Arterial Lactate Research Articles

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.

Factors associated with mortality of patients with COVID-19 on invasive mechanical ventilation: A retrospective cohort study in a university hospital in Northeastern Brazil.

The aim of this study is to identify the factors associated with mortality in patients with COVID-19 undergoing invasive mechanical ventilation at a university hospital in Northeastern Brazil. This is a retrospective cohort from April to August 2020 through an analysis of medical records, considering the demographic profile, comorbidities, complications, supports, respiratory and laboratory parameters. A total of 65 patients required invasive mechanical ventilation, of which 64.6% died in the ICU. They were older, had more comorbidities, shorter length of stay in the intensive care unit, received more support such as palliative care and two vasopressors simultaneously, showed lower levels of pH, hemoglobin and calcium, and higher levels of bicarbonate, lactate, prothrombin time, international normalized ratio, troponin and ferritin at the start of invasive mechanical ventilation. Furthermore, the time course of pH, arterial oxygen partial pressure to fractional inspired oxygen ratio, arterial carbon dioxide partial pressure, lactate, hemoglobin, platelets, lymphocytes, neutrophil-to-lymphocyte ratio, coagulation parameters, calcium, urea, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, ferritin, static compliance, airway resistance, tidal volume, and noradrenaline doses showed association with mortality. There was a high mortality rate in invasively mechanically ventilated COVID-19 patients, with some associated factors identified at the start of invasive mechanical ventilation and others identified over time.

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.

Effect of ultrashort-acting β-blockers on 28-day mortality in patients with sepsis with persistent tachycardia despite initial resuscitation: a meta-analysis of randomized controlled trials and trial sequential analysis.

This meta-analysis aims to identify whether patients with sepsis who have persistent tachycardia despite initial resuscitation can benefit from ultrashort-acting β-blockers. Relevant studies from MEDLINE, the Cochrane Library, and Embase were searched by two independent investigators. RevMan version 5.3 (Cochrane Collaboration) was used for statistical analysis. A total of 10 studies were identified and incorporated into the meta-analysis. The results showed that the administration of ultrashort-acting β-blockers (esmolol/landiolol) in patients with sepsis with persistent tachycardia despite initial resuscitation was significantly associated with a lower 28-day mortality rate (risk ratio [RR], 0.73; 95% confidence interval [CI], 0.57-0.93; and p˂0.01). Subgroup analysis showed that the administration of esmolol in patients with sepsis was significantly associated with a lower 28-day mortality rate (RR, 0.68; 95% CI, 0.55-0.84; and p˂0.001), while there was no significant difference between the landiolol and control groups (RR, 0.98; 95% CI, 0.41-2.34; and p = 0.96). No significant differences between the two groups were found in 90-day mortality, mean arterial pressure (MAP), lactate (Lac) level, cardiac index (CI), and troponin I (TnI) at 24h after enrollment. The meta-analysis indicated that the use of esmolol in patients with persistent tachycardia, despite initial resuscitation, was linked to a notable reduction in 28-day mortality rates. Therefore, this study advocates for the consideration of esmolol in the treatment of sepsis in cases where tachycardia persists despite initial resuscitation.

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.

Association between Peripheral Arterial Lactate Levels and Malignant Brain Edema Following Endovascular Treatment for Ischemic Stroke.

To investigate the factors of postoperative malignant brain edema (MBE) in patients with acute ischemic stroke (AIS) treated with endovascular treatment (EVT). MBE is a severe complication following EVT for AIS, and it is essential to identify risk factors early. Peripheral arterial lactate (PAL) levels may serve as a potential predictive marker for MBE. To determine whether immediate postoperative PAL levels and the highest PAL level within 24 hours of EVT are independently associated with MBE development in AIS patients. We retrospectively analyzed patients with AIS who underwent EVT from October 2019 to October 2022. Arterial blood was collected every 8 h after EVT to measure PAL, and record the immediate postoperative PAL and the highest PAL level within 24 h. Brain edema was evaluated using brain computed tomography scans within 7 days of EVT. The study included 227 patients with a median age of 71 years, of whom 59.5% were male and MBE developed in 25.6% of patients (58/227). Multivariate logistic regression analysis showed that the immediate postoperative PAL (odds ratio, 1.809 [95% confidence interval (CI), 1.215-2.693]; p = 0.004) and the highest PAL level within 24 h of EVT (odds ratio, 2.259 [95% CI, 1.407-3.629]; p = 0.001) were independently associated with MBE. The area under the curve for predicting MBE based on the highest PAL level within 24 hours of EVT was 0.780 (95% CI, 0.711-0.849). Early increase in PAL levels is an independent predictor of MBE after EVT in AIS patients.

Prognostic value of arterial lactate index in ST-elevation myocardial infarction treated with primary percutaneous coronary intervention: a prospective cohort study.

Aim: Limited knowledge exists on the pathophysiological cascade beyond serum lactate's association with myocardial injury. Method: Assessed the prognostic value of lactate index on periprocedural variables and its impact on 30-day major adverse cardiovascular events (MACE)in 300 prospective ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (pPCI). Results: Significant correlations were observed between admission lactate and Killip class, periprocedural time intervals, postprocedure thrombolysis in myocardial infarction (TIMI) flow and myocardial blush grade (MBG;p<0.01). Lactate levels correlated with diminished ST-deviation resolution, cardiac enzymes (CK-MB, troponin;p<0.001; 0.004), and lower ejection fraction (p<0.001). This relationship impacted 30-day MACE (p<0.001). Conclusion: Hyperlactatemia in STEMI patients undergoing pPCI is associated with worse Killip class, unsatisfactory TIMI flow, MBG, larger infarct size and higher 30-day MACE. Serum lactate aids risk stratification in pPCI for STEMI patients.

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.

Effect of shenfu injection in patients with septic shock: A systemic review and meta-analysis for randomized clinical trials

Ethnopharmacological relevanceShenfu injection (SFI) is a well-known Chinese herbal medicine widely used in the treatment of septic shock in China. Aim of the studyTo explore the clinical safety and effectiveness of combined application of Shenfu injection in the treatment of septic shock on the basis of routine western medical treatment. Materials and methodsRandomized controlled trials published before February 28, 2022 in patients with septic shock were searched in the Chinese Biomedical Literature Service System (SinoMed), Embase, PubMed, Cochrane Library, WOS, Scopus. Stata 15.0 and R 4.2.2 were used to meta-analyze sequential organ failure assessment (SOFA) score, case fatality rate, mean arterial pressure (MAP), arterial lactate (Lac). Adverse effects were analyzed by description. ResultsA total of 904 articles were searched and 56 RCTs were included, with a total of 4279 participants. Among them, there were 2148 cases in the SFI group and 2131 cases in the control group. The meta-analysis showed that, comparing with routine western medical therapy, the combined use of SFI could effectively reduce 24 h SOFA (MD = −0.79, 95%CI: (−1.12) - (−0.46)), 72 h SOFA (MD = −1.53, 95%CI: (−1.89) - (−1.17)) and 7 d SOFA (MD = −1.55; 95%CI: (−2.86) - (−0.24)). Besides, combined use of SFI could reduce 14 d case fatality rate (RR = 0.16, 95% CI: 0.07–0.37) and 28 d case fatality rate (RR = 0.82, 95% CI: 0.71–0.95). While SFI group showed almost the same effect in 7 d case fatality rate as control (RR: 0.76; 95% CI: 0.42–1.37; P = 0.37). SFI could increase 6 h MAP (MD = 6.40, 95% CI: 3.43–9.37) and 24 h MAP (MD = 4.79, 95% CI: 1.62–7.95). Additionally, SFI could decrease 6 h Lac (MD = −0.90, 95% CI: (−1.34) - (−0.45)), 24 h Lac (MD = −0.80, 95% CI: (−1.20) - (−0.40)), 48 h Lac (MD = −0.67, 95% CI: (-1.05) - (−0.29)). ConclusionsShenfu injection combined with RWT showed better therapeutic effect than RWT. SFI plus RWT can improve clinical prognosis of patients with septic shock.

Improve the prediction of liver transplant mortality based on pre-transplant factors: A multi-center study from China: Mortality prediction of LT

AimsTo designed a new model using pre-transplant data to predict post-transplant mortality for Chinese population and compared its performance to that of existing models. MethodsIn this multicenter study, 544 recipients of liver transplants for non-tumor indications were enrolled in the training group and 276 patients in the validation group. The new Simplified Mortality Prediction Scores (SMOPS) model was compared to the MELD and four existing models using the C-statistic. ResultsSMOPS model used 6 independent pre-transplantation risk factors screened from the training group (chronic liver failure/organ failure scores, fever > 37.6 ℃, ABO blood-type compatibility, arterial lactate level, leukocyte count and re-transplantation). The SMOPS accurately predicted patients' 30-day, 90-day and 365-day mortality following liver transplantation, and its' scores were more accurate than those of the other models. The SMOPS generated four levels of risk: low risk (<10 points), moderate risk (11–20 points), high risk (21–25 points) and futile risk (≥26 points). The survival within all risk levels was not different between MELD=40 and MELD<40. The survival within moderate-, high- or extreme-risk ALF was not different between ALF and non-ALF. ConclusionThe SMOPS model uses pre-transplant risk factors to stratify post-transplant survival and is superior to current models for Chinese population, and has the potential to contribute to improvements in organ-allocation policies.

TiME OUT: Time-specific machine-learning evaluation to optimize ultramassive transfusion.

Ultramassive transfusion (UMT) is a resource-demanding intervention for trauma patients in hemorrhagic shock, and associated mortality rates remains high. Current research has been unable to identify a transfusion ceiling or point where UMT transitions from lifesaving to futility. Furthermore, little consideration has been given to how time-specific patient data points impact decisions with ongoing high-volume resuscitation. Therefore, this study sought to use time-specific machine learning modeling to predict mortality and identify parameters associated with survivability in trauma patients undergoing UMT. A retrospective review was conducted at a Level I trauma (2018-2021) and included trauma patients meeting criteria for UMT, defined as ≥20 red blood cell products within 24 hours of admission. Cross-sectional data were obtained from the blood bank and trauma registries, and time-specific data were obtained from the electronic medical record. Time-specific decision-tree models predicating mortality were generated and evaluated using area under the curve. In the 180 patients included, mortality rate was 40.5% at 48 hours and 52.2% overall. The deceased received significantly more blood products with a median of 71.5 total units compared with 55.5 in the survivors ( p < 0.001) and significantly greater rates of packed red blood cells and fresh frozen plasma at each time interval. Time-specific decision-tree models predicted mortality with an accuracy as high as 81%. In the early time intervals, hemodynamic stability, undergoing an emergency department thoracotomy, and injury severity were most predictive of survival, while, in the later intervals, markers of adequate resuscitation such as arterial pH and lactate level became more prominent. This study supports that the decision of "when to stop" in UMT resuscitation is not based exclusively on the number of units transfused but rather the complex integration of patient and time-specific data. Machine learning is an effective tool to investigate this concept, and further research is needed to refine and validate these time-specific decision-tree models. Prognostic and Epidemiological; Level IV.

Cardiac energetics and end-organ perfusion with veno-arterial extracorporeal membrane oxygenation versus ecmella for cardiogenic shock in a large animal model

Abstract Background The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is in severe cases of left ventricular (LV) failure associated with pulmonary edema due to inadequate LV emptying. In clinical practice VA-ECMO may be combined with Impella CP (ECMELLA), to unload the LV. We hypothesized that ECMELLA improves cardiac energetics without compromising end-organ perfusion compared to VA-ECMO alone in a porcine model of cardiogenic shock (CS). Methods Land-race pigs (weight 70 kg) were instrumented, including a LV conductance catheter and a carotid artery Doppler flow probe. Arterial blood samples were analyzed for lactate level. CS was induced with embolization in the left main coronary artery and was defined as a reduction of 50% or more in cardiac output (CO) or mixed oxygen saturation (SvO2) or a SvO2 &amp;lt; 30%. VA-ECMO was initiated at CS and embolization was continued until arterial pulse pressure was below 10 mmHg. At this point, Impella CP was placed in the ECMELLA arm. Support was maintained for four hours. Results CS was induced in 15 pigs (VA-ECMO n=7, ECMELLA n=8) and at CS the CO declined from 6.1 L/min (0.8) to 2.5 L/min (1.1) in the VA-ECMO arm and from 5.2 L/min (SD: 0.6) to 2.0 L/min (SD: 0.7) in the ECMELLA arm. The pressure-volume area (PVA) was comparable at CS, but significantly higher with VA-ECMO compared to ECMELLA after four hours (9567 SD: 1733 versus 6921 SD: 0536 mmHg*mL, p=0.014). Carotid blood flow increased from CS and was similar in VA-ECMO and ECMELLA (239 mL/min SD: 97 versus 213mL/min SD: 133) at four hours p=0.6. Arterial lactate was equally elevated in both groups at four hours (VA-ECMO 5.2 SD: 3.4 versus 4.2 SD: 2.9 mmol/l for ECMELLA), p=0.5). Conclusion In a porcine model of CS, we found lower PVA with the ECMELLA configuration compared to VA-ECMO, yet similar lactate levels after four hours of mechanical circulation. These findings indicate that ECMELLA better cardiac energetics without compromising systemic perfusion.Central hemodynamicsEnd-organ perfusion

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.

Impact of discontinuing oxytocin in active labour on neonatal morbidity: an open-label, multicentre, randomised trial

Oxytocin is effective in reducing labour duration but can be associated with fetal and maternal complications that could potentially be reduced by discontinuing the treatment during labour. We aimed to assess the impact of discontinuing oxytocin during active labour on neonatal morbidity. STOPOXY was a multicentre, randomised, open-label, controlled, superiority trial conducted in 21 maternity units in France. Participants who received oxytocin before 4 cm dilation were randomly assigned 1:1 to either discontinuous oxytocin (oxytocin infusion stopped beyond a cervical dilation equal to or greater than 6 cm) or continuous oxytocin (administration of oxytocin continued until delivery). Randomisation was stratified by centre and parity. The primary outcome, neonatal morbidity, was assessed at birth using a composite variable defined by an umbilical arterial pH at birth less than 7·10, a base excess greater than 10 mmol/L, umbilical arterial lactates greater than 7 mmol/L, a 5-min Apgar score less than 7, or admission to the neonatal intensive care unit. Efficacy and safety was assessed in participants who were randomly assigned (excluding those who withdrew consent or were deemed ineligible after randomisation) and had reached a cervical dilation of at least 6 cm. This trial is registered with ClinicalTrials.gov, NCT03991091. Of 2459 participants randomly assigned between Jan 13, 2020, and Jan 24, 2022, 2170 were eligible to receive the intervention and were included in the final modified intention-to-treat analysis. The primary outcome occurred for 102 (9·6%) of 1067 participants (95% CI 7·9 to 11·5) in the discontinuous oxytocin group and for 101 (9·2%) of 1103 participants (7·6 to 11·0) in the continuous oxytocin group; absolute difference 0·4% (95% CI -2·1 to 2·9); relative risk 1·0 (95% CI 0·8 to 1·4). There were no clinically significant differences in adverse events between the two groups of the safety population. Among participants receiving oxytocin in early labour, discontinuing oxytocin when the active phase is reached does not clinically or statistically significantly reduce neonatal morbidity compared with continuous oxytocin. French Ministry of Health and the Département de la Recherche Clinique et du Développement de l'Assistance Publique-Hôpitaux de Paris.

Lactate’s behavioral switch in the brain: An in-silico model

Emerging evidence emphasizes lactate’s involvement in both physiological processes (energy metabolism, memory, etc.) and disease (traumatic brain injury, epilepsy, etc.). Furthermore, the usefulness of mathematical modeling in deciphering underlying dynamics of the brain to investigate lactate roles and mechanisms of action has been well established. Here, we analyze a novel mathematical model of brain lactate exchanges between four compartments: neurons, astrocytes, capillaries, and extracellular space. A system of four ordinary differential equations is proposed to explain interactions between these compartments. We first optimize and analyze the model’s parameters under normal, resting state conditions, and then use it to simulate changes linked to elevated arterial lactate. Our results show that even though increased arterial lactate results in increased uptake by astrocytes and release to the extracellular space, it cannot strongly recover the initial drop in neuronal lactate concentration. Also, we show that the direction of lactate transport between the compartments is influenced by the maximum astrocyte production rate and the transport rate between astrocytes and extracellular space.

Peripheral venous lactate levels substitute arterial lactate levels in the emergency department

Background: The level of arterial lactate has been a significant indicator of studied case's prognosis. Blood gas analysis's low concordance rate between AL &amp; peripheral venous lactate makes PVL ineffective as AL alternative. Nevertheless, PVL can be a different way to forecast studied case's prognosis, &amp; risk of arterial puncture problems with AL can be decreased if AL range may be predicted from PVL. This can be a quick &amp; secure test technique. Aim: To assess if VL levels may replace certain ranges of AL levels, we reviewed association among VL &amp; AL levels in same critically sick studied cases at time of initial evaluation. Venous blood gas analysis (which lowers risk of problems related to arterial puncture required for AL measurement) can be safer &amp; quicker test for critically ill studied cases if VL values may be utilized as substitute for AL levels. Summary: The level of arterial lactate has been significant indicator of studied case's prognosis. Blood gas analysis's low concordance rate between AL &amp; peripheral venous lactate makes PVL ineffective as AL alternative.

Comparison of Incidence and Prognosis of Myocardial Injury in Patients with COVID-19-Related Respiratory Failure and Other Pulmonary Infections: A Contemporary Cohort Study.

Myocardial injury (MI) is frequent in critically ill patients with COVID-19, but its pathogenesis remains unclear. We hypothesized that MI is not solely due to viral infection by SARS-CoV-2 but rather due to the common pathophysiological mechanisms associated with severe pulmonary infections and respiratory failure. This contemporary cohort study was designed to compare the incidence of MI in patients with acute respiratory failure caused by COVID-19 to patients with other pulmonary infections. In addition, we aimed to investigate whether MI was a distinct risk factor for in-hospital mortality in patients with COVID-19 compared to those with non-COVID-19 infections. This study included 1444 patients with COVID-19 (55.5% men; age 58 (46;68) years) and 182 patients with other pulmonary infections (46.9% men; age 62 (44;73) years). The incidence of MI at ICU admission was lower in COVID-19 patients (36.4%) compared to non-COVID-19 patients (56%), and this difference persisted after adjusting for age, sex, coronary artery disease, heart failure, SOFA score, lactate, and C-reactive protein (RR 0.84 (95% CI, 0.71-0.99)). MI at ICU admission was associated with a 59% increase in mortality (RR 1.59 (1.36-1.86); p < 0.001), and there was no significant difference in the mortality between patients with COVID-19 and those with other pulmonary infections (p = 0.271). We concluded that MI is less frequent in patients with critical COVID-19 pneumonia and respiratory failure compared to those with other types of pneumonia. The occurrence of MI is a significant risk factor for in-hospital mortality, regardless of the etiology of the pulmonary infection.

Preoperative arterial lactate and outcome after surgery for type A aortic dissection: The ERTAAD multicenter study

BackgroundAcute type A aortic dissection (TAAD) is associated with significant mortality and morbidity. In this study we evaluated the prognostic significance of preoperative arterial lactate concentration on the outcome after surgery for TAAD. MethodsThe ERTAAD registry included consecutive patients who underwent surgery for acute type A aortic dissection (TAAD) at 18 European centers of cardiac surgery. ResultsData on arterial lactate concentration immediately before surgery were available in 2798 (71.7 %) patients. Preoperative concentration of arterial lactate was an independent predictor of in-hospital mortality (mean, 3.5 ± 3.2 vs 2.1 ± 1.8 mmol/L, adjusted OR 1.181, 95%CI 1.129–1.235). The best cutoff value preoperative arterial lactate concentration was 1.8 mmol/L (in-hospital mortality, 12.0 %, vs. 26.6 %, p < 0.0001). The rates of in-hospital mortality increased along increasing quintiles of arterial lactate and it was 12.1 % in the lowest quintile and 33.6 % in the highest quintile (p < 0.0001). The difference between multivariable models with and without preoperative arterial lactate was statistically significant (p = 0.0002). The NRI was 0.296 (95%CI 0.200–0.391) (p < 0.0001) with −17 % of events correctly reclassified (p = 0.0002) and 46 % of non-events correctly reclassified (p < 0.0001). The IDI was 0.025 (95%CI 0.016–0.034) (p < 0.0001). Six studies from a systematic review plus the present one provided data for a pooled analysis which showed that the mean difference of preoperative arterial lactate between 30-day/in-hospital deaths and survivors was 1.85 mmol/L (95%CI 1.22–2.47, p < 0.0001, I2 64 %). ConclusionsHyperlactatemia significantly increased the risk of mortality after surgery for acute TAAD and should be considered in the clinical assessment of these critically ill patients.

Monitoring tissue perfusion during extracorporeal circulation with laser speckle contrast imaging

Objective: The laser speckle contrast imaging (LSCI) system is a method to evaluate microcirculation. The primary aim of our study&#x0D; is to evaluate the relationship between LSCI and perfusion markers in coronary artery bypass grafting (CABG). Our second aim is to&#x0D; investigate the relationship between LSCI and extubation time in the intensive care unit.&#x0D; Patients and Methods: Fifteen patients aged 43-80 years who will undergo on-pump CABG were included in the prospective study.&#x0D; Mean arterial pressure (mmHg), heart rate (min-1), PO2 (mmHg), PCO2 (mmHg) and lactate (mmol/L) levels were measured preinduction,&#x0D; post-induction, 10th minute of the extracorporeal circulation, post-crossclamp, and post-operatively. At the same time&#x0D; points, LSCI values from the skin were measured and recorded. The intubation times of the patients were also recorded.&#x0D; Results: There was no significant change in systemic tissue perfusion markers (P&gt;0.05). LSCI perfusion values decreased significantly&#x0D; from induction and remained low until the end of surgery (P

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.