Increased Blood Lactate Levels Research Articles

Anesthetic managements, morbidities and mortalities in retroperitoneal sarcoma patients experiencing perioperative massive blood transfusion.

Given high risks of major bleeding during retroperitoneal sarcoma(RPS) surgeries, severe complications and deaths are common to see perioperatively. Thus, effective anesthetic management is the key point to ensuring the safety of patients. This study aimed to introduce anesthesia management and mortalities in RPS patients receiving massive blood transfusions during surgeries. Records of RPS surgeries under general anesthesia from January 2016 through December 2021 were retrospectively retrieved from our database. Patients who received massive blood transfusions (MBT) exceeding 20 units in 24h duration of operations were finally included in this study. Demographics, modalities of anesthesia management, blood loss, transfusion, peri-anesthesia biochemical tests as well as morbidities and mortalities were collected. Risk factors of postoperative 60d mortality were determined through logistic regression in uni-and multi-variety analysis using the statistics software STATA 17.0. A total of 70 patients (male 31) were included. The mean age was 50.1 ± 15.8 years. All patients received combined resections of sarcoma with involved organs under general anesthesia. Mean operation time and anesthesia time were 491.7 ± 131.1mins and 553.9 ± 132.6mins, respectively. The median intraoperative blood loss was 7000ml (IQR 5500,10000ml). Median red blood cells (RBC) and fresh frozen plasma (FFP) transfusion were 25.3u (IQR 20,28u), and 2400ml (IQR 2000,3000ml), respectively. Other blood products infusions included prothrombin complex concentrate (PCCs), fibrinogen concentrate (FC), platelet(plt) and albumin(alb) in 82.9% (58/70), 88.6% (62/70), 81.4% (57/70) and 12.9% (9/70) of patients. The postoperative severe complication rate(Clavien-Dindo grade≥3a) was 35.7%(25/70). A total of 7 patients (10%) died during the postoperative 60-day period. BMI, volumes of crystalloid infusion in anesthesia, and hemoglobin and lactate levels at the termination of operation were found significantly associated with postoperative occurrence of death in univariate analysis. In logistic multivariate analysis, extended anesthesia duration was found associated with postoperative venous thrombosis embolism (VTE) and severe complication. The lactate level at the immediate termination of the operation was the only risk factor related to perioperative death (p<0.05). RPS patients who endure MBT in surgeries face higher risks of death postoperatively, which needs precise and effective anesthesia management in high-volume RPS centers. Increased blood lactate levels might be predictors of postoperative deaths which should be noted.

The first results of the international multicenter clinical study RheoSTAT-CP0669 on the effectiveness and safety of infusion solution Rheosorbilact® in the complex treatment of patients with burns

Mechanization and urbanization are accompanied by an increase in the prevalence of burns. A burn causes both local damage and systemic inflammatory response that leads to inadequate oxygen delivery to vital organs and inadequate elimination of metabolites. Infusion therapy for burns aims to restore perfusion and prevent ischemia. The implementation of effective dynamic schemes of infusion therapy has led to a decrease in mortality, however, an excessive amount of injected fluid does not improve the patient’s volumetric status, instead increasing tissue swelling and causing a number of complications. Therefore, doctors are faced with the question of choosing the optimal infusion therapy, which will allow maintaining the patient’s status at the needed level called normovolemia. According to the results of the open, blinded evaluation of the randomized controlled trial RheoSTAT-СР0669, administration of Rheosorbilact to patients with burns by intravenous infusion at a dose of 200-400 ml/day for 3 days significantly improves the clinical condition, reduces the manifestations of (poly-) organ failure and endogenous intoxication. Small-volume infusion therapy with Rheosorbilact causes a statistically significant decrease in the breathing rate, a decrease in endogenous intoxication and the intensity of inflammation, as well as positive dynamics of the blood gas composition. Administration of the drug in this mode has a favorable safety profile: it does not lead to fluid overload, associated complications, or other serious undesirable side effects, and does not cause a clinically significant increase in blood lactate level. The RheoSTAT-СР0669 study substantiates the feasibility of using Rheosorbilact in the complex therapy of burns.

Redox state and altered pyruvate metabolism contribute to a dose-dependent metformin-induced lactate production of human myotubes.

Metformin-induced glycolysis and lactate production can lead to acidosis as a life-threatening side effect, but slight increases in blood lactate levels in a physiological range were also reported in metformin-treated patients. However, how metformin increases systemic lactate concentrations is only partly understood. Because human skeletal muscle has a high capacity to produce lactate, the aim was to elucidate the dose-dependent regulation of metformin-induced lactate production and the potential contribution of skeletal muscle to blood lactate levels under metformin treatment. This was examined by using metformin treatment (16-776 μM) of primary human myotubes and by 17 days of metformin treatment in humans. As from 78 µM, metformin induced lactate production and secretion and glucose consumption. Investigating the cellular redox state by mitochondrial respirometry, we found metformin to inhibit the respiratory chain complex I (776 µM, p < 0.01) along with decreasing the [NAD+]:[NADH] ratio (776 µM, p < 0.001). RNA sequencing and phospho-immunoblot data indicate inhibition of pyruvate oxidation mediated through phosphorylation of the pyruvate dehydrogenase (PDH) complex (39 µM, p < 0.01). On the other hand, in human skeletal muscle, phosphorylation of PDH was not altered by metformin. Nonetheless, blood lactate levels were increased under metformin treatment (p < 0.05). In conclusion, the findings suggest that metformin-induced inhibition of pyruvate oxidation combined with altered cellular redox state, shifts the equilibrium of the lactate dehydrogenase (LDH) reaction leading to a dose-dependent lactate production in primary human myotubes.

A key role for platelet GPVI in neutrophil recruitment, migration, and NETosis in the early stages of acute lung injury

AbstractAcute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with high morbidity and mortality. Excessive neutrophil infiltration into the pulmonary airspace is the main cause for the acute inflammation and lung injury. Platelets have been implicated in the pathogenesis of ALI/ARDS, but the underlying mechanisms are not fully understood. Here, we show that the immunoreceptor tyrosine-based activation motif–coupled immunoglobulin-like platelet receptor, glycoprotein VI (GPVI), plays a key role in the early phase of pulmonary thrombo-inflammation in a model of lipopolysaccharide (LPS)-induced ALI in mice. In wild-type (WT) control mice, intranasal LPS application triggered severe pulmonary and blood neutrophilia, hypothermia, and increased blood lactate levels. In contrast, GPVI-deficient mice as well as anti-GPVI–treated WT mice were markedly protected from pulmonary and systemic compromises and showed no increased pulmonary bleeding. High-resolution multicolor microscopy of lung sections and intravital confocal microcopy of the ventilated lung revealed that anti-GPVI treatment resulted in less stable platelet interactions with neutrophils and overall reduced platelet–neutrophil complex (PNC) formation. Anti-GPVI treatment also reduced neutrophil crawling and adhesion on endothelial cells, resulting in reduced neutrophil transmigration and alveolar infiltrates. Remarkably, neutrophil activation was also diminished in anti-GPVI–treated animals, associated with strongly reduced formation of PNC clusters and neutrophil extracellular traps (NETs) compared with that in control mice. These results establish GPVI as a key mediator of neutrophil recruitment, PNC formation, and NET formation (ie, NETosis) in experimental ALI. Thus, GPVI inhibition might be a promising strategy to reduce the acute pulmonary inflammation that causes ALI/ARDS.

Effect of Globin Digests on Physical Fatigue in Mice.

Globin digest (GD) inhibits dietary hypertriglyceridemia; however, its effects on physical fatigue remain unknown. Therefore, this study aimed to investigate the potential anti-fatigue effects of GD. Repeated administration of GD and valine (Val)-Val-tyrosine (Tyr)-proline (Pro), a component of GD, for five days prevented the forced walking-induced decrease in locomotion. Furthermore, GD treatment reversed the forced walking-induced increase in blood lactate levels in mice and increased phosphorylated AMP-activated protein kinase (p-AMPK) in the soleus muscle, suggesting that the anti-fatigue effect of GD involves AMPK activation in the soleus muscle through reduced blood lactate.

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.

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.

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.

Significance of oxidative endotoxemia and hypoxia in the pathogenesis of testicular insufficiency in patients with inguinal hernia

Aim. To determine the level of “oxidative stress” and hypoxia markers in the blood and venous blood flowing from the testicle in inguinal hernias and the postoperative period after inguinal hernioplasty.Materials and Methods. 34 patients with inguinal hernias were under the observation in Istiqlol health complex of Dushanbe. The age of patients ranged from 18 to 30 years old. The patients were divided into 3 groups: 14 patients with long (5 or more years) inguinal hernia combined with varicocele, 12 patients with infertility, and 8 patients with inguinal herniotomy. The content of LPO products and hypoxia markers in the blood flowing from the testicle was studied in 34 patients with various groups of inguinal hernias.Results and discussion. An analysis of the level of “oxidative” toxemia and hypoxia indices in the studied groups of patients showed their increased levels in the peripheral blood. The levels of DA and MDA in peripheral blood in Group I patients reached 1.3±0.02 units pg/ml and 2.4±0.09 nmol/ml, which was caused by prolonged compression of the spermatic cord elements by the hernial sac; the presence of ischemia was confirmed by increased blood lactate level. Marked pathophysiological changes result in the disturbance of hormonal background and spermatogenesis disorder.Conclusion. Increased content of LPO products in the testicular parenchyma further results in the branching of chain reactions and final LPO products with high damaging activity followed by the development of systemic damage to cellular structures of the contralateral testis with subsequent progression and development of testicular insufficiency.

Hypoxemia in the presence or absence of systemic inflammation does not increase blood lactate levels in healthy volunteers.

Elevated lactate levels are a sign of critical illness and may result from insufficient oxygen delivery. We investigated whether hypoxemia and/or systemic inflammation, results in increased lactate levels in healthy volunteers. 30 healthy volunteers were exposed to either 3.5 h of hypoxemia (FiO2 ± 11.5%), normoxemic endotoxemia (FiO2 21%, administration of 2 ng/kg endotoxin), or hypoxemic endotoxemia (n = 10 per group). Blood lactate, hemoglobin, SpO2, PaO2, PaCO2, pH, and hemodynamic parameters were serially measured. Hypoxemic treatment resulted in lower SpO2 (81.7 ± 2.6 and 81.4 ± 2.4% in the hypoxemia and hypoxemic endotoxemia groups, respectively) and hyperventilation with a PaCO2 decrease of 0.8 ± 0.5 and 1.5 ± 0.6 kPa and an increase in pH. Arterial oxygen content (CaO2) decreased by 20.5 ± 2.9 and 23.5 ± 4.4%, respectively. Lactate levels were slightly, but significantly higher in both hypoxemic groups compared with the normoxemic endotoxemia group over time (p < 0.0001 for both groups), but remained below 2.3 mmol/L in all subjects. Whereas PaO2 and SpO2 did not correlate with lactate levels, PaCO2, pH and CaO2 did. Hypoxemia, in the absence or presence of inflammation does not result in relevant increases of lactate. The small increases in lactate observed are likely to be due to hyperventilation-related decreases in glycolysis.

Cigarette smoke exposure reduces hemorrhagic shock induced circulatory dysfunction in mice with attenuated glucocorticoid receptor function.

IntroductionWe previously showed that attenuated glucocorticoid receptor (GR) function in mice (GRdim/dim) aggravates systemic hypotension and impairs organ function during endotoxic shock. Hemorrhagic shock (HS) causes impaired organ perfusion, which leads to tissue hypoxia and inflammation with risk of organ failure. Lung co-morbidities like chronic obstructive pulmonary disease (COPD) can aggravate tissue hypoxia via alveolar hypoxia. The most common cause for COPD is cigarette smoke (CS) exposure. Therefore, we hypothesized that affecting GR function in mice (GRdim/dim) and pre-traumatic CS exposure would further impair hemodynamic stability and organ function after HS.MethodsAfter 3 weeks of CS exposure, anesthetized and mechanically ventilated GRdim/dim and GR+/+ mice underwent pressure-controlled HS for 1h via blood withdrawal (mean arterial pressure (MAP) 35mmHg), followed by 4h of resuscitation with re-transfusion of shed blood, colloid fluid infusion and, if necessary, continuous intravenous norepinephrine. Acid–base status and organ function were assessed together with metabolic pathways. Blood and organs were collected at the end of the experiment for analysis of cytokines, corticosterone level, and mitochondrial respiratory capacity. Data is presented as median and interquartile range.ResultsNor CS exposure neither attenuated GR function affected survival. Non-CS GRdim/dim mice had a higher need of norepinephrine to keep target hemodynamics compared to GR+/+ mice. In contrast, after CS exposure norepinephrine need did not differ significantly between GRdim/dim and GR+/+ mice. Non-CS GRdim/dim mice presented with a lower pH and increased blood lactate levels compared to GR+/+ mice, but not CS exposed mice. Also, higher plasma concentrations of some pro-inflammatory cytokines were observed in non-CS GRdim/dim compared to GR+/+ mice, but not in the CS group. With regards to metabolic measurements, CS exposure led to an increased lipolysis in GRdim/dim compared to GR+/+ mice, but not in non-CS exposed animals.ConclusionWhether less metabolic acidosis or increased lipolysis is the reason or the consequence for the trend towards lower catecholamine need in CS exposed GRdim/dim mice warrants further investigation.

Effect of Continuous-Exercise and Modification Interval-Exercise on Decreasing Malondialdehyde and Blood Lactate Levels in Non-Professional Shorinji Kempo Athletes

The study purpose was to analyze the effect of continuous exercise and modification interval exercise on decreasing malondialdehyde (MDA) and blood lactate levels in non-professional Shorinji Kempo athletes.&#x0D; Materials and methods. This study used a quasi-experimental method with a randomized pretest posttest-only group design. Subjects were 16 male adolescents aged 18-20, body mass index (BMI) 20-24 kg/m2, who had normal blood pressure, normal resting heart rate, and no history of chronic disease. The subjects were randomly divided into two groups: CEG (n = 8, continuous exercise group) and MIEG (n = 8, modification interval exercise group). Continuous and modification interval exercises were carried out in 30 minutes/exercise sessions, with an intensity of 75% HRmax and 75% RM, as often as 3 times/week, for one week. Measurements of resting heart rate, blood lactate and MDA levels were performed 30 minutes pre-exercise and 10 minutes post-exercise. The data analysis technique used the Paired Sample T-Test and the independent T-test with SPSS software version 21.&#x0D; Results. The results showed significant differences in resting heart rate, blood lactate and MDA levels pre-exercise vs. post-exercise on CEG and MIEG (p ≤ 0.05). A difference was also observed in Delta (Δ) heart rate pre-exercise vs. post-exercise on CEG (–3.88 ± 3.36 bpm) and MIEG (–15.25 ± 3.45 bpm) (p ≤ 0.001), but no differences were observed in the Delta (Δ) blood lactate and MDA levels in both groups.&#x0D; Conclusion. Based on the study results, it was shown that continuous exercise and modification interval exercise increase blood lactate and MDA levels shortly after intervention but both exercises could reduce acute stress, which was indicated by a decrease in resting heart rate.

Influence of biological sex and exercise on murine cardiac metabolism

Although the structural and functional effects of exercise on the heart are well established, the metabolic changes that occur in the heart during and after exercise remain unclear. In this study, we used metabolomics to assess time-dependent changes in the murine cardiac metabolome following 1 session of treadmill exercise. After the exercise bout, we also recorded blood lactate, glucose, and ketone body levels and measured cardiac mitochondrial respiration. In both male and female mice, moderate- and high-intensity exercise acutely increased blood lactate levels. In both sexes, low- and moderate-intensity exercise augmented circulating 3-hydroxybutryrate levels immediately after the exercise bout; however, only in female mice did high-intensity exercise increase 3-hydroxybutyrate levels, with significant increases occurring 1 h after the exercise session. Untargeted metabolomics analyses of sedentary female and male hearts suggest considerable sex-dependent differences in basal cardiac metabolite levels, with female hearts characterized by higher levels of pantothenate, pyridoxamine, homoarginine, tryptophan, and several glycerophospholipid and sphingomyelin species and lower levels of numerous metabolites, including acetyl coenzyme A, glucuronate, gulonate, hydroxyproline, prolyl-hydroxyproline, carnosine, anserine, and carnitinylated and glycinated species, as compared with male hearts. Immediately after a bout of treadmill exercise, both male and female hearts had higher levels of corticosterone; however, female mice showed more extensive exercise-induced changes in the cardiac metabolome, characterized by significant, time-dependent changes in amino acids (e.g., serine, alanine, tyrosine, tryptophan, branched-chain amino acids) and the ketone body 3-hydroxybutyrate. Results from experiments using isolated cardiac mitochondria suggest that high-intensity treadmill exercise does not acutely affect respiration or mitochondrial coupling; however, female cardiac mitochondria demonstrate generally higher adenosine diphosphate sensitivity compared with male cardiac mitochondria. Collectively, these findings in mice reveal key sex-dependent differences in cardiac metabolism and suggest that the metabolic network in the female heart is more responsive to physiological stress caused by exercise.

Differences in the Effect of Active Recovery Post Long Duration Interval Training towards Lactate in Young Men with Blood Type O and A

Accumulation of lactate in the blood can cause fatigue and decreased physical performance. Therefore, proper recovery after physical activity is needed. This study aims to determine the effect of long duration interval training (LDIT) and active recovery on blood lactate and to determine the difference in the decrease in lactate levels between blood groups O and A after active recovery. This research is included in comparative research. The independent variable in this study was active recovery, and the dependent variable in this study was blood lactate levels (mmol/L). The sample in this study was taken from the NFC Academy which has a population of 35 members. Sampling was done by purposive randomized sampling, and obtained 16 members who are declared eligible and willing to be the research sample. Then the sample was given LDIT physical activity and active recovery. Data analysis used the T-Test difference test with the help of SPSS 25 software. The results in this study showed a significant increase in blood lactate levels after doing LDIT exercise. After performing active recovery, lactate levels from both groups decreased significantly. It can be said that the two groups had no difference in the effect of active recovery after doing physical activity.

Attentive Processes and Blood Lactate in the Sambo.

Background: Sambo is a martial art and combat sport that originated in the Soviet Union. There are two main stiles, Sport Sambo and Combat Sambo which resembles modern mixed martial arts. Very little literature is available about physiological aspects of Sambo and, in particular, on the possible effects on cognitive domains. The purpose of the present research was to determine if there is a correlation between a blood lactate increase and the intensity and/or selectivity of attentions. Methods: Sixteen male athletes practicing Sambo for at least 5 years participated voluntarily in the study. Each athlete had to sustain, with an interval of one week, both a Sport Sambo match and a Combat Sambo match, each lasting 5 min. Blood lactate levels as well as attentive capacities were evaluated at three different times: at rest, i.e., 5 min before the start of the session (pre), at end of the session and 15 min after its conclusion. Reaction time protocol was used to evaluate the intensity of attention, whereas divided attention was assessed for analyzing the selectivity of attention together with errors and omissions. Results: Concerning Sport Sambo, blood lactate was 1.66 mmol/L (±0.55 SD) before the session, reached a mean value of 3.40 mmol/L (±0.45 SD) at the end of the session (end) and returned to values similar to initial ones (a mean value of 1.98 mmol/L (±0.37 SD) after 15 min (15-end). None of the attentive parameters examined, showed statistically significant differences. Conversely, for Combat Sambo, it was found a significant increase in blood lactate levels that went from 1.66 mmol/L (±0.55 SD) before the session (pre), to 4.76 mmol/L (±0.60 SD) at the end (end) and then back to values similar to those observed before the session 15 min after its conclusion (15-end), i.e., 1.97 mmol/L (±0.37 SD); however, after a Combat Sambo session increases in blood lactate were associated with significant worsening of attentional mechanisms. Conclusions: In conclusion, in all the participants, the worsening of attentional mechanisms was observed only after the Combat Sambo session in which blood lactate values exceeded 4 mmol/L. This figure, also known as the Onset of Blood Lactate Accumulation (OBLA), is commonly used to determine the anaerobic threshold.

Does severe hyperlactatemia during cardiopulmonary bypass predict a worse outcome?

IntroductionThe aim of the current study was to evaluate the impact of increased blood lactate levels during cardiopulmonary bypass (CPB) on immediate results in patients who underwent open heart surgery. Materials and methodsWe performed a retrospective single-center study on 1290 patients. Adult cardiac surgical patients who underwent valve surgery, coronary artery bypass graft, combined procedure, adult congenital anomalies and aortic surgery were enrolled. Patients with associated comorbidities such as liver dysfunction, hemodynamic instability before surgery were excluded. Arterial blood lactate concentration was measured immediately after weaning from CPB and evaluated together with clinical data and outcomes including in hospital mortality. Patients were classified into 3 groups according to their peak arterial lactate level: group I [normal lactatemia, lactate ˂ 2 mmol/l (n = 749)], group II [mild hyperlactatemia, lactate 2–5 mmol/l (n = 489)], group III [severe hyperlactatemia, lactate ˃ 5 mmol/l (n = 52)] ResultsWhen comparing outcomes across the 3 groups, severe hyperlactatemia was correlated with worse outcomes including higher in-hospital mortality, low output cardiac syndrome, postoperative renal insufficiency, myocardial infarction, red blood cell transfusion (RBC) transfusion, prolonged mechanical ventilation and longer intensive care unit (ICU) stay hours. ConclusionBlood lactate level above 5 mmol/l and more during CPB is associated with higher in-hospital mortality rate and postoperative complications. More attention must be given to correct the common abnormalities conditions inherent of CPB in order to conduct adequate tissue perfusion and reduce the risk of hyperlactatemia.

Blood lactate concentration in COVID-19: a systematic literature review.

Coronavirus disease 2019 (COVID-19) is an infectious respiratory condition sustained by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which manifests prevalently as mild to moderate respiratory tract infection. Nevertheless, in a number of cases the clinical course may deteriorate, with onset of end organ injury, systemic dysfunction, thrombosis and ischemia. Given the clinical picture, baseline assessment and serial monitoring of blood lactate concentration may be conceivably useful inCOVID-19. We hence performed a systematic literature review to explore the possible association between increased blood lactate levels, disease severity and mortality in COVID-19 patients, including comparison of lactate values between COVID-19 and non-COVID-19 patients. We carried out an electronic search in Medline and Scopus, using the keywords "COVID-19" OR "SARS-CoV-2" AND "lactate" OR "lactic acid" OR "hyperlactatemia", between 2019 and present time (i.e. October 10, 2021), which allowed to identify 19studies, totalling 6,459 patients. Overall, we found that COVID-19 patients with worse outcome tend to display higher lactate values than those with better outcome, although most COVID-19 patients in the studies included in our analysis did not have sustained baseline hyperlactatemia. Substantially elevated lactate values were neither consistently present in all COVID-19 patients who developed unfavourable clinical outcomes. These findings suggest that blood lactate monitoring upon admission and throughout hospitalization may be useful for early identification of higher risk of unfavourable COVID-19 illness progression, though therapeutic decisions based on using conventional hyperlactatemia cut-off values (i.e.,2.0mmol/L) upon first evaluation may be inappropriate in patients with SARS-CoV-2 infection.

Clinical impact of visually assessed right ventricular dysfunction in patients with septic shock

We retrospectively analyzed data from the Medical Information Mart for Intensive Care-III critical care database to determine whether visually-assessed right ventricular (RV) dysfunction was associated with clinical outcomes in septic shock patients. Associations between visually-assessed RV dysfunction by echocardiography and in-hospital mortality, lethal arrhythmia, and hemodynamic indicators to determine the prognostic value of RV dysfunction in patients with septic shock were analyzed. Propensity score analysis showed RV dysfunction was associated with increased risk of in-hospital death in patients with septic shock (adjusted odds ratio [OR] 2.15; 95% confidence interval [CI] 1.99–2.32; P < 0.001). In multivariate logistic regression analysis, RV dysfunction was associated with in-hospital death (OR 2.19; 95% CI 1.91–2.53; P < 0.001), lethal arrhythmia (OR 2.19; 95% CI 1.34–3.57; P < 0.001), and tendency for increased blood lactate levels (OR 1.31; 95% CI 1.14–1.50; P < 0.001) independent of left ventricular (LV) dysfunction. RV dysfunction was associated with lower cardiac output, pulmonary artery pressure index, and RV stroke work index. In patients with septic shock, visually-assessed RV dysfunction was associated with in-hospital mortality, lethal arrhythmia, and circulatory insufficiency independent of LV dysfunction. Visual assessment of RV dysfunction using echocardiography might help to identify the short-term prognosis of patients with septic shock by reflecting hemodynamic status.

Caffeine decreases ammonemia in athletes using a ketogenic diet during prolonged exercise

ObjectivesBoth exercise and a ketogenic (low-carbohydrate) diet favor glycogen depletion and increase ammonemia, which can impair physical performance. Caffeine supplementation has been routinely used to improve exercise performance. Herein, the effect of xanthine was evaluated on ammonemia in cyclists who were placed on a ketogenic diet and engaged in prolonged exercise. MethodsFourteen male cyclists followed a ketogenic diet for 2 d before and during the experimental trial. The cyclists were assigned to either the caffeine- (CEx; n = 7) or placebo-supplemented (LEx; n = 7) group. Blood samples were obtained during cycling and the recovery periods. ResultsThe CEx group showed a significant decrease (up to 25%) in blood ammonia at 60, 90, and 120 min after beginning exercise compared with the LEx group. A higher concentration of apparent blood urea was observed in the LEx group than in the CEx group at 60 to 90 min of exercise (~10%). In addition, a significant increase in blood glucose levels was evident at 30 min of exercise (~28%), and an increase in blood lactate levels was visible during the first 30 to 60 min of exercise (~80%) in the CEx group. ConclusionsOur results suggest that the consumption of caffeine might attenuate the increase in ammonemia that occurs during exercise.

Effects of General Fatigue Induced by Exhaustive Exercise on Posture and Gait Stability of Healthy Young Men.

Bipedal walking is a composite task requiring integration of many control circuitries in the brain and spinal cord. The present study was carried out to verify whether an increase in blood lactate, such as that associated with a high intensity exercise, is able to significantly modify the qualitative and/or quantitative aspects of human walking. Eighteen healthy physically male participants, aged between 20 and 24 years (M = 21.8, SD = 1.22), were recruited for the study. For this purpose, the experimental protocol included the measure of blood lactate levels with the aim of assessing possible relations between lactate blood values and different aspect of walking after an exhaustive exercise. An exhaustive exercise was associated with a strong increase of blood lactate levels and produced a significant worsening in the ability to maintain the bipodalic upright posture as well as the fluidity of walking. Our results suggest that exhausting bouts impose greater challenges on postural control.