Venous Lactate Research Articles

A Pediatric Sepsis Protocol Reduced Mortality and Dysfunctions in a Brazilian Public Hospital.

Introduction: Few studies in the literature discuss the benefits of compliance with sepsis bundles in hospitals in low- and middle-income countries, where resources are limited and mortality is high.Methods: This is a retrospective cohort study conducted at a public hospital in a low-income region in Brazil. We evaluated whether completion of a sepsis bundle is associated with reduced in-hospital mortality for sepsis, severe sepsis, and septic shock, as well as prevention of septic shock and organ dysfunction. Bundle compliance required the completion of three items: (1) obtaining blood count and culture, arterial or venous blood gases, and arterial or venous lactate levels; (2) antibiotic infusion within the first hour of diagnosis; and (3) infusion of 10–20 ml/kg saline solution within the first hour of diagnosis.Results: A total of 548 children with sepsis, severe sepsis, or septic shock who were treated at the emergency room from February 2008 to August of 2016 were included in the study. Of those, 371 patients were included in the protocol group and had a lower median length of stay (3 days vs. 11 days; p < 0.001), fewer organ dysfunctions during hospitalization (0 vs. 2, p < 0.001), and a lower probability of developing septic shock. According to a propensity score analysis, mortality was lower during the post-implementation period [2.75 vs. 15.4% (RR 95%IC 0.13 (0.06, 0.27); p < 0.001)].Conclusions: A simple and low-cost protocol was feasible and yielded good results at a general hospital in a low-income region in Brazil. Protocol use resulted in decreased mortality and progression of dysfunctions and was associated with a reduced probability of developing septic shock.

Point‐of‐care assessment of combined umbilical arterial and venous lactate: A potential screening test for neonatal acidosis

To examine the relationship between point-of-care (POC) measurement of combined umbilical arterial and venous (CUAV) lactate and umbilical artery (UA) lactate to determine whether POC assessment of this sample could be an alternative screening modality for neonatal acidosis and aid prediction of neonatal morbidity. In this cross-sectional pilot study, UA and CUAV cord blood samples were collected from live, singleton neonates delivered between June and August 2019, at a tertiary care center. UA samples were analyzed for pH and lactate using a blood gas analyzer. CUAV lactate was also assessed on a blood gas analyzer and at the POC. Linear regression was used to determine the correlation between these samples. A total of 152 neonates were included. There was a statistically significant correlation between CUAV lactate concentrations and UA lactate concentrations (R2 =0.744). Additionally, CUAV lactate concentration measured at the POC was significantly correlated with that measured on a traditional blood gas analyzer (R2 =0.928). POC testing of CUAV lactate is reliable and closely correlated with UA lactate concentrations, making POC testing of CUAV lactate a potential screening test for neonatal acidosis. More data are needed to establish standardization of this test relative to its predictive value in clinical neonatal outcomes.

Influence of physical rehabilitation on oxygen and lactate status in "inotrope-dependent" patients with chronic heart failure in class III–IV

Aim. To assess the effect of physical rehabilitation on dynamics of oxygen and lactate status indicators in inotrope-dependent patients with stable chronic heart failure (CHF) of IIIIV functional class (FC).&#x0D; Material and methods. A randomized prospective study included 120 men, aged 1865, hospitalized at Almazov National Medical Research Centre due to CHF IIIIV FC, left ventricular ejection fraction (LVEF) 30%; with blood pressure (BP)90/60 mm Hg. Patients who received dobutamine or dopamine for 2 weeks were randomized into 3 groups: 1st participating in the program of physical training (PPT), 2nd not participating; 3rd group patients without inotropic support participating in PPT.&#x0D; Results. Oxygen extraction ratio (O2ER) at rest was increased, while central venous oxygen saturation (ScvO2) was decreased in all groups at baseline, after 3 and 6 months. Initially, at rest, central venous blood lactate (lactate) was normal in all groups. By the 6th month, lactate in group 2 became higher than in group 1 (p=0.005) and group 3 (p=0.008). Initially, after 3 and 6 months, at peak of exercise in groups 1 and 3, lactate and O2ER increased, and ScvO2 decreased without development of life-threatening adverse events. By the 6th month, in groups 1 and 3, the distance of 6-minute walk test increased: p=0.004 and p0.00001 and the strength of hand muscles increased: p=0.01 and p=0.005.&#x0D; Conclusion. In patients with CHF IIIIV FC at rest, regardless of participation in PPT and inotropic therapy, there were comparable disturbances of oxygen status, characterized by decreased level of ScvO2 and increased level of O2ER, in the absence of decrease in arterial blood saturation. At peak of aerobic exercise of mild and moderate intensity in patients with advanced CHF, regardless of inotropic support, there was a comparable increase in the level of lactate and O2ER, as well as a decrease in ScvO2, which was not accompanied by life-threatening adverse events. The participation of inotrope-dependent patients in PPT is associated with decrease in blood lactate at rest, which, along with increase in hand muscle strength and exercise tolerance, may indicate an improvement in condition of muscle tissue.

Hydrogen inhalation in rehabilitation program of the medical staff recovered from COVID-19

Active hydrogen inhalation (H(H2O)m) has powerful antioxidant and antiapoptotic effects. In recent years, it has been used in a number of experimental and clinical studies.Aim. To study the safety and effectiveness of inhalation of the “active form of hydrogen” (AFV;(H(H2O)m)) in the rehabilitation program of coronavirus disease 2019 (COVID-19) survivors during the recovery period.Material and methods. This randomized controlled parallel prospective study included 60 COVID-19 survivors with post-COVID-19 syndrome (ICD-10: U09.9) during the recovery period, with clinical manifestations of chronic fatigue syndrome (CFS), who received standard therapy in accordance with the management protocol of patients with CFS (ICD-10: G93.3): physiotherapy and medication therapy with drugs containing magnesium, B vitamins and L-carnitine. The patients were divided into 2 groups. The experimental group (n=30) included patients who received hydrogen inhalation for 90 minutes every day during 10 days (SUISONIA hydrogen inhalation device, Japan). The control group (n=30) consisted of patients who received standard therapy. In both groups, patients were comparable in sex and mean age: in the experimental group — 53 (22; 70) years, in the control group — 51 (25; 70) years. Biological markers of systemic inflammation, oxygen transport, lactate metabolism, intrapulmonary shunting, 6-minute walk test, and vascular endothelial function were determined in all patients on the 1st and 10th days of follow-up.Results. In the experimental group, a decrease in following parameters was revealed: stiffness index (SI), from 8,8±1,8 to 6,8±1,5 (p&lt;0,0001); ALT, from 24,0±12,7 to 20,22±10,61 U/L (p&lt;0,001); venous blood lactate, from 2,5±0,8 to 1,5±1,0 mmol/L (p&lt;0,001); capillary blood lactate, from 2,9±0,8 to 2,0±0,8 mmol/L (p&lt;0,0001); estimated pulmonary shunt fraction (Qs/Qt, Berggren equation, 1942) from 8,98±5,7 to 5,34±3,2 (p&lt;0,01); white blood cells, from 6,64±1,57 to 5,92±1,32 109/L. In addition, we revealed an increase in the refractive index (RI) from 46,67±13,26% to 63,32±13,44% (p&lt;0,0001), minimum blood oxygen saturation (SpO2) from 92,25±2,9 to 94,25±1, 56% (p&lt;0,05), direct bilirubin from 2,99±1,41 to 3,39±1,34 pmol/L (p&lt;0,01), partial oxygen tension (PvO2) from 26,9±5,0 to 34,8±5,6 mm Hg (p&lt;0,0001), venous oxygen saturation (SvO2) from 51,8±020,6 to 61,1±018,1% (p&lt;0,05), partial capillary oxygen tension (PcO2) from 48,7±15,4 to 63,8±21,2 mm Hg (p&lt;0,01), capillary oxygen saturation (ScO2) from 82,2±4,2 to 86,2±4,8% (p&lt;0,01), distance in 6 minute walk test from 429±45,0 to 569±60 m.Conclusion. Inhalation therapy with H(H2O)m in the rehabilitation program of COVID-19 survivors during the recovery period is a safe and highly effective method. Manifestations of silent hypoxemia and endothelial dysfunction decreased, while exercise tolerance increased. As for laboratory tests, a decrease in the white blood cell count, estimated pulmonary shunt fraction and lactate content parameters was revealed.

Role of Venous Lactate in Predicting Outcomes in Patients with Acute Upper Gastro-Intestinal Bleeding

Background: Several risk scores were clinically assessed for risk stratification of patients with UGIB including Glascow–Blatchford score (GBS) and Rockall score pre and post endoscopy. Many studies tried to detect value of lactate as a predictor of mortality but its role in association with other systems is not well defined. Objective: To deduct the role of lactate and other scoring systems in assessment of outcomes of UGIB. Patients and Methods: We conducted a prospective cohort study of patients admitted to ICU of Tropical Medicine Department, Zagazig University Hospitals through the period from December 2019 to March 2020 with a charted diagnosis of upper gastrointestinal bleeding (UGIB). Results: Regarding performance of GBS, Rockall score and lactate among the studied group, cutoff point of GBS was equal or less than 10.5 can be used as a predictor for recovery with sensitivity of 63.6%, specificity 100%. Cut off of Pre Rockall score was less than or equal to 4.5 can be used as a predictor for recovery with sensitivity of 60.6%, specificity of 80%. As regards venous lactate, cutoff point was equal to or less than 1.85 can be used as a predictor for recovery with sensitivity of 75.8% and specificity of 100%. Regarding lactate clearance, the cutoff point of equal to or more than 18.8% can be used as a predictor for active bleeding with sensitivity of 63.2% and specificity of 42%. Conclusion: Elevated venous lactate in association with GBS, Rockall scoring systems were found as independent predictor factors for ICU admission, transfusion, endoscopy, length of hospital stay and mortality in patients with acute UGIB.

3-DIMENSIONAL CARDIOGENIC SHOCK SIMULATOR PHASE I: SUCCESSFUL DEVELOPMENT OF A LARGE ANIMAL CARDIOGENIC SHOCK MODEL

<h3>BACKGROUND</h3> Post-myocardial infarction (Post-MI) cardiogenic shock (CS) is a serious life-threatening condition that requires complex coordinated care. Despite this, early mortality remains as high as 50%, likely owing to still inadequate understanding of pathophysiology and the potential benefits of percutaneous ventricular assist devices (pVADs). Although all pVADs increase circulatory flow, they vary in their ability to help restore cardiac pump function. Additionally, shortcomings in terms of our understanding of the optimal timing of such devices in STEMI and shock algorithms likely contributes to the high mortality. Currently, preclinical pVAD evaluation is limited by the need for animal research where the induction of CS is often lethal before devices can be tested. We therefore plan to develop a high-fidelity simulator to facilitate device evaluation and help train clinical teams. The first phase to this program requires the elaboration of a stable animal post-MI CS model that can generate the physiologic data necessary for simulator validation. <h3>METHODS AND RESULTS</h3> Using 10 anesthetized 65-75kg female pigs, we sought to induce a large anterior infarct by percutaneous balloon occlusion of the left anterior descending artery with a provision for ethanol injection if CS was not observed within 2 hours of balloon occlusion. Continuous physiologic monitoring was ensured in order to record right and left heart and arterial pressures, mixed venous oxygen saturation, cardiac output, and serum lactate levels. Indices of myocardial contractility and relaxation were calculated at regular intervals. At the end of the experiment, Evans Blue was injected into the coronary circulation in order to determine the size of the myocardium at risk. The explanted heart was then stained with TTC mitochondrial stain and fixed with formaldehyde to determine the size of the infarct. A rate of survival of the anterior infarct of ≥50% and a rate of induction of CS in at least 50% of the survivors was considered necessary for the viability of the program. We successfully induced myocardial infarction in all 10 pigs and 5 pigs survived to develop cardiogenic shock. <h3>CONCLUSION</h3> While challenging, we successfully demonstrated that a large animal model of cardiogenic shock is possible and stable enough to generate the physiologic data necessary for the development of a CS simulator. The second phase will consist of the collection of detailed physiological data in a CS state with and without different pVAD support.

Agreement and Correlation Between Arterial and Venous Blood pH, PO2, PCO2, Lactate, and HCO3.

Retracted

Prehospital Lactate is Associated with the Need for Blood in Trauma

Background: Traumatic hemorrhage is the leading cause of preventable death, and its effects are often evident within the first 24 hours of hospital admission. We investigated the relationship between prehospital lactate measurement and administration of hospital blood products and life-saving interventions (LSIs) within 24 hours of hospital admission. Methods: We included trauma patients with recorded prehospital venous lactate transported by a single critical care transport service to a Level I trauma center between 2012 and 2019. We abstracted vital signs, mission type, anatomic location of injury, prehospital administration of crystalloid and blood products, and hospital LSIs started within 24 hours of admission. We used logistic regression to determine the association of prehospital lactate and in-hospital administration of blood products in groups with or without hypotensive patients. We investigated the effect of prehospital lactate concentration on secondary outcomes such as LSIs and mortality. Results: We included 2,170 patients transported from the scene or emergency department (ED), of whom 1,821 (84%) were normotensive. The median concentration of prehospital lactate was 2.10 mmol/L for the main population (IQR = 1.40–3.30) and 2.00 mmol/L for the normotensive subgroup (IQR = 1.30–2.90). A higher prehospital lactate concentration was associated with higher odds of needing early hospital blood products in the whole study population (OR = 1.12, (95% CI 1.06–1.20), p < 0.01) and in the normotensive subgroup (OR = 1.13, (95% CI 1.03–1.22), p = 0.01). These positive associations were also observed with the secondary outcome of hospital LSIs, and higher prehospital lactate was also associated with higher odds of mortality (OR = 1.32, (95% CI 1.20–1.45), p < 0.01). Conclusions: Higher concentrations of prehospital lactate were associated with the need for in-hospital blood transfusion within 24 hours of admission. The relationship between lactate and blood transfusion persisted among normotensive patients. Further work is needed to incorporate prehospital lactate into decision support tools for prehospital blood administration.

Electrical-tomographic imaging of physiological-induced conductive response in calf muscle compartments during voltage intensity change of electrical muscle stimulation (vic-EMS)

Objectives. The electrical-tomographic imaging has been achieved for exploring differential tendency of physiological-induced conductive response in calf muscle compartments during voltage intensity change of electrical muscle stimulation (vic-EMS). Approach. In the experiments, the differential tendency of conductivity distribution images σ during vic-EMS were clearly imaged as three responsive muscle compartments, which are called M 1 compartment composed of gastrocnemius muscle, M 2 compartment composed of tibialis anterior, extensor digitorum longus, and peroneus longus muscles, and M 3 compartment composed of soleus muscle. Main results. The differential tendency of spatial-mean conductivity 〈σ〉 M1 is the same as the differential tendency of venous blood flow velocity v bl and blood lactate concentration C bl during vic-EMS by the increased tendency of spatial-mean conductivity difference Δ〈σ〉 M1, venous blood flow velocity difference Δv bl and blood lactate concentration difference ΔC bl . The 〈σ〉 M1 is increased with the increase of voltage intensity from 〈σ pre 〉 M1 = 0.142 [-] to 〈σ l14 〉 M1 = 0.442 [-] (pre: pre-training, l14: voltage level during vic-EMS l = 14) by Δ〈σ l14-pre 〉 M1 = 204.2% (n = 16, p < 0.01). Correspondingly, the v bl and C bl are increased with the increase of voltage intensity by Δv bl l14-pre = 1480.5% (n = 16, p < 0.01) and ΔC bl l14-pre = 230.1% (n = 16, p < 0.01) respectively. Significance: The reason for the differential tendency of increase in <σ> M1 suggests an increase in muscle extracellular volumes during vic-EMS due to the co-effect of venous blood flow velocity and blood lactate metabolism. Based on the conductivity second-order difference images and spatial-mean conductivity second-order difference optimum voltage intensity φ OVI is discussed among sixteen volunteer subjects, which increased with a thicker subcutaneous fat layer.

Gastric outlet obstruction secondary to paraumbilical hernia

An 80-year-old woman with a history of paraumbilical hernia presented with a 5-day history of abdominal pain, nausea, and vomiting. She reported a dull pressure that progressively increased in her abdomen with post-prandial vomiting. On examination, there was a large non-tender reducible supra-umbilical hernia with no overlying erythema. Blood examination revealed a white cell count of 15.96 × 109/L, C-reactive protein of 29 mg/L, and venous lactate of 3.0 mmol/L. Computed tomography (CT) of the abdomen and pelvis revealed a large paraumbilical hernia containing the distal stomach and loops of small and large bowel (Fig 1).

Bedside microdialysis for detection of early brain injury after out-of-hospital cardiac arrest

Bedside detection and early treatment of lasting cerebral ischemia may improve outcome after out-of-hospital cardiac arrest (OHCA). This feasibility study explores the possibilities to use microdialysis (MD) for continuous monitoring of cerebral energy metabolism by analyzing the draining cerebral venous blood. Eighteen comatose patients were continuously monitored with jugular bulb and radial artery (reference) MD following resuscitation. Median time from cardiac arrest to MD was 300 min (IQR 230–390) with median monitoring time 60 h (IQR 40–81). The lactate/pyruvate ratio in cerebral venous blood was increased during the first 20 h after OHCA, and significant differences in time-averaged mean MD metabolites between jugular venous and artery measurements, were documented (p < 0.02). In patients with unfavorable outcome (72%), cerebral venous lactate and pyruvate levels remained elevated during the study period. In conclusion, the study indicates that jugular bulb microdialysis (JBM) is feasible and safe. Biochemical signs of lasting ischemia and mitochondrial dysfunction are frequent and associated with unfavorable outcome. The technique may be used in comatose OHCA patients to monitor biochemical variables reflecting ongoing brain damage and support individualized treatment early after resuscitation.

Effect of the beta-adrenergic blockade on intestinal lactate production and glycogen concentration in dogs infused with hexoses

To investigate effect of beta adrenergic blockade on intestinal lactate production and glycogen concentration in dogs infused with hexoses. Experiments were carried out on 35 fasted male anaesthetized dogs weighing between 9 and 16kg. The animals were divided into 7 (5 dogs per group) groups. Group I dogs served as control and infused with normal saline, groups II-IV were intravenously infused with glucose (1.1mg/kg/min), fructose (1.1mg/kg/min) and galactose (1.1mg/kg/min) respectively while groups V-VII animals were pretreated with propranolol (0.5mg/kg) and were infused with glucose, fructose or galactose respectively. A vein draining the proximal segment of the jejunum was cannulated along with right and left femoral arteries and veins. Glucose uptake was calculated as the product of jejunal blood flow and the difference between arterial and venous glucose levels (A-V glucose), part of the jejunum tissue was homogenized for estimation of glycogen concentration, and plasma lactate was assayed using lactate colorimetric kit. The result showed significant increase in venous lactate production in response to glucose (78.30±4.57mg/dL), fructose (60.72±1.82mg/dL) and galactose (71.70±1.30mg/dL) when compared with the control group (51.75±1.32mg/dL) at (p<0.05) with no significant difference in animals pretreated with propranolol. There was no significant difference in glycogen concentration (p>0.05) in animals infused with hexoses only compared with propanolol pretreated group. Results suggests that one of the possible fates of the enormous amount of glucose taken up by the intestine is conversion to lactate and not glycogen and β-adrenergic receptor does not affect it.

Venous lactate level as a predictor to determine the outcome in patients with acute upper gastrointestinal hemorrhage in the emergency department

Introduction: Gastrointestinal bleeding (GIB) is occasionally seen in various clinical conditions in emergency departments (EDs). It is associated with more disease burden and mortality. Most severe patients with upper GIB (UGIB) have an increased level of lactate, whereas it is still not considering a risk predictor among the patients. The present study aimed to evaluate several levels and a cut-off value of lactate for predicting outcomes of patients with UGIB. Materials and Methods: The present cross-sectional observational prospective study was conducted in the ED of Max Hospital, Saket, New Delhi, over a study period of 18 months from June 2015 to December 2016. The participants selected for the study were more than 17 years old from both genders with UGIB. In the study, 300 subjects were selected by the convenient sampling method. All the analyses was done by SPSS-20. Results: In this study, male and female subjects were 75.7% and 24.3%, respectively. Nearly 25% of the participants were hypertensive and diabetic. The study highlighted that the mean lactate level was 4.55±2.45 mmol/L; however, the range of the lactate level was 1.4–14. Based on the receiver operating characteristic curve analysis, the optimum cutoff of lactate was 4.55 mmol/L, had an area under the curve of 0.905 (confidence interval: 0.861–0.949), sensitivity of 80.5%, specificity of 98.9%, and P-value of less than 0.05. Likewise, the results of this study also communicated that there was a significant positive correlation (P-value = 0.001*) between the level of lactate and the outcome of the patients. The present study also discriminated that venous lactate levels 4.55 mmol/L and above are associated with mortality and hospital stay. Conclusion: Findings of this research study suggested that venous lactate level is an effective predictor of patient outcome among patients with UGIB. Furthermore, early assessment and management are needed to reduced mortality and morbidity among patients with UGIB.

Central venous–arterial CO2 pressure difference in correlation to dynamic changes of serum lactate level in patients with polytrauma

Background and aim of work Early diagnosis, rapid intervention, and correction of tissue hypoperfusion are the major aims in the management of polytraumatized patients. The venous-to-arterial carbon dioxide tension difference is a marker of the adequacy of cardiac output to global metabolic demand, and so, its detection is a helpful method to determine patients who stay under resuscitation way. Regarding this, its monitoring could help the physicians to make the decision to give treatment targeting at improving cardiac output. Patients and methods This is a prospective single-center observational study done on 40 patients with polytrauma admitted to Assiut University Hospital resuscitation room and followed for the first 12 h of ICU stay. At the start of resuscitation, central venous and arterial blood samples were obtained to estimate the mixed venous-to-arterial carbon dioxide tension difference from the baseline values. All consecutive paired blood samples were collected for each studied patient within the following first hour, after the sixth hour, and after the 12th hour. Other data collection Hourly urine output during the early 12 h, kidney function, and hemodynamics of arterial carbon dioxide tension, arterial oxygen tension, central venous carbon dioxide tension, and central venous oxygen tension were assessed. Arterial oxygen saturation and mixed venous oxygen saturation, arterial and central venous lactate, hemoglobin concentration, and ICU stay were examined as well. Results The differences between arterial tenson and oxygen tension showed insignificant differences. There were changes in the mixed venous-to-arterial carbon dioxide tension difference over time period. Comparison between basal value and the follow-up results showed insignificant difference as well. There was significant difference between baseline lactate level and its corresponding measure at the 12th hour after resuscitation reflecting to somewhat optimal resuscitation. The hemodynamic changes (increases) over time included mean arterial blood pressure and central venous pressure. There were significant changes during the whole follow-up period in comparison with the baseline values. Urine output showed significant increases over time when compared with the second hour urine volume. There is significant correlation between blood lactate level and the difference between venous and arterial oxygen after 6 h of resuscitation; this was a strong positive correlation. The difference between blood lactate level and the difference between venous and arterial carbon dioxide is statistically significant at the baseline of resuscitation there is a moderate positive correlation. Conclusion Central venous–arterial carbon dioxide pressure difference in correlation to dynamic changes of serum lactate could be used as an indicator of tissue perfusion in patients with polytrauma.

Meckel’s diverticulitis with neuroendocrine tumor

A 61-year-old man with no significant medical history presented with abdominal pain, diarrhea, and fever. On presentation, he was hypertensive at 220/95 mmHg, tachypneic with respiratory rate of 30, tachycardia at 120 beats/min, and febrile at 40.1°C. On examination, his abdomen was soft with diffuse tenderness in all quadrants and minor distension. The white cell count was elevated at 14×109 mm/cell, with C-reactive protein of 180 mg/L and a venous lactate of 2.1 mmol/L. Computed tomography of abdomen and pelvis demonstrated inflammatory stranding surrounding a 2-inch-long blind-ending structure arising from the small bowel approximately 2 feet from the ileocecal valve with associated extraluminal gas (Fig 1).

Outcome of patients with different clinical presentations of high-risk pulmonary embolism.

AimsThe 2019 European Society of Cardiology (ESC) guidelines provide a revised definition of high-risk pulmonary embolism (PE) encompassing three clinical presentations: Cardiac arrest, obstructive shock, and persistent hypotension. This study investigated the prognostic implications of this new definition.Methods and resultsData from 784 consecutive PE patients prospectively enrolled in a single-centre registry were analysed. Study outcomes include an in-hospital adverse outcome (PE-related death or cardiopulmonary resuscitation) and in-hospital all-cause mortality. Overall, 86 patients (11.0%) presented with high-risk PE and more often had an adverse outcome (43.0%) compared to intermediate-high-risk patients (6.1%; P < 0.001). Patients with cardiac arrest had the highest rate of an in-hospital adverse outcome (78.4%) and mortality (59.5%; both P < 0.001 compared to intermediate-high-risk patients). Obstructive shock and persistent hypotension had similar rates of adverse outcomes (15.8% and 18.2%, respectively; P = 0.46), but the only obstructive shock was associated with an increased all-cause mortality risk. Use of an optimised venous lactate cut-off value (3.8 mmol/L) to diagnose obstructive shock allowed differentiation of adverse outcome risk between patients with shock (21.4%) and persistent hypotension (9.5%), resulting in a net reclassification improvement (0.24 ± 0.08; P = 0.002).ConclusionThe revised ESC 2019 guidelines definition of high-risk PE stratifies subgroups at different risk of in-hospital adverse outcomes and all-cause mortality. Risk prediction can be improved by using an optimised venous lactate cut-off value to diagnose obstructive shock, which might help to better assess the risk-to-benefit ratio of systemic thrombolysis in different subgroups of high-risk patients.

Can the CT by-product Time to threshold be a prognostic factor in patients with acute pulmonary embolism?

Bolus tracking is applied in computed tomography pulmonary angiography. The time that it takes for contrast to reach a predefined threshold in the pulmonary artery is called time to threshold (TTT). Our purpose was to analyse possible associations between TTT and circulatory state and prognosis in patients with acute pulmonary embolism (PE). In a single-centre, retrospective study 138 patients with PE and contrast administration via peripheral venous line were included. Clinical parameters of circulatory state were arterial pH, systolic blood pressure, heart rate, sPESI score, Wells score and GENEVA score. Survival was defined as surviving the following 30 days after the PE diagnosis. Time to threshold was only weakly correlated with Fi02 (r = 0.26, P = 0.04), pH (r = -0.22, P = 0.009), venous base excess (r = -0.18, P = 0.04) and venous lactate (r = 0.21, P = 0.01). TTT did not correlate with clinical parameters/scores and mortality. There were weak associations between TTT and blood gas analysis parameters. There were no associations with clinically relevant prognosis scores and overall survival. Therefore, albeit TTT is an easily assessable parameter of CTPA, the potential use in clinical routine is limited for prognosis stratification in patients with PE.

Prehospital End-Tidal CO2: A Superior Marker for Mortality Risk in the Acutely Injured Patient.

Emergency medical personnel must expeditiously triage acutely injured patients to the appropriate medical facility. Efficient and objective variables to facilitate this process and provide information to the receiving trauma center are needed. Currently, multiple variables are used to prognosticate injury severity and risk of mortality including vital signs, mental status, lactate, and base excess. We investigated the prehospital use of end-tidal carbon dioxide (ETCO2) as a noninvasive physiologic measure that can be obtained in the acutely injured patient. We performed a retrospective analysis of 557 acutely injured patients over 2years at a Level 1 trauma center. All patients arriving as trauma activations with ETCO2 measurements were included in analysis. End-tidal carbon dioxide measurements were categorized as low, normal, and high based on reference levels. Mortality was the primary outcome. Secondary receiver operator curves (ROC) for base excess, venous lactate, blood pressure, and venous pH were compared. We hypothesized ETCO2 levels would be able to predict mortality. End-tidal carbon dioxide levels conferred a mortality rate of 38%, 17.3%, and 2.9% for low, normal, and high, respectively (P < .001). Receiver operator curve analysis produced an area under the curve predictive value for ETCO2 (.748) which was superior to lactate (.660), SBP (.578), pH (.560), and base excess (.497). End-tidal carbon dioxide is a more sensitive and specific predictor of mortality in the acutely injured patient compared to venous lactate, base deficit, blood pressure, or venous pH. Additional studies are needed to determine if ETCO2 can be used as an effective prehospital adjunct to prevent mortality in acutely injured patients.

The agreement between arterial and venous lactate in patients with sepsis.

Arterial sampling, which is the gold standard for measuring lactate levels in sepsis, is more painful, requires experience and is associated with a higher incidence of morbidity, when compared with venous sampling. This study attempted to measure the correlation and agreement between arterial and peripheral venous (PV) lactate and between arterial and central venous (CV) lactate, with the objective to test interchangeability of the two and possibly support the use of venous lactate levels in resuscitating patients with sepsis. Eighty-seven patients admitted to the critical care unit of our hospital with the diagnosis of sepsis or septic shock were included in the study after taking informed consent. The arterial, PV and CV samples were taken within the first 24hours following admission and within 10minutes of each other. Lactate levels, CV oxygen saturation (ScvO2 ) and base excess of each sample type were reported within 15minutes of collection. Patients were followed up for a period of 28days to record the need for organ support (newly diagnosed renal failure, need for renal replacement therapy [RRT], liver failure, coagulopathy and need for ventilation) and mortality. Pearson correlation for arterial versus PV lactate was 0.76 and for arterial versus CV lactate was 0.992. The mean difference between arterial and PV lactate was found to be -0.30 (95% confidence interval [CI], -0.38 to -0.21). The upper and lower limits of agreement were 0.51 and -1.10, respectively. Mean difference between arterial and CV lactate was found to be -0.13 (95% CI, -0.21 to -0.05). Upper and lower limits of agreement were 0.63 and -0.89, respectively. Our study demonstrates a high level of agreement in the lactate levels as measured on venous samples and arterial samples. Venous lactate levels are reliable in resuscitation of patients with sepsis.

High venous to arterial CO2 gap is related to cardiovascular death in cardiogenic shock

Abstract Funding Acknowledgements Type of funding sources: None. Background Venous to arterial CO2 gap (CO2gap) is calculated by subtracting partial pressure of arterial CO2 to central venous partial pressure of CO2 (ScvCO2). This marker has been studied in septic shock and indicates hypoperfusion when exceeds 6mmHg. Its kinetics and applicability in cardiogenic shock (CS) are unclear, being mixed/central venous saturation and lactate more commonly used. Purpose The objective of the study is to describe CO2gap kinetics in patients with CS. Secondary objective is to analyze if CO2gap is as marker of prognosis in CS. Methods Prospective observational study that included patients admitted for CS in the Acute Cardiovascular Care Unit of a tertiary hospital. Gasometric samples were obtained at admission, 6, 12, 24 and 48 hours from the onset of shock. In-hospital mortality was registered. Results We included 40 patients with CS during 1 year. Most patients were male (80%), average age was 68 years. There was a high incidence of cardiac arrest (58%), most frequent cause of CS was STEMI (45%), in-hospital mortality was 45%, most cases from non-cardiovascular causes (61%). Refractory shock was frequent (28%). Average lactate peak was 6.02 mmol / L. CO2gap kinetics consisted in a peak at admission (8.8mmHg), a valley 6h (7.7mmHg), new peak at 12h (8.5mmHg) and progressive decrease at at 24 (6.8mmHg) and 48h (5.7 mmHg). Significantly, higher CO2gap values at admission (10.97mmHg vs 8.16mmHg, p = 0.007) was predictor of cardiovascular mortality. Lactate values at 6, 12 and 48 hours were also predictors of cardiovascular mortality, as well as ScvO2 at admission. Conclusions Patients with CS present with high CO2gap values during first hours of admission. The kinetics of this marker consists in two peaks at admission and 12 hours from CS onset, a valley at 6 hours and a progressive decrease at 24 and 48 hours. Its determination at admission is associated with cardiovascular mortality. We suggest the potential benefit of combining this marker, along with lactate and ScvO2 values, to guide management of patients with CS. Abstract Figure. CO2 gap and cardiovascular mortality