Gas Analysis Research Articles

Clinical features of pulmonary hypertension in lymphangioleiomyomatosis

Objective: To describe the prevalence of lymphangioleiomyomatosis-pulmonary hypertension (LAM-PH), to explore the clinical features of patients with LAM-PH, and to evaluate the role of pulmonary artery optical coherence tomography (OCT) in the diagnosis of LAM-PH. Methods: Among 234 patients diagnosed with LAM in our center from June 2017 to August 2023, echocardiography was performed in 167 patients, 15 patients with PH indicated by echocardiography were selected as the LAM-PH group. From the remaining 152 patients, 32 patients were randomly selected as the control group. We compared the demographic data, clinical manifestations, pulmonary function, blood gas analysis, and serum vascular endothelial growth factor D (VEGF-D) levels between the two groups. We also evaluated the data from right heart catheterization in five patients and the images from optical coherence tomography of pulmonary arteries in two patients. Results: Echocardiography showed pulmonary hypertension in 15 patients (8.98%). Compared with the control group, LAM-PH group had a higher proportion of patients receiving oxygen therapy. Patients with PH had lower FEV1, FVC, FEV1/FVC, DLCO and higher serum VEGF-D levels compared with those without PH. Right heart catheterization was performed in five patients. Five patients had a pre-capillary pattern and three of these patients had severe pulmonary hypertension. Optical coherence tomography showed that there were no obvious abnormalities in the intima and lumen of the blood vessels in the two patients. Conclusions: The prevalence of PH in LAM is low. Patients in the LAM-PH group had more severe hypoxemia, worse lung function and higher serum VEGF-D levels than those in the control group. PH in LAM is mainly pre-capillary. Optical coherence tomography can evaluate the pulmonary artery vascular condition and help to identify the cause of pulmonary hypertension in LAM patients.

Metal line emission around $z<1$ galaxies

We characterize, for the first time, the average extended emission in multiple lines ( and around a statistical sample of 560 galaxies at $z By stacking the Multi Unit Spectroscopic Explorer (MUSE) 3D data from two large surveys, the MUSE Analysis of Gas around Galaxies (MAGG) and the MUSE Ultra Deep Field (MUDF), we detect significant emission out to approx 40 kpc, while and emission is detected out to approx 30 kpc. Via comparisons with the nearby average stellar continuum emission, we find that the line emission at 20--30 kpc likely arises from the disk-halo interface. Combining our results with that of our previous study at $z we find that the average surface brightness increases independently with redshift over $z and with stellar mass over which is likely driven by the star formation rate as well as the physical conditions of the gas. By comparing the observed line fluxes with photoionization models, we find that the ionization parameter declines with distance, going from log q (cm $) approx 7.7 at le 5 kpc to approx 7.3 at 20--30 kpc, which reflects a weaker radiation field in the outer regions of galaxies. The gas-phase metallicity shows no significant variation over 30 kpc, with a metallicity gradient of approx 0.003 dex kpc$^ $, which indicates an efficient mixing of metals on these scales. Alternatively, there could be a significant contribution from shocks and diffuse ionized gas to the line emission in the outer regions.

Pyrometallurgical Reduction of Copper Slag with Biochar for Metal Recovery

AbstractLarge amounts of slag are generated during pyrometallurgical processing in copper production. Due to the presence of valuable elements, the improper disposal of huge quantities of copper slag produced, results in significant loss of resources as well as environmental issues. Analyses of the copper slag show that it contains valuable metals, particularly copper and nickel. In this work, four biochars were employed as fossil-free reducing agents to recover valuable metals from the slag. Reduction experiments were performed in a vertical furnace at temperatures 1250, 1300 and 1350 °C for 60 min in order to investigate the effect of temperature. Moreover, the effect of time on reduction progress was studied at 1250 °C and the concentrations of CO and CO2 in the off-gas were measured with a gas analyzer. Copper slag was reacted with metallurgical coke for comparison and the products were analyzed with EPMA and LA-ICPMS. The results revealed that reduction rapidly progresses to the formation of metal alloy within 10 min. Valuable metals like copper, nickel and arsenic were the first to be reduced to the metal phase. As reduction time increased, iron was also reduced and combined with the metal droplet. The use of biochar as reductant was shown to be more effective than coke especially at lower temperatures. In addition, thermodynamic modelling was performed with FactSage and HSC and compared with the experimental results. The simulations with HSC showed the sequence of reactions taking place and the calculations by FactSage were in agreement with the experiments. Graphical Abstract

Development of an Ion Mobility Spectrometer Based on a Pulsed Photoelectric Effect Ionization Source.

Ion mobility spectrometry (IMS) is a compact and sensitive trace gas analysis instrument that ionizes the sample into ions for detection. Typically, an ion gate is used to cut the continuous ion beam into ion packets for separation and detection. However, commonly used ion gates suffer from complex structures or low ion transmission rates, making the gateless IMS a viable alternative. In this study, an IMS based on a pulsed photoelectric effect ionization source was designed. The photoelectrons were generated by irradiating a photoelectric material with a back-illuminated pulsed xenon lamp. This allows for low-energy photoelectron generation and the production of simple reactant ions (O2-(H2O)n) and thus negative product ions. The photoelectron current generated by this ionization source was analyzed, which can reach an intensity of a few microamperes and can be converted into an ion signal exceeding 10 nA. The introduction of the pulsed photoelectric effect ionization source makes it possible to generate separate ion packets and complete ion injection when a constant electric field is maintained in the ionization region. And with an assisted pulsed electric field in the ionization region, the resolving power of the system can be effectively improved to 1.85 times that of the constant electric field. The IMS developed in this study was used for the detection of common volatile hazardous chemicals, yielding effective results. The detection limit for phenol was below 1 ppb, and the dynamic response range exceeded 1 order of magnitude, which implies the potential applications of this IMS to detect substances with high electron affinity, such as explosives detection in public safety.

Oxygen Consumption During Moderate-Intensity Interval Exercise in Overweight Young Adults

Background: Overweight and obesity have become a problem for younger generations, so weight management must be introduced. Moderate-intensity interval training (MIIT) has been recommended for aging and obese populations because it is friendly and accessible. However, little information is known about the physiological response during moderate-interval intensity exercise, especially for overweight and obese persons. Objectives: To evaluate cardiorespiratory alteration upon a single bout of MIIT exercise among sedentary, overweight young Thai adults. Methods: Fifteen overweight young adults (8 males and 7 females, body mass index between 25.0 - 29.9 kg/m2, aged between 18 - 25 years) underwent cycling ergometry for 45 minutes (warm-up 5 minutes; 3 × 5 minutes at 20 - 40% of heart rate reserve and 5 minutes at 50 - 60%; cool down 10 minutes). A gas analyzer and limb lead electrocardiogram were used to record oxygen consumption (V̇O2), heart rate (HR), and dioxide production (V̇CO2) throughout the experiment. Results: During the 45-minute MIIT exercise protocol, the participants consumed 25.1 ± 8.1 L, equal to approximately 530 ± 171 kJ. As expected, heart rate, O2 uptake, and CO2 production increased during moderated-intensity exercise and declined during low-intensity exercise. A low to moderate duration ratio of 1: 1 was sufficient to return both O2 consumption and CO2 production to their stage level, but not for heart rate. Although there was a very linear relationship between V̇O2 and heart rate for the overall period (0.761 ± 0.090), the correlation was weaker when selectively computed during low (0.549 ± 0.161) or moderate exercises (0.658 ± 0.105). Interestingly, RER larger than one during moderate-intensity exercise indicated the possibility of high acid accumulation. Conclusions: The MIIT protocol in the present study provided a responsive effect on overweight persons toward anaerobic metabolism but was a little aggressive.

Exploratory analysis of serum Krebs von den Lungen-6, blood gas analysis & Brixia score in determining COVID-19 severity & mortality

Background & objectives Krebs von den Lungen-6 (KL-6) is primarily expressed by the damaged type II pneumocytes. In this context, the relationship of KL-6 with blood gas analysis (BGA) parameters and Brixia score is still limitedly discussed. This study aims to analyze the correlation of KL-6, BGA and Brixia scores to the severity and mortality of COVID-19. Methods A cross-sectional study was conducted in adult COVID-19 positive individuals at Universitas Airlangga Hospital, Surabaya, East Java, Indonesia, from March to August 2021. KL-6, BGA, and Brixia scores were compared according to severity (severe vs. non-severe) and mortality (non-survivor vs. survivor). The receiver operating characteristic (ROC) analysis was also performed to define the optimal cut-off, sensitivity, as well as the specificity of KL-6, BGA and Brixia scores to determine the COVID-19 severity and mortality. Results Total 35 severe and 20 non-severe COVID-19 positive individuals were enrolled in this study. Of those, there were 22 non-survivors. No significant difference in serum KL-6 levels was observed in the severity and mortality groups. KL-6 and HCO3– had positive correlation in the severe group (r=0.37). KL-6 and Brixia scores showed a significant negative correlation among COVID-19 positive individuals (r=–0.283; P=0.036). KL-6 and Brixia scores together served as the best severity markers in the current study [AUC 0.809 (0.697–0.920); Sn/Sp=0.686/0.900)], followed by KL-6 and P/F ratio [AUC 0.800 (0.637–0.963); Sn/Sp=0.971/0.750]. Interpretation & conclusions The findings of this study suggest that KL-6 has the potential to be a useful adjunct laboratory parameter to the BGA and Brixia score representing COVID-19 severity and mortality.

Testing and approval standard development of online dissolved gas analysis monitors for oil‐filled transformers—Part I hydrogen monitors

Testing and approval standard development of online dissolved gas analysis monitors for oil‐filled transformers—Part I hydrogen monitors

Correlation of arterial and venous blood gas analysis in respiratory failure in children

IntroductionArterial and venous blood gases provide similar and very close measurements in terms of PH, pCO2, HCO3, pO2 levels. The study aims to investigate correlation of arterial and venous blood gas analysis in respiratory failure caused by pneumonia in children.MethodsThis cross-sectional study employed a consecutive sampling method from pediatric patients experiencing respiratory failure. Point of Care (POCT) was used to examine blood gas analysis.ResultThere was no significant difference between pH artery and venous with p = 0,232 (95% confidence interval [CI]: -14.628-59,488). The Mean difference between arterial and venous pH was 0,22 with a strong Spearman correlation of 0,643 (p < 0,001). There was a significant difference between arterial and venous pCO2 with p = 0,022 (95% confidence interval [CI]: -8,7- (− 0,69)). The mean difference between arterial and venous pCO2 was 4,69 with a moderate Spearman correlation of 0,485 (p < 0,001). There was no significant difference between arterial and venous HCO3 with p = 0,38. The Mean difference between arterial and venous HCO3 was 3,1 with a very strong Spearman correlation of 0,848 (p < 0,001). There was a very significant difference between arterial and venous pO2 with p < 0,001. The Mean difference between arterial and venous pO2 was 27,4 with a weak Spearman correlation of 0,17 (p = 0,117).ConclusionThere was strong correlation between arterial and venous pH, a moderate correlation between arterial and venous pCO2, a very strong correlation between arterial and venous HCO3 and a very weak correlation between arterial and venous pO2 using POCT.

Environmental analysis of Acid Gas Sweetening with DEA

Environmental analysis of Acid Gas Sweetening with DEA

Role of Preoperative Arterial Blood Gas Analysis in American Society of Anesthesiologists Grade III and IV Patients in a Tertiary Care Hospital

Role of Preoperative Arterial Blood Gas Analysis in American Society of Anesthesiologists Grade III and IV Patients in a Tertiary Care Hospital

Dissolved gas analysis comparison of electrically stressed methyl ester and mineral oil

Methyl ester is considered one of the alternative substitutes to mineral oil as an insulating liquid. This study investigates the dissolved gas analysis (DGA) of the methyl ester derived from palm oil, under low energy discharge faults. The aims are to understand the gas composition and evaluate the applicability of the well-established fault interpretation methods for mineral oil to the methyl ester. Experimental procedures were conducted based on the International Electrotechnical Commission (IEC) standards. It involved simulating electrical breakdowns in laboratory conditions as per IEC-156 standard and analyzing gas samples using gas chromatography based on IEC-567. Results show that methyl ester oils produce similar types of gases as mineral oils but at higher concentrations. The interpretation of DGA results using fault identification methods such as Duval Triangle, Duval Pentagon, and IEC ratio indicates an overestimation of fault severity in methyl ester oils, and categorizing the faults as high energy discharge. However, the key gas method correctly identifies the discharge in both methyl ester and mineral oils. These findings suggest the need for adjustments in existing DGA methods to account for the higher gas concentrations in methyl ester oils, for effective condition monitoring and maintenance of transformers if it was filled with methyl ester oil.

Integrated interferometers as a new platform for low cost gas chromatography detection

Gas chromatography is a reference method for gas analysis. As part of efforts to miniaturize gas chromatography systems, the miniaturization of detectors is essential. In this work, we report a new integrated photonic platform for gas chromatography analyte detection. The fabricated silicon die integrates Mach-Zehnder interferometers into low dead volume microfluidic channels, with coherent cost-effective detection scheme with a fixed 850 nm wavelength laser. A proof of concept is demonstrated with the separation and detection of three volatile organic compounds: heptane, octane, and toluene. Peaks’ widths at half height range from 1 to 5 seconds. Peaks are very well resolved by our system, which acquires more than 100 points per second. From a heptane dilution range, we evaluate the limit of detection of our system to be the headspace of a 0.22% heptane concentration solution. To our knowledge, these are the first integrated Mach-Zehnder interferometers reported for gas chromatography detection. This work could open new strategies for fast low cost and low limit of detection specific gas chromatography silicon micro-detectors.

Acute Bronchiolitis: The Less, the Better?

Acute bronchiolitis is a viral infection of the lower respiratory tract affecting infants aged under 12 months, variably presenting with respiratory distress, diffuse crackles and inflammatory wheezing. The main causative agent is Respiratory Syncytial Virus (RSV). The diagnosis is clinical and treatment mainly supportive. Despite the availability of more than 30 international guidelines, consistent management recommendations are lacking and considerable variability in patients' care persists among different providers. To review and describe current knowledge about epidemiology, physiopathology, clinic, diagnosis and management of acute bronchiolitis, with particular emphasis on updated evidence and future perspectives in terms of treatment and prevention. We searched Cochrane for systematic reviews and PubMed for scientific articles published in the last 10 years, using a combination of the following search terms: "bronchiolitis", "respiratory syncytial virus", "epidemiology", "risk factors", "severity", "diagnosis", "clinic", "diagnostic imaging", "management", "asthma", "wheezing", "bronchodilator", "steroids", "hypertonic saline", "oxygen", "blood gas analysis", "HHHFNC", "rehydration", "enteral feeding", "parenteral hydration", "prevention", "vaccine" and "COVID-19 or SARS-CoV2". We accordingly performed a deep and extensive selection of the most updated and considerable literature on the matter, summarizing the most significant evidence concerning all aspects of acute bronchiolitis (epidemiology, clinic, diagnosis, management and prevention). Furthermore, we examined references and available guidelines from UK, USA, Canada, Italy and Spain. Results are extensively discussed below. Although acute bronchiolitis has been a widely known disease for decades, its therapeutic approach remained unchanged and essentially limited to respiratory and metabolic support. Despite the abundance of studies, there is no significant evidence concerning therapeutic alternatives (e.g. steroids, inhaled hypertonic solution), which are therefore not recommended. According to most recent data, "acute bronchiolitis" definition encompasses a plethora of different clinical entities related to each subject's genetic and immune predisposition. Therefore, future research should focus on the precise characterization of such subcategories in order to individualize therapeutic management and ensure the most appropriate evidence-based care.

Mechanism of Status Evaluation for Water Blocking Buffer Layer of High-Voltage Cable Based on Characteristic Gas Analysis

Mechanism of Status Evaluation for Water Blocking Buffer Layer of High-Voltage Cable Based on Characteristic Gas Analysis

Assessing the Carbon Footprint of Viticultural Production in Central European Conditions

A number of factors will increasingly play a role in the sustainability of wine production in the coming period. The current situation suggests that the analysis of energy consumption and greenhouse gas (GHG) emissions will play a particularly important role. The so-called carbon footprint, expressed in CO₂ equivalents, is used to express the sum of GHG emissions. This study presents an analysis of vine cultivation in a particular Central European region, with the main focus on quantifying the inputs, yield, fuel consumption, and GHG emissions. The emphasis was placed on conventional, integrated, and ecological production systems of growing, evaluated with the help of the developed AGROTEKIS version 5 software. A total of 30 wine-grower entities in the Morava wine-growing region, the subregion Velké Pavlovice, in the Czech Republic weather climate, were included in the input data survey. By analyzing the aggregated values, the real savings in energy and curbing of CO2 emissions of vineyards could be observed, relating to individual work procedures with lower energy demand used in the vineyard treatment as well as the amounts and doses of agrochemicals used. The average values of the total impacts did not show any statistically significant differences between the conventional (971 ± 78 kg CO2eq·ha−1·year−1) and integrated production systems (930 ± 62 kg CO2eq·ha−1·year−1), whereas the values for the ecological production system were significantly higher (1479 ± 40 kg CO2eq·ha−1·year−1). The results show that growing vines under ecological production conditions generates a higher proportion of the carbon footprint than under conventional production conditions. Overall, the best results can be achieved in an integrated production system.

Pre-treatment with tocilizumab reduces lipopolysaccharide-induced acute lung injury in biliary cirrhotic rats

Infection-related lipopolysaccharide (LPS) release causes cytokine storm and acute lung injury. Emerging data show that the interleukin 6 (IL-6) inhibitor tocilizumab can improve lung damage in patients with sepsis. This study aimed to investigate the therapeutic effect of tocilizumab on acute lung injury in cirrhotic rats. Biliary cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). Sham-operated rats served as surgical controls. Tocilizumab was administered on post-operative day 21, and LPS was injected intraperitoneally on day 29. Three hours after LPS injection, hemodynamic parameters, biochemistry data, and arterial blood gas analysis were evaluated, along with measurements of IL-6 and tumor necrosis factor-α (TNF-α). Liver and lung histology was examined, and protein levels were analyzed. LPS administration reduced portal pressure, portal venous flow and cardiac index in the BDL rats. In addition, LPS administration induced acute lung injury, hypoxia and elevated TNF-α and IL-6 levels. Pre-treatment with tocilizumab did not affect hemodynamic and biochemistry data, but it ameliorated lung injury and decreased TNF-α, IL-6, and CD68-positive macrophage infiltration. Moreover, tocilizumab administration improved hypoxia and gas exchange in the BDL rats, and downregulated hepatic and pulmonary inflammatory protein expression. In conclusion, LPS administration induced acute lung injury in biliary cirrhotic rats. Pre-treatment with tocilizumab reduces lung damage and hypoxia, possibly by downregulating inflammatory proteins and reducing IL-6, TNF-α and CD68-positive macrophage recruitment in the lung.

Pyrolysis-gasification conversion of waste pharmaceutical blisters: Thermo-kinetic and thermodynamic study, fuel gas analysis and machine learning modeling

It delved into the pyrolysis-gasification behavior of waste pharmaceutical blisters (WPBs), exploring both kinetics and thermodynamics, and employing machine learning modeling. The decomposition of WPBs occurred in three stages, with temperature intervals of 140–350, 350–500, and 500–900 °C, respectively. Cyclization/aromatization reactions were hindered, as indicated by mass spectrometric analysis, which revealed the main evolved products, including CxHy, CH3OH, CH4, and H2. Apparent activation energy values obtained from FWO, KAS, Friedman, Cai & Chen models were comparable, showing a decreasing trend ranging from 264.9 to 48.4 kJ mol−1 at α ≤ 0.70, followed by a subsequent increase to 283.1 kJ mol−1 at a conversion of 0.80. The D1 model was more reliable in describing the pyrolysis-gasification process of WPBs. Machine learning modeling results indicated that the ANN19 with a topology structure of 5 ∗ 15 ∗ 1 and genetic programming models showed superior performance in predicting TG data.

Temperature effects on chemical reactions and product yields in the Co-pyrolysis of wood sawdust and waste tires: An experimental investigation

This study investigates the effects of varying temperatures on the co-pyrolysis of wood sawdust (WS) and waste tires (WT) within a stainless steel fixed-bed reactor under a nitrogen atmosphere. The experiments were conducted at three different temperatures: 400 °C, 500 °C, and 600 °C, focusing on the thermal behavior and resultant product yields. At 600 °C, WS produced the highest oil yield (63.6 wt%), suggesting a tendency to generate more aqueous and volatile components. Conversely, WT alone showed an optimal oil yield of 46.4 wt% at 500 °C, while the WS-WT blend achieved 55.6 wt%. Gas chromatography-mass spectrometry (GC-MS) analyses of the pyrolytic oils indicated that WS-heavy mixtures were rich in aliphatic compounds, whereas WT-dominant samples had increased aromatic and phenolic contents, demonstrating the potential for creating valuable chemicals from waste. Additionally, gas analysis highlighted significant variations in syngas composition, with increased methane and decreased CO2 levels at higher temperatures, emphasizing the role of the water-gas shift reaction. These findings underscore the critical importance of temperature control in optimizing the efficiency and quality of products from co-pyrolysis, presenting a viable method for enhancing the value derived from waste materials.

Significant Relationship Between Brixia Score And The Degree Of Acute Respiratory Distress Syndrome In Covid 19 Patients

BACKGROUND: Chest X-ray has an important role in detecting early features of COVID-19. To improve risk stratification, a scoring system in chest x-ray called Brixia Score was developed. The Brixia score is designed to measure the severity of lung abnormalities in COVID-19, with an 18-point severity scale. Deaths in COVID-19 occur mainly due to Acute Respiratory Distress Syndrome (ARDS). ARDS is classified into mild, moderate, and severe degrees. If the degree can be predicted earlier, patients can receive earlier therapy and death rate can be reduced. AIMS: to analyze relationship between Brixia Score and degree of ARDS in COVID-19 patients. METHOD: the research used an observational analytic method with a cross-sectional approach to 95 subjects who are positive for COVID-19 and diagnosed with ARDS, in January to December 2021. Brixia Score data was collected based on chest X-ray expertise, ARDS degree was based on medical records and blood gas analysis. Analysis of relationship between Brixia score and degree of ARDS was carried out using the Kruskal-Wallis test. RESULT: There was a significant difference in Brixia score based on degree of ARDS (p value &lt;0.05). The highest Brixia score was obtained in severe ARDS, while the low Brixia score was obtained in mild ARDS. This proves that there is a relationship between Brixia score and degree of ARDS. CONCLUSION: Brixia score has a significant relationship to the degree of ARDS in COVID-19 patients.

Oxygen saturation recovery after 6-minute walk test in patients with idiopathic pulmonary fibrosis

BackgroundThe six-minute walk test (6MWT) is widely used to assess functional capacity and prognosis in patients with idiopathic pulmonary fibrosis (IPF). However, studies on oxygen saturation recovery after the 6MWT in patients with IPF are rare. In our study, we investigated the relationship between oxygen saturation recovery time and dyspnea, fatigue, quality of life, prognostic markers and pulmonary hypertension (PH).MethodsIn this cross-sectional study, IPF patients diagnosed according to current guidelines and followed up in our Interstitial Lung Disease Outpatient Clinic between 2021 and 2022 were included. Demographics, data from spirometry, diffusion capacity measurement, arterial blood gas analysis, transthoracic echocardiography and the 6MWT were recorded. The oxygen saturation recovery time, distance saturation product (DSP), gender-age-physiology (GAP) index and composite physiological index (CPI) scores were calculated. Dyspnea severity was assessed by the modified Medical Research Council (mMRC) and Dyspnoea-12 (D-12) scales, fatigue severity by the Multidimensional Fatigue Inventory (MFI-20) and quality of life by the St George’s Respiratory Questionnaire (SGRQ).ResultsFifty IPF patients (34 men, 16 women, age: 66.8 ± 7.3 years) were included in the study. The mean FVC was 77.8 ± 19.3%, the DLCO was 52.9 ± 17.1%, the 6-minute walk distance (6MWD) was 385.7 ± 90.6 m, the GAP index was 3.5 ± 1.5, and the CPI was 43.7 ± 14.1. Oxygen saturation after the 6MWT reached pretest values at an average of 135.6 ± 73.5 s. The oxygen saturation recovery time was longer in patients with higher GAP index scores (Rs = 0.870, p < 0.001), CPI scores (Rs = 0.906, p < 0.001), desaturation (Rs = 0.801, p < 0.001), FVC%/DLCO% (Rs = 0.432, p = 0.002), sPAP (Rs = 0.492, p = 0.001), TRV (Rs = 0.504, p = 0.001), mMRC (Rs = 0.913, p < 0.001), MFI-20 (Rs = 0.944, p < 0.001), D-12 scale (Rs = 0.915, p < 0.001) and SGRQ scores (Rs = 0.927, p < 0.001); lower FVC (%) (Rs=-0.627, p < 0.001), DLCO (%) (Rs=-0.892, p < 0.001), PaO2 (Rs=-0.779, p < 0.001), DSP (Rs=-0.835, p < 0.001), and 6MWD (Rs=-0.763, p < 0.001). A total of twenty patients (40%) exhibited an increased risk of PH. According to our multiple regression analysis, oxygen saturation recovery time was independently associated with the GAP index (p = 0.036), the lowest oxygen saturation occurring during the 6MWT (p = 0.011) and the SGRQ score (p < 0.001).ConclusionsOur results showed that oxygen saturation recovery time is associated with dyspnea, fatigue, quality of life, increased risk of PH and prognostic markers in IPF. Therefore, we recommend continuous measurement of oxygen saturation after 6MWT until pretest values are reached.