Effects of combined oxygen and surgical masks on inspired fraction of oxygen: relevance to COVID-19-induced respiratory failure.
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ABSTRACT:
SUBMITTER: Hamada S
PROVIDER: S-EPMC7934693 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Postnatal adaptation of preterm infants entails a series of difficulties among which the immaturity of the respiratory system is the most vital. To overcome respiratory insufficiency, caregivers attending in the delivery room use positive pressure ventilation and oxygen. A body of evidence in relation of oxygen management in the delivery room has been accumulated in recent years; however, the optimal initial inspired fraction of oxygen, the time to achieve specific oxygen saturation targets, and oxygen titration have not been yet clearly established. The aim of this review is to update the reader by critically analyzing the most relevant literature.
| S-EPMC6406550 | biostudies-literature
Project description:There have been many studies on the microplastic pollution, influence and control mechanisms of different plastic products. The potential harm of microplastic pollution to the environment has been confirmed. With the outbreak and spread of the COVID-19 in the world, disposable surgical masks as effective and cheap protective medical equipment have been widely used by the public. Disposable masks have been a new social norm, but they must have a sense of environmental responsibilities. The random disposal of masks may result in new and greater microplastic pollution, because masks made of polymer materials would release microplastics after entering the environment. Current results showed that masks are a potential and easily overlooked source of environmental microplastics. The release amount of microplastics in the static water by one mask was 360 items, and with the increase of vibration rate, the release amount also increased. The addition of organic solvents (detergent and alcohol) in water would increase the release of microplastics from masks. When the mask became fragments, the ability to release microplastic fibers into the environment was greatly improved due to the increase of exposure area. After two months of natural weathering, the masks become very fragile pieces and microplastics. A fully weathered mask could release several billions of microplastic fibers into the aquatic environment once these fragile fragments enter the water without reservation. The rapid growth of mask production and consumption and improper disposable is worrying. It is urgent to understand the potential environmental risks and significance of masks.
| S-EPMC8164515 | biostudies-literature
Project description:PurposeWhether the use of high-flow nasal oxygen in adult patients with COVID-19 associated acute respiratory failure improves clinically relevant outcomes remains unclear. We thus sought to assess the effect of high-flow nasal oxygen on ventilator-free days, compared to early initiation of invasive mechanical ventilation, on adult patients with COVID-19.MethodsWe conducted a multicentre cohort study using a prospectively collected database of patients with COVID-19 associated acute respiratory failure admitted to 36 Spanish and Andorran intensive care units (ICUs). Main exposure was the use of high-flow nasal oxygen (conservative group), while early invasive mechanical ventilation (within the first day of ICU admission; early intubation group) served as the comparator. The primary outcome was ventilator-free days at 28 days. ICU length of stay and all-cause in-hospital mortality served as secondary outcomes. We used propensity score matching to adjust for measured confounding.ResultsOut of 468 eligible patients, a total of 122 matched patients were included in the present analysis (61 for each group). When compared to early intubation, the use of high-flow nasal oxygen was associated with an increase in ventilator-free days (mean difference: 8.0 days; 95% confidence interval (CI): 4.4 to 11.7 days) and a reduction in ICU length of stay (mean difference: - 8.2 days; 95% CI - 12.7 to - 3.6 days). No difference was observed in all-cause in-hospital mortality between groups (odds ratio: 0.64; 95% CI: 0.25 to 1.64).ConclusionsThe use of high-flow nasal oxygen upon ICU admission in adult patients with COVID-19 related acute hypoxemic respiratory failure may lead to an increase in ventilator-free days and a reduction in ICU length of stay, when compared to early initiation of invasive mechanical ventilation. Future studies should confirm our findings.
| S-EPMC7876530 | biostudies-literature
Project description:When hemoglobin (Hb) is fully saturated with oxygen, the additional gain in oxygen delivery (DO2) achieved by increasing the fraction of inspired oxygen (FiO2) is often considered clinically insignificant. In this study, we evaluated the change in DO2, interrogated by mixed venous oxygen saturation (SvO2), in response to a change in FiO2 of 0.5 during cardiac surgery. When patients were hemodynamically stable, FiO2 was alternated between 0.5 and 1.0 in on-pump cardiac surgery patients (pilot study), and between 0.3 and 0.8 in off-pump coronary artery bypass grafting patients (substudy of the CARROT trial). After the patient had stabilized, a blood gas analysis was performed to measure SvO2. The observed change in SvO2 (ΔSvO2) was compared to the expected ΔSvO2 calculated using Fick's equation. A total 106 changes in FiO2 (two changes per patient; total 53 patients; on-pump, n = 36; off-pump, n = 17) were finally analyzed. While Hb saturation remained near 100% (on-pump, 100%; off-pump, mean [SD] = 98.1% [1.5] when FiO2 was 0.3 and 99.9% [0.2] when FiO2 was 0.8), SvO2 changed significantly as FiO2 was changed (the first and second changes in on-pump, 7.7%p [3.8] and 7.6%p [3.5], respectively; off-pump, 7.9%p [4.9] and 6.2%p [3.9]; all P < 0.001). As a total, regardless of the surgery type, the observed ΔSvO2 after the FiO2 change of 0.5 was ≥ 5%p in 82 (77.4%) changes and ≥ 10%p in 31 (29.2%) changes (mean [SD], 7.5%p [3.9]). Hb concentration was not correlated with the observed ΔSvO2 (the first changes, r = - 0.06, P = 0.677; the second changes, r = - 0.21, P = 0.138). The mean (SD) residual ΔSvO2 (observed - expected ΔSvO2) was 0%p (4). Residual ΔSvO2 was more than 5%p in 14 (13.2%) changes and exceeded 10%p in 2 (1.9%) changes. Residual ΔSvO2 was greater in patients with chronic kidney disease than in those without (median [IQR], 5%p [0 to 7] vs. 0%p [- 3 to 2]; P = 0.049). DO2, interrogated by SvO2, may increase to a clinically significant degree as FiO2 is increased during cardiac surgery, and the increase of SvO2 is not related to Hb concentration. SvO2 increases more than expected in patients with chronic kidney disease. Increasing FiO2 can be used to increase DO2 during cardiac surgery.
| S-EPMC8429729 | biostudies-literature
Project description:Patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19), exhibit a wide spectrum of disease behavior. Since DNA methylation has been implicated in the regulation of viral infections and the immune system, we performed an epigenome- wide association study (EWAS) to identify candidate loci regulated by this epigenetic mark that could be involved in the onset of COVID-19 in patients without comorbidities.
2021-04-15 | GSE168739 | GEO
Project description:Left atrial (LA) size is an established marker of risk for adverse outcomes in heart failure with preserved ejection fraction (HFpEF). However, the independent prognostic importance of LA function in HFpEF is not known.We assessed LA function measured by speckle-tracking echocardiography in 357 patients with HFpEF enrolled in the Treatment Of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist (TOPCAT) trial who were in sinus rhythm at the time of echocardiography. Lower peak LA strain, indicating LA dysfunction, was associated with older age, higher prevalence of atrial fibrillation and left ventricular (LV) hypertrophy, worse LV and right ventricular systolic function, and worse LV diastolic function. At a mean follow-up of 31 months (interquartile range, 18-43months), 91 patients (25.5%) experienced the primary composite end point of cardiovascular death, HF hospitalization, and aborted sudden death. Lower peak LA strain was associated with a higher risk of the composite end point (hazard ratio, 0.96 per unit of reduction in strain; 95% confidence interval, 0.94-0.99; P=0.009) and of HF hospitalization alone (hazard ratio, 0.95 per unit of reduction in strain; 95% confidence interval, 0.92-0.98; P=0.003). The association of LA strain with incident HF hospitalization remained significant after adjustment for clinical confounders, but not after further adjustment for LV global longitudinal strain and the E/E' ratio, parameters of LV systolic and diastolic function, respectively.LA dysfunction in HFpEF is associated with a higher risk of HF hospitalization independent of potential clinical confounders, but not independent of LV strain and filling pressure. Impairment in LV systolic and diastolic function largely explains the association between impaired LA function and higher risk of HF hospitalization in HFpEF.URL: http://www.clinicaltrials.gov. Unique identifier: NCT00094302.
| S-EPMC4826720 | biostudies-other
Project description:PurposeWe aimed to describe the use of high-flow nasal oxygen (HFNO) in patients with COVID-19 acute respiratory failure and factors associated with a shift to invasive mechanical ventilation.MethodsThis is a multicenter, observational study from a prospectively collected database of consecutive COVID-19 patients admitted to 36 Spanish and Andorran intensive care units (ICUs) who received HFNO on ICU admission during a 22-week period (March 12-August 13, 2020). Outcomes of interest were factors on the day of ICU admission associated with the need for endotracheal intubation. We used multivariable logistic regression and mixed effects models. A predictive model for endotracheal intubation in patients treated with HFNO was derived and internally validated.ResultsFrom a total of 259 patients initially treated with HFNO, 140 patients (54%) required invasive mechanical ventilation. Baseline non-respiratory Sequential Organ Failure Assessment (SOFA) score [odds ratio (OR) 1.78; 95% confidence interval (CI) 1.41-2.35], and the ROX index calculated as the ratio of partial pressure of arterial oxygen to inspired oxygen fraction divided by respiratory rate (OR 0.53; 95% CI: 0.37-0.72), and pH (OR 0.47; 95% CI: 0.24-0.86) were associated with intubation. Hospital site explained 1% of the variability in the likelihood of intubation after initial treatment with HFNO. A predictive model including non-respiratory SOFA score and the ROX index showed excellent performance (AUC 0.88, 95% CI 0.80-0.96).ConclusionsAmong adult critically ill patients with COVID-19 initially treated with HFNO, the SOFA score and the ROX index may help to identify patients with higher likelihood of intubation.
| S-EPMC7934982 | biostudies-literature
Project description:ObjectivesThe coronavirus disease 2019 pandemic increased global demand for personal protective equipment (PPE) and resulted in shortages. The study evaluated the re-use of surgical masks and respirators by analysing their performance and safety before and after reprocessing using the following methods: oven, thermal drying, autoclave, and hydrogen peroxide plasma vapour.MethodsIn total, 45 surgical masks and 69 respirators were decontaminated. Visual integrity, air permeability, burst resistance, pressure differential and particulate filtration efficiency of new and decontaminated surgical masks and respirators were evaluated. In addition, 14 used respirators were analysed after work shifts before and after decontamination using reverse transcription polymerase chain reaction (RT-PCR) and viral culturing. Finally, reprocessed respirators were evaluated by users in terms of functionality and comfort.ResultsOven decontamination (75 °C for 45 min) was found to be the simplest decontamination method. Physical and filtration assays indicated that all reprocessing methods were safe after one cycle. Oven decontamination maintained the characteristics of surgical masks and respirators for at least five reprocessing cycles. Viral RNA was detected by RT-PCR in two of the 14 used respirators. Four respirators submitted to viral culture were PCR-negative and culture-negative. Reprocessed respirators used in work shifts were evaluated positively by users, even after three decontamination cycles.ConclusionOven decontamination is a safe method for reprocessing surgical masks and respirators for at least five cycles, and is feasible in the hospital setting.
| S-EPMC7832149 | biostudies-literature
Project description:BackgroundThere is little evidence addressing the use and differential impact of respiratory support in acute heart failure (AHF) patients with preserved (HFPEF) vs reduced (HFREF) ejection fraction. Therefore, our objective was to determine the usage and clinical outcomes of critical care respiratory support in AHF across the two populations.HypothesisRespiratory support would be associated with adverse outcome in both HFPEF and HFREF.MethodsWe identified HFPEF, HFREF, invasive mechanical ventilation (IMV), and noninvasive ventilation (NIV) using International Classification of Disease-Ninth Edition codes in the National Inpatient Sample between January 1, 2008 and December 31, 2014. We determined rates of IMV and NIV use. We identified predictors of need for IMV and NIV and the association between ventilation strategies and in-hospital mortality in HFPEF vs HFREF.Results1.3 million AHF-HFPEF and 1.7 million AHF-HFREF hospitalizations were included; 5.98% of AHF HFPEF hospitalizations included NIV and 0.57% included IMV. Among HFREF hospitalizations, fewer (4.1%) included NIV and more (0.93%) included IMV. In HFPEF hospitalization, NIV use was associated with 2.24-fold increased risk for death compared to no respiratory support in an adjusted model (HR 2.24 95% CI 2.05-2.44) and IMV use was associated with 2.85-fold increased risk for death (HR 2.85 95% CI 2.30-3.53). This increased risk of in-hospital mortality was similar among HFREF patients.ConclusionsUse of respiratory support is increasing among patients with both HFPEF and HFREF and associated with substantially increased mortality in both heart failure subtypes.
| S-EPMC7144479 | biostudies-literature
Project description:BackgroundPre-pandemic empirical studies have produced mixed statistical results on the effectiveness of masks against respiratory viruses, leading to confusion that may have contributed to organizations such as the WHO and CDC initially not recommending that the general public wear masks during the COVID-19 pandemic.MethodsA threshold-based dose-response curve framework is used to analyse the effects of interventions on infection probabilities for both single and repeated exposure events. Empirical studies on mask effectiveness are evaluated with a statistical power analysis that includes the effect of adherence to mask usage protocols.ResultsWhen the adherence to mask-usage guidelines is taken into account, the empirical evidence indicates that masks prevent disease transmission: all studies we analysed that did not find surgical masks to be effective were under-powered to such an extent that even if masks were 100% effective, the studies in question would still have been unlikely to find a statistically significant effect. We also provide a framework for understanding the effect of masks on the probability of infection for single and repeated exposures. The framework demonstrates that masks can have a disproportionately large protective effect and that more frequently wearing a mask provides super-linearly compounding protection.ConclusionsThis work shows (1) that both theoretical and empirical evidence is consistent with masks protecting against respiratory infections and (2) that nonlinear effects and statistical considerations regarding the percentage of exposures for which masks are worn must be taken into account when designing empirical studies and interpreting their results.
| S-EPMC8499874 | biostudies-literature