Arterial Blood Lactate Research Articles

Efficacy and safety of inhaled molecular hydrogen therapy in patients with respiratory failure due to chronic obstructive pulmonary disease exacerbation in post-COVID period

Molecular hydrogen (H2) is a powerful antioxidant and anti-apoptotic agent. H2 has been studied in a number of clinical studies in the recent years.The aim of this research was to investigate the efficacy and safety of H2 inhalation therapy in patients with hypoxemic and hypercapnic respiratory failure (RF) against exacerbation of chronic obstructive pulmonary disease (COPD) in the post-COVID (Corona Virus Disease 2019) period.Methods. The randomized prospective parallel comparative study included patients (n = 60: 40 men aged 71.2 ± 1.8 years, 20 women aged 70.9 ± 2.8 years) with a post-COVID-19 exacerbation of COPD complicated by hypoxemic/hypercapnic RF. The patients were divided into 2 groups: group 1 (main) (n = 30: 18 men, 12 women), group 2 (control) (n = 30: 18 men, 12 women). To maintain arterial blood saturation ≥ 90 %, patients in both groups received respiratory support (non-invasive ventilation) using the Prisma 25ST device (Lowenstein Medical, Germany) in the BiPAP S/T mode (BiLevel Positive Airway Pressure Spontaneous/Time spontaneous/forced mode 20–24/4–6 cm H2O and O2, respectively; the fractional oxygen concentration in the inhaled gas mixture was ≥ 24%). In addition to standard treatment, patients in the main group received additional H2 therapy (Suisonia device, Japan) through a nasal cannula for 90 minutes daily for 14 days.Results. In patients of the main group, a decrease in the stiffness index was detected from 14.6 ± 1.2 to 6.2 ± 0.6 m/s, and the arterial blood lactate level – from 2.84 ± 0.1 to 0.02 ± 0.1 mmol/l (p < 0.001), the calculated shunt fraction Qs/Qt (venous admixture) – from 27.21 ± 3.4 to 7.14 ± 1.23 (p < 0.01) and an increase in the following parameters: reflection index – from 42.2 ± 2.0 to 66.2 ± 4.9% (p < 0.05), virus-specific IgG level – from 134 ± 125 to 669 ± 164 (p < 0. 05), blood flow velocity in arterioles – from 473 ± 108 to 868 ± 64 μm/s (p < 0.05), blood flow velocity in venules – from 299 ± 56 to 862 ± 69 μm/s (p < 0.05), the 6-minute walk distance – from 57.1 ± 4.4 to 328.9 ± 33.7 m (p < 0.05).Conclusion. H2 inhalations were safe and increased the therapeutic effect when added to standard therapy for patients with hypoxemic and hypercapnic RF during exacerbation of COPD in the post-COVID period.

Доклинические испытания отечественных устройств, применяемых при внегоспитальной остановке кровообращения

Summary. The aim of the study was to evaluate the effectiveness of domestic devices for supporting blood circulation in case of out-of-hospital circulatory arrest during preclinical trials. Research materials and methods. The study assessed the effectiveness of the Russian cardiac massager “CardioRobot” – an automated device for performing indirect cardiac massage of domestic design. This device has the following technical characteristics: piston type design; compression depth – (50-60±2) mm; compression frequency – (102±2) compressions/min; 2 operating modes – continuous and 30:2; weight – 6.5 kg; continuous battery life – 45 min; trapezoidal compression curve. To evaluate the device, a comparative experiment was conducted on large mammals (pigs), during which the work of the domestic prototype and the foreign device “LUCAS-2” was compared by comparing the indicators of central hemodynamics and gas exchange. During the clinical trials of LifeStream ECMO, postmortem extracorporeal membrane oxygenation (ECMO) of two donors was performed. During the experiment, the following were assessed: pO2, pH, pCO2, arterial blood lactate and creatinine concentrations. Research results and their analysis. During preclinical trials, domestically produced devices demonstrated experimental effectiveness comparable to similar foreign-made products. Currently, the LIFESTREAM ECMO perfusion emergency circulatory restoration complex for human resuscitation has received a certificate and is actively used in the Russian Federation, and the CardioRobot automated chest compression device is undergoing state registration.

Umbilical arterial blood lactate as predictor of early neonatal outcome and evaluation of intrapartum asphyxia

BackgroundPerinatal asphyxia is a leading cause of under-5 mortality and exerts great pressure on the health system. Adequate foetal monitoring in labour is paramount in the early detection of foetal distress to prevent perinatal asphyxia. Several methods of foetal monitoring are in use with varying efficacy. This study investigated the efficacy of umbilical arterial (UA) lactate assay in predicting adverse perinatal outcomes. MethodologyThis was a prospective longitudinal study involving 160 pregnant women in the active phase of labour at term who met the inclusion criteria. They were recruited using a consecutive sampling technique and underwent a cardiotocography. Then they were classified into normal and abnormal cardiotocographic groups. At delivery, the UA blood of all of the babies was collected and assayed for serum lactate, and the levels were correlated with the perinatal outcome. The perinatal outcomes were measured by Apgar scores, admission into the neonatal unit, and hypoxic ischaemic encephalopathy. Analysis was done to determine the sensitivity and specificity of UA lactate in predicting birth asphyxia, hypoxic ischaemic encephalopathy, and neonatal unit admission. ResultsThe mean age ± standard deviation (SD) between the two cardiotocography (CTG) groups, normal years (30.55 ± 5.59) and abnormal years (29.86 ± 5.51), were similar. A critical UA lactate concentration > 9.1 mmol/L predicted Apgar scores < 7 at 5 min with a sensitivity and specificity of 76.47% (CI: 50.1–93.2) and 91.55% (CI: 85.7–95.6%), respectively. Also, the need for neonatal unit admission was predicted at a cut-off point >9.1 mmol/L with a sensitivity of 61.90% (CI: 38.4–81.9) and specificity of 91.30% (CI: 85.3–95.4). Umbilical artery lactate levels > 11.2 mmol/L predicted the development of hypoxic ischaemic encephalopathy in neonates with a sensitivity of 100% (CI: 39.8–100.0) and specificity of 88.39% (CI: 82.3–93.0). ConclusionUmbilical artery lactate correlates with adverse pregnancy outcomes and is an excellent tool for predicting adverse neonatal outcome.

Relationships of Jugular Bulb Parameters with Cerebral Perfusion and Metabolism After Resuscitation from Cardiac Arrest: A Post-Hoc Analysis of Experimental Studies Using a Minipig Model.

Cerebral blood flow (CBF) decreases in the first few hours or days following resuscitation from cardiac arrest, increasing the risk of secondary cerebral injury. Using data from experimental studies performed in minipigs, we investigated the relationships of parameters derived from arterial and jugular bulb blood gas analyses and lactate levels (jugular bulb parameters), which have been used as indicators of cerebral perfusion and metabolism, with CBF and the cerebral lactate to creatine ratio measured with dynamic susceptibility contrast magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. We retrospectively analyzed 36 sets of the following data obtained during the initial hours following resuscitation from cardiac arrest: percent of measured CBF relative to that at the prearrest baseline (%CBF), cerebral lactate to creatine ratio, and jugular bulb parameters, including jugular bulb oxygen saturation, jugular bulb lactate, arterial-jugular bulb oxygen content difference, cerebral extraction of oxygen, jugular bulb-arterial lactate content difference, lactate oxygen index, estimated respiratory quotient, and arterial-jugular bulb hydrogen ion content difference. Linear mixed-effects models were constructed to examine the effects of each jugular bulb parameter on the %CBF and cerebral lactate to creatine ratio. The arterial-jugular bulb oxygen content difference (P = 0.047) and cerebral extraction of oxygen (P = 0.030) had a significant linear relationship with %CBF, but they explained only 12.0% (95% confidence interval [CI] 0.002-0.371) and 14.2% (95% CI 0.005-0.396) of the total %CBF variance, respectively. The arterial-jugular bulb hydrogen ion content difference had a significant linear relationship with cerebral lactate to creatine ratio (P = 0.037) but explained only 13.8% (95% CI 0.003-0.412) of the total variance in the cerebral lactate to creatine ratio. None of the other jugular bulb parameters were related to the %CBF or cerebral lactate to creatine ratio. In conclusion, none of the jugular bulb parameters appeared to provide sufficient information on cerebral perfusion and metabolism in this setting.

The absolute lactate levels versus clearance for prognostication of post-cardiotomy patients on veno-arterial ECMO.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a life-saving procedure for supporting patients with cardiogenic shock after cardiac surgery. This work aimed to analyse the impact of changes in blood lactate levels on the survival of patients on post-cardiotomy ECMO (PC-ECMO) and whether lactate clearance (LC) performs better than absolute lactate levels. We retrospectively analysed the data of adult patients who received PC-ECMO at our centre between 2016 and 2022. The primary outcome was the in-hospital mortality rate. Arterial lactate levels were measured at ECMO initiation, peak and 12 and 24h after VA-ECMO support. LC was calculated at 12 and 24h. Out of 2368 patients who received cardiac surgeries, 152 (median age, 48years; 57.9% of them were men) received PC-ECMO. Of them, 48 (31.6%) survived and were discharged, while 104 (68.4%) died during the index hospitalization. Non-survivors had higher frequencies of atrial fibrillation (41.35% vs. 12.5%, P<0.001), chronic kidney disease (26.9% vs. 6.3%, P=0.004), prolonged cardiopulmonary bypass (237 vs. 192min, P=0.016) and aortic cross-clamping times (160 vs. 124min, P=0.04) than survivors. Non-survivors had a significantly higher median Sequential Organ Failure Assessment (SOFA) score at ECMO initiation (13.5 vs. 9, P<0.001) and a lower median Survival After Veno-arterial ECMO (SAVE) score (-3 vs. 3, P<0.001) with higher SAVE classes (P<0.001) than survivors. After 12h of VA-ECMO support, the blood lactate level was negatively correlated with LC in survivors (r=-0.755, P<0.001) and non-survivors (r=-0.601, P<0.001). After 24h, the same negative correlation was identified between survivors (r=-0.764, P<0.001) and non-survivors (r=-0.847, P<0.001). Blood lactate levels measured at 12h to determine hospital mortality [>8.2mmol/L, area under the receiver operating characteristic curve (AUROC): 0.868] and 24h (>2.6mmol/L, AUROC: 0.896) had the best performance, followed by LC-T12 (<21.94%, AUROC: 0.807), LC-T24 (<40.3%, AUROC: 0.839) and peak blood lactate (>14.35mmol/L, AUROC: 0.828). The initial pre-ECMO blood lactate (>6.25mmol/L, AUROC: 0.731) had an acceptable ability to discriminate mortality but was less than the following measurements and clearance. Kaplan-Meier curves demonstrated that LC of <21.94% at T12h and <40.3% at T24h was associated with decreased survival (log-rank P<0.001). Cox proportional hazards regression analysis for mortality revealed that LC of <21.94% at T12h had an adjusted hazard ratio (HR) of 2.73 [95% confidence interval (CI): 1.64-5.762, P<0.001] and LC of <40.3% at T24h had an adjusted HR of 1.98 (95% CI: 1.46-4.173, P<0.001). The predictors of hospital mortality after PC-ECMO were the lactate level at 12h [odds ratio (OR): 1.67, 95% CI: 1.121-2.181, P=0.001], initial SOFA score (OR: 1.593, 95% CI: 1.15-2.73, P<0.001), initial blood lactate (OR: 1.21, 95% CI: 1.016-1.721, P=0.032) and atrial fibrillation (OR: 6.17, 95% CI: 2.37-57.214, P=0.003). Bivariate models using lactate levels and clearance at the same points revealed that blood lactate levels performed better than the clearance percentage. Serial measurements of arterial blood lactate and LC help in obtaining early prognostic guidance in adult patients supported by VA-ECMO after cardiac surgery. Absolute lactate levels, compared with LC at the same time points, demonstrated better performance in differentiating mortality.

Effects of NF-κB Inhibitor on Sepsis Depend on the Severity and Phase of the Animal Sepsis Model.

Hyperinflammation occurs in sepsis, especially in the early phase, and it could have both positive and negative effects on sepsis. Previously, we showed that a new concept of NF-κB inhibitor, exosome-based super-repressor IκBα (Exo-srIκB) delivery, has a beneficial effect on sepsis. Here, we further investigate the therapeutic effects of Exo-srIκB at different severities and phases of sepsis using an animal polymicrobial intra-abdominal infection model. We used a rat model of fecal slurry polymicrobial sepsis. First, we determined the survival effects of Exo-srIκB on sepsis according to the severity. We used two different severities of the animal sepsis model. The severe model had a mortality rate of over 50%. The mild/moderate model had a less than 30% mortality rate. Second, we administered the Exo-srIκB at various time points (1 h, 6 h, and 24 h after fecal slurry administration) to determine the therapeutic effect of Exo-srIκB at different phases of sepsis. Lastly, we determined the effects of the Exo-srIκB on cytokine production, arterial blood gas, electrolyte, and lactate. The survival gain was statistically significant in the severe sepsis model when Exo-srIκB was administered 6 h after sepsis. Interleukin 6 and interleukin-10 were significantly decreased in the kidney when administered with Exo-srIκB. The laboratory data showed that lactate, glucose, and potassium levels were significantly lowered in the NF-κB inhibitor group. In conclusion, Exo-srIκB exhibited a beneficial therapeutic effect when administered 6 h post fecal slurry administration in a severe sepsis model.

Assessing the Prognostic Significance of Lactate Levels and Arterial Base Excess in Patients After Pancreatic Surgery: A Retrospective Analysis

Assessing the Prognostic Significance of Lactate Levels and Arterial Base Excess in Patients After Pancreatic Surgery: A Retrospective Analysis

Immediate inflammatory response to mechanical circulatory support in a porcine model of severe cardiogenic shock

BackgroundIn selected cases of cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is combined with trans valvular micro axial flow pumps (ECMELLA). Observational studies indicate that ECMELLA may reduce mortality but exposing the patient to two advanced mechanical support devices may affect the early inflammatory response. We aimed to explore inflammatory biomarkers in a porcine cardiogenic shock model managed with V-A ECMO or ECMELLA.MethodsFourteen landrace pigs had acute myocardial infarction-induced cardiogenic shock with minimal arterial pulsatility by microsphere embolization and were afterwards managed 1:1 with either V-A ECMO or ECMELLA for 4 h. Serial blood samples were drawn hourly and analyzed for serum concentrations of interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha, and serum amyloid A (SAA).ResultsAn increase in IL-6, IL-8, and SAA levels was observed during the experiment for both groups. At 2–4 h of support, IL-6 levels were higher in ECMELLA compared to V-A ECMO animals (difference: 1416 pg/ml, 1278 pg/ml, and 1030 pg/ml). SAA levels were higher in ECMELLA animals after 3 and 4 h of support (difference: 401 ng/ml and 524 ng/ml) and a significant treatment-by-time effect of ECMELLA on SAA was identified (p = 0.04). No statistical significant between-group differences were observed in carotid artery blood flow, urine output, and lactate levels.ConclusionsLeft ventricular unloading with Impella during V-A ECMO resulted in a more extensive inflammatory reaction despite similar end-organ perfusion.

Lactate-to-albumin ratio: A promising predictor of 28-day all-cause mortality in critically Ill patients with acute ischemic stroke

IntroductionNumerous diseases have been found to be associated with the lactate-to-albumin ratio (LAR), as confirmed by existing research. This study aims to investigate the relationship between LAR within 24 hours of admission and a 28-day mortality rate in patients manifesting ischemic stroke. MethodsThis retrospective cohort study utilized data from the Medical Information Mart for Intensive Care IV (MIMIC-IV, version 2.1) database. We included adult patients with acute ischemic stroke (AIS) who were admitted to the intensive care unit. The primary outcome entailed evaluating the ability of LAR to predict death at 28-day of hospital admission in patients with AIS. ResultsA total of 502 patients with ischemic stroke were enrolled in the study, of which 185 (36.9 %) died within 28 days after hospital admission. We identified a linear association between LAR and mortality risk. Compared with the reference group (first LAR tertile), the 28-day mortality was increased in the highest tertile; the fully adjusted HR value was 1.21 (1.08 to 1.40). the Area Under the Curve (AUC) value for LAR was 58.26 % (95 % CI: 53.05 % - 63.46 %), which was higher than that for arterial blood lactate (AUC = 56.88 %) and serum albumin (AUC = 55.29 %) alone. It was not inferior even when compared to SOFA (AUC = 56.28 %). The final subgroup analysis exhibited no significant interaction of LAR with each subgroup (P for interaction: 0.079 - 0.848). ConclusionIn our study, LAR emerged as a promising predictor of all-cause mortality in acute ischemic stroke patients within 28 days of admission.

Perioperative Evaluation of Arterial and Venous Whole Blood in the Lamb (Ovis aries) Fontan Model.

Whole blood analysis can evaluate numerous parameters, including pH, pCO₂, pO₂, HCO₃ - , base excess, glucose, electrolytes, lactate, blood urea nitrogen, creatinine, bilirubin, and hemoglobin. This valuable tool enables clinicians to make more informed decisions about patient care. However, the current body of literature describing perioperative whole blood analysis in Dorset sheep (Ovis aries) is small, so clinicians lack adequate information to guide their decision-making when evaluating test results. We evaluated arterial and venous whole blood pH, bicarbonate, pCO₂, lactate, creatinine, and blood urea nitrogen before and for the first 24 hours after surgery in 2 cohorts of male and female Ovis arie s undergoing one of 2 major cardiovascular procedures, a Single-Stage Fontan or an inferior vena cava to pulmonary artery extracardiac conduit implantation (IP-ECC). The cohort undergoing a Single-Stage Fontan, which is the more complex procedure, exhibited greater deviation from baseline measurements than did the cohort undergoing the IP-ECC for lactate, bicarbonate, and creatinine. The cohort undergoing the IP-ECC showed no significant deviation from baseline for any parameters, potentially indicating a better safety margin than expected when compared with the Single-Stage Fontan. Together, these results indicate the clinical value of arterial and venous whole blood measurements in perioperative management of sheep and can provide a reference for clinicians managing sheep after significant cardiovascular procedures.

Biomarkers and predictors of postoperative necrotizing enterocolitis in neonates with duct-dependent congenital heart defects undergoing cardiac surgery: a cohort study

The development of necrotizing enterocolitis (NEC) in neonates with duct-dependent congenital heart defects (CHD) who underwent cardiac surgery is accompanied by high mortality. Analysis of predictors is necessary for understanding the pathophysiology of NEC and development of approaches for prevention to achieve favorable outcomes of cardiac surgery. The purpose of the study was to develop a prognostic model for predicting the development of NEC after cardiac surgery in neonates with duct-dependent CHD. Methods. A prognostic cohort study was performed that included full-term neonates with duct-dependent CHD who underwent cardiac surgery at the Almazov National Medical Research Center from January 2021 to September 2023. The outcome was the development/absence of stage IB-III NEC in the postoperative period. Biomarkers of NEC (intestinal fatty acid binding protein (i-FABP, ng/ml), claudin-3 (CLDN3, ng/ml), calprotectin (CALPR, ng/ml), ischemia modified albumin (IMA, ng/ml), vascular endothelial growth factor A (VEGF A, pg/ml)) were measured by ELISA in the blood serum before cardiac surgery and 12-14 hours after surgery. We also analyzed clinical characteristics of neonates, C-reactive protein levels, complete blood count, abdominal ultrasound, ejection fraction (EF, Teicholtz) in the preoperative and postoperative periods, surgical parameters, P(v-a)CO2/C(a-v)O2 upon arrival from the operating room, vasoactive inotropic score (VIS) and arterial blood lactate levels in the first 24 hours after surgery. The association between predictors and the development of NEC after cardiac surgery was assessed using univariate and multivariate logistic regression analysis. Internal validation of the model was performed using 10-fold cross-validation. Results. During the observation period, 187 neonates underwent surgical treatment of duct-dependent CHD, of which 32 children developed stage IB-III NEC in the postoperative period (17.1%), two neonates required surgical treatment of NEC (6.3%). After meeting the non-inclusion and exclusion criteria, two groups of patients were formed: a main group (30 neonates who developed stages IB-III NEC in the postoperative period, of which stage III NEC was in one neonate) and a comparison group (40 neonates without NEC). Groups were comparable by types of CHD. Predictors associated with NEC (univariate analysis): intrauterine growth retardation (IUGR), formula feeding before surgery, high levels of IMA before on the first postoperative day (POD), procedures performed before surgery (Rashkind procedure/valvuloplasty/stenting), lower EF in in the early postoperative period, a higher maximum level of VIS in the first 24 hours after surgery, as well as a higher level of IR in the superior mesenteric artery (SMA) and thickening of the intestinal wall on the first postoperative day (POD) Independent preoperative predictors of NEC (AUC of model 0.885, specificity 0.867): IUGR (OR 32.2 (1.4-730.3), p=0.029), formula feeding (OR 12.6 (2.6-60.2), p=0.002), IMA level before surgery (OR 1.03 (1.01-1.04), p=0.004), CLDN3 level before surgery (OR 0.5 (0.3-0.9), p=0.013). Independent early postoperative predictors of NEC: IMA level on 12-14 hour after surgery (OR 1.02 (1.01-1.03), p=0.030), P(v-a)CO2/C(a-v)O2 immediately after surgery (OR 2.3 (1.2-4.4), p=0.008), IR&gt;0.93 in SMA (OR 7.2 (1.6-32.4), p=0.011) and thickness of intestinal wall by ultrasound on POD 1 (OR 4.9 (1.3-19.2), p=0.021). Adding of VEGF A level (12-14 hour after surgery, negatively associated with NEC) to the model increased the specificity, but the predictor was not significant. AUC of postoperative model 0.862, specificity 0.800. The final model included preoperative (IUGR, formula feeding) and postoperative predictors (IMA, P(v-a)CO2/C(a-v)O2, IR of SMA&gt;0.93, intestinal wall thickness), AUC=0.921, specificity 0.83. Conclusion. The identified predictors indirectly indicate the role of hypoxia in the pathophysiology of NEC in term neonates with duct-dependent CHD. Breast milk feeding/mixed feeding in the preoperative period may help reduce the risk of NEC in the postoperative period. Low levels of CLDN3 before surgery were associated with the development of NEC, but the interpretation of the result is controversial.

The origin of the maximal lactate steady state (MLSS).

The maximal lactate steady state, abbreviated as MLSS, is the maximal exercise intensity where the concentration of earlobe capillary or arterial blood lactate remains constant over time. In the late 1970s and early 1980s, we (i.e. Hermann Heck and co-workers) developed a direct test to determine the MLSS to investigate whether it occurred at a lactate concentration of 4 mmol.L- 1, as earlier predicted by Alois Mader and colleagues. The test consisted of each participant performing several constant-intensity running bouts of ≈ 30min at intensities close to the estimated MLSS. During each run, we measured lactate every 5min. Based on the results, we defined the MLSS as the "workload where the concentration of blood lactate does not increase more than 1 mmo.L- 1during the last 20 min of a constant load exercise". This MLSS protocol is impractical for performance testing as it requires too many exercise bouts, but it is a gold standard to determine the real MLSS. It is especially useful to validate indirect tests that seek to estimate the MLSS.

Association between lactate to hematocrit ratio and 30-day all-cause mortality in patients with sepsis: a retrospective analysis of the Medical Information Mart for Intensive Care IV database.

The lactate to hematocrit ratio (LHR) has not been assessed for predicting all-cause death in sepsis patients. This study aims to evaluate the relationship between LHR and 30-day all-cause mortality in sepsis patients. This retrospective study used the data from Medical information mart for intensive care IV (MIMIC-IV, version 2.0). Our study focused on adult sepsis patients who were initially hospitalized in the Intensive care unit (ICU). The prognostic significance of admission LHR for 30-day all-cause mortality was evaluated using a multivariate Cox regression model, ROC curve analysis, Kaplan-Meier curves, and subgroup analyses. A total of 3,829 sepsis patients participated in this study. Among the cohort, 8.5% of individuals died within of 30 days (p < 0.001). The area under the curve (AUC) for LHR was 74.50% (95% CI: 71.6-77.50%), higher than arterial blood lactate (AUC = 71.30%), hematocrit (AUC = 64.80%), and shows no significant disadvantage compared to qSOFA, SOFA, and SAPS II. We further evaluated combining LHR with qSOFA score to predict mortality in sepsis patients, which shows more clinical significance. ROC curve analysis showed that 6.538 was the optimal cutoff value for survival and non-survival groups. With LHR ≥6.538 vs. LHR <6.538 (p < 0.001). Subgroup analysis showed significant interactions between LHR, age, sex, and simultaneous acute respiratory failure (p = 0.001-0.005). LHR is an independent predictor of all-cause mortality in sepsis patients after admission, with superior predictive ability compared to blood lactate or hematocrit alone.

Clinical, laboratory and morphological comparisons in cellular alteration under conditions of hypoxia

To compare structural changes in tissues with clinical and laboratory parameters and immunohistochemical determination of proteins HIF1α, HIF2α, caspase-3 during cellular alteration under conditions of hypoxia in the liver and kidneys in an experiment on pigs. Laboratory parameters related to the state of gas exchange (decrease in partial pressure of arterial blood oxygen (PaO2), arterial blood saturation, lactate level, kidney function (creatinine, urea) and liver (ALT, AST, bilirubin) in 18 animals were analyzed in comparison with the results of a morphological study. Histological examination evaluated alterative and inflammatory tissue changes of varying severity, and also determined the expression of transcription factors HIF1α and HIF2α and a marker of apoptosis - caspase-3. The ratio between laboratory parameters and structural changes was assessed individually for each animal. In the liver, a statistically significant dependence of the content of HIF2α protein in cells on the severity of dystrophic changes and serum lactate levels was revealed. A statistically significant correlation was shown between an increase in transaminase and bilirubin levels and the severity of alterative changes in liver tissue. However, there was no significant relationship between the number of caspase-3 positive cells and the severity of dystrophic changes. A statistically significant correlation was found between creatinine and urea levels and the severity of alterative changes in kidney tissues. With significant dystrophic changes, a statistically significant dependence of the expression of HIF2α and caspase-3 proteins and a very high correlation of caspase-3 - lactate indicators were revealed. A significant correlation was shown between histological changes in tissues and clinical and laboratory parameters. Severe hypoxia with lactate accumulation directly affects the integrity and function of cells, which manifests itself in structural changes. Based on the results of a comparative study, it can be concluded that the assessment of alterative changes in liver and kidney tissues is important.

Metabolic Evaluation in Children aged 3 months to 2 years with Global Developmental Delay

Abstract Objectives To study the clinical profile and role of metabolic evaluation in children aged 3 mo to 2 y with global developmental delay (GDD) of unclear etiology. Methods In this prospective study, demographic and clinical data along with first line metabolic test results [blood glucose, arterial blood sample analysis, renal function tests, uric acid, serum electrolytes, liver function tests (LFTs), plasma ammonia, arterial blood lactate and pyruvate, urine ketone/ reducing substances] were documented and analyzed. Tandem Mass Spectroscopy (TMS) and Gas Chromatography and Mass Spectrometry (GC-MS) data were also analysed. Results Of 101 eligible children, 48 were excluded. Among 53 children included in the study, 32 (60.3%) were less than 1 y and 21 (39.7%) were more than 1 y. Four major developmental domains were almost equally affected in 16 (30.1%), three domains in 4 (7.5%) and two domains in 33 (62.4%) children. Fourteen (26.4%) children were found to have a probable metabolic disorder based on initial tests- 10 mitochondrial disorders, 3 organic-acidemias and 1 fatty-acid-oxidation defect. Further, on TMS and GC-MS tests, 11 (20.7%) had a metabolic disorder- 7 mitochondriopathies, 2 methylmalonic-aciduria, 1 each with glutaric-acidemia and ethylmalonic-aciduria. Conclusions Among children with GDD of unclear etiology, metabolic errors constitute a small proportion of etiology. In this group early metabolic tests could identify potentially treatable conditions.

Influence of pneumatic tube delivery system on laboratory results.

The pneumatic tube system (PTS) is an automated and fast modality of transportation of biological samples, but it has been reported to induce preanalytical errors. To study the influence of transportation by PTS on biochemistry tests which are particularly sensitive to haemolysis and atmospheric pressure variation. We compared laboratory results of arterial blood gas, sodium, potassium, chloride, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, glucose and haemolysis index of samples conveyed simultaneously by PTS and by courier. We recruited 30 patients from the sampling room and 40 patients from the intensive care unit. Transport through PTS resulted in a significant increase in aspartate aminotransferase and potassium without exceeding the limits of acceptability. Potassium was significantly more increased for samples transported in a higher speed line (p = .048) but without exceeding the limits of acceptability. No significant impact was noted on haemolysis indices. The pO2 variations due to PTS transportation exceeded the limit of acceptability with significant intra-individual variations. Our PTS is validated for biochemistry tests results. It reduces turnaround times without affecting sample quality. However, the interpretation of arterial blood gas results should be careful for samples transported by PTS.

Prognostic value of combined central venous oxygen saturation and lactate in pediatric patients after cardiac surgery

ObjectivesThis study assessed the value of measuring both arterial lactate levels and central venous oxygen saturation (ScvO2) in predicting cardiac surgery outcomes in pediatric patients.MethodsA prospective cohort study was conducted on 73 patients who underwent surgery for congenital heart disease. Vasoactive-inotropic score (VIS), serial mean arterial blood pressures (MAP), lactate levels, and ScvO2 were measured immediately and 3, 6, 12, 18, and 24 h after admission to the pediatric intensive care unit (PICU). To test the prognostic values of these markers, we calculated the areas under the receiver operating characteristic curves (AUCs). Binary logistic regression was used to identify the determinants of postsurgical complications.ResultsThe most common complications after cardiac surgery were the prolonged need for mechanical ventilation (38.36%), chest infection (30.14%), prolonged stay in the PICU (24.66%), and sepsis (9.59%). ScvO2 6 h after admission was most predictive of complications (AUC = 85.5%), followed by ScvO2/lactate (AUC = 83.0%), lactate level 12 h after admission (AUC = 75.0%), MAP (AUC = 73.6%), and VIS (AUC = 63.4). In multivariate analysis, body weight and ScvO2 6 h after PICU admission were the main predictors of complications (OR = 0.01, 95% CI 0.001–0.689, p = 0.033), and (OR = 0.87, 95% CI 0.798–0.948, p = 0.002) respectively.ConclusionsTo predict complications after pediatric cardiac surgery, lactate measurement does not add value to ScvO2 measurement 6 h after admission.The Cochrane TRNPACTR202104905893217.Date of registration 12 April 2021.

Arterial blood analysis of healthy residents in Huamachuco, Peru (3,164 m): a cross-sectional study.

Background: Given that arterial blood gas is affected by altitude and ethnicity, establishing reliable reference standards for these values requires analysis of arterial blood at different elevations and locations. Our objective was to measure the arterial blood gases of healthy young volunteers in Huamachuco, Peru, at 3,164 m above sea level. This is likely the first study of arterial blood gas analysis of healthy Northern Peruvians living at high altitude. Methods: Healthy residents of Huamachuco were recruited for this cross-sectional convenience sample study and arterial blood was drawn by standard procedures. People with obesity, diabetes, high levels of physical activity and a history of using selected substances were excluded. The samples were analyzed on-site in less than 15 minutes using a Stat Profile Prime CCS analyzer (Nova Biomedical). Results: Data from 46 participants (17 male, 29 female) were included in the study. The median values for arterial blood pH, oxygen, carbon dioxide, ionized calcium, glucose, lactate, hematocrit, oxygen saturation, and bicarbonate were 7.42, 9.3 kPa (70 mmHg), 4.5 kPa (33.5 mmHg), 1.04 mM, 5.19 mM, 1.8 mM, 50 %, 94 %, and 21.6 mM, respectively. We also found a lower prevalence of diabetes among highlanders compared to the Peruvian population. Conclusions: The results determined here were comparable to other results determined at different altitudes in the Americas, although arterial blood oxygen was slightly higher than predicted. These results indicate that Northern Peruvians have an Andean-style adaptation to high altitude.

Positive association between arterial blood lactate level before extra-corporeal membrane oxygenation and 30-day mortality in pediatric patients with severe cardiopulmonary failure.

This study aimed to investigate the relationship between blood lactate level and mortality in pediatric patients receiving extracorporeal membrane oxygenation (ECMO) for severe cardiopulmonary failure. A retrospective observational study was conducted on pediatric patients who received ECMO from January 2013 to December 2021 at the Seventh Medical Center of PLA General Hospital. Patient demographic characteristics, arterial blood lactate level prior to ECMO (pre-ECMO), ECMO settings, ECMO duration, and 30-days mortality were retrieved from patients' medical records. The relationships between pre-ECMO blood lactate level and mortality were interpreted using the logistic regression analysis and Kaplan-Meier survival analysis. A total of 160 pediatric patients who had either refractory respiratory failure (n = 89) or circulatory failure (n = 71) and received ECMO were included in this study. In both the respiratory failure and circulatory failure groups, the non-survivors showed a higher mean pre-ECMO arterial blood lactate level than the survivors. In the respiratory failure group, a pre-ECMO lactate concentration at ≥11.6mmol/L had a sensitivity of 51% and a specificity of 82% for predicting mortality. In the circulatory failure group, a pre-ECMO lactate concentration at ≥7.2mmol/L had a sensitivity of 90% and a specificity of 57% for predicting mortality. The Kaplan-Meier survival curves showed that respiratory failure patients with a pre-ECMO lactate level over 11.6mmol/L or circulatory failure patients with a pre-ECMO lactate level over 7.2mmol/L had a higher 30-days mortality rate than those with a lower lactate level. High pre-ECMO arterial blood lactate level serves as an independent risk factor for mortality in pediatric patients who receive ECMO for severe cardiopulmonary failure.

A Retrospective Study on the Availability of Arterial Lactate Levels as a Biomarker of Mortality in Critically Ill Children

Objective: We aimed to determine the threshold value of lactate levels, and to analyze its avaliability as mortality biomarker by correlating it with scoring systems in pediatric intensive care unit (PICU). Material and Methods: Observational retrospective cohort study. Our study was conducted among patients admitted to the 24-bed tertiary PICU of our hospital in 2015. All children between the ages of 1 month and 18 years were evaluated. Among 433 patients whose arterial blood gases were obtained during hospitalization, a total of 382 were included in the study. Patients with congenital metabolic disease with lactic acidosis were excluded. The arterial blood lactate levels on admission, PIM-2, PRISM-III and PELOD scores and survival status of the patients were evaluated. Correlation between lactate levels and mortality scores, threshold values of lactate levels and the factors affecting mortality risk were the main variable of interest. Results: There was a significant correlation between lactate levels and scores in patients who died (p&amp;lt;0.001). Receiver operating characteristic (ROC) curve analysis showed that blood lactate level was an effective parameter on mortality (area under the curve=AUC: 0.861; p&amp;lt;0.001) with a cut-off value of 2.55 mmol/L. The mortality risk was 1.38 fold higher in patients with higher levels of lactate. Conclusion: In our series, the levels of lactate were higher in critically ill children who died. Again, lactate levels and mortality scores of these children were correlated. In our series, the levels of lactate were higher in critically ill children who died. Again, lactate levels and mortality scores of these children were correlated. We were able to establish a cut-off point with high specificity for predicting evolution. These findings should be validated in prospective and multicenter studies for their incorporation into scoring systems.