pCO2 Values Research Articles

Using satellite imagery to estimate CO2 partial pressure and exchange with the atmosphere in the Songhua River

Rivers play a vital role in the global carbon cycle, even though they account for only 0.58 % of the Earth's non-glaciated land surface area. Owing to the significant spatial and temporal variability of the partial pressure of CO2 (pCO2) in river water, there is a large degree of uncertainty in the estimation of CO2 flux from the river water-atmosphere interface. This study assembled more than 200 in-situ measured pCO2 in the mainstream water of Songhua River and matched with Sentinel-2 overpasses within ± 7 days from the GEE platform. Multiple linear regression (MLR) and two machine learning models (Random Forest and XGBoost) algorithms were used to estimate pCO2 in Songhua River. MLR, Random Forest, and XGBoost all demonstrated good performance and have the potential to map pCO2 for different years using high-quality Sentinel-2 images. In all the tested modeling approaches, the XGBoost model exhibited stable performance in the validation set (R2 > 0.79, RMSE < 228 µatm, MAPE < 42.93 %, SMAPE < 30.64 %). The distribution of mapped pCO2 by XGBoost model significantly varied with seasonal change, and the pCO2 in summer (445 ± 125 µatm) was higher than in autumn (373 ± 58 µatm) and spring (351 ± 57 µatm). CO2 emission flux from the mainstream water of Songhua River was calculated based on the inverse pCO2 value with a net annual uptake of 15.6 Gg C during the ice-free period. The findings suggest that the Songhua River functions as a carbon sink during both spring and autumn but as a carbon source during the summer. In addition, the potential control of annual CO2 flux spatial variability was attributed to the characteristics of the watershed landscapes. The study is critical to clarify the role of river systems in the global carbon cycle.

A survey of water chemistry used in zebrafish facilities and their effects on early zebrafish development

Background There are a variety of published standard methods and water chemistry recommendations for zebrafish (Danio rerio) husbandry, but empirical evidence for their justification is often lacking, as is information on some variables that have important biological effects on fish. Importantly, these different recommendations could contribute to variability in results and fish welfare between or within institutions. Methods Here we document the current range of water chemistry used by various research institutions around the world and report initial findings on their effects on the development and growth of zebrafish. Over 40 institutes responded to a survey that revealed a large variation in water chemistry used for zebrafish husbandry including differences in the set-points and acceptable ranges for temperature, pH and conductivity. In subsequent experiments, zebrafish (D. rerio, WIK) embryos/larvae exposed to a large range of salt concentrations (50μM to 10mM Na+ or 30 – 2500 μS/cm) and CO2 levels (400 – 8,000 μatm). Results Larvae exposed to the lowest salt concentration (5 μM Na+ or &lt; 30μS/cm) had a slower response to touch and their swim bladders were not inflated. Larvae exposed to 5-100 μM Na+ were 5 % shorter in total body length than those exposed to higher salt concentrations (&gt;100 μM Na+). Zebrafish embryo/larvae exposed to intermediate pCO2 values (~2000 μatm) were 1 to 3.5% longer than those exposed to either ambient (400 μatm) or higher (4000 μatm) pCO2, but pCO2 did not affect developmental endpoints up to 4 dpf. Conclusions Overall, we highlight the magnitude of variation in water chemistry used within zebrafish research and provide some empirical evidence to show that not all of these water conditions might be optimal for developing zebrafish and reproducibility of research, although further research is necessary to determine longer-term effects of water chemistry on older larvae, juveniles and adults.

A carbonate system time series in the Eastern Mediterranean Sea. Two years of high-frequency in-situ observations and remote sensing

The rate of ocean uptake of anthropogenic CO2 has declined over the past decade, so a critical question for science and policy is whether the ocean will continue to act as a sink. Large areas of the ocean remain without observations for carbonate system variables, and oceanic CO2 observations have declined since 2017. The Mediterranean Sea is one such an area, especially its eastern part, where there is a paucity of carbonate system data, with large areas not sampled or only sampled by ship-based discrete measurements as opposed to high frequency, sensor-equipped time-series fixed stations. The aim of this study was to analyze a multi-year time-series of high-frequency (hourly) partial pressure CO2 (pCO2) and pH measurements in the Eastern Mediterranean, along with low-frequency (monthly) measurements of total dissolved inorganic carbon and total alkalinity. The pCO2 time-series was the first obtained in the Eastern Mediterranean. The study was conducted at a fixed platform of the POSEIDON system (Heraklion Coastal Buoy) located near Crete Island. Temperature was the dominant factor controlling the temporal variability of pCO2 and pH, while the remaining non-thermal variability appeared to be related to evaporation, water mixing, and biological remineralization-production. The air-sea CO2 fluxes indicated a transition from a winter-spring sink period to a summer-autumn source period. The annual air-sea CO2 flux was too low (-0.16 ± 0.02 mol m-2 yr-1) and variable to conclusively characterize the area as a net source or sink of CO2, highlighting the need for additional high frequency observation sites. Algorithms were developed using temperature, chlorophyll and salinity data to estimate pCO2 and total alkalinity, in an effort to provide tools for estimates in poorly observed areas/periods from remotely sensed products. The applicability of the algorithms was tested using Surface Ocean CO2 Atlas (SOCAT) data from the Eastern Mediterranean Sea (1999 to 2020) which showed that the algorithm pCO2 estimates were generally within ±20 μatm of the pCO2 values reported by SOCAT. Finally, the integration and analysis of the data provided directions on how to optimize the observing strategy, by readapting sensor location and using estimation algorithms with remote sensing data.

A Data-Driven Framework for Clinical Decision Support Systems in Positive Airway Pressure and Oxygen Titration

Background: Current obstructive sleep apnea treatment relies on manual PAP titration, but it has limitations. Complex interactions during titration and variations in SpO2 data accuracy pose challenges. Patients with co-occurring chronic hypercapnia may require precise oxygen titration. To address these issues, we propose a Clinical Decision Support System using Markov decision processes. Methods: This study, compliant with data protection laws, focused on adults with OSA-induced hypoxemia utilizing supplemental oxygen and CPAP/BiPAP therapy. PAP titration, conducted over one night, involved vigilant monitoring of vital signs and physiological parameters. Adjustments to CPAP pressure, potential BiLevel transitions, and supplemental oxygen were precisely guided by patient metrics. Markov decision processes outlined three treatment actions for disorder management, incorporating expert medical insights. Results: In our study involving 14 OSA patients (average age: 63 years, 27% females, BMI 41 kg m−2), significant improvements were observed in key health parameters after manual titration. The initial AHI of 61.8 events per hour significantly decreased to an average of 18.0 events per hour after PAP and oxygen titration (p &lt; 0.0001), indicating a substantial reduction in sleep-disordered breathing severity. Concurrently, SpO2 levels increased significantly from an average of 79.7% before titration to 89.1% after titration (p &lt; 0.0003). Pearson correlation coefficients demonstrated aggravation of hypercapnia in 50% of patients (N = 5) with initial pCO2 &lt; 55 mmHg during the increase in CPAP pressure. However, transitioning to BiPAP exhibited a reduction in pCO2 levels, showcasing its efficacy in addressing hypercapnia. Simultaneously, BiPAP therapy correlated with a substantial increase in SpO2, underscoring its positive impact on oxygenation in OSA patients. Markov Decision Process analysis demonstrated realistic patient behavior during stable night conditions, emphasizing minimal apnea and good toleration to high CPAP pressure. Conclusions: The development of a framework for Markov decision processes of PAP and oxygen titration algorithms holds promise for providing algorithms for improving pCO2 and SpO2 values. While challenges remain, including the need for high-quality data, the potential benefits in terms of patient management and care optimization are substantial, and this approach represents an exciting frontier in the realm of telemedicine and respiratory healthcare.

PCO2 values in asphyxiated infants under therapeutic hypothermia after tailored respiratory management: a retrospective cohort study.

Hypoxic-ischemic encephalopathy (HIE) represents one of the major causes of neonatal death and long-term neurological disability. Both hypoxic-ischemic insults and therapeutic hypothermia (TH) can affect respiratory function. Currently, there is no evidence regarding optimal respiratory management in these infants. This is a retrospective cohort study examining newborns with HIE treated with TH between January 2015 and September 2020. The study population was divided into two groups based on different respiratory assistance during TH: spontaneous breathing (Group A) or mechanical ventilation (Group B). The primary outcome of the study was the mean pCO2 ± SD evaluation during TH in ventilated and non-ventilated asphyxiated infants. The secondary outcome was the correlation between ventilation strategy and short-term neurologic outcome according to Rutherford et al.'s MRI scoring system. A total of 126 newborns were enrolled, 75 in Group A and 51 in Group B. Respiratory management was individualized, and volume guarantee (VG) ventilation was the first choice for ventilated infants. Group B infants showed more severe conditions at birth. During TH, ventilated infants showed optimal mean pCO2 comparable with those breathing spontaneously (40.6 mmHg vs. 42.3 mmHg, respectively, p 0.091), with no significant difference in pCO2 standard deviation between (7.7 mmHg vs. 8.1 mmHg, respectively, p 0.522). Mean pH, pH standard deviation, mean pO2, pO2 standard deviation, and mean respiratory rate also did not differ between groups. MRI patterns of brain injury predictive of abnormal neurodevelopmental outcomes were similar in both groups. Logistic regression analysis demonstrated that only umbilical cord arterial blood pH-affected MRI lesions were associated with poor neurodevelopmental outcomes (OR 1.505; CI 95% 1.069-2.117). Infants cooled after HIE should receive individualized respiratory management, not necessarily involving intubation. In those infants requiring mechanical ventilation, a volume-targeted strategy appeared to be effective in maintaining stable blood gas levels. Short-term neurological outcomes appeared comparable in ventilated and non-ventilated infants.

Application of Compensation Rules in the Four-quadrant Graphical Tool for Arterial Blood Gas Interpretation: A Cross-sectional Study

Introduction: Arterial Blood Gas (ABG) interpretation plays an indispensable role in emergency medicine and the care of intensive care patients, yet it remains a challenging task. Although several graphical methods exist for ABG interpretation, they are not commonly used at the bedside. The existing graphs are complicated, difficult to understand, and unable to diagnose many disorders. In previous research articles, the current author developed and published a four-quadrant graphical tool for ABG interpretation. The tool incorporates compensation rules, which are crucial for identifying changes resulting from compensations or the presence of a second primary acid-base disorder. Aim: To develop a method for applying compensation rules in a four-quadrant graphical tool to interpret ABG reports for complex acid-base disorders in clinical practice. Materials and Methods: This cross-sectional study was conducted at Shri Sathya Sai Medical College and Research Institute, Chennai, Tamil Nadu, India, from November 2022 to April 2023. A total of 232 ABG samples were utilised, and the values of pH, pCO2, HCO3, Standard HCO3, and Standard Base Excess (SBE) were recorded. These values were classified according to different acid-base disorders. Three derived ratios were calculated using the values of pCO2, bicarbonate, and standard bicarbonate, as these ratios change in various acid-base disorders and provide clues for differentiating between different acid-base disturbances. A four-quadrant graph method was constructed using the values of SBE, pCO2, and these ratios. Subsequently, compensation rules were applied to this graph method. Results: The four-quadrant method facilitated the easy identification of different acid-base disorders, and the application of compensation rules further simplified the identification of mixed or compensatory acid-base disorders. Conclusion: The application of compensation rules in this four- quadrant graphical tool for ABG interpretation distinguishes this tool as a unique method among existing approaches. This tool offers an optimal and simplified approach for interpreting ABG results for complex acid-base disturbances, making it highly suitable for clinical practice at the bedside.

Characteristics and Outcome of Neonates With Postnatally Diagnosed Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is one of the most severe neonatal malformations with a mortality of 20-35%. Currently, the rate of prenatally recognized CDHs is 60-80%. This study investigated the characteristics and outcome data of children with prenatally unrecognized CDH. Postnatally diagnosed CDH newborns treated at the University Hospital Bonn between 2012 and 2021 were included. Treatment and outcome data were compared according to type of maternity hospital, Apgar values, and between prenatally and postnatally diagnosed CDH. Of 244 CDH newborns, 22 were included. Comparison for birth in a facility with vs. without pediatric care showed for mortality: 9% vs. 27%, p=0.478; ECMO rate: 9% vs. 36%, p=0.300; age at diagnosis: 84 vs. 129 min, p=0.049; time between intubation and diagnosis: 20 vs. 86 min, p=0.019. Newborns in the second group showed significantly worse values for pH and pCO2. Furthermore, there was a tendency for higher mortality and ECMO rates in children with an Apgar score<7 vs.≥7. Children diagnosed postnatally were significantly more likely to have moderate or severe PH and tended to have cardiac dysfunction more often than those diagnosed prenatally. In our cohort, ca. one in 10 newborns received a postnatal CDH diagnosis. Birth in a facility without pediatric care is associated with later diagnosis, which may favor hypercapnia/acidosis and more severe pulm.

A novel minimally invasive fixation method for flail chest management in a Canine model: an animal research

BackgroundMultiple rib fractures can lead to flail chest with up to 35% mortality rate due to severe pulmonary complications. Current treatments of flail chest remain controversial. Studies have shown that surgical treatments can improve outcomes and reduce mortality, comparing to non-operative treatments. Current surgical fixation methods focus on stabilization of ribs on the outward facing side, and they require division of intercostal muscles. Damages to surrounding nerves and vessels may lead to chronic pain. This study tests a novel interior fixation method that minimizes neurovascular injuries.MethodsTwelve healthy canines were divided in two surgical operation groups for exterior and interior fixation using titanium metal plates. Osteotomy with oblique fractures was prepared under general anesthesia. Exterior fixation was performed in open surgery. Interior fixation was minimally invasive using custom made tools including a flexible shaft extension screwdriver, solid plate stand, guiding wire loop and metal plates with threaded holes.ResultsRespiratory and cardiovascular functions (RR, PO2, PCO2, SpO2, and HR) together with body temperature were measured before anesthesia and within 48 h after surgery. The difference in measurements was not statistically significant between the two groups before surgery with P values greater than 0.05. However, the interior group canines had better RR and PO2 values starting from the 24th hour, and better PCO2, SpO2, and HR values starting from the 48th hour. It took longer operation time to complete the minimally invasive interior fixation surgery (P value less than 0.001), but the total blood loss was less than the exterior fixation group (P value less than 0.001). Results also showed that interior group canines suffered less pain, and they had quicker recovery in gastrointestinal and physical mobility.ConclusionsThe investigative interior fixation method was safe and effective in rib stabilization on a canine rib fracture model, comparing to the exterior fixation method. The interior fixation was minimally invasive, with less damages to tissues and nerves surrounding the ribs, leading to better postoperative outcomes.

Satellite Estimation of pCO2 and Quantification of CO2 Fluxes in China’s Chagan Lake in the Context of Climate Change

The massive increase in the amount of greenhouse gases in the atmosphere, especially carbon dioxide (CO2), has had a significant impact on the global climate. Research has revealed that lakes play an important role in the global carbon cycle and that they can shift between the roles of carbon sources and sinks. This study used Landsat satellite images to analyze the spatiotemporal characteristics and factors influencing the CO2 changes in Chagan Lake in China. We conducted six water sampling campaigns at Chagan Lake in 2020–2021 and determined the partial pressure of carbon dioxide (pCO2) from 110 water samples. Landsat surface reflectance was matched with water sampling events within ±7 days of satellite overpasses, yielding 75 matched pairs. A regression analysis indicated strong associations between pCO2 and both the band difference model of the near-infrared band and green band (Band 5-Band 3, R2 = 0.83, RMSE = 27.55 μatm) and the exponential model [((exp(b3) − exp(b5))2/(exp(b3) + exp(b5))2, R2 = 0.82, RMSE = 27.99 μatm]. A comparison between the performances of a linear regression model and a machine learning model found that the XGBoost model had the highest fitting accuracy (R2 = 0.94, RMSE = 16.86 μatm). We used Landsat/OLI images acquired mainly in 2021 to map pCO2 in Chagan Lake during the ice-free period. The pCO2 in the surface water of Chagan Lake showed considerable spatiotemporal variability within a range of 0–200 μatm. pCO2 also showed significant seasonal variations, with the lowest and highest mean values in autumn (30–50 μatm) and summer (120–150 μatm), respectively. Spatially, the pCO2 values in the southeast of Chagan Lake were higher than those in the northwest. The CO2 fluxes were calculated based on the pCO2 and ranged from −3.69 to −2.42 mmol/m2/d, indicating that Chagan Lake was absorbing CO2 (i.e., it was a weak carbon sink). Temperature, chlorophyll a, total suspended matter, and turbidity were found to have reinforcing effects on the overall trend of pCO2, while the Secchi disk depth was negatively correlated with pCO2. The results of this study provide valuable insights for assessing the role of lakes in the carbon cycle in the context of climate change.

Single-species dinoflagellate cyst carbon isotope fractionation in core-top sediments: environmental controls, CO2 dependency and proxy potential

Abstract. Sedimentary bulk organic matter and various molecular organic components exhibit strong CO2-dependent carbon isotope fractionation relative to dissolved inorganic carbon sources. This fractionation (εp) has been employed as a proxy for paleo-pCO2. Yet, culture experiments indicate that CO2-dependent εp is highly specific at genus and even species level, potentially hampering the use of bulk organic matter and non-species-specific organic compounds. In recent years, significant progress has been made towards a CO2 proxy using controlled growth experiments with dinoflagellate species, also showing highly species-specific εp values. These values were, however, based on motile specimens, and it remains unknown whether these relations also hold for the organic-walled resting cysts (dinocysts) produced by these dinoflagellate species in their natural environment. We here analyze dinocysts isolated from core tops from the Atlantic Ocean and Mediterranean Sea, representing several species (Spiniferites elongatus, S. (cf.) ramosus, S. mirabilis, Operculodinium centrocarpum sensu Wall and Dale (1966) (hereafter referred to as O. centrocarpum) and Impagidinium aculeatum) using laser ablation–nano-combustion–gas-chromatography–isotope ratio mass spectrometry (LA/nC/GC-IRMS). We find that the dinocysts produced in the natural environment are all appreciably more 13C-depleted compared to the cultured motile dinoflagellate cells, implying higher overall εp values, and, moreover, exhibit large isotope variability. Where several species could be analyzed from a single location, we often record significant differences in isotopic variance and offsets in mean δ13C values between species, highlighting the importance of single-species carbon isotope analyses. The most geographically expanded dataset, based on O. centrocarpum, shows that εp correlates significantly with various environmental parameters. Importantly, O. centrocarpum shows a CO2-dependent εp above ∼ 240 µatm pCO2. Similar to other marine autotrophs, relative insensitivity at low pCO2 is in line with active carbon-concentrating mechanisms at low pCO2, although we here cannot fully exclude that we partly underestimated εp sensitivity at low pCO2 values due to the relatively sparse sampling in that range. Finally, we use the relation between εp and pCO2 in O. centrocarpum to propose a first pCO2 proxy based on a single dinocyst species.

Porcelaneous larger foraminiferal responses to Oligocene–Miocene global changes

Sea surface temperatures (SST) have been identified as a main controlling factor on larger benthic foraminifera (LBF) living in tropical to sub-tropical shallow-water carbonate and mixed siliciclastic‑carbonate platforms. Changes in SST, along with those in ocean acidification and nutrient content recorded in the global oceans throughout their history will not only continue but also be amplified in the future at an unprecedented rate of change possibly reaching levels found in the geological record. This study focuses on the Oligocene (mean SST 8 °C higher than present) and the Miocene (SST 5–8 °C higher than present) epochs which were characterized by a higher richness in porcelaneous LBF (pLBF) than today. A systematic re-assessment and comprehensive literature survey of stratigraphic ranges and palaeogeographic distribution in the Western Tethyan (Mediterranean) and Indo-Pacific regions are used to evaluate the impact of changes in SST, seawater pCO2 and pH on the biodiversity of the Oligocene–Miocene pLBF Alveolinella, Austrotrillina, Borelis, Bullalveolina, Flosculinella, and Praebullalveolina. Two peaks in species richness were identified during the Aquitanian and Langhian–Serravallian. These peaks occurred when SST was ∼29 °C, with pCO2 of ∼400 ppm and pH > 7.8. These values are comparable to those of today. The minima in species richness recorded in the Rupelian–early Chattian, in the Burdigalian and from the Tortonian onward can be correlated to the detrimental effects of both minimum (< 26 °C) and maximum (> 31 °C) SST thresholds. High pCO2 (> 600 ppm) values, which are limited to the Rupelian–early Chattian, are also detrimental to species richness. Seawater pH higher than 7.7 did not negatively affect species richness. These historical trends have serious implications for the future diversity of pLBFs with the increasing likely scenario of rising SST and pCO2 and lowering of pH values in the near future. These developments can potentially lead to diversity decrease and even extinction of pLBFs. However, the resilience of present-day pLBF species to rising SST and pCO2 levels is underpinned by the evolutionary histories of their fossil counterparts during climate variations, albeit at much different rates of change.

Arctic Permafrost Thawing Enhances Sulfide Oxidation

AbstractPermafrost degradation is altering biogeochemical processes throughout the Arctic. Thaw‐induced changes in organic matter transformations and mineral weathering reactions are impacting fluxes of inorganic carbon (IC) and alkalinity (ALK) in Arctic rivers. However, the net impact of these changing fluxes on the concentration of carbon dioxide in the atmosphere (pCO2) is relatively unconstrained. Resolving this uncertainty is important as thaw‐driven changes in the fluxes of IC and ALK could produce feedbacks in the global carbon cycle. Enhanced production of sulfuric acid through sulfide oxidation is particularly poorly quantified despite its potential to remove ALK from the ocean‐atmosphere system and increase pCO2, producing a positive feedback leading to more warming and permafrost degradation. In this work, we quantified weathering in the Koyukuk River, a major tributary of the Yukon River draining discontinuous permafrost in central Alaska, based on water and sediment samples collected near the village of Huslia in summer 2018. Using measurements of major ion abundances and sulfate () sulfur (34S/32S) and oxygen (18O/16O) isotope ratios, we employed the MEANDIR inversion model to quantify the relative importance of a suite of weathering processes and their net impact on pCO2. Calculations found that approximately 80% of in mainstem samples derived from sulfide oxidation with the remainder from evaporite dissolution. Moreover, 34S/32S ratios, 13C/12C ratios of dissolved IC, and sulfur X‐ray absorption spectra of mainstem, secondary channel, and floodplain pore fluid and sediment samples revealed modest degrees of microbial sulfate reduction within the floodplain. Weathering fluxes of ALK and IC result in lower values of pCO2 over timescales shorter than carbonate compensation (∼104 yr) and, for mainstem samples, higher values of pCO2 over timescales longer than carbonate compensation but shorter than the residence time of marine (∼107 yr). Furthermore, the absolute concentrations of and Mg2+ in the Koyukuk River, as well as the ratios of and Mg2+ to other dissolved weathering products, have increased over the past 50 years. Through analogy to similar trends in the Yukon River, we interpret these changes as reflecting enhanced sulfide oxidation due to ongoing exposure of previously frozen sediment and changes in the contributions of shallow and deep flow paths to the active channel. Overall, these findings confirm that sulfide oxidation is a substantial outcome of permafrost degradation and that the sulfur cycle responds to permafrost thaw with a timescale‐dependent feedback on warming.

The Effect of High Fat Formula Liquid Feeding on the Value of PCO2 and Duration of Use of Respiratory Aids for COVID-19 Patients with Critical Illness

Background: In December 2019, WHO announced the outbreak of COVID-19 disease caused by SARSCOV2. COVID-19 is a global pandemic characterized by high morbidity and mortality. SARS-CoV2 with there are many symptoms, about 20-26% of patients with COVID-19 pneumonia become severe or critical, requiring hospitalization for respiratory support. In Indonesia, COVID-19 has been increasing since 2020, and on February 2021, the Covid-19.go.id page had 1.157.837 confirmed cases, 176.291 active cases, 949.990 recovered, and 31.556 death cases. Acute respiratory complications requiring treatment in the intensive care unit are the main cause of high morbidity and mortality in patients with COVID-19. Nutrition therapy has influenced for outcomes of COVID-19 patients. Methods: The primary purpose of this study was to compare the value of PCO2, and duration of use of respiratory support for COVID-19 patients with critical illness. The result compared the COVID-19 patients who had been administered with high lipid formula nutrition (PULMOSOL) and patients who had been administered with standard liquid formula nutrition. The rate of the intervention group that experienced an increase in PCO2 was 55.6%, higher than those who experienced a decrease in PCO2 (50%). Results: Based on the analysis results, there was no difference in the administration of PULMOSOL and standard formula based on PCO2 in the use of ventilators in COVID-19 critically ill patients in Dr. M Djamil Padang General Hospital (p&gt;0.05) with HR = 1.39 (95% CI 1.55-3.55). In patients with increased PCO2, it was found that the intervention group who died was 55.6%, lower compared to the control group (62.5%). The same in patients with decreased pCO2, group the intervention group who died was 50.0%, higher than the control group (40%). Conclusion: Statistical tests demonstrated there was no relationship between the administration of PULMOSOL and the outcome of critically ill COVID-19 (p&gt;0.05). Keywords: Covid-19, critically ill, nutrition, high lipid formula

A study of comparison of outcomes of positive pressure ventilation and face mask oxygen on arterial blood gas parameters in children with congestive heart failure

Aims and objective. To compare the effects of Positive Pressure Ventilation (PPV) and Face Mask oxygen on arterial blood gas (ABG) parameters in children with congestive heart failure. Materials and methods. A prospective, randomized, single-blind, cross-sectional study was undertaken in eastern India’s Dr. B.C. Roy Post Graduate Institute of Pediatric Sciences PICU. From December 2014 to June 2016, single-blind randomization was used to diagnose congestive heart failure in children aged 3 months to 12 years. Results. Patients receiving face mask oxygen had a mean pH of 7.2150, while those receiving NIV had a mean pH of 7.2740 (P value = 0.012, &lt;0.05). After 6 hours, the pH improved more in the NIV group (mean pH = 7.3023) than the face mask oxygen group (mean pH = 7.2503), P value = 0.003 (&lt;0.05). The group receiving face mask oxygen had a mean pCO2 of 54.93 at the start of the study, while the NIV group had 52.83 (P value = 0.395, &gt;0.05). The baseline pCO2 values of the two groups were similar. After 1-2 hours of investigation, the face mask oxygen group had a mean pCO2 of 53.50, whereas the NIV group had 47.77, with a P value of 0.008 (&lt;0.05). After 4-6 hours, the face mask oxygen group had a mean pCO2 of 50.90, while the NIV group had 46.77, with a P value of 0.001 (&lt;0.05). Conclusion. After 6 hours of therapy, NIV improved mean pH more than face mask oxygen. NIV ventilation improved pCO2 readings more than face mask oxygen after 2 hours. The mean pCO2 drop over 4-6 hours in the NIV group was greater than in the face mask oxygen group.

Extra corporeal membrane oxygenation therapy in acute respiratory distress syndrome due to Coronavirus-2019 (COVID-19): a retrospective study

Aims: Extra corporeal membrane oxygenation (ECMO) has been used as a supportive treatment in ARDS due to COVID-19. Although different results have been reported in the literature regarding its efficacy, ECMO is recommended as a salvage therapy for severe forms of the disease after standard therapy fails. In our study,we aimed to evaluate the survival outcomes of patients supported with ECMO for COVID-19.&#x0D; Methods: Our study was conducted by scanning the data of consecutive adult patients hospitalized in our intensive care unit due to COVID-19. The ECMO process was planned according to the Extracorporeal Life Support Organization (ELSO) and Berlin criteria.&#x0D; Results: 51 patients hospitalized for acute respiratory failure due to COVID-19 were taken to ECMO. Demographic data of patients; 39 (76.5%) men and 12 (23.5%) women. 46 (90.2%) of the patients died. The mean intubation time before ECMO is 3.9 days, and the mean time for non-invasive mechanical ventilation is 5.8 days. The mean PaO2 value before ECMO was79.09 mmHg, the mean PCO2 value was 63.62 mmHg and the mean PaO2/FiO2 ratio was 82.80.&#x0D; Conclusion: The use of ECMO by considering prognostic factors and guidelines is seen as factors that increase the chance of success.Despite the fact that the patients were admitted to ECMO in accordance with the guidelines in our study, the high mortality rate suggests that there is a need for investigation of other supportive treatments and studies to reduce ECMO complications.

Occupational Exposure during Pregnancy and Effects on Newborns: A Nested Case-Control Study.

The protection of pregnant workers should be based on evidence regarding the risks to reproductive health from exposure to specific work environments and conditions. The objective of this study was to identify the effects on mothers and newborns resulting from environmental exposure to various occupational risks. The study cohort was composed of 399 women admitted to the Obstetrics/Postpartum ward at Hospital La Fe in Valencia, Spain. Face-to-face interviews were conducted to establish associations between workplace exposure during pregnancy and its effects on maternal and newborn health. Sex, anthropometric characteristics, and blood gas analysis in arterial and venous umbilical cord blood at delivery were collected. A total of 138 women were exposed to biological and/or chemical risks, 122 to physical risks, and 139 at no risk of exposure. In the group with chemical and/or biological risks, the frequency of women who resorted to in vitro fertilization to achieve the studied pregnancy is less than half of the group exposed to physical risks, with statistically significant differences (p = 0.047). The mean values for the arterial analysis in both exposure groups were within average values, with similar pH values between them, but the mean values of PCO2 and PO2 were lower in the group of neonates of mothers exposed to physical risks, with a significant difference for arterial PO2 (p = 0.027). Our analysis contributes evidence for planning and prioritizing preventive actions to protect women's reproductive health. The results suggest the continuation of a future project that would consider more factors and potentially increase the sample size.

Significant Daily CO2 Source–Sink Interchange in an Urbanizing Lake in Southwest China

Inland lake water–air interfaces, particularly the partial pressure of CO2 (pCO2), have become key parameters in the study of global carbon cycle changes. However, there are few studies on short-term daily variations in pCO2 in urbanizing lakes. The fluctuations in pCO2 and CO2 fluxes (fCO2) were monitored biweekly on-site for pCO2 assessments during daytime hours (7:00–17:00 CST) from January to September 2020 in an urbanizing lake located in Southwest China. We found a pronounced and uninterrupted decline in the average levels of pCO2 and fCO2 from 7:00 to 17:00 CST. Notably, the mornings (7:00–12:00 CST) exhibited substantially elevated pCO2 and fCO2 values compared to the afternoons. Specifically, compared to 7:00, the mean pCO2 and fCO2 at 17:00 CST decreased by ca. 74% and 112%, respectively. The average daytime pCO2 was 707 ± 642 μatm, significantly higher than the typical atmospheric CO2 levels of 380–420 μatm, while the average pCO2 on 9 January, 1 April, and 27 July was lower than typical atmospheric CO2. Each month, all water environmental parameters showed significant differences. pCO2 and fCO2 reached maximums in September; water temperature and turbidity significantly increased; and pH, dissolved oxygen and transparency markedly decreased. Additionally, the correlation between pCO2 and environmental factors demonstrated that the nutrient levels, dissolved oxygen, pH, and transparency/turbidity had significant roles in CO2 dynamics in this lake. Therefore, this urbanizing lake could serve as a CO2 source and sink during the daytime.

Influence of typology and management practices on water pCO[formula omitted] and atmospheric CO2 fluxes over two temperate shelf–estuary–marsh water continuums

Within the coastal zone, salt marshes often behave as atmospheric CO2 sinks, allowing for blue carbon (C) sequestration associated with intense autotrophic metabolism. However, C dynamics over salt marshes are complex since various biogeochemical processes and fluxes occur at different terrestrial–aquatic–atmospheric exchange interfaces and spatiotemporal scales. This study focuses on seasonal, tidal and diurnal variations of water pCO2, estimated water–air CO2 fluxes and controlling factors along two temperate shelf–estuary–marsh continuums. The latter include typical coastal systems with artificial salt marshes that have contrasting water management practices and primary producer types. Our high-frequency biogeochemical measurements (seasonal 24-hour cycles) highlighted a strong control of ecosystem typology on inorganic C dynamics with lower water pCO2 values in the artificial salt marshes, due to stronger biological activity and longer water residence times, than in the tidal estuary. In the marine-dominated estuary, water pCO2 variations (267 - 569 ppmv) were strongly controlled by tidal effects and phytoplankton activity particularly in spring/summer. On the contrary, the greatest amplitudes in water pCO2 were recorded in the artificial salt marshes (6 - 721 ppmv) due to intense macrophyte activity. In the rewilded marsh, eutrophication favoured spring/summer fast-growing macroalgae produced, in turn, strong fall atmospheric CO2 outgassing from degraded algae waters and thus a net annual source of CO2 to the atmosphere (17.5 g C m−2 yr−1). Conversely, specific management practices at the working marsh for salt-farming activity favoured rather slow-growing macrophytes (i.e. seagrasses) which greatly contribute to the yearly observed atmospheric CO2 sink (-97.7 g C m−2 yr−1). In this work, we suggest that salt marsh management can be used to control the contribution of primary producers to marsh C budget as atmospheric CO2 (sink and/or source).

In vitro evaluation of the performance of an oxygenator depending on the non-standard gas content of the inlet blood with special regard on CO2 elimination.

The performance of an oxygenator, as found in literature, is evaluated according to protocols that define standard values of the gas content in the inlet blood. However, when dealing with simulations of lung insufficiency, a more extensive evaluation is needed. This work aims to investigate and assess the gas exchange performance of an oxygenator for different input values of gas content in blood. Three commercially available oxygenators with different membrane surfaces were investigated in a mock loop for three blood flow rates (0.5l/min, 1l/min, and 5l/min) and two gas-to-blood ratios (1:1, and 15:1). The initial CO2 and O2 partial pressures (pCO2 and pO2) in blood were set to≥100mmHg and ≤10mmHg, respectively. For each ratio, the efficiency, defined as the ratio between the difference of pressure inlet and outlet and the inlet pCO2 (pCO2(i)), was calculated. The CO2 elimination in an oxygenator was higher for higher pCO2(i). While for a pCO2(i) of 100mmHg, an oxygenator eliminated 80mmHg, the same oxygenator at the same conditions eliminated 5mmHg CO2 when pCO2(i) was 10mmHg. The efficiency of the oxygenator decreased from 76,9% to 49,5%. For simulation reasons, the relation between the pCO2(i) and outlet (pCO2(o)) for each oxygenator at different blood and gas flows, was described as an exponential formula. The performance of an oxygenator in terms of CO2 elimination depends not only on the blood and gas flow, but also on the initial pCO2 value. This dependence is crucial for simulation studies in the future.

Spatiotemporal variability in pH and carbonate parameters on the Canadian Atlantic continental shelf between 2014 and 2022

Abstract. The Atlantic Zone Monitoring Program (AZMP) was established by Fisheries and Oceans Canada (DFO) in 1998 with the aim of monitoring physical and biological ocean conditions in Atlantic Canada in support of fisheries management. Since 2014, at least two of the carbonate parameters (pH; total alkalinity, TA; and dissolved inorganic carbon, DIC) have also been systematically measured as part of the AZMP, enabling the calculation of derived parameters (e.g., carbonate saturation states, Ω, and partial pressure of CO2, pCO2). The present study gives an overview of the spatiotemporal variability in these parameters between 2014 and 2022. Results show that the variability in the carbonate system reflects changes in both physical (e.g., temperature and salinity) and biological (e.g., plankton photosynthesis and respiration) parameters. For example, most of the region undergoes a seasonal warming and freshening. While the former will tend to increase Ω, the latter will decrease both TA and Ω. Spring and summer plankton blooms decrease DIC near the surface and then remineralize and increase DIC at depth in the fall. The lowest pCO2 values (down to ∼ 200 µatm) are located in the cold coastal Labrador Current, whereas the highest values (&gt;1500 µatm) are found in the fresh waters of the Gulf of St. Lawrence and the St. Lawrence Estuary. The latter is also host to the lowest pH values of the zone (7.48 in the fall of 2022). Finally, most of the bottom waters of the Gulf of St. Lawrence (&gt;90 %) are undersaturated with respect to aragonite (Ωarg&lt;1). In addition to providing a baseline of carbonate parameters for the Atlantic Zone as a whole, this comprehensive overview is a necessary and useful contribution for the modelling community and for more in-depth studies. The full dataset of measured and derived parameters is available from the Federated Research Data Repository: https://doi.org/10.20383/102.0673 (Cyr et al., 2022a).