Browsing by Subject "VENTILATION"

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  • Olasveengen, Theresa M.; de Caen, Allan R.; Mancini, Mary E.; Maconochie, Ian K.; Aickin, Richard; Atkins, Dianne L.; Berg, Robert A.; Bingham, Robert M.; Brooks, Steven C.; Castren, Maaret; Chung, Sung Phil; Considine, Julie; Couto, Thomaz Bittencourt; Escalante, Raffo; Gazmuri, Raul J.; Guerguerian, Anne-Marie; Hatanaka, Tetsuo; Koster, Rudolph W.; Kudenchuk, Peter J.; Lang, Eddy; Lim, Swee Han; Lofgren, Bo; Meaney, Peter A.; Montgomery, William H.; Morley, Peter T.; Morrison, Laurie J.; Nation, Kevin J.; Ng, Kee-Chong; Nadkarni, Vinay M.; Nishiyama, Chika; Nuthall, Gabrielle; Ong, Gene Yong-Kwang; Perkins, Gavin D.; Reis, Amelia G.; Ristagno, Giuseppe; Sakamoto, Tetsuya; Sayre, Michael R.; Schexnayder, Stephen M.; Sierra, Alfredo F.; Singletary, Eunice M.; Shimizu, Naoki; Smyth, Michael A.; Stanton, David; Tijssen, Janice A.; Travers, Andrew; Vaillancourt, Christian; Van de Voorde, Patrick; Hazinski, Mary Fran; Nolan, Jerry P.; ILCOR Collaborators (2017)
    The International Liaison Committee on Resuscitation has initiated a near-continuous review of cardiopulmonary resuscitation science that replaces the previous 5-year cyclic batch-and-queue approach process. This is the first of an annual series of International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations summary articles that will include the cardiopulmonary resuscitation science reviewed by the International Liaison Committee on Resuscitation in the previous year. The review this year includes 5 basic life support and 1 paediatric Consensuses on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Each of these includes a summary of the science and its quality based on Grading of Recommendations, Assessment, Development, and Evaluation criteria and treatment recommendations. Insights into the deliberations of the International Liaison Committee on Resuscitation task force members are provided in Values and Preferences sections. Finally, the task force members have pri-oritised and listed the top 3 knowledge gaps for each population, intervention, comparator, and outcome question. (C) 2017 European Resuscitation Council and American Heart Association, Inc. Published by Elsevier B.V. All rights reserved.
  • Harve-Rytsälä, Heini; Ångerman, Susanne; Kirves, Hetti; Nurmi, Jouni (2021)
    Background Normoventilation is crucial for many critically ill patients. Ventilation is routinely guided by end-tidal capnography during prehospital anaesthesia, based on the assumption of the gap between arterial partial pressure of carbon dioxide (PaCO2) and end-tidal carbon dioxide partial pressure (PetCO(2)) of approximately 0.5 kPa (3.8 mmHg). Methods We retrospectively analysed the airway registry and patient chart data of patients who had been anaesthetised and intubated endotracheally by the prehospital critical care team and had their prehospital arterial blood gases analysed. Bland-Altman analysis was used to estimate the bias and limits of agreement. Results Altogether 502 patients were included in the study, with a median age of 58 years. The most common patient groups were post-resuscitation (155, 31%), neurological emergencies (96, 19%), intoxication (75, 15%) and trauma (68, 14%). The median of the gap between PaCO2 and PetCO(2) was 1.3 kPa (interquartile range 0.7 to 2.2) (9.8 (5.3-16.5) mmHg). Mean bias of PetCO(2) was -1.6 kPa/12.0 mmHg (standard deviation 1.7 kPa/12.8 mmHg) with 95% confidence limits of agreement -4.9 to 1.9 kPa (-36.8 to 14.3 mmHg). The gap was >= 1.0 kPa (>7.5 mmHg) in 297 (66%, 95% confidence interval 55 to 63) patients. Conclusion Our results suggest that end-tidal capnography alone might not be an adequate method to achieve normoventilation for critically ill patients intubated and mechanically ventilated in prehospital setting. Thus, an arterial blood gas analysis might be useful to recognize patients with an increased gap between PaCO2 and PetCO(2).
  • Kurola, Jouni; Paakkonen, Heikki; Kettunen, Tapio; Laakso, Juha-Pekka; Gorski, Jouko; Silfvast, Tom (2011)
  • Karttunen, Sasu; Kurppa, Mona; Auvinen, Mikko; Hellsten, Antti; Järvi, Leena (2020)
    Street vegetation has been found to have both positive and negative impacts on pedestrian-level air quality, but the net effect has remained unclear. In this study, the effect of street trees on aerosol mass (PM10 and PM2.5) and number in a boulevard-type street canyon with high traffic volumes in Helsinki is examined using the large-eddy simulation model PALM. Including a detailed aerosol module and a canopy module to comprise permeable trees, PALM allows to examine the effect of street trees in depth. The main aim is to understand the relative importance of dry deposition and the aerodynamic impact of street trees on the different aerosol measures at pedestrian-level and to find a suitable street-tree layout that would minimise the pedestrian-level aerosol particle concentrations over the boulevard pavements. The layout scenarios were decided together with urban planners who needed science-based knowledge to support the building of new neighbourhoods with boulevard-type streets in Helsinki. Two wind conditions with wind being parallel and perpendicular to the boulevard under neutral atmospheric stratification are examined. Adding street trees to the boulevard increases aerosol particle concentrations on the pavements up to 123%, 72% and 53% for PM10, PM2.5 and total number, respectively. This shows decreased ventilation to be more important for local aerosol particle concentrations than dry deposition on vegetation. This particularly for PM10 and PM2.5 whereas for aerosol number, dominated by small particles, the importance of dry deposition increases. Therefore the studied aerosol measure is important when the effect of vegetation on pedestrian-level air quality is quantified. Crown volume fraction in the street space is one of the main determining factors for elevated mass concentrations on the pavements. The lowest pedestrian-level mass concentrations are seen with three rows of trees of variable height, whereas the lowest number concentrations with four rows of uniform trees. The tree-height variation allows stronger vertical turbulent transport with parallel wind and largest volumetric flow rates with perpendicular wind. Introducing low (height <1 m) hedges under trees between the traffic lanes and pavements is found to be a less effective mitigation method for particle mass than introducing tree-height variability, and for particle number less effective than maximising the tree volume in the street canyon. The results show how street trees in a boulevard-type street canyon lead to decreased pedestrian-level air quality with the effect being particularly strong for larger aerosol particles. However, with careful planning of the street vegetation, significant reductions in pedestrian-level aerosol particle concentrations can be obtained.
  • Vuorinen, Ville; Aarnio, Mia; Alava, Mikko; Alopaeus, Ville; Atanasova, Nina; Auvinen, Mikko; Balasubramanian, Nallannan; Bordbar, Hadi; Erasto, Panu; Grande, Rafael; Hayward, Nick; Hellsten, Antti; Hostikka, Simo; Hokkanen, Jyrki; Kaario, Ossi; Karvinen, Aku; Kivisto, Ilkka; Korhonen, Marko; Kosonen, Risto; Kuusela, Janne; Lestinen, Sami; Laurila, Erkki; Nieminen, Heikki J.; Peltonen, Petteri; Pokki, Juho; Puisto, Antti; Raback, Peter; Salmenjoki, Henri; Sironen, Tarja; Osterberg, Monika (2020)
    We provide research findings on the physics of aerosol and droplet dispersion relevant to the hypothesized aerosol transmission of SARS-CoV-2 during the current pandemic. We utilize physics-based modeling at different levels of complexity, along with previous literature on coronaviruses, to investigate the possibility of airborne transmission. The previous literature, our 0D-3D simulations by various physics-based models, and theoretical calculations, indicate that the typical size range of speech and cough originated droplets (d
  • Ervasti, Jenni; Kivimaki, Mika; Kawachi, Ichiro; Subramanian, S. V.; Pentti, Jaana; Oksanen, Tuula; Puusniekka, Riikka; Pohjonen, Tiina; Vahtera, Jussi; Virtanen, Marianna (2012)
    Background: Poor indoor air quality (IAQ) and psychosocial problems are common in schools worldwide, yet longitudinal research on the issue is scarce. We examined whether the level of or a change in pupil-reported school environment (IAQ, school satisfaction, and bullying) predicts recorded sick leaves among teachers. Methods: Changes in the school environment were assessed using pupil surveys at two time points (2001/02 and 2004/05) in 92 secondary schools in Finland. Variables indicating change were based on median values at baseline. We linked these data to individual-level records of teachers' (n = 1678) sick leaves in 2001-02 and in 2004-05. Results: Multilevel multinomial logistic regression models adjusted for baseline sick leave and covariates showed a decreased risk for short-term (one to three days) sick leaves among teachers working in schools with good perceived IAQ at both times (OR = 0.6, 95% CI: 0.5-0.9), and for those with a positive change in IAQ (OR = 0.6, 95% CI: 0.4-0.9), compared to teachers in schools where IAQ was constantly poor. Negative changes in pupil school satisfaction (OR = 1.8, 95% CI: 1.1-2.8) and bullying (OR = 1.5, 95% CI: 1.0-2.3) increased the risk for short-term leaves among teachers when compared to teachers in schools where the level of satisfaction and bullying had remained stable. School environment factors were not associated with long-term sick leaves. Conclusions: Good and improved IAQ are associated with decreased teacher absenteeism. While pupil-related psychosocial factors also contribute to sick leaves, no effect modification or mediation of psychosocial factors on the association between IAQ and sick leave was observed.
  • Linko, Rita Teresa; Hedger, Mark P.; Pettila, Ville; Ruokonen, Esko; Ala-Kokko, Tero; Ludlow, Helen; de Kretser, David M. (2014)
  • Vesala, Risto; Harjuntausta, Anni; Hakkarainen, Anu; Rönnholm, Petri; Pellikka, Petri; Rikkinen, Jouko (2019)
    Background Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth. Objectives In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts. Methods External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons. Results Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to “hot nests.” Conclusions Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.
  • Int Network Evaluation Outcomes iN; Lui, Kei; Lee, Shoo K.; Kusuda, Satoshi; Andersson, Sture (2019)
    Objective To evaluate outcome trends of neonates born very preterm in 11 high-income countries participating in the International Network for Evaluating Outcomes of neonates. Study design In a retrospective cohort study, we included 154 233 neonates admitted to 529 neonatal units between January 1, 2007, and December 31, 2015, at 24(0/7) to 31(6/7) weeks of gestational age and birth weight Results For composite outcome including BPD, the trend decreased in Canada and Israel but increased in Australia and New Zealand, Japan, Spain, Sweden, and the United Kingdom. For composite outcome excluding BPD, the trend decreased in all countries except Spain, Sweden, Tuscany, and the United Kingdom. The risk of composite outcome was lower in epoch 2 than epoch 1 in Canada (adjusted relative risks 0.78; 95% CI 0.74-0.82) only. The risk of composite outcome excluding BPD was significantly lower in epoch 2 compared with epoch 1 in Australia and New Zealand, Canada, Finland, Japan, and Switzerland. Mortality rates reduced in most countries in epoch 2. BPD rates increased significantly in all countries except Canada, Israel, Finland, and Tuscany. Conclusions In most countries, mortality decreased whereas BPD increased for neonates born very preterm.