The risk of venous thromboembolism and blood hyperlactatemia is associated with increased mortality among critically ill patients with Covid-19.

INTRODUCTION: Coronavirus disease 2019 (Covid-19) following venous thromboembolism (VTE) and blood hyperlactatemia are associated with higher mortality. However, reliable biomarkers for this association remain to be elucidated. This study investigated the associations of VTE risk and blood hyperlactatemia with mortality among critically ill Covid-19 patients admitted to the intensive care unit (ICU). METHODS: In this single-centre retrospective study, we included 171 patients aged ≥18 years with confirmed Covid-19 admitted to the ICU at a tertiary healthcare clinic in the Eastern region of Saudi Arabia between 1 March 2020 and 31 January 2021. Patients were divided into two groups: survivor and non-survivor. The survivors have been identified as the patients discharged from the ICU alive. The VTE risk was defined using a Padua prediction score (PPS) >4. The blood lactate concentration (BLC) cut-off value >2 mmol/L was used to determine the blood hyperlactatemia. RESULTS: Multi-factor Cox analysis showed that PPS >4 and BLC >2 mmol/L were more likely to be significantly associated with higher odds of ICU mortality in critically ill Covid-19 patients (hazard ratio [HR] = 2.80, 95% confidence interval [CI] = 1.00-8.08, p = 0.050; HR = 3.87, 95% CI = 1.12-13.45, p = 0.033, respectively). The Area under the Curve for VTE and blood hyperlactatemia were 0.62 and 0.85, respectively. CONCLUSION: VTE risk and blood hyperlactatemia have been associated with a higher mortality risk in critically ill Covid-19 patients who are hospitalized in the ICU in Saudi Arabia. According to our findings, these people needed more effective VTE prevention strategies based on a personalized assessment of their risk of bleeding. Moreover, persons without diabetes and other groups with a high risk of dying from COVID-19 may be recognized by measuring glucose as having elevated glucose and lactate jointly.

Bioactive and Physico-Chemical Assessment of Innovative Poly(lactic acid)-Based Biocomposites Containing Sage, Coconut Oil, and Modified Nanoclay.

The bioactivity of the versatile biodegradable biopolymer poly(lactic acid) (PLA) can be obtained by combining it with natural or synthetic compounds. This paper deals with the preparation of bioactive formulations involving the melt processing of PLA loaded with a medicinal plant (sage) and an edible oil (coconut oil), together with an organomodifed montmorillonite nanoclay, and an assessment of the resulting structural, surface, morphological, mechanical, and biological properties of the biocomposites. By modulating the components, the prepared biocomposites show flexibility, both antioxidant and antimicrobial activity, as well as a high degree of cytocompatibility, being capable to induce the cell adherence and proliferation on their surface. Overall, the obtained results suggest that the developed PLA-based biocomposites could potentially be used as bioactive materials in medical applications.

Addressing Cognitive Biases in Interpreting an Elevated Lactate in a Patient with Type 1 Diabetes and Thiamine Deficiency.

We present the case of a young woman admitted for diabetic ketoacidosis with persistent, asymptomatic lactic acid (LA) elevation during the evolving COVID-19 pandemic. Cognitive biases in interpreting an elevated LA in this patient's care resulted in an extensive infectious workup instead of the low-cost and potentially diagnostic provision of empiric thiamine. We discuss clinical patterns and etiologies of LA elevation and the role of thiamine deficiency. We also address cognitive biases potentially affecting the interpretation of elevated lactate levels and provide guidance for clinicians to determine appropriate patients for empiric thiamine administration.

Multiple branch retinal artery occlusions following the new facial cosmetic filler (Poly-D, L-lactic Acid) injection a case report.

BACKGROUND: Poly-D, L-lactic acid is (PDLLA) a new cosmetic filler. We reported the first case of PDLLA-related devastating complication of multiple branch retinal artery occlusion (BRAO). CASE PRESENTATION: A 23-year-old female had sudden blindness after injection of PDLLA at the glabella. After emergency intraocular pressure-lowering medicine, ocular massage, steroid pulse therapy, heparin and alprostadil infusion, and subsequent treatments including acupuncture and 40 sessions of hyperbaric oxygen therapy, her best-corrected visual acuity improved from hand motion at 30 cm to 0.3 within 2 months. CONCLUSION: Although safety of PDLLA was evaluated in animal studies and in 16,000 human cases, it could still cause rare but devastating retinal artery occlusion as in the present case. Proper and immediate therapies could still improve patient's vision and scotoma. Surgeons should keep in mind the possibility of iatrogenic filler-related retinal artery occlusion.

Evaluation of Short-Term Mortality Prediction Using Initial Lactate and NEWS+L at Admission in COVID-19 Patients.

OBJECTIVE: To predict the short-term mortality of the serum lactate level and the National Early Warning Score + lactate (NEWS+L) at the time of first admission to the emergency department in COVID-19 patients. MATERIALS AND METHODS: This retrospective analysis was performed by screening the data of COVID-19 patients over a 6-month period (from January 15, 2021, to June 15, 2021). The demographic, comorbidities, vital parameters, and lactate values, as well as C- reactive protein (CRP), blood urea nitrogen (BUN), and 28-day mortality data were recorded. RESULTS: A total of 70 patients were included in our study. The median (25th - 75th percentile) age was 58 (47.3 - 73.5) years, and 33 (47.1%) patients were female. The mean lactate value was 1.6 (1.2 - 1.98) mmol/L, the mean NEWS was 6 (4-7.75), and the mean NEWS+L was 7.24 ± 2.54. Mortality occurred in 13 (18.2%) of the 70 patients at 28 days. Lactate, NEWS, and NEWS+L had no significant relationship with mortality. None of these parameters was able to predict mortality (P = 0.132, 0.670, and 0.994, respectively). CONCLUSION: Our findings showed that the NEWS+L, NEWS, and lactate level could not predict short-term mortality in COVID-19 patients at the time of first admission.

Blood lactate in mild and moderate ARDS secondary to SARS COV 2.

BACKGROUND AND OBJECTIVES: Elevated blood lactate levels are associated with poor outcome in several critical conditions. Patients with SARS-CoV-2 rarely develop hyperlactatemia. The purpose of this study is to evaluate the trend of lactatemia in patients affected by mild/moderate SARS-Co V-2-ARDS and if it affected prognosis. METHODS: We analyzed blood lactate levels in thirty-eight patients with severe SARS-CoV-2 infection admitted to COVID Care Unit of Santa Maria delle Grazie Hospital, Pozzuoli. RESULTS: Twenty patients survived and were discharged at home and 18 patients died. Despite severe hypoxia that affected all patients enrolled, T0 lactate was within normal values. All survivors showed a significant increase in lactate concentration the day prior to clinical improvement. In not-survivors levels of lactate did not increase significantly. CONCLUSION: In our study, patients who survive SARS CoV-2 ARDS have a fleeting increase in lactate, which precedes clinical improvement by one day.

Nanoparticle Formulation Composition Analysis by Liquid Chromatography on Reversed-Phase Monolithic Silica.

Multifunctional nanoparticle (NP) formulations for medical purposes have already found their way toward envisaged translation. A persistent challenge of those systems is, next to NP size analysis, the compositional analysis of the NPs with the polymer as the matrix component and the encapsulated drug, particularly in a quantitative manner. Herein, we report the formulation of poly(lactic-co-glycolic acid) (PLGA) NPs by nanoprecipitation and the analysis of their integrity and size by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Those NPs feature a variety of encapsulated drugs including the well-known ibuprofen (Ibu) as well as dexamethasone (Dex) and dexamethasone acetate (DexAce), with the latter being of potential interest for clinical treatment of SARS-CoV-2 patients. All those dissolved formulation compositions have been subjected to liquid chromatography on reversed-phase silica monolithic columns, allowing to quantitatively assess amounts of small molecule drug and NP constituting PLGA polymer in a single run. The chromatographically resolved hydrophobicity differences of the drugs correlated with their formulation loading and were clearly separated from the PLGA matrix polymer with high resolution. Our study identifies the viability of reversed-phase monolithic silica in the chromatography of both small drug molecules and particularly pharmapolymers in a repeatable and simultaneous fashion, and can provide a valuable strategy for analysis of diverse precursor polymer systems and drug components in multifunctional drug formulations.

Can lactate levels and lactate kinetics predict mortality in patients with COVID-19 with using qCSI scoring system?

INTRODUCTION: In this study, we aimed to investigate the relationship between blood lactate levels and lactate kinetics (lactate clearance and Δ lactate) for predicting mortality in patients with COVID-19 admitted to the emergency department. METHODS: This study was performed as a retrospective study that included patients admitted to the emergency department between March 1st, 2020, and January 1st, 2022. Lactate levels were recorded at the first admission (0 h lactate) and the highest blood lactate levels in the first 24 h of follow-up (2nd highest lactate). Lactate kinetics were calculated. Clinical severity was determined according to the quick COVID Severity Index (qCSI). RESULTS: 300 patients were included in the study. Lactate levels at admission were similar in groups with or without mortality, but 2nd highest lactate levels were found to be significantly higher in the group with mortality (p < 0.001). Lactate clearance and ∆ lactate levels were also found to be lower in the mortality group (p < 0.001). Lactate kinetics in patients in the clinically low severity group were lower in the mortality group (p = 0.02 and p = 0.039, respectively). In the low-intermediate and high-intermediate groups, 0-h lactate and 2nd highest lactate levels were found to be higher in the mortality group, and lactate kinetics were similar in the groups with and without mortality. In the group with high clinical severity, 2nd highest lactate levels were found to be higher in the group with mortality (p = 0.010). Lactate kinetics were also found to be significantly lower in the mortality group (p < 0.001). In the high qCSI group, based on ROC analysis, the AUC for 2nd highest lactate levels predicting mortality was 0.642 (95% CI: 0.548-0.728). The optimal cut-off value for mortality was greater than >2.4 mmol/L (60.6% sensitivity, 67.4% specificity). The AUC for lactate clearance was 0.748 (95% CI: 0.659-0.824). The lactate clearance cut-off value was ≤ -177.78% (49.3% sensitivity, 100% specificity). The AUC for ∆ lactate was 0.707 (95% CI: 0.616-0.787). The optimal ∆ lactate cut-off was ≤ -2 mmol/L (45.1% sensitivity, 93.5% specificity). CONCLUSION: In COVID-19, 2nd highest blood lactate and lactate kinetics were found to be prognostic indicators of the disease. High 2nd highest lactate levels and low lactate kinetics in patients with high clinical severity were guiding physicians regarding the outcome of the disease.

Risk stratification of patients with acute respiratory distress syndrome complicated with sepsis using lactate trajectories.

BACKGROUND: No consensus has been reached on an optimal blood lactate evaluation system although several approaches have been reported in the literature in recent years. A group-based trajectory modeling (GBTM) method could better stratify patients with acute respiratory distress syndrome (ARDS) complicated with sepsis in the intensive care unit (ICU). PATIENTS AND METHODS: 760 patients from the comprehensive ICU of Tianjin Medical University General Hospital with ARDS complicated with sepsis were eligible for analysis. Serial serum lactate levels were measured within 48 h of admission. In addition to the GBTM lactate groups, the initial lactate, peak lactate level, the area under the curve of serial lactate (lactate AUC), and lactate clearance were also considered for comparison. The short- and long-term outcomes were the 30- and 90-day mortality, respectively. RESULTS: Three lactate groups were identified based on GBTM, with group 3 exhibiting the worse short- [hazard ratio (HR) for 30-day mortality: 2.96, 95% confidence interval (CI) 1.79-4.87, P < 0.001] and long term (HR for 90-day mortality: 3.49, 95% CI 2.06-5.89, P < 0.001) outcomes followed by group 2 (HR for 30-day mortality: 2.05, 95% CI 1.48-2.84, P < 0.001 and HR for 90-day mortality: 1.99, 95% CI 1.48-2.67, P < 0.001). GBTM lactate groups exhibited significantly improved diagnostic performance of initial lactate + SOFA scores/APACHE II scores models. Based on the multivariable fractional polynomial interaction (MFPI) approach, GBTM lactate groups could better differentiate high-risk patients than the initial lactate groups in short- and long-term outcomes. CONCLUSIONS: To the best of our knowledge, this is the first report that GBTM-based serial blood lactate evaluations significantly improve the diagnostic capacity of traditional critical care evaluation systems and bring many advantages over previously documented lactate evaluation systems.

Association of the Transmembrane Serine Protease-2 (TMPRSS2) Polymorphisms with COVID-19.

SARS-CoV-2 uses the ACE2 receptor and the cellular protease TMPRSS2 for entry into target cells. The present study aimed to establish if the TMPRSS2 polymorphisms are associated with COVID-19 disease. The study included 609 patients with COVID-19 confirmed by RT-PCR test and 291 individuals negative for the SARS-CoV-2 infection confirmed by RT-PCR test and without antibodies anti-SARS-CoV-2. Four TMPRSS2 polymorphisms (rs12329760, rs2298659, rs456298, and rs462574) were determined using the 5'exonuclease TaqMan assays. Under different inheritance models, the rs2298659 (pcodominant2 = 0.018, precessive = 0.006, padditive = 0.019), rs456298 (pcodominant1 = 0.014, pcodominant2 = 0.004; pdominant = 0.009, precessive = 0.004, padditive = 0.0009), and rs462574 (pcodominant1 = 0.017, pcodominant2 = 0.004, pdominant = 0.041, precessive = 0.002, padditive = 0.003) polymorphisms were associated with high risk of developing COVID-19. Two risks (ATGC and GAAC) and two protectives (GAGC and GAGT) haplotypes were detected. High levels of lactic acid dehydrogenase (LDH) were observed in patients with the rs462574AA and rs456298TT genotypes (p = 0.005 and p = 0.020, respectively), whereas, high heart rate was present in patients with the rs462574AA genotype (p = 0.028). Our data suggest that the rs2298659, rs456298, and rs462574 polymorphisms independently and as haplotypes are associated with the risk of COVID-19. The rs456298 and rs462574 genotypes are related to high levels of LDH and heart rate.

Microfluidic preparation of antimicrobial microparticles composed of l-lactide/1,3-dioxolane (co)polymers loaded with quercetin.

The resistance of microorganisms against commonly used antibiotics is becoming an increasingly important problem in the food and pharmaceutical industries. Therefore, the development of novel bactericidal agents, as well as the design of drug delivery systems based on materials composed of biocompatible and biodegradable building blocks, has attracted increasing attention. To address this challenge, microparticles composed of l-lactide homopolymer and l-lactide/1,3-dioxolane (co)polymers loaded with quercetin (Q) were fabricated by using a microfluidic technique. This method enables the preparation of homogeneous particles with sizes ranging from 60 to 80 µm, composed of degradable semicrystalline or amorphous (co)polyesters. The microencapsulation of Q in a (co)polymeric matrix enables prolonged release of the antimicrobial agent. The antibacterial properties of the obtained biocompatible microparticles are confirmed by the agar diffusion plate method for various bacterial strains. Therefore, Q-loaded microparticles can have important applications in food preservation as a novel antimicrobial system.

Effects of Dryland Training During the COVID-19 Lockdown Period on Swimming Performance.

PURPOSE: To examine the effect of dryland training during an 11-week lockdown period due to COVID-19 on swimming performance. METHODS: Twelve competitive swimmers performed 50- and 300-m maximum-effort tests in their preferred stroke and 200-, 400-, and four 50-m front crawl sprints (4 × 50 m) before and after the lockdown period. Critical speed as an index of aerobic endurance was calculated using (1) 50-, 300-, and (2) 200-, 400-m tests. Blood lactate concentration was measured after the 400- and 4 × 50-m tests. To evaluate strength-related abilities, the dryland tests included handgrip and shoulder isometric strength. Tethered swimming force was measured during a 10-second sprint. During the lockdown period, dryland training was applied, and the session rating of perceived exertion training (sRPE) load was recorded daily. RESULTS: sRPE training load during the lockdown was decreased by 78% (16%), and critical speed was reduced 4.7% to 4.9% compared to prelockdown period (P < .05). Performance time in 200, 300, and 400 m deteriorated 2.6% to 3.9% (P < .05), while it remained unaltered in 4 × 50- and 50-m tests (P > .05). Tethered force increased 9% (10%) (P < .01), but handgrip and shoulder isometric force remained unaltered (P > .05). Blood lactate concentration decreased 19% (21%) after the 400-m test and was unchanged following the 4 × 50-m tests (P > .05). CONCLUSIONS: Performance deterioration in the 200, 300, and 400 m indicates reduced aerobic fitness and impaired technical ability, while strength and repeated-sprint ability were maintained. When a long abstention from swimming training is forced, dryland training may facilitate preservation in short-distance but not middle-distance swimming performance.

The Lactate and the Lactate Dehydrogenase in Inflammatory Diseases and Major Risk Factors in COVID-19 Patients.

Lactate dehydrogenase (LDH) is a terminating enzyme in the metabolic pathway of anaerobic glycolysis with end product of lactate from glucose. The lactate formation is crucial in the metabolism of glucose when oxygen is in inadequate supply. Lactate can also be formed and utilised by different cell types under fully aerobic conditions. Blood LDH is the marker enzyme, which predicts mortality in many conditions such as ARDS, serious COVID-19 and cancer patients. Lactate plays a critical role in normal physiology of humans including an energy source, a signaling molecule and a pH regulator. Depending on the pH, lactate exists as the protonated acidic form (lactic acid) at low pH or as sodium salt (sodium lactate) at basic pH. Lactate can affect the immune system and act as a signaling molecule, which can provide a "danger" signal for life. Several reports provide evidence that the serum lactate represents a chemical marker of severity of disease similar to LDH under inflammatory conditions. Since the mortality rate is much higher among COVID-19 patients, associated with high serum LDH, this article is aimed to review the LDH as a therapeutic target and lactate as potential marker for monitoring treatment response of inflammatory diseases. Finally, the review summarises various LDH inhibitors, which offer potential applications as therapeutic agents for inflammatory diseases, associated with high blood LDH. Both blood LDH and blood lactate are suggested as risk factors for the mortality of patients in serious inflammatory diseases.

The role of lactate in sepsis and COVID-19: Perspective from contracting skeletal muscle metabolism.

NEW FINDINGS: What is the topic of this review? Lactate is considered an important substrate for mitochondria in the muscles, heart and brain during exercise and is the main gluconeogenetic precursor in the liver and kidneys. In this light, we review the (patho)physiology of lactate metabolism in sepsis and coronavirus disease 2019 (COVID-19). What advances does it highlight? Elevated blood lactate is strongly associated with mortality in septic patients. Lactate seems unrelated to tissue hypoxia but is likely to reflect mitochondrial dysfunction and high adrenergic stimulation. Patients with severe COVID-19 exhibit near-normal blood lactate, indicating preserved mitochondrial function, despite a systemic hyperinflammatory state similar to sepsis. ABSTRACT: In critically ill patients, elevated plasma lactate is often interpreted as a sign of organ hypoperfusion and/or tissue hypoxia. This view on lactate is likely to have been influenced by the pioneering exercise physiologists around 1920. August Krogh identified an oxygen deficit at the onset of exercise that was later related to an oxygen 'debt' and lactate accumulation by A. V. Hill. Lactate is considered to be the main gluconeogenetic precursor in the liver and kidneys during submaximal exercise, but hepatic elimination is attenuated by splanchnic vasoconstriction during high-intensity exercise, causing an exponential increase in blood lactate. With the development of stable isotope tracers, lactate has become established as an important energy source for muscle, brain and heart tissue, where it is used for mitochondrial respiration. Plasma lactate > 4 mM is strongly associated with mortality in septic shock, with no direct link between lactate release and tissue hypoxia. Herein, we provide evidence for mitochondrial dysfunction and adrenergic stimulation as explanations for the sepsis-induced hyperlactataemia. Despite profound hypoxaemia and intense work of breathing, patients with severe coronavirus disease 2019 (COVID-19) rarely exhibit hyperlactataemia (> 2.5 mM), while presenting a systemic hyperinflammatory state much like sepsis. However, lactate dehydrogenase, which controls the formation of lactate, is markedly elevated in plasma and strongly associated with mortality in severe COVID-19. We briefly review the potential mechanisms of the lactate dehydrogenase elevation in COVID-19 and its relationship to lactate metabolism based on mechanisms established in contracting skeletal muscle and the acute respiratory distress syndrome.

Low molecular weight heparin reduces arterial blood lactic acid content and increases estimated glomerular filtration rate in patients with moderate Covid-19 pneumonia.

BACKGROUND: Coronavirus disease 2019 (Covid-19) remains a serious health threat worldwide. We aimed to investigate whether low molecular weight heparin (LMWH) can promote organ function recovery in moderate Covid-19 pneumonia patients. METHODS: We initiated an LMWH protocol in Covid-19 patients with increased D-dimer, body mass index >30 kg/m2 or a history of diabetes from January 18, 2020 at Shanghai Public Health Clinical Center. In this retrospective study, we assigned moderate Covid- 19 pneumonia patients admitted between January 18th and April 18, 2020 receiving the LMWH protocol to the LMWH group. Moderate patients who met the inclusion criteria but did not receive LMWH protocol were included in the control group by 1:2 propensity score matching. General clinical information, indicators for renal function, arterial blood gas analyses, arterial blood lactic acid content (mmol/L), and coagulation indexes at 0 day, 3 days, 7 days, and 11 days after admission were recorded and compared between the two groups. RESULTS: There were 41 patients in the LMWH group and 82 patients in the control group. General information in both groups were similar. Compared to the control group, the arterial blood lactic acid content (mmol/L) at day 11 (1.3 [1.1, 1.7] vs. 1.2 [0.9, 1.3], P = 0.016) was reduced in the LMWH group. The estimated glomerular filtration rate (eGFR) in the LMWH group was higher than that in the control group at day 7 (108.54 [89.11, 128.17] vs. 116.85 [103.39, 133.47], P = 0.039) and day 11 (113.74 [94.49, 126.34] vs. 128.31 [112.75, 144, 12], P  = 0.003). The serum creatinine levels (Scr) in the LMWH group were lower than that in the control group at day 7 (62.13 [51.47, 77.64] vs. 55.49 [49.50, 65.75], P = 0.038) and day 11 (63.35 [50.17, 75.73] vs. 51.62 [44.62, 61.24], P = 0.005). CONCLUSIONS: LMWH treatment can reduce arterial blood lactic acid levels and improve eGFR in moderate Covid-19 pneumonia patients. Randomized controlled trials are warranted to further investigate this issue. TRIAL REGISTRATION: ChiCTR.org.cn, ChiCTR2000034796.

Assessing the Prognostic Value of Crp/Albumin Ratio and Lactate/Albumin Ratio in Critically Ill Patients.

The ability to predict the fate of critically ill patients admitted to an intensive care unit is very important, as there are only few studies which have focused on this aspect. Our study has focused to determine the relationship between C-Reactive protein/Albumin ratio (CAR) and Lactate/Albumin ratio (LAR) and Intensive care unit stay, the requirement for vasopressor and mechanical ventilator support, recovery and mortality in the patients admitted to critical care unit. MATERIAL: The study group comprised of 100 patients who were admitted to critical care unit. These patients were evaluated using a structured proforma, detailed case history and clinical examination. Blood sample collection was done after obtaining valid consent from the subjects immediately after admission and serum Albumin, Lactate and C- reactive protein levels were estimated in these patients. OBSERVATION: The mean age of the patients in our study was 54.05.Out of the total patients admitted 74% of the patients were males. The common diagnosis was COVID bronchopneumonia (12%). 75% cases were seen having Glasgow Coma scale 15. 88% cases required FIO2 less than 50%. Based on Youden's index, LAR of 0.84 is the ideal cut off with 76.9% sensitivity and 83.8% specificity. Similarly for CAR, the ideal cut off is 88.2 with 84.6% sensitivity and 98.6% specificity. LAR and CAR values greater than 0.84 and 88.2 respectively were considered to be higher values. The patients with high LAR and high CAR values either had increased risk of mortality or increased duration of stay in the hospital (p=0.0001). Patients with low Albumin level and high CRP required Ventilator support which was statistically significant. Patients who needed inotropic support and mechanical ventilator support had higher CAR (P=0.001). Patients who received inotrope support had higher ESR and CRP levels. CONCLUSION: CAR and LAR are better indicators of mortality and duration of stay in the intensive care unit as the patients with higher values of these ratios were found to have increased risk of mortality. However CAR was found to be a better indicator of mortality than LAR and it was also noted that the patients who required inotropes and mechanical ventilator support were found to have higher CAR.

Laminar flow ventilation system to prevent airborne infection during exercise in the COVID-19 crisis: A single-center observational study.

Particulate generation occurs during exercise-induced exhalation, and research on this topic is scarce. Moreover, infection-control measures are inadequately implemented to avoid particulate generation. A laminar airflow ventilation system (LFVS) was developed to remove respiratory droplets released during treadmill exercise. This study aimed to investigate the relationship between the number of aerosols during training on a treadmill and exercise intensity and to elucidate the effect of the LFVS on aerosol removal during anaerobic exercise. In this single-center observational study, the exercise tests were performed on a treadmill at Running Science Lab in Japan on 20 healthy subjects (age: 29±12 years, men: 80%). The subjects had a broad spectrum of aerobic capacities and fitness levels, including athletes, and had no comorbidities. All of them received no medication. The exercise intensity was increased by 1-km/h increments until the heart rate reached 85% of the expected maximum rate and then maintained for 10 min. The first 10 subjects were analyzed to examine whether exercise increased the concentration of airborne particulates in the exhaled air. For the remaining 10 subjects, the LFVS was activated during constant-load exercise to compare the number of respiratory droplets before and after LFVS use. During exercise, a steady amount of particulates before the lactate threshold (LT) was followed by a significant and gradual increase in respiratory droplets after the LT, particularly during anaerobic exercise. Furthermore, respiratory droplets ≥0.3 µm significantly decreased after using LFVS (2120800±759700 vs. 560 ± 170, p<0.001). The amount of respiratory droplets significantly increased after LT. The LFVS enabled a significant decrease in respiratory droplets during anaerobic exercise in healthy subjects. This study's findings will aid in exercising safely during this pandemic.

Cardiovascular Dysfunction in COVID-19: Association Between Endothelial Cell Injury and Lactate.

Coronavirus disease 2019 (COVID-19), an infectious respiratory disease propagated by a new virus known as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has resulted in global healthcare crises. Emerging evidence from patients with COVID-19 suggests that endothelial cell damage plays a central role in COVID-19 pathogenesis and could be a major contributor to the severity and mortality of COVID-19. Like other infectious diseases, the pathogenesis of COVID-19 is closely associated with metabolic processes. Lactate, a potential biomarker in COVID-19, has recently been shown to mediate endothelial barrier dysfunction. In this review, we provide an overview of cardiovascular injuries and metabolic alterations caused by SARS-CoV-2 infection. We also propose that lactate plays a potential role in COVID-19-driven endothelial cell injury.

Extracorporeal membrane oxygenation for severe COVID-19-associated acute respiratory distress syndrome in Poland: a multicenter cohort study.

BACKGROUND: In Poland, the clinical characteristics and outcomes of patients with COVID-19 requiring extracorporeal membrane oxygenation (ECMO) remain unknown. This study aimed to answer these unknowns by analyzing data collected from high-volume ECMO centers willing to participate in this project. METHODS: This retrospective, multicenter cohort study was completed between March 1, 2020, and May 31, 2021 (15 months). Data from all patients treated with ECMO for COVID-19 were analyzed. Pre-ECMO laboratory and treatment data were compared between non-survivors and survivors. Independent predictors for death in the intensive care unit (ICU) were identified. RESULTS: There were 171 patients admitted to participating centers requiring ECMO for refractory hypoxemia due to COVID-19 during the defined time period. A total of 158 patients (mean age: 46.3 ± 9.8 years) were analyzed, and 13 patients were still requiring ECMO at the end of the observation period. Most patients (88%) were treated after October 1, 2020, 77.8% were transferred to ECMO centers from another facility, and 31% were transferred on extracorporeal life support. The mean duration of ECMO therapy was 18.0 ± 13.5 days. The crude ICU mortality rate was 74.1%. In the group of 41 survivors, 37 patients were successfully weaned from ECMO support and four patients underwent a successful lung transplant. In-hospital death was independently associated with pre-ECMO lactate level (OR 2.10 per 1 mmol/L, p = 0.017) and BMI (OR 1.47 per 5 kg/m2, p = 0.050). CONCLUSIONS: The ICU mortality rate among patients requiring ECMO for COVID-19 in Poland was high. In-hospital death was independently associated with increased pre-ECMO lactate levels and BMI.

Are we aware of COVID-19-related acute kidney injury in intensive care units?

OBJECTIVE: Coronavirus disease-19 (COVID-19) primarily affects the respiratory system. In some cases, the heart, kidney, liver, circulatory system, and nervous system are also affected. COVID-19-related acute kidney injury (AKI) occurs in more than 20% of hospitalized patients and more than 50% of patients in the intensive care unit (ICU). In this study, we aimed to review the prevalence of COVID-19-related acute kidney injury, risk factors, hospital and ICU length of stay, the need for renal replacement therapy. We also examined the effect of AKI on mortality in patients in the ICU that we treated during a 1-year period. PATIENTS AND METHODS: The files of patients with COVID-19 (n=220) who were treated in our ICU between March 21st, 2020, and June 1st, 2021, were analyzed retrospectively. Demographic data of the patients, laboratory data, and treatments were examined. Patients were divided into two groups, group I patients without AKI and, group II patients with AKI. The patients with AKI were evaluated according to the theKidney Disease Improving Global Outcomes (KDIGO) classification and were graded. RESULTS: Of the 220 patients included in the study, 89 were female and 131 were male. The mean age of patients with AKI (70.92±11.28 years) was statistically significantly higher than among those without AKI (58.87±13.63 years) (p<0.001). In patients with AKI, ICU length of stay, Acute Physiology and Chronic Health Evaluation (APACHE) II scores, initial lactate levels, need for mechanical ventilation, duration of mechanical ventilation, and secondary infection rates were found to be statistically significantly higher. Discharge rates from the ICU in patients without AKI were statistically higher (75.3% vs. 26.6%), and mortality rates were significantly higher in patients with AKI (67.8% vs. 14.3%). CONCLUSIONS: Various studies conducted have shown that patients with COVID-19 are at risk for AKI, and this is closely related to age, sex, and disease severity. The presence of AKI in patients with COVID-19 increases mortality, and this is more evident in patients hospitalized in the ICU. In our study, the prevalence of AKI was higher in older patients with high APACHE II scores and initial lactate levels. Comorbidities such as hypertension, chronic kidney disease, and coronary artery disease in patients with AKI were higher than in those without AKI.