiber optic laryngoscope with video capability.Results and discussion: In 69% of the patients the tumor mass causing obstruction is localized in the area of the larynx, and in 31% of them the tumor mass is localized in the area of the hypopharynx. From the patients with tumor mass causing laryngeal obstruction 42% are with 1st degree of obstruction, 29% are with 2nd degree, 27% are with 3rd degree and 2% are with respiratory failure at rest. Twenty six percent (26%) of the patients had pulse rate<45 beats per minute during putting on the tube of Kleinsasser. This is very dangerous reflex reaction of the heart, which we believe is caused by parasympathetic nervous system. The rate of difficult endotracheal intubation among patients presenting for microlaryngeal surgery is higher than among the general surgical patient population. Difficulties during endotracheal intubation in our study are due to higher percent of laryngeal obstruction and pharyngeal restriction because of the intraoral masses.Conclusion: Anesthesia for microlaryngeal surgery has always been demanding, as often pathology interferes with the anesthesiologist’s field of work

Of gastro and the gold standard: evaluation and policy implications of norovirus test performance for outbreak detection

<p>Abstract</p> <p>Background</p> <p>The norovirus group (NVG) of caliciviruses are the etiological agents of most institutional outbreaks of gastroenteritis in North America and Europe. Identification of NVG is complicated by the non-culturable nature of this virus, and the absence of a diagnostic gold standard makes traditional evaluation of test characteristics problematic.</p> <p>Methods</p> <p>We evaluated 189 specimens derived from 440 acute gastroenteritis outbreaks investigated in Ontario in 2006–07. Parallel testing for NVG was performed with real-time reverse-transcriptase polymerase chain reaction (RT²-PCR), enzyme immunoassay (EIA) and electron microscopy (EM). Test characteristics (sensitivity and specificity) were estimated using latent class models and composite reference standard methods. The practical implications of test characteristics were evaluated using binomial probability models.</p> <p>Results</p> <p>Latent class modelling estimated sensitivities of RT²-PCR, EIA, and EM as 100%, 86%, and 17% respectively; specificities were 84%, 92%, and 100%; estimates obtained using a composite reference standard were similar. If all specimens contained norovirus, RT²-PCR or EIA would be associated with > 99.9% likelihood of at least one test being positive after three specimens tested. Testing of more than 5 true negative specimens with RT²-PCR would be associated with a greater than 50% likelihood of a false positive test.</p> <p>Conclusion</p> <p>Our findings support the characterization of EM as lacking sensitivity for NVG outbreaks. The high sensitivity of RT²-PCR and EIA permit identification of NVG outbreaks with testing of limited numbers of clinical specimens. Given risks of false positive test results, it is reasonable to limit the number of specimens tested when RT²-PCR or EIA are available.</p

Molecular epidemiology of rotaviruses in Bulgaria: annual shift of the predominant genotype

International audienceRotavirus molecular epidemiology investigations provide important information about the incidence of rotavirus diseases and rotavirus strains in circulation in the prevaccine era. The purpose of this investigation was to study the burden of rotavirus disease, rotavirus strain diversity, and epidemiology specificities of rotavirus infections in Bulgaria. A total of 3,130 stools collected between 2005 and 2008 were tested by immune enzyme tests. G-P genotype identification of rotavirus strains were performed by reverse transcriptase polymerase chain reaction (RT-PCR). Rotavirus etiology was confirmed in 32.4% of the samples tested. Rotaviruses affected predominantly children under 5 years of age (95.5%), with a peak prevalence between the ages of 7 and 36 months. Four of the five globally distributed rotavirus strains (G1P[8], G2P[4], G4P[8], and G9P[8]) constituted 97.7% of all rotavirus strains in circulation. However, annual shifts of predominant rotavirus G-P genotypes were observed from season to season—G4P[8] was predominant in rotavirus season 2004/2005 (56.8%), but was replaced by G9P[8] in 2005/2006 (77.7%), and G2P[4] (41.6%) and G1P[8] (39.5%) in the following two consecutive rotavirus seasons. Year-round circulation of rotaviruses in the country with increased incidence in the winter–spring season and unexpected peaks preceding the rotavirus seasons were observed. Molecular epidemiology data are needed in Bulgaria for health policy makers in order to introduce routine rotavirus vaccination. The monitoring of rotavirus genetic diversity in Bulgaria in the postvaccination period will contribute to a successful rotavirus vaccination program

Gases permeability study in dual membrane fuel cell

International audienceGases permeability in a porous mixed (proton and oxide ion) conductive membrane, which is a component of a new high temperature dual membrane fuel cell design is investigated by specially designed testing system based on measurements of the gas flow [ml/min] and pressure P (mm H2O) when penetrating through porous media. A strong correlation expressed in increase of the permeability with the decrease of the gases molecular weight is registered. The water vapor permeability decreases with the temperature. This is in agreement with data from the literature which show that the viscosity of gases, including water vapor, increases with the temperature. The results obtained suggest optimal porosity in respect to permeability, mechanical stability and conductivity in the range of 35-40%. They confirm the need of optimization concerning not only the pores fraction, but also the pores geometry and distribution, as well as the central membrane geometry and the configuration of the cell. This approach can be applied also for optimization of the electrodes porosity (pores concentration, geometry, distribution etc), especially in cases when gas mixtures (including water vapor) are used or produced