The COVID-19 pandemic required careful management of intensive care unit (ICU) admissions, to reduce ICU overload while facing limitations in resources. We implemented a standardized, ...physiology-based, ICU admission criteria and analyzed the mortality rate of patients refused from the ICU. In this retrospective observational study, COVID-19 patients proposed for ICU admission were consecutively analyzed; Do-Not-Resuscitate patients were excluded. Patients presenting an oxygen peripheral saturation (SpO.sub.2) lower than 85% and/or dyspnea and/or mental confusion resulted eligible for ICU admission; patients not presenting these criteria remained in the ward with an intensive monitoring protocol. Primary outcome was both groups' survival rate. Secondary outcome was a sub analysis correlating SpO.sub.2 cutoff with ICU admission. From March 2020 to January 2021, 1623 patients were admitted to our Center; 208 DNR patients were excluded; 97 patients were evaluated. The ICU-admitted group (n = 63) mortality rate resulted 15.9% at 28 days and 27% at 40 days; the ICU-refused group (n = 34) mortality rate resulted 0% at both intervals (p < 0.001). With a SpO.sub.2 cut-off of 85%, a significant correlation was found (p = 0.009), but with a 92% a cut-off there was no correlation with ICU admission (p = 0.26). A similar correlation was also found with dyspnea (p = 0.0002). In COVID-19 patients, standardized ICU admission criteria appeared to safely reduce ICU overload. In the absence of dyspnea and/or confusion, a SpO.sub.2 cutoff up to 85% for ICU admission was not burdened by negative outcomes. In a pandemic context, the SpO.sub.2 cutoff of 92%, as a threshold for ICU admission, needs critical re-evaluation.
Although the Covid-19 pandemic is still ongoing, the environmental factors beyond virus transmission are only partially known. This statistical study has the aim to identify the key factors that have ...affected the virus spread during the early phase of pandemic in Italy, among a wide set of potential determinants concerning demographics, environmental pollution and climate. Because of its heterogeneity in pollution levels and climate conditions, Italy provides an ideal scenario for an ecological study. Moreover, the selected period excludes important confounding factors, as different virus variants, restriction policies or vaccines. The short-term relationship between the infection maximum increase and demographic, pollution and meteo-climatic parameters was investigated, including both winter-spring and summer 2020 data, also focusing separately on the two seasonal periods and on North vs Centre-South. Among main results, the importance of population size confirmed social distancing as a key management option. The pollution hazardous role undoubtedly emerged, as NO2 affected infection increase in all the studied scenarios, PM2.5 manifested its impact in North of Italy, while O3 always showed a protective action. Whereas higher temperatures were beneficial, especially in the cold season with also wind and relative humidity, solar irradiance was always relevant, revealing several significant interactions with other co-factors. Presented findings address the importance of the environment in Sars-CoV-2 spread and indicated that special carefulness should be taken in crowded areas, especially if they are highly polluted and weakly exposed to sun. The results suggest that containment of future epidemics similar to Covid-19 could be supported by reducing environmental pollution, achieving safer social habits and promoting preventive health care for better immune system response, as an only comprehensive strategy.
Particulate matter (PM) has well-known negative health effects on humans. PM exposure occurs mainly indoors because people spend most of their time inside buildings, especially in their homes. This ...study aimed at investigating the impact of the principal outdoor factors, house characteristics and indoor activities on size-fractionated PM concentrations in a real exposure scenario consisting of 60 living rooms in the province of Lodi (River Po Valley, Northern Italy), characterized by high pollution levels. Nearby road traffic played a pivotal role for all the studied fractions, with heavy duty vehicles affecting the coarser fractions especially when building density was lower. PM2.5–10 arose also from indoor determinants linked to cleaning activities and house occupancy and was inversely related with house volume. Statistical analysis showed that ambient PM10 was a reliable predictor of PM fractions <2.5 μm, but other indoor sources should be considered, such as ETS for PM0.5 and open fireplaces use for the PM0.5-1. Some protective factors were identified, such as the use of exhaust ventilation in kitchens (PM0.5–1) and sealed windows and doors (PM0.25). Some determinants were also season-related (open fireplaces use, floor level, built-on garages). In conclusion, the study provides an insight on the main PM determinants commonly present in residential environments. The results can be useful in addressing some self-corrected choices by home occupants and in developing meaningful risk mitigation strategies by local institutions.
•PM determinants were of outdoor or indoor origin and activity-related.•The proximity to heavily-trafficked roads affected all PM size-fraction levels.•Contributions from different sources varied depending on the season.•Some determinants of indoor PM could be effectively managed by occupants.•Results will be useful in new building design improving indoor environmental quality.
TomoEDGETM refers to the sliding window motion of the jaws along the superior-inferior edge of the treatment target. An automatic procedure, (“Dynamic Jaws Sweep” DJS), tests the movement functions ...with specific exercises and measures the alignment of the linac photon source in relation to jaw collimation evaluating the longitudinal dose profiles. The results of the DJS were retrospectively analyzed using the statistical control charts.
From June 2013 to September 2016 the DJS was performed, on a weekly basis, on a TomoHDATM system for a total amount of 130 runs. All measurements were analyzed with TomoTherapy Quality Assurance (TQA) software that provides: the fluence output factor (FOF) for the three clinical jaws aperture (J20, J14, J7), the time skew and the linac photon source position along the longitudinal direction (IECy SP). Qualitative graphs related to specific exercises are also produced.
For each quantitative parameter the Individual (ICC) and the Moving Range chart control (MRCC) were implemented. For both charts the Central value, the Upper and Lower Control Limit are based on the average and on the statistical variance of the first 10 runs.
The control chart results were compared to the TQA limits, suggested by the vendor.
The FOF values outside the limits overlap with erroneous qualitative graphs, pointing out a real critical issue of jaw movements. Both the Individual and the Moving range control chart showed analogous results; indeed, with the ICC the FOF were outside limits in 12.3%, 13.1% and 20% of their measurements for J20, J14 and J7 jaw settings respectively and the time skew parameter only in 4.6%, while, with the MRCC, the corresponding values were 9.2%, 10.1%, 14.3% and 9.0% for the time skew parameter.
The IECy SP, while remaining within vendor specific values, rapidly diverged from its initial value with an increasing trend, eventually approaching the zero value.
Control chart approach seems to be an useful tool for studying in depth the results of the DJS procedure.
Much more stringent TQA limits, based on the own machine behavior, are useful to easily detect critical issue related to the dynamic jaws movements.
Human exposure to polycyclic aromatic hydrocarbons (PAHs) in indoor environments can be particularly relevant because people spend most of their time inside buildings, especially in homes. This study ...aimed to investigate the most important particle-bound PAH sources and exposure determinants in PM2.5 samples collected in 19 homes located in northern Italy. Complementary information about ion content in PM10 was also collected in 12 of these homes. Three methods were used for the identification of PAH sources and determinants: diagnostic ratios with principal component and hierarchical cluster analyses (PCA and HCA), chemical mass balance (CMB) and linear mixed models (LMMs). This combined and tiered approach allowed the infiltration of outdoor PAHs into indoor environments to be identified as the most important source in winter, with a relevant role played by biomass burning and traffic exhausts to be identified as a general source of PAHs in both seasons. Tobacco smoke exhibited an important impact on PAH levels in smokers' homes, whereas in the whole sample, cooking food and natural gas sources played a minor or negligible role. Nitrate, sulfate and ammonium were the main inorganic constituents of indoor PM10 owing to the secondary formation of ammonium sulfates and nitrates.
Display omitted
•A tiered approach is conducted to identify sources/determinants of PAHs indoors.•Environmental tobacco smoke was responsible of high PAH levels in some homes.•Biomass burning was a dominant source of PAHs in winter.•The impact of vehicular traffic on indoor PAHs was higher in summer.
The infiltration of outdoor air, road traffic, tobacco smoke and biomass burning were identified as the most relevant sources of polycyclic aromatic hydrocarbons in residential homes.
The aim of this study was to identify determinants of aldehyde and volatile organic compound (VOC) indoor air concentrations in a sample of more than 140 office rooms, in the framework of the ...European OFFICAIR research project. A large field campaign was performed, which included (a) the air sampling of aldehydes and VOCs in 37 newly built or recently retrofitted office buildings across 8 European countries in summer and winter and (b) the collection of information on building and offices’ characteristics using checklists. Linear mixed models for repeated measurements were applied to identify the main factors affecting the measured concentrations of selected indoor air pollutants (IAPs). Several associations between aldehydes and VOCs concentrations and buildings’ structural characteristic or occupants’ activity patterns were identified. The aldehyde and VOC determinants in office buildings include building and furnishing materials, indoor climate characteristics (room temperature and relative humidity), the use of consumer products (eg, cleaning and personal care products, office equipment), as well as the presence of outdoor sources in the proximity of the buildings (ie, vehicular traffic). Results also showed that determinants of indoor air concentrations varied considerably among different type of pollutants.
Accuracy of TomoEDGE dynamic jaw field widths Urso, Patrizia; Corradini, Nathan A.; Vite, Cristina
Journal of applied clinical medical physics,
September 2018, Volume:
19, Issue:
5
Journal Article
Peer reviewed
Open access
Dynamic jaw delivery on the TomoTherapy H‐series platform, entitled TomoEDGE™, is an effective tool to decrease the patient dose along the superior and inferior edges of the treatment target. The ...aperture of the TomoTherapy jaws, that is, field width (FW), defines the longitudinal dose profile. A consistent FW dose profile is an important quantity for accurate and reproducible dose delivery in TomoTherapy. To date, no evaluation has been made of the accuracy and precision of the dose profiles produced by dynamic jaws. This study aims to provide a long‐term evaluation of the dynamic jaw FW dose profiles obtained on TomoTherapy utilizing the TomoTherapy Quality Assurance procedure (TQA). A total of 840 dose profiles were measured during 84 TQA procedures, performed over a 2‐yr period. The full width at half maximum (FWHM) and constancy of the FW dose profile measurements were analyzed and compared with the tolerances proposed by AAPM Task Group 148 (TG‐148) and those used by the manufacturer. The FWHM evaluation showed that the FWs > 2.0 cm respect the TG‐148 tolerance of 1%, while the asymmetric FWs ≤ 2.0 cm were outside the limit in 17.3% of measurements. Constancy results evaluated along the full profiles showed that 95.2% of measurements were within 3% of the baseline for symmetric FWs and 94.8% of measurements were within 4% of the baseline for asymmetric FWs. In conclusion, the analysis confirms the accuracy and precision of TomoEDGE™ technology in jaw positioning. This study has identified the potential to establish an appropriate QA tolerance for the asymmetric FWs used in dynamic jaw movement. Finally, the clinical significance of the observed discrepancies should be studied further to understand the dosimetric effect on patient treatments.
Octavius®‐4D is a very effective device in radiotherapy treatment quality assurance (QA), due to its simple set‐up and analysis package. However, even if it is widely used, its main characteristics ...and criticalities were only partially investigated. Taking start from its commissioning, the aim of this work was to study the main dependencies of the device response. The outcome dependence was studied comparing results by different delivery techniques Intensity Modulated Radiation Therapy, IMRT (n = 29) and RapidArc, RA (n = 15), anatomical regions 15 head/neck, 19 pelvis and 10 pancreas and linear accelerators DHX (n = 14) and Trilogy (n = 30). Moreover, the agreement dependency on the section of the phantom was assessed. Plan evaluations obtained by 2D, 3D, and volumetric γ‐index (both local and global) were also compared. Generally, high dose gradient resulted critically managed by the assembly, with a smoother effect in RA technique. Worse agreements emerged in the 2D γ‐index vs those of 3D and volumetric (P < 0.001), that were instead statistically comparable in global metric (P > 0.300). Volumetric plan evaluation was coherent with the average of passing rates on the 3 phantom axes (r ≥ 0.9), but transversal section provided best agreements vs sagittal and coronal ones (P < 0.050). The three studied districts furnished comparable results (P > 0.050) while the two LINACs provided different agreements (P < 0.005). The study pointed out that the phantom transversal section better fits the planned dose distribution, so this should be accounted when a two‐dimensional evaluation is needed. Moreover, the major reliability of the 3D metric with respect to the 2D one, as it better agrees with the dosimetric evaluation on the whole volume, suggests that it should be preferred in a two‐dimensional evaluation. Better agreements, obtained with RA vs IMRT technique, confirm that Octavius®‐4D is specifically conceived for rotational delivery. Lastly, the assembly resulted sensitive to different technology.
Accuracy of Tomo EDGE dynamic jaw field widths Urso, Patrizia; Corradini, Nathan A.; Vite, Cristina
Journal of applied clinical medical physics,
09/2018, Volume:
19, Issue:
5
Journal Article
Peer reviewed
Open access
Abstract
Dynamic jaw delivery on the TomoTherapy H‐series platform, entitled Tomo
EDGE
™, is an effective tool to decrease the patient dose along the superior and inferior edges of the treatment ...target. The aperture of the TomoTherapy jaws, that is, field width (
FW
), defines the longitudinal dose profile. A consistent
FW
dose profile is an important quantity for accurate and reproducible dose delivery in TomoTherapy. To date, no evaluation has been made of the accuracy and precision of the dose profiles produced by dynamic jaws. This study aims to provide a long‐term evaluation of the dynamic jaw
FW
dose profiles obtained on TomoTherapy utilizing the TomoTherapy Quality Assurance procedure (
TQA
). A total of 840 dose profiles were measured during 84
TQA
procedures, performed over a 2‐yr period. The full width at half maximum (
FWHM
) and constancy of the
FW
dose profile measurements were analyzed and compared with the tolerances proposed by
AAPM
Task Group 148 (
TG
‐148) and those used by the manufacturer. The
FWHM
evaluation showed that the
FW
s > 2.0 cm respect the
TG
‐148 tolerance of 1%, while the asymmetric
FW
s ≤ 2.0 cm were outside the limit in 17.3% of measurements. Constancy results evaluated along the full profiles showed that 95.2% of measurements were within 3% of the baseline for symmetric
FW
s and 94.8% of measurements were within 4% of the baseline for asymmetric
FW
s. In conclusion, the analysis confirms the accuracy and precision of Tomo
EDGE
™ technology in jaw positioning. This study has identified the potential to establish an appropriate
QA
tolerance for the asymmetric
FW
s used in dynamic jaw movement. Finally, the clinical significance of the observed discrepancies should be studied further to understand the dosimetric effect on patient treatments.
Invasive mechanical ventilation (IMV) is the standard treatment in critically ill COVID-19 patients with acute severe respiratory distress syndrome (ARDS). When IMV setting is extremely aggressive, ...especially through the application of high positive-end-expiratory respiration (PEEP) values, lung damage can occur. Until today, in COVID-19 patients, two types of ARDS were identified (L- and H-type); for the L-type, a
lower PEEP strategy
was supposed to be preferred, but data are still missing. The aim of this study was to evaluate if a clinical management with lower PEEP values in critically ill L-type COVID-19 patients was safe and efficient in comparison to usual standard of care. A retrospective analysis was conducted on consecutive patients with COVID-19 ARDS admitted to the ICU and treated with IMV. Patients were treated with a
lower PEEP strategy
adapted to BMI: PEEP 10 cmH
2
O if BMI < 30 kg m
−2
, PEEP 12 cmH
2
O if BMI 30–50 kg m
−2
, PEEP 15 cmH
2
O if BMI > 50 kg m
−2
. Primary endpoint was the PaO
2
/FiO
2
ratio evolution during the first 3 IMV days; secondary endpoints were to analyze ICU length of stay (LOS) and IMV length. From March 2 to January 15, 2021, 79 patients underwent IMV. Average applied PEEP was 11 ± 2.9 cmH
2
O for BMI < 30 kg m
−2
and 16 ± 3.18 cmH
2
O for BMI > 30 kg m
−2
. During the first 24 h of IMV, patients’ PaO
2
/FiO
2
ratio presented an improvement (
p
<0.001; CI 99%) that continued daily up to 72 h (
p
<0.001; CI 99%). Median ICU LOS was 15 days (10–28); median duration of IMV was 12 days (8–26). The ICU mortality rate was 31.6%. Lower PEEP strategy treatment in L-type COVID-19 ARDS resulted in a PaO
2
/FiO
2
ratio persistent daily improvement during the first 72 h of IMV. A
lower PEEP strategy
could be beneficial in the first phase of ARDS in critically ill COVID-19 patients.
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