Influence of air velocity on indoor environment quality in unidirectional flow operating theatres: A study based on Computational Fluid Dynamics

It is necessary to characterise air-conditioning airflow in omanuscriprder to optimize hospital Indoor Environment Quality in high-performance operating theatres, and also reduce the risk of nosocomial infection due to pathogen contamination. The aim of this article is to study the prevalence of optimal healthy conditions from controlled air flow quality in hospital facilities, and to minimize energy consumption. To this purpose, the indoor air movement was modelled by Computational Fluid Dynamics technology. The optimal results showed that it is necessary to drive ultra-clean air ranging between 0.25 m/s and 0.40 m/s, values which are adequate to perform efficient sweeping and cleaning of the air near the patient, maintaining unidirectional air flow permanently as the air passes through the surgical field. These speeds must be taken into account as calculation parameters in new hospital facility projects, and as control parameters for the existing operating theatres

Sustainable solutions for thermal energy saving in hospital operating theatres

Heating, ventilating and air conditioning systems in hospital operating theatres consume high amounts of energy, operate for long periods of time and provide high performance. For this reason, it is necessary to study their energy consumption and determine sustainable solutions that optimize their operation and improve their performance. In this paper, annual thermal energy consumption of a conventional operating theatre is evaluated. Potential energy savings is evaluated by maintaining an adequate indoor environmental quality for these rooms. In addition, how to minimize energy consumption depending on the air renewal flow rate used and installing a sensible heat recovery system was studied. Results show that energy demand of an operating room is reduced by 24.1% by recirculating 25% of air flow extracted from the room. Energy cost decreases 44.31% by increasing the recirculated air flow rate to 50% of the air flow extracted from the room

Assessment of nocturnal autonomic cardiac imbalance in positional obstructive sleep apnea. A multiscale nonlinear approach

Producción CientíficaPositional obstructive sleep apnea (POSA) is a major phenotype of sleep apnea. Supine-predominant positional patients are frequently characterized by milder symptoms and less comorbidity due to a lower age, body mass index, and overall apnea-hypopnea index. However, the bradycardia-tachycardia pattern during apneic events is known to be more severe in the supine position, which could affect the cardiac regulation of positional patients. This study aims at characterizing nocturnal heart rate modulation in the presence of POSA in order to assess potential differences between positional and non-positional patients. Patients showing clinical symptoms of suffering from a sleep-related breathing disorder performed unsupervised portable polysomnography (PSG) and simultaneous nocturnal pulse oximetry (NPO) at home. Positional patients were identified according to the Amsterdam POSA classification (APOC) criteria. Pulse rate variability (PRV) recordings from the NPO readings were used to assess overnight cardiac modulation. Conventional cardiac indexes in the time and frequency domains were computed. Additionally, multiscale entropy (MSE) was used to investigate the nonlinear dynamics of the PRV recordings in POSA and non-POSA patients. A total of 129 patients (median age 56.0, interquartile range (IQR) 44.8–63.0 years, median body mass index (BMI) 27.7, IQR 26.0–31.3 kg/m2) were classified as POSA (37 APOC I, 77 APOC II, and 15 APOC III), while 104 subjects (median age 57.5, IQR 49.0–67.0 years, median BMI 29.8, IQR 26.6–34.7 kg/m2) comprised the non-POSA group. Overnight PRV recordings from positional patients showed significantly higher disorderliness than non-positional subjects in the smallest biological scales of the MSE profile (τ = 1: 0.25, IQR 0.20–0.31 vs. 0.22, IQR 0.18–0.27, p < 0.01) (τ = 2: 0.41, IQR 0.34–0.48 vs. 0.37, IQR 0.29–0.42, p < 0.01). According to our findings, nocturnal heart rate regulation is severely affected in POSA patients, suggesting increased cardiac imbalance due to predominant positional apneas.Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (Proyects DPI2017-84280-R and RTC-2017-6516-1)Sociedad Española de Neumología y Cirugía Torácica (Proyects 649/2018 and 66/2016)Gerencia Regional de Salud de Castilla y León (Proyecto GRS 1950/A/19)Ministerio de Educación, Cultura y Deporte (Proyecto FPU16/02938)Gerencia Regional de Salud de Castilla y León - (Projecto INT/M/15/20

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Desarrollo de estrategias sostenibles para reducir el impacto medioambiental de los edificios sanitarios de Extremadura (España)

Tesis doctoral con Mención de “Doctor Internacional”.Tesis doctoral por compendio de publicaciones.Programa de Doctorado en Modelización y Experimentación en Ciencia y Tecnología por la Universidad de Extremadura.El complejo funcionamiento técnico de los edificios sanitarios para proveer servicios asistenciales le confieren como un hiperconsumidor de suministros, lo que deriva en la emisión de ingentes cantidades de Gases de Efecto Invernadero. El objetivo de esta Tesis Doctoral es mejorar el perfil medioambiental de los edificios sanitarios de Extremadura (España), presuponiendo mantener los niveles de calidad de los servicios asistenciales y el nivel prestacional de estos edificios sanitarios. Se exploraron estrategias de desarrollo sostenible desde el macrocontexto que rodea al sistema -el desplazamiento de los usuarios- hacia el microcontexto interno del propio edificio -sus instalaciones técnicas-. Para la dimensión externa, se modelaron relaciones entre las emisiones de Gases de Efecto invernadero y los parámetros funcionales de los edificios, así como con las variables meteorológicas del emplazamiento. Para la dimensión interna, se diseñó y validó un modelo de degradación de la producción energética fotovoltaica, se evaluó la viabilidad económica y medioambiental de incorporar energía solar térmica y, finalmente, se exploraron posibilidades de mejorar el patrón de movimiento del aire ultra limpio interior a los quirófanos para mejorar su eficiencia energética. Las estrategias diseñadas y validadas en esta Tesis Doctoral amplían el prisma cubierto hasta ahora por las directrices de gestión medioambiental, garantizando así la sostenibilidad del proceso asistencial a largo plazo. Estos resultados son útiles a nivel directivo -estratégico- para asistir a la planificación y diseño de nuevos servicios asistenciales, y operativo -táctico- de la gestión de operación y mantenimiento de los edificios, sus instalaciones y sus equipos.The complex technical operation of healthcare buildings to provide care services makes them a hyper-consumer of supplies, which results in the emission of huge amounts of Greenhouse Gases. The aim of this Doctoral Thesis is to improve the environmental profile of healthcare buildings in Extremadura (Spain), assuming that the quality levels of healthcare services and the level of performance of these healthcare buildings are maintained. Sustainable development strategies were explored from the macro-context surrounding the system – users’ journeys- to the internal micro-context of buildings -technical facilities-. For the external dimension, relationships were modelled between greenhouse gas emissions and the functional parameters of the buildings, as well as with the meteorological variables of the site. For the internal dimension, a degradation model of photovoltaic energy production was designed and validated, the economic and environmental feasibility of incorporating solar thermal energy was assessed, and finally, possibilities of improving the pattern of ultra-clean air movement inside operating theatres to improve their energy efficiency were explored. The strategies designed and validated in this Doctoral Thesis broaden the prism covered so far by environmental management guidelines, thus ensuring the long-term sustainability of the care process. These results are useful at a managerial -strategic- level to assist in the planning and design of new care services, and at an operational -tactical- level for the operation and maintenance management of buildings, their facilities and equipment.- Junta de Extremadura por financiar mi contrato predoctoral (expediente PD18047), cofinanciado por el Fondo Social Europeo. Seguidamente, al Fondo Europeo de Desarrollo Regional por la financiación provista a través del expediente GR18029 ligado al VI Plan Regional de Investigación, Desarrollo Tecnológico e Innovación de la Comunidad Autónoma de Extremadura. - Empresa InnoDesarrollo por su colaboración en el proyecto de Investigación Industrial y Desarrollo Experimental “Algoritmo predictivo de limpieza de paneles fotovoltaicos” (expediente IDA4-17-0005-2)

Influence of air velocity on indoor environment quality in unidirectional flow operating theatres: A study based on Computational Fluid Dynamics

It is necessary to characterise air-conditioning airflow in omanuscriprder to optimize hospital Indoor Environment Quality in high-performance operating theatres, and also reduce the risk of nosocomial infection due to pathogen contamination. The aim of this article is to study the prevalence of optimal healthy conditions from controlled air flow quality in hospital facilities, and to minimize energy consumption. To this purpose, the indoor air movement was modelled by Computational Fluid Dynamics technology. The optimal results showed that it is necessary to drive ultra-clean air ranging between 0.25 m/s and 0.40 m/s, values which are adequate to perform efficient sweeping and cleaning of the air near the patient, maintaining unidirectional air flow permanently as the air passes through the surgical field. These speeds must be taken into account as calculation parameters in new hospital facility projects, and as control parameters for the existing operating theatres

Sustainable solutions for thermal energy saving in hospital operating theatres

Heating, ventilating and air conditioning systems in hospital operating theatres consume high amounts of energy, operate for long periods of time and provide high performance. For this reason, it is necessary to study their energy consumption and determine sustainable solutions that optimize their operation and improve their performance. In this paper, annual thermal energy consumption of a conventional operating theatre is evaluated. Potential energy savings is evaluated by maintaining an adequate indoor environmental quality for these rooms. In addition, how to minimize energy consumption depending on the air renewal flow rate used and installing a sensible heat recovery system was studied. Results show that energy demand of an operating room is reduced by 24.1% by recirculating 25% of air flow extracted from the room. Energy cost decreases 44.31% by increasing the recirculated air flow rate to 50% of the air flow extracted from the room

Markov chains estimation of the optimal periodicity for cleaning photovoltaic panels installed in the dehesa

The European Dehesa has a very high potential for the production of clean energy due to the solar irradiation it receives. Its arid climate, however, means that airborne dust particles accumulate on the photovoltaic panels, with the resulting reduction in transmittance of the glass top-sheets. Cleaning the module surfaces involves an economic investment that, to be profitable, has to be offset by sufficient increased energy production. The objective of the present study was to determine the optimal periodicity for cleaning photovoltaic panels installed in the Dehesa, and thus subject to its specific climate. To this end, an experimental installation was set up, and three cleaning plans (monthly, quarterly, and semi-annually) were tested against equivalent not-cleaned controls. The results showed monthly cleaning to increase a year's worth of energy generation by 11.15%. From weekly inspections and continuous monitoring of the panels' output power, a Markov-chains based mathematical model of the degradation of energy production was developed. The conclusion drawn from it was that the cleaning frequency should be monthly from July to October (with the optimal frequency being every three weeks), but that from November to June cleaning is unprofitable since it provides no significant improvement in output. Modelling the degradation of energy output constitutes a powerful tool with which to increase the bankability of photovoltaic plants.peerReviewe