Search results for " ventilation"
showing 10 items of 372 documents
Survey of neonatal respiratory support use in very preterm infants in Italy
2012
Background: Respiratory support in very preterm infants is often a life-saving procedure and several techniques are available. There is lack of data on the current use of these techniques. Methods and aim: We analyzed a cohort of infants <30 weeks gestation or < 1501 g birth weight, enrolled in the Italian Neonatal Network in 2009 and 2010 (n = 8297, mean gestation = 29.3 weeks, mean birth weight = 1089 g) to ascertain the use of several techniques. We also conducted a questionnaire survey of all neonatal units adhering to the Italian Neonatal Network, inquiring about preferred methods of respiratory support. Results: Conventional ventilation was used in 53% of these infants, high frequency…
Functional MR imaging of pulmonary ventilation using hyperpolarized noble gases.
2000
The current status of experimental and clinical applications for functional MR imaging of pulmonary ventilation using hyperpolarized noble gases are reviewed. 3-helium (3He) and 129-xenon (129Xe) can be hyperpolarized by optical pumping techniques such as spin exchange or metastability exchange in sufficient amounts. This process leads to an artificial, non-equilibrium increase of the density of excited nuclei which represents the source of the MR signal. Those hyperpolarized gases are administered mostly via inhalation, and will fill airways and airspaces allowing for ventilation imaging. Recent human studies concentrate on imaging the airways and airspaces with high spatial resolution. N…
Nasal provocation testing as an international standard for evaluation of allergic and nonallergic rhinitis.
2005
Standardized nasal provocation testing (NPT) has been shown to be a safe and very useful tool in the diagnosis of allergic and nonallergic rhinitis. However, in the United States, its use has been mostly limited to scientific investigations, and it has not yet been widely accepted as a standard diagnostic procedure in clinical practice. NPT aims to identify and quantify the clinical relevance of inhalant allergens or occupational irritants. During NPT, nasal respiratory mucosa is exposed to an airborne substance suspected to cause symptoms in the respective individual. Clinical reactions are monitored in a controlled and standardized fashion. Nasal secretions, symptoms such as itching, snee…
The new agreement of the international RIGA consensus conference on nasal airway function tests.
2018
The report reflects an agreement based on the consensus conference of the International Standardization Committee on the Objective Assessment of the Nasal Airway in Riga, 2nd Nov. 2016. The aim of the conference was to address the existing nasal airway function tests and to take into account physical, mathematical and technical correctness as a base of international standardization as well as the requirements of the Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. Rhinomanometry, acoustic rhinometry, peak nasal inspiratory flow, Odiosoft-Rhino, optical rhinometry, 24-h measurements, computational fluid dynamics, nasometry and the mirrow test were evaluated for importa…
Bayesian joint modeling of bivariate longitudinal and competing risks data: An application to study patient-ventilator asynchronies in critical care …
2017
Mechanical ventilation is a common procedure of life support in intensive care. Patient-ventilator asynchronies (PVAs) occur when the timing of the ventilator cycle is not simultaneous with the timing of the patient respiratory cycle. The association between severity markers and the events death or alive discharge has been acknowledged before, however, little is known about the addition of PVAs data to the analyses. We used an index of asynchronies (AI) to measure PVAs and the SOFA (sequential organ failure assessment) score to assess overall severity. To investigate the added value of including the AI, we propose a Bayesian joint model of bivariate longitudinal and competing risks data. Th…
Nasal pressure swings as the measure of inspiratory effort in spontaneously breathing patients with de novo acute respiratory failure.
2022
Abstract Background Excessive inspiratory effort could translate into self-inflicted lung injury, thus worsening clinical outcomes of spontaneously breathing patients with acute respiratory failure (ARF). Although esophageal manometry is a reliable method to estimate the magnitude of inspiratory effort, procedural issues significantly limit its use in daily clinical practice. The aim of this study is to describe the correlation between esophageal pressure swings (ΔPes) and nasal (ΔPnos) as a potential measure of inspiratory effort in spontaneously breathing patients with de novo ARF. Methods From January 1, 2021, to September 1, 2021, 61 consecutive patients with ARF (83.6% related to COVID…
Ventilation rates and unsatisfied percentage from indoor CO2 concentration.
2011
This work reports the results of a survey carried out on a hall in a historic building in Palermo (Italy) with the aim of assessing the air quality by means of objective measurement of carbon dioxide (CO2) concentration and its subjective evaluation through a questionnaire. The measured values of CO2 concentration were compared with those evaluated using the Meckler equation under steady-state conditions, having verified necessary parameters such as the constancy of the indoor and outdoor CO2 levels and the uniformity of the CO2 generation rate for all the occupants. The positive correspondence between measured and calculated results allowed us to utilise, under differing circum- stances, t…
Energy Saving Optimizing the Ventilation Control in a Big Shopping Center
2018
The paper investigates the potential energy savings in the context of big shopping centers, thanks to the introduction of innovative technologies able to control the ventilation according the real requirement for comfort and health of indoor spaces. The case study analyses a big shopping center, where the ventilation is realized with a centralized air-conditioning plant, working with fixed air flows. Two solutions are proposed to reduce the energy consumption for ventilation. The first considers the installation of heat recovery exchangers, the second the introduction of a control system able to modulate the air exchange, according to the real requirements. An energetic and economic evaluat…
Electrical hybrid heat pumps assisted by natural gas boilers: a review
2022
In this paper, a comprehensive review is performed on hybrid systems using electrical Heat Pumps for Heating, Ventilation & Air Conditioning systems and Domestic Hot Water production using case studies from 2016 to 2022. This work particularly focuses on studies that investigated systems with electrical Heat Pumps assisted by a gas boiler. Some studies that considered the exploitation of renewable energy sources, but not as a whole sub-stitute for fossil sources, have also been included. In particular, the analysis investigated the layouts of the systems by considering the type and the size of the components, the control methods applied (by distinguishing rule-based control methods and …
Computer model and simulation of a traditional passive cooling ventilation system in a Modern building in Mazara del Vallo (Italy)
2008
Traditional and modern natural ventilation techniques have been integrated in a hybrid system for a retrofitting of public building in the city of Mazara del Vallo (Italy). The hybrid ventilation and air cooling system integrates a wind tower, an indirect evaporative heat exchanger, a ground cooling pipe network and ventilated façade. The first idea was to design a passive cooling system inspired to the typical wind towers of the Middle East, being the area very well ventilated. On the other hand, air humidity in summer is quite high and therefore the effectiveness of indirect evaporative cooling is quite low. For this reason, it was adopted a second passive cooling system consisting in a g…