Blood Lactate Levels Research Articles

Utility of Lactate to Bilirubin Index in Predicting Short-Term Mortality in Acute on Chronic Liver Failure: A Single Centered Study

Introduction: Most of the lactate in the body is cleared in the liver. Tissue hypoxia results in increased production of lactate and decreased utility of it. Hepatic insult results not only an increase in the blood lactate levels but also is an independent prognostic marker in critically ill cirrhotic patients. Alteration of liver function is indicated by rise in serum bilirubin. The aim of this study was to therefore to assess the utility of blood lactate to Bilirubin index (LBi) in predicting mortality in patients with acute on chronic liver failure (ACLF).
 Methods: This prospective observational study was conducted from January 2019 to June 2021 at the Department of Hepatogastroenterology, Sindh Institute of Urology and Transplantation. Patients aged > 12 years and presenting ACLF were included and their baseline characteristics were recorded. Primary outcome was observed in terms of 30-days mortality and secondary outcome was six months mortality. These indices were then used to calculate the lactate to bilirubin index (LBi) as [1000 × lactate (mmol/L) × bilirubin (µmol/L)]/2. Area under Receiver operating curves (AUROC) for LBi, Child Turcotte Pugh score(CTP) and Model for End-stage Liver Disease score (MELD) were obtained in predicting both 30 days and six months mortality and at an optimal cutoff sensitivity, specificity and diagnostic accuracy for these scores were calculated.
 Results: A total number 159 patients with ACLF were included in the study. Most of the patients were young with mean age of 35.1 ±16.8 years. Males were 97(61%). Hepatitis C was the most common cause of chronic liver disease followed by hepatitis B and autoimmune hepatitis seen in 41 (25.8%), 39(24.5%) and 36 (22.6%) respectively. Hepatitis E was the most common cause of acute injury noted in 60 (37.7%) patients. The baseline characteristics showed mean serum lactate levels of 0.93±1.33 mmol/L, bilirubin levels of 258.5 ± 155.3 µmol/L, CTP score of 10.7 ± 1.8 and MELD score of 26 ±7.6. Out of 159 patients, 26 (16.4%) patients died within 30 days due to ACLF related complicaitons while 133 (83.6%) were discharged. AUROC obtained for LBi, CTP score and MELD score in predicting 30-day mortality in ACLF was 0.98, 0.79 and 0.78 respectively. A cut off of ≥11.8 for LBi Index, ≥30 for MELD score and ≥13 for CTP score were significantly associated with increased risk of 30-day mortality in ACLF patients in our population. However, the sensitivity, specificity, PPV, NPV and diagnostic accuracy of LBi in predicting 30-day mortality was significantly higher than that of CTP and MELD score. The diagnostic accuracy of LBi in predicting 30 days mortality was 87.5%. Similarly, AUROC obtained for LBi, CTP score and MELD score in predicting 6-month mortality in ACLF was 0.89, 0.72 and 0.66 respectively and the diagnostic accuracy of LBi dropped down to 76.6% with a sensitivity of 49.28%, specificity of 97.28%, PPV of 94.4% and NPV of 71.54%. 
 Conclusion: Our results showed that LBi score of >11.8 had an excellent sensitivity and specificity in predicting mortality in ACLF with an excellent diagnostic accuracy in predicting one month mortality as compared to the other scores. However, its utility in predicting long term mortality is yet to be proven. Further studies are needed to validate this index.

Combined Therapeutic Plasma Exchange and Continuous Renal Replacement Therapy in Children With Dengue-Associated Acute Liver Failure and Shock Syndrome: Single-Center Cohort From Vietnam.

Pediatric acute liver failure (PALF) is a fatal complication in patients with severe dengue. To date, clinical data on the combination of therapeutic plasma exchange (TPE) and continuous renal replacement therapy (CRRT) for managing dengue-associated PALF concomitant with shock syndrome are limited. Retrospective cohort study (January 2013 to June 2022). Thirty-four children. PICU of tertiary Children's Hospital No. 2 in Vietnam. We assessed a before-versus-after practice change at our center of using combined TPE and CRRT (2018 to 2022) versus CRRT alone (2013 to 2017) in managing children with dengue-associated acute liver failure and shock syndrome. Clinical and laboratory data were reviewed from PICU admission, before and 24 h after CRRT and TPE treatments. The main study outcomes were 28-day in-hospital mortality, hemodynamics, clinical hepatoencephalopathy, and liver function normalization. A total of 34 children with a median age of 10 years (interquartile range: 7-11 yr) underwent standard-volume TPE and/or CRRT treatments. Combined TPE and CRRT ( n = 19), versus CRRT alone ( n = 15), was associated with lower proportion of mortality 7 of 19 (37%) versus 13 of 15 (87%), difference 50% (95% CI, 22-78; p < 0.01). Use of combined TPE and CRRT was associated with substantial advancements in clinical hepatoencephalopathy, liver transaminases, coagulation profiles, and blood lactate and ammonia levels (all p values < 0.001). In our experience of children with dengue-associated PALF and shock syndrome, combined use of TPE and CRRT, versus CRRT alone, is associated with better outcomes. Such combination intervention was associated with normalization of liver function, neurological status, and biochemistry. In our center we continue to use combined TPE and CRRT rather than CRRT alone.

In vivo toxicity evaluation of a polyoxotungstate nanocluster as a promising contrast agent for computed tomography

In this study, we demonstrate for the first time, that a discrete metal-oxo cluster α-/β-K6P2W18O62 (WD-POM) exhibits superior performance as a computed tomography (CT) contrast agent, in comparison to the standard contrast agent iohexol. A toxicity evaluation of WD-POM was performed according to standard toxicological protocols using Wistar albino rats. The maximum tolerable dose (MTD) of 2000 mg/kg was initially determined after oral WD-POM application. The acute intravenous toxicity of single WD-POM doses (1/3, 1/5, and 1/10 MTD), which are at least fifty times higher than the typically used dose (0.015 mmol W kg−1) of tungsten-based contrast agents, was evaluated for 14 days. The results of arterial blood gas analysis, CO-oximetry status, electrolyte and lactate levels for 1/10 MTD group (80% survival rate) indicated the mixed respiratory and metabolic acidosis. The highest deposition of WD-POM (0.6 ppm tungsten) was found in the kidney, followed by liver (0.15 ppm tungsten), for which the histological analysis revealed morphological irregularities, although the renal function parameters (creatinine and BUN levels) were within the physiological range. This study is the first and important step in evaluating side effects of polyoxometalate nanoclusters, which in recent years have shown a large potential as therapeutics and contrast agents.

Landing Posture in Elite Female Athletes During a Drop Vertical Jump Before and After a High-Intensity Ergometer Fatigue Protocol: A Study of 20 Japanese Women’s Soccer League Players

Background: Even elite athletes, who usually show stable postural control, sometimes cannot control their posture after high-load training. This instability may contribute to anterior cruciate ligament injury. Purpose/Hypothesis: The purpose of this study was to evaluate the landing posture of elite female soccer players before and after a novel high-intensity fatigue-inducing exercise protocol. We hypothesized that the landing posture will change before versus after the fatigue protocol. Study Design: Descriptive laboratory study. Method: The study participants were 20 female elite soccer players. All athletes performed 3 drop vertical jumps (DVJs), pedaled an ergometer 8 times with full force for 10 seconds each (fatigue protocol), and then repeated the 3 DVJs. We measured and compared the athletes’ blood lactate levels before and after the fatigue protocol, as well as the hip flexion, knee flexion, and ankle dorsiflexion angles and final landing posture during the DJVs. Results: Blood lactate levels increased significantly pre- to postprotocol (from 2.7 ± 1.9 to 15.0 ± 3.6 mmol/L; P &lt; .001), while there were decreases in hip flexion angle (from 35.0° ± 11.2° to 22.4° ± 8.8°; P &lt; .001) and ankle dorsiflexion angle (from 26.4° ± 3.9° to 20.0° ± 3.7°; P &lt; .001). The number of athletes who could not maintain a stable DVJ final landing posture increased from 10% before the fatigue protocol to 70% after. Conclusion: The elite female athletes in our study showed significant decreases in hip flexion and ankle dorsiflexion angles in the DVJ landing after a fatigue-inducing protocol. Most elite athletes were unable to maintain a stable posture on the DVJ landing after the fatigue protocol. Clinical Relevance: This study advances our understanding of how elite athletes land in a fatigued state.

Effect of number of college baseball pitching on movement, performance, physical strength, physiological, and psychological functions of pitchers

This study aimed to examine the effects of college baseball pitching on movement, performance, physical strength, and physiological and psychological functions of pitchers. The participants were 10 right-handed male pitchers from the University baseball team. The number of pitches were 15 per inning and 135 per nine innings. Ball speed and accuracy were measured for each pitching. The grip strength, back muscle strength, and standing long jump were measured before and after all pitches. Blood lactate levels were measured before pitching, at the end of the 5th and 7th innings, and at 3rd, 6th, and 9th minutes after pitching. The participant’s heart rate and subjective exercise intensity were measured at the beginning and end of each inning using the Borg scale measurement. Five high-speed cameras were used to capture the pitching motions. The displacement of the center of gravity, lower and upper limb joint angles, and the speed of each segment were calculated. The baseball speed and accuracy did not change with the increased number of pitches. However, the grip strength decreased. Although blood lactate and heart rate were not altered, subjective exercise intensity was increased. The lower limb kinematics remained unchanged; however, elbow height was reduced in the upper limb. These results suggest that highly competitive pitchers experience subjective fatigue with the increased number of pitches, however, they maintain pitch performance, speed, and accuracy without altering whole-body physiology and lower-body function and form.

HEALTH ASSESSMENT OF PAINTED TURTLES (CHRYSEMYS PICTA) IN A RESTORED WETLAND HABITAT IN NORTHWESTERN INDIANA, USA.

Freshwater turtles are sensitive to environmental changes and can serve as sentinel species for ecosystem health assessments. The Efroymson Restoration at Kankakee Sands in northwestern Indiana, USA has been restored in the past 25 yr from primarily agricultural land to a mosaic of prairie and wetland habitats. Health assessments of 40 free-ranging painted turtles (Chrysemys picta) at Kankakee Sands were performed in May 2021 to evaluate overall health status, screen for infectious diseases, and obtain baseline clinical pathology values in this population. Assessment of each turtle included a physical examination, complete blood count, plasma biochemistry panel, blood lactate level, venous blood gas analysis, serum trace mineral panel, serum vitamin D3 level, and plasma protein electrophoresis. Oral and cloacal swabs were tested for adenoviruses, herpesviruses, frog virus 3, and Mycoplasmopsis species by PCR in 39 painted turtles. Four turtles were positive for adenovirus, which shared 100% homology to Sulawesi tortoise adenovirus. Two turtles were herpesvirus-positive with 100% homology to emydid herpesvirus 1. No Mycoplasmopsis spp. or frog virus 3 was detected. Female turtles had significantly higher manganese, prealbumin, uric acid, triglycerides, and ionized calcium levels, while male turtles had significantly higher cholesterol, glutamate dehydrogenase, and CO2 levels. These baseline data can be used for future research into freshwater turtle health in restored wetland habitats.

Toxic copper level increases erythrocyte glycolytic rate, glutathione production and alters electrolyte balance in male Wistar rats

BackgroundCopper is a micronutrient vital to several cellular energy metabolic processes and drives erythropoiesis. However, it disrupts cellular biological activities and causes oxidative damage when in excess of cellular needs. This study investigated the effects of copper toxicity on erythrocyte energy metabolism in male Wistar rats. MethodsTen Wistar rats (150–170 g) were randomly divided into 2 groups: control (given 0.1 ml distilled water) and copper toxic (given 100 mg/kg copper sulphate). Rats were orally treated for 30 days. Blood, collected retro-orbitally after sodium thiopentone anaesthesia (50 mg/kg i.p.) into fluoride oxalate and EDTA bottles, was subjected to blood lactate assay and extraction of red blood cell respectively. Red blood cell nitric oxide (RBC NO), glutathione (RBC GSH), adenosine triphosphate (RBC ATP) levels, RBC hexokinase, glucose-6-phosphate (RBC G6P), glucose-6-phosphate dehydrogenase (RBC G6PDH), and lactate dehydrogenase (RBC LDH) activity was estimated spectrophotometrically. Values (Mean±SEM, n = 5) were compared by Student’s unpaired T-test at p < 0.05. Results and conclusionCopper toxicity significantly increased RBC hexokinase (23.41 ± 2.80 µM), G6P (0.48 ± 0.03 µM), G6PDH (71.03 ± 4.76nmol/min/ml) activities, ATP (624.70 ± 57.36 µmol/gHb) and GSH (3.08 ± 0.37 µM) level compared to control (15.28 ± 1.37 µM, 0.35 ± 0.02 µM, 330.30 ± 49.58 µmol/gHb, 54.41 ± 3.01nmol/min/ml and 2.05 ± 0.14 µM respectively, p < 0.05). Also, RBC LDH activity (145.00 ± 19.88mU/ml), NO (3.45 ± 0.25 µM) and blood lactate (31.64 ± 0.91 mg/dl) level were lowered significantly compared to control (467.90 ± 94.23mU/ml, 4.48 ± 0.18 µM and 36.12 ± 1.06 mg/dl respectively). This study shows that copper toxicity increases erythrocyte glycolytic rate and glutathione production. This increase could be connected to a compensatory mechanism for cellular hypoxia and increased free radical generation.

Relationship between the postoperative lactate dynamic levels, the acute gastrointestinal injury and the prognosis among patients who undergo surgical treatment for acute type A aortic dissection

IntroductionThis study aimed to determine the relationship between the postoperative lactate dynamic levels, the postoperative acute gastrointestinal injury (AGI), and the prognosis among the patients who underwent surgical treatment for an acute Stanford type-A aortic dissection (aTAAD). MethodsA total of 271 aTAAD patients were recruited and monitored. Of the 271 aTAAD patients, 29.2% developed an AGI and were designated as the AGI group (n = 79); the other patients (n = 192) were designated as the non-AGI group. According to the 2-year follow up, the aTAAD patients were also divided into the alive and death subgroups for further analysis. ResultsBinary logistic regression analysis revealed that the postoperative 4-h lactate (P4L) level, time-to-return to the normal blood lactate level (TRNL), postoperative 16-h lactate (P16L) level, and neutrophil granulocyte (NEU) count had a good predictive value for an AGI after aTAAD. The 8-week and 2-year mortality rates were higher in the AGI group than the non-AGI group (P < 0.05). Basic data and clinical characteristics were significantly different between the alive and death groups (P < 0.05). A higher AGI rate and mortality occurred in the P4L level ≥10.15 mmol/L subgroup, TRNL ≥21-h subgroup, P16L level ≥2.95 mmol/L subgroup, NEU count ≥10.9 × 109/L subgroup, PaO2 < 77.7 mmHg subgroup, WBC count ≥9.58 × 109/L subgroup, and the operative time ≥427 min subgroup than the corresponding comparison subgroups (P < 0.05). The postoperative 0-h lactate (P0L) level, TRNL, postoperative 24-h lactate (P24L) level, D-dimer level, fibrinogen degradation products (FDP) level, duration of mechanical ventilation, and length of hospitalization were independent factors influencing the 30-day mortality rate in patients who underwent surgery for an aTAAD (P < 0.05). Cox regression multivariate analysis after univariate analysis of all-cause mortality showed the TRNL, postoperative 12-h lactate (P12L) level, P16L level, P24L level, D-dimer level, FDP level, and length of hospitalization were independently associated with the 2-year mortality rate in patients who underwent surgery for an aTAAD (P < 0.05). ConclusionThe postoperative lactate changes and TRNL effectively predicted postoperative AGI and the mortality rate in patients with who underwent surgery for an aTAAD. The TRNL and P24L level were independent risk factors for the 30-day and 2-year mortality rates in patients who underwent surgery for an aTAAD.

Exercise precision medicine for type 2 diabetes: Targeted benefit or risk?

Concurrent exercise and metformin administration may reduce the acute and chronic effects of exercise on glucose metabolism in the patients with type 2 diabetes (T2D). However, several studies suggest that combing metformin and exercise treatment may have neither additive effect nor even cause adverse effects in T2D patients. This case report aimed to highlight the challenges associated with prescribing exercise to type 2 diabetes patients undergoing metformin treatment. A 67-years old woman was followed-up for five months, including assessment of the acute and chronic glucose and lactate metabolism induced by concomitant exercise and metformin. The findings were four-fold: 1) During a high-intensity interval training bout, blood glucose systematically decreased, while blood lactate concentrations fluctuated randomly; 2) Basal blood lactate levels were well above 2 mmol/L on days with medication only; 3) Combined exercise and metformin administration induced additive effects on the normalization of glucose and 4) high levels of physical activity had a positive impact on the continuous glucose fluctuations, while decreased levels of physical activity induced a large fluctuation of glucose due to home confinement of an infectious disease caused by the SARS-CoV-2 virus. Our findings showed that when combined with exercise and metformin treatment for T2D patients, exercise may contribute to improving glycemic control while metformin may elevate lactate levels in the long term. The observed results underline the need to prescribe exercise and monitor lactate levels for reducing possible risks associated with metformin treatment and reinforce the importance of tailoring exercise therapy.

Insufficient oxygen inhalation during cardiopulmonary resuscitation induces early changes in hemodynamics followed by late and unfavorable systemic responses in post-cardiac arrest rats.

Cardiac arrest (CA) and concomitant post-CA syndrome lead to a lethal condition characterized by systemic ischemia-reperfusion injury. Oxygen (O2 ) supply during cardiopulmonary resuscitation (CPR) is the key to success in resuscitation, but sustained hyperoxia can produce toxic effects post CA. However, only few studies have investigated the optimal duration and dosage of O2 administration. Herein, we aimed to determine whether high concentrations of O2 at resuscitation are beneficial or harmful. After rats were resuscitated from the 10-min asphyxia, mechanical ventilation was restarted at an FIO2 of 1.0 or 0.3. From 10 min after initiating CPR, FIO2 of both groups were maintained at 0.3. Bio-physiological parameters including O2 consumption (VO2 ) and mRNA gene expression in multiple organs were evaluated. The FIO2 0.3 group decreased VO2 , delayed the time required to achieve peak MAP, lowered ejection fraction (75.1 ± 3.3% and 59.0 ± 5.7% with FIO2 1.0 and 0.3, respectively; p < .05), and increased blood lactate levels (4.9 ± 0.2 mmol/L and 5.6 ± 0.2 mmol/L, respectively; p < .05) at 10 min after CPR. FIO2 0.3 group had significant increases in hypoxia-inducible factor, inflammatory, and apoptosis-related mRNA gene expression in the brain. Likewise, significant upregulations of hypoxia-inducible factor and apoptosis-related gene expression were observed in the FIO2 0.3 group in the heart and lungs. Insufficient O2 supplementation in the first 10 min of resuscitation could prolong ischemia, and may result in unfavorable biological responses 2 h after CA. Faster recovery from the impairment of O2 metabolism might contribute to the improvement of hemodynamics during the early post-resuscitation phase; therefore, it may be reasonable to provide the maximum feasible O2 concentrations during CPR.

Growth Performance, Physiological Responses, and Histoarchitectural Changes in Juvenile Pangasianodon hypophthalmus under Different Environmental Salinities

Environmental salinity is an important abiotic factor that directly affects the growth, metabolism, osmoregulatory processes, and physiological performance of fish. Herein, the effects of long-term salinity stress on juvenile Pangasianodon hypophthalmus have been evaluated. Fish were allotted in five triplicate groups and exposed to five different salinities (0.0, 4.0, 8.0, 12.0, and 16.0‰) for 56 days. After exposure, the final weight, weight gain percent, and specific growth rate were significantly decreased in groups reared in 8‰, 12‰, and 16‰ salinities. The feed intake was also significantly reduced in groups raised in water salinities of 12‰ and 16‰ compared with other groups. Conversely, the feed conversion ratio values were significantly increased in groups reared in water salinities between 8‰ and 16‰ compared with other groups. The lowest survival rates were observed in groups reared at salinities of 12‰ and 16‰ (91.1% and 77.8%, respectively). Body moisture (%) was significantly decreased, while crude protein and crude lipids (%) were significantly increased in groups exposed to salinities ranging from 8.0‰ to 16.0‰. Stress biomarkers (such as blood glucose, lactate, and cortisol levels) and oxidative stress indicators (such as carbonyl proteins, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX)) were significantly increased in groups exposed to different salinities compared with the control group, and their highest levels were in the group exposed to 16‰ salinity. The histoarchitectural changes were different among groups in relation to the salinity level. Moreover, the scored histopathological lesions showed a significant increase in groups exposed to different salinities compared with the control, and the highest scores were reported in groups exposed to the highest salinities (12‰ and 16‰). Based on the fitting curves, the present study suggests that P. hypophthalmus could tolerate salinities up to 8.0‰ with no mortalities; however, 4‰ salinity was more suitable with no effects on the growth and little impact on histology and physiological responses.

Evaluation of plasma prealbumin as a novel inflammatory biomarker in dogs: a pilot study.

Prealbumin (PAB) is a plasma protein synthesized in the hepatic parenchymal cells. PAB has a short half-life (~2 days), and its concentration is affected by changes in transcapillary escape. Measurement of PAB is widely used in hospitalized patients in human medicine due to its decreasing concentration in states of inflammation and malnutrition. However, only a few studies are available in dogs. The aim of this study is to determine whether the plasma PAB concentration decreases in dogs with inflammation and to evaluate the relationship between the plasma PAB concentration and inflammation-related parameters in dogs. A total of 94 dogs were divided into healthy (n = 33) and diseased (n = 61) groups. These were further divided into group A (n = 24) and group B (n = 37) according to plasma C-reactive protein (CRP) levels. Group A included dogs with a plasma CRP < 10 mg/L, and group B consisted of dogs with a plasma CRP ≥ 10 mg/L. Patient signalment, history, physical examination findings, hematologic and biochemical parameters, various inflammatory markers, and plasma PAB levels were investigated and compared between groups. The plasma PAB concentration was found to be lower in group B than in the other groups (p < 0.001), but no statistical difference was found when comparing the control group and group A (p > 0.05). A plasma PAB < 6.3 mg/dL predicted an increased CRP level (10 mg/L or greater) with a sensitivity of 89.5% and a specificity of 86.5%. Receiver operating characteristic curve analysis revealed that the area under the curve for PAB was higher than that for the white blood cell count, neutrophil count, albumin level, lactate level, neutrophil-to-lymphocyte ratio, and neutrophil percentage-to-albumin ratio. In addition, the PAB concentration was significantly negatively correlated with the CRP concentration (r = -0.670, p < 0.001). In conclusion, this is the first study to demonstrate the clinical usefulness of the plasma PAB concentration as an inflammatory marker in dogs. These findings suggest that measuring the plasma PAB concentration along with the CRP concentration may be more useful for evaluating inflammation than measuring CRP alone in canine patients.

Anion gap(AG) or serum lactate-in search of a better prognostic marker in sepsis a cross-sectional study in a rural tertiary care hospital

Background: In intensive care units, sepsis is a common diagnosis. Serum lactate rise has been established as an essential measure for predicting the outcome of sepsis. Higher anion gap(AG) has been associated with an increased risk of death in critically ill individuals. We measured blood lactate levels and AG and looked at how these predicted in-hospital outcomes (death or discharge).This study aimed to estimate anion gap values in sepsis syndrome, to measure the serum lactate levels in sepsis syndrome, to correlate the anion gap and serum lactate values with the outcome (mortality and discharge) in patients with sepsis syndrome. Methods: The Department of Medicine at Jawaharlal Nehru Medical College conducted this single-center, prospective, observational cross-sectional study with a cohort design. A total of 160 patients with sepsis were screened in the ICU. Sepsis was diagnosed using SEPSIS-3 criteria. Results: In this study, we included 160 patients with sepsis with sequential organ failure assessment (SOFA) score &gt;2.Mean serum lactate was 5.1±1.2 mmol/L and it was ≥4 mmol/L in 90% of patients. Mean AG was 14.0±3.9 and it was ≥12 in 75.6% of patients. Similarly, the proportion of patients who had lactate levels ≥4 mmol/L was higher in those with AG ≥12 than AG &lt;12 (95.9% vs. 71.8%, p&lt;0.0001). The AUC of ROC in predicting mortality was significant for both serum lactate (AUC 0.797, p&lt;0.0001) and AG (AUC 0.835, p&lt;0.0001). Conclusions: Along with other parameters predicting mortality, serum lactate and AG also act as important predictors of mortality in sepsis patients. We conclude that on admission serum lactate ≥4 mmol/L and AG ≥12 can be used in predicting short-term mortality in patients with sepsis.

Air-Bubble-Insensitive Microfluidic Lactate Biosensor for Continuous Monitoring of Lactate in Sweat.

This study aimed to develop a lactate sensor with a microchannel that overcomes the issue of air bubbles interfering with the measurement of lactate levels in sweat and to evaluate its potential for continuous monitoring of lactate in sweat. To achieve continuous monitoring of lactate, a microchannel was used to supply and drain sweat from the electrodes of the lactate sensor. A lactate sensor was then developed with a microchannel that has an area specifically designed to trap air bubbles and prevent them from contacting the electrode. The sensor was evaluated by a person while exercising to test its effectiveness in monitoring lactate in sweat and its correlation with blood lactate levels. Furthermore, the lactate sensor with a microchannel in this study can be worn on the body for a long time and is expected to be used for the continuous monitoring of lactate in sweat. The developed lactate sensor with a microchannel effectively prevented air bubbles from interfering with the measurement of lactate levels in sweat. The sensor showed a concentration correlation ranging from 1 to 50 mM and demonstrated a correlation between lactate in sweat and blood. Additionally, the lactate sensor with a microchannel in this study can be worn on the body for an extended period and is expected to be useful for the continuous monitoring of lactate in sweat, particularly in the fields of medicine and sports.

A Comparative Study of Peri-Operative Fluid Therapy With Ringer Lactate and PlasmaLyte in Children Undergoing Intra-Abdominal Surgery: A Randomized Control Trial.

Background In this study, we compared Ringer's lactate solution (RL) with PlasmaLyte (PL), a relatively new IV fluid, for perioperative fluid therapy in the pediatric population. Methods This prospective and interventional randomized comparative study was carried out after obtaining clearance from the Institutional Ethics Committee. The study period was from November 2016 to December 2017. Results Hemodynamic parameters such as SpO2, ETCO2, heart rate, blood pressure, temperature, and urine output were stable in both groups throughout the perioperative period without any statistically or clinically significant variations. Children receiving PL (group PL) had better acid-base status, serum electrolytes, and blood lactate profiles compared with children receiving RL (group RL), who had hyponatremia and increased blood lactate levels, which continued to increase in the immediate postoperative period. No significant differences in pH, pCO2, HCO3, serum potassium, serum chloride, blood urea, serum creatinine, or blood sugar were observed. Conclusions PL is better than RL for perioperative fluid therapy in children undergoing abdominal surgeries.

Use of CO2-Derived Variables in Cardiac Intensive Care Unit: Pathophysiology and Clinical Implications.

Shock is a life-threatening condition, and its timely recognition is essential for adequate management. Pediatric patients with congenital heart disease admitted to a cardiac intensive care unit (CICU) after surgical corrections are particularly at risk of low cardiac output syndrome (LCOS) and shock. Blood lactate levels and venous oxygen saturation (ScVO2) are usually used as shock biomarkers to monitor the efficacy of resuscitation efforts, but they are plagued by some limitations. Carbon dioxide (CO2)-derived parameters, namely veno-arterial CO2 difference (ΔCCO2) and the VCO2/VO2 ratio, may represent a potentially valuable addition as sensitive biomarkers to assess tissue perfusion and cellular oxygenation and may represent a valuable addition in shock monitoring. These variables have been mostly studied in the adult population, with a strong association between ΔCCO2 or VCO2/VO2 ratio and mortality. In children, particularly in CICU, few studies looked at these parameters, while they reported promising results on the use of CO2-derived indices for patients' management after cardiac surgeries. This review focuses on the physiological and pathophysiological determinants of ΔCCO2 and VCO2/VO2 ratio while summarizing the actual state of knowledge on the use of CO2-derived indices as hemodynamical markers in CICU.

Blood lactate levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease in type 2 diabetes: a real-world study.

To investigate the association between blood lactate levels and metabolic dysfunction-associated fatty liver disease (MAFLD) in type 2 diabetes mellitus (T2DM). 4628 Chinese T2DM patients were divided into quartiles according to blood lactate levels in this real-world study. Abdominal ultrasonography was used to diagnosis MAFLD. The associations of blood lactate levels and quartiles with MAFLD were analyzed by logistic regression. There were a significantly increased trend in both MAFLD prevalence (28.9%, 36.5%, 43.5%, and 54.7%) and HOMA2-IR value (1.31(0.80-2.03), 1.44(0.87-2.20), 1.59(0.99-2.36), 1.82(1.15-2.59)) across the blood lactate quartiles in T2DM patients after adjustment for age, sex, diabetic duration, and metformin use (all p<0.001 for trend). After correcting for other confounding factors, not only increased blood lactate levels were obviously associated with MAFLD presence in the patients with (OR=1.378, 95%CI: 1.210-1.569, p<0.001) and without taking metformin (OR=1.181, 95%CI: 1.010-1.381, p=0.037), but also blood lactate quartiles were independently correlated to the increased risk of MAFLD in T2DM patients (p<0.001 for trend). Compared with the subjects in the lowest blood lactate quartiles, the risk of MAFLD increased to 1.436-, 1.473-, and 2.055-fold, respectively, in those from the second to the highest lactate quartiles. The blood lactate levels in T2DM subjects were independently associated with an increased risk of MAFLD, which was not affected by metformin-taking and might closely related to insulin resistance. Blood lactate levels might be used as a practical indicator for assessing the risk of MAFLD in T2DM patients.

Lactate Clearance – A surrogate for Mortality in Cardiogenic Shock

Objectives: Raised blood lactate levels are strongly associated with mortality in patients with cardiogenic shock. Recent practices of the early identification and initiation of mechanical circulatory support have improved outcomes in cardiogenic shock, but therapeutic targets to guide real-time clinical decision making are lacking. Recent evidence suggests that the degree and rate at which blood lactate levels decrease after the initiation of treatment is important in patient prognosis. With this background, lactate clearance has been suggested as a potential treatment target due to its independent association with morality. Materials and Methods: Lactate levels were measured at baseline and at 6, 12, and 24 h. Patients were grouped into survivors and non-survivors based on in-hospital mortality. Patients who had normal lactate (&lt;2.0 mmoL/L) at baseline were excluded from the study. Statistical analysis done using appropriate tests. Results: Absolute lactate levels were compared between groups at baseline and 6, 12, and 24 h. Lactate clearance was calculated at 6, 12, and 24 h among survivors and non-survivors. In total, 90 patients were enrolled, and 65 (72.2%) of them survived to hospital discharge. Absolute blood lactate levels were 4.71 ± 1.36 mmoL/lit in survivors and 6.17 ± 2.88 mmoL/lit in non-survivors at baseline (P = 0.007). The mean lactate clearance at 6 h was 12.22 ± 85.96% in survivors and 12.98 ± 30.97% in non-survivors (P = 0.3). At 24 h, the mean lactate clearance was 54.63 ± 22.34% and 26.34 ± 19.3% in survivors and non-survivors, respectively (P &lt; 0.01). Conclusion: Survivors had significantly greater lactate clearance at 12 and 24 h compared with non-survivors, suggesting that lactate clearance is an important prognostic marker in cardiogenic shock. These results further support the validity of lactate clearance as an appropriate surrogate for mortality and as a potential therapeutic target in clinical practice. Especially in centers lacking invasive hemodynamic monitoring.

Blood lactate levels, base excess values and lactic acidosis predict short-term and long-term survival in patients admitted to the ICU after and out-of-hospital cardiac arrest

Abstract Funding Acknowledgements Type of funding sources: None. Background Global hypoperfusion causes tissue hypoxia, resulting in overproduction of lactate because of impaired mitochondrial oxidation, causing lactic acidosis (LA). Base excess (BE) is defined as the amount of acid or base required to return the pH to 7.4 in the setting of a normal Paco2 and is therefore related to the degree of acid production following injury. Purpose Our hypothesis was that lactate levels, BE levels and occurrence of LA on admission could help in early risk stratification in patients admitted to the ICU after an out-of-hospital cardiac arrest (OHCA). Methods we enrolled 171 consecutive patients resuscitated from an OHCA and admitted to ICU at our center from September 2017 to April 2021. Blood gas analysis on admission was available for 140 patients [77%male, mean age 60 (18-90) years, 54% with first shockable rhythm, median number of shocks delivered 1 (0-14), median dose of adrenaline administered 3 mg (0-12), 26% received amiodarone, median cardiac arrest duration 38 min (IQR 22-74 min)]. Patients with low lactate levels were compared with patients with high lactate levels (cutoff 2 mmol/l as per standard practice), patients with low BE levels were compared with patients with high BE levels (cutoff -8.5 mmol/l, median value) and patients with LA were compared with patients without LA (defined as pH &amp;lt;7.36 and lactate&amp;gt;2mmol/). Survival with good neurological outcome (CPC 1-2) at ICU discharge and 30-day survival were investigated for each group with chi-squared test. Then, one-year survival was investigated for each group with Kaplan-Meier analysis. Results Patients with low BE (&amp;lt; -8.5 mmol/l) had a significantly lower survival with good neurological outcome at ICU discharge (p=0.0017), lower survival at 30 days (p &amp;lt; 0.0001) and 365 days (p&amp;lt;0.0001) compared to patients with high BE (&amp;gt; - 8.5 mmol/l). Low lactate levels (&amp;lt; 2 mmol/L) were associated with higher survival with good neurological outcome at ICU discharge (p&amp;lt; 0.0001), higher survival at 30 days (p &amp;lt; 0.0001) and 365 days (p = 0.0002) compared to higher lactate levels (&amp;gt; 2 mmol/l). The occurrence of LA on admission was significantly associated with lower survival with good neurological outcome at ICU discharge (p=0.001), lower 30-days survival (p=0.001) and 365-days survival (p&amp;lt;0.0001). Conclusion high blood lactate levels, low base excess and lactic acidosis predict short-term and long-term survival in patients admitted to the ICU after an OHCA. These results could help clinician in the identification of populations with different risk profile with the first blood gas analysis obtained at ICU admission.

Effects of Neuromuscular Electrical Stimulation on Fasting Blood Glucose

Muscle contraction during physical activity improves glucose metabolism and glycemic control by facilitating muscle glucose uptake and utilization. Neuromuscular electrical stimulation (NMES) is an involuntary alternative mode of muscle contraction and is widely applicable and suitable for individuals with sedentary lifestyle including people with physical functional limitations and other mobility impairments. Use of NMES has the potential to improve metabolic health analogous to voluntary exercise. Purpose: To determine the acute effect of 30 mins of NMES on energy metabolism and fasting blood glucose level. Methods: Fifteen participants without diabetes participated in the study (Males: 6; Females: 9; Age: 33.80 ± 12.99 years; BMI: 32.59 ± 9.17 kg/m2). Each participant underwent 30 mins of cyclical NMES on the quadricep muscles of both legs while lying supine on a bed. NMES was applied at a frequency of 50Hz with a pulse width of 300μs up to maximum tolerable intensity. Blood glucose and lactate levels were determined at baseline and at 5 mins intervals during the stimulation. Energy expenditure and substrate utilization were measured at baseline and monitored continuously during the NMES via indirect calorimetry. The experimental procedure was performed in a fasting condition and was directly preceded by a day of dietary control. Results: A decreasing blood glucose effect of NMES was observed between baseline glucose level (95.94 ± 7.81 mg/dL) and after 25 mins (92.85 ± 8.82 mg/dL) and 30 mins (91.79 ± 9.00 mg/dL) of NMES (p&lt;0.05). Average energy expenditure rate during the 30min of NMES (19.37 ± 4.49 Kcal/kg/day) was relatively higher than that of the resting baseline rate (19.24 ± 3.57 Kcal/kg/day) (p&lt;0.05). Blood lactate level and respiratory exchange ratio (substrate utilization) however, remained unaffected throughout the experimental procedure. Conclusion: Neuromuscular electrical stimulation is effective in decreasing blood glucose level and hence could serve as a beneficial intervention for blood glucose management. Supported by NIH Grant R01 DK132430 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.