Relationship between injury severity and lactate levels in severely injured patients

The 2023 WSES guidelines on the management of trauma in elderly and frail patients

BACKGROUND

The trauma mortality rate is higher in the elderly compared with younger patients. Ageing is associated with physiological changes in multiple systems and correlated with frailty. Frailty is a risk factor for mortality in elderly trauma patients. We aim to provide evidence-based guidelines for the management of geriatric trauma patients to improve it and reduce futile procedures.

METHODS

Six working groups of expert acute care and trauma surgeons reviewed extensively the literature according to the topic and the PICO question assigned. Statements and recommendations were assessed according to the GRADE methodology and approved by a consensus of experts in the field at the 10th international congress of the WSES in 2023.

RESULTS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage, including drug history, frailty assessment, nutritional status, and early activation of trauma protocol to improve outcomes. Acute trauma pain in the elderly has to be managed in a multimodal analgesic approach, to avoid side effects of opioid use. Antibiotic prophylaxis is recommended in penetrating (abdominal, thoracic) trauma, in severely burned and in open fractures elderly patients to decrease septic complications. Antibiotics are not recommended in blunt trauma in the absence of signs of sepsis and septic shock. Venous thromboembolism prophylaxis with LMWH or UFH should be administrated as soon as possible in high and moderate-risk elderly trauma patients according to the renal function, weight of the patient and bleeding risk. A palliative care team should be involved as soon as possible to discuss the end of life in a multidisciplinary approach considering the patient's directives, family feelings and representatives' desires, and all decisions should be shared.

CONCLUSIONS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage based on assessing frailty and early activation of trauma protocol to improve outcomes. Geriatric Intensive Care Units are needed to care for elderly and frail trauma patients in a multidisciplinary approach to decrease mortality and improve outcomes.

Measuring the Level of Agreement for Lactate Measurements in Hispaniolan Amazon Parrots (Amazona ventralis) Among 2 Point-of-Care Analyzers and a Benchtop Analyzer

Lactate is an important biochemistry analyte used in human and veterinary medicine to assess tissue perfusion and can be used as a prognostic indicator for certain disease conditions. Whereas lactate is commonly measured using "patient-side" handheld meters, these meters have not been validated for companion avian species. The purpose of this study was to measure the level of agreement between 2 commercially available point-of-care lactate meters and a laboratory benchtop blood analyzer in Hispaniolan Amazon parrots (Amazona ventralis). Blood samples were collected from 20 adult parrots at Louisiana State University by drawing 1.5 mL of blood from the right jugular vein. One drop of whole blood was used for the Lactate Plus analyzer and the remainder of the sample transferred into a lithium heparin microtainer. From the blood in the microtainer, 0.2 mL whole blood was analyzed using the epoc Blood Analysis System, and the remaining sample was centrifuged to obtain plasma that was immediately frozen at -80°C (-112°F) and submitted to the Texas A&M University Clinical Pathology Laboratory for analysis on the VITROS 4500 benchtop analyzer. Bland-Altman agreement plots and Passing-Bablok regression were used to measure the level of agreement between the methods. There was poor agreement between all 3 methods with mean percentage differences in lactate concentrations ≥22% (epoc and Lactate Plus: 33.6% [95% CI: 27-40]; epoc and VITROS 4500: 55% [95% CI:52-58]; VITROS 4500 and Lactate Plus: 22% [95% CI:16-28]). Based on these results, the point-of-care meters tested in this study are not interchangeable, and separate reference intervals were calculated for each method. Blood lactate concentrations may have more utility in tracing lactate trends over time in an individual rather than being able to utilize this information at 1 time point for disease diagnosis and prognosis.

Serum Lactate Level as a Predictor for Blood Transfusion in Postpartum Hemorrhage

OBJECTIVE

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality. At present, there are no reliable clinical or laboratory indicators to identify which patients might require blood transfusions during a PPH. Serum lactate has long been used as an early biomarker of tissue hypoperfusion in trauma settings. The aim of this study is to understand serum lactate's role in the management of obstetric hemorrhage.

STUDY DESIGN

A retrospective chart review was performed of women who delivered between 2016 and 2019 at our institution and experienced a PPH. The patients were divided into two groups: those with a normal serum lactate level, defined as ≤2 mmol/L, and those with an abnormal serum lactate level, defined as >2 mmol/L. Need for packed red blood cell transfusion, as part of the resuscitation, was assessed for both groups.

RESULTS

During the study period, 938 women experienced PPH. Of these, 108 (11.5%) had a normal serum lactate, ≤2 mmol/L, and 830 (88.5%) had an abnormal lactate, >2 mmol/L. Women with elevated lactate levels were more likely to receive a blood transfusion versus those with a normal lactate level (57.0 vs. 46.3%, p = 0.035, respectively). Additionally, the average number of blood transfusions administered was significantly higher in the abnormal lactate group versus in the normal lactate group (1.34 vs. 0.97, respectively, p = 0.004). In a multivariable linear regression model, increasing serum lactate levels were found to be predictive of requiring more than 1 unit of blood (p < 0.001).

CONCLUSION

Women with elevated serum lactate levels were more likely to require blood transfusions during a PPH versus those with a normal serum lactate level. Thus, serum lactate levels are useful as an early indicator of requirement for blood transfusion in the management of obstetric hemorrhage.

KEY POINTS

· Lactate is a biomarker for blood transfusion in trauma.. · Lactate's role in PPH is unknown.. · Elevated lactate predicts receiving more blood transfusions..

Metabolome Profiling in the Plasma of Dogs with Idiopathic Dilated Cardiomyopathy: A Multiplatform Mass-Spectrometry-Based Approach

Dilated cardiomyopathy is one of the important diseases in dogs and humans. The second most common cause of heart failure in dogs is idiopathic dilated cardiomyopathy (iDCM), which results in heart failure or sudden cardiac death due to arrhythmia. This study aimed to determine changes in the plasma metabolome of dogs with iDCM compared to healthy dogs. For that purpose, a multiplatform mass-spectrometry-based approach was used. In this study, we included two groups of dogs: 12 dogs with iDCM and 8 healthy dogs. A total of 272 metabolites were detected in the plasma samples of dogs by combining three approaches but four MS-based platforms (GC-MS, LC-MS (untargeted), LC-MS (targeted), and FIA-MS (targeted) methods). Our findings demonstrated changes in the canine plasma metabolome involved in the development of iDCM, including the different concentrations of amino acids, biogenic amines, acylcarnitines, triglycerides and diglycerides, sphingomyelins, and organic acids. The results of this study will enable the detection and monitoring of pathophysiological mechanisms involved in the development of iDCM in the future.

Preoperative shock index in major abdominal emergency surgery

Introduction

Major abdominal emergency surgery (MAES) patients have a high risk of mortality and complications. The time-sensitive nature of MAES necessitates an easily calculable risk-scoring tool. Shock index (SI) is obtained by dividing heart rate (HR) by systolic blood pressure (SBP) and provides insight into a patient's haemodynamic status. We aimed to evaluate SI's usefulness in predicting postoperative mortality, acute kidney injury (AKI), requirements for intensive care unit (ICU) and high-dependency monitoring, and the ICU length of stay (LOS).

Method

We retrospectively reviewed 212,089 MAES patients from January 2013 to December 2020. The cohort was propensity matched, and 3960 patients were included. The first HR and SBP recorded in the anaesthesia chart were used to calculate SI. Regression models were used to investigate the association between SI and outcomes. The relationship between SI and survival was explored with Kaplan-Meier curves.

Results

There were significant associations between SI and mortality at 1 month (odds ratio [OR] 2.40 [1.67-3.39], P<0.001), 3 months (OR 2.13 [1.56-2.88], P<0.001), and at 2 years (OR 1.77 [1.38-2.25], P<0.001). Multivariate analysis revealed significant relationships between SI and mortality at 1 month (OR 3.51 [1.20-10.3], P=0.021) and at 3 months (OR 3.05 [1.07-8.54], P=0.034). Univariate and multivariate analysis also revealed significant relationships between SI and AKI (P<0.001), postoperative ICU admission (P<0.005) and ICU LOS (P<0.001). SI does not significantly affect 2-year mortality.

Conclusion

SI is useful in predicting postopera-tive mortality at 1 month, 3 months, AKI, postoperative ICU admission and ICU LOS.

Effect of Injury Patterns on the Development of Complications and Trauma-Induced Mortality in Patients Suffering Multiple Trauma

Patients that suffer from severe multiple trauma are highly vulnerable to the development of complications that influence their outcomes. Therefore, this study aimed to evaluate the risk factors that can facilitate an early recognition of adult patients at risk. The inclusion criteria were as follows: admission to a level 1 trauma center, injury severity score (ISS) ≥ 16 (severe injury was defined by an abbreviated injury score (AIS) ≥ 3) and ≥18 years of age. Injury- and patient-associated factors were correlated with the development of four complication clusters (surgery-related, infection, thromboembolic events and organ failure) and three mortality time points (immediate (6 h after admission), early (>6 h-72 h) and late (>72 h) mortality). Statistical analysis was performed using a Chi-square, Mann-Whitney U test, Cox hazard regression analysis and binominal logistic regression analysis. In total, 383 patients with a median ISS of 24 (interquartile range (IQR) 17-27) were included. The overall mortality rate (27.4%) peaked in the early mortality group. Lactate on admission significantly correlated with immediate and early mortality. Late mortality was significantly influenced by severe head injuries in patients with a moderate ISS (ISS 16-24). In patients with a high ISS (≥25), late mortality was influenced by a higher ISS, older age and higher rates of organ failure. Complications were observed in 47.5% of all patients, with infections being seen most often. The development of complications was significantly influenced by severe extremity injuries, the duration of mechanical ventilation and length of ICU stay. Infection remains the predominant posttraumatic complication. While immediate and early mortality is mainly influenced by the severity of the initial trauma, the rates of severe head injuries influence late mortality in moderate trauma severity, while organ failure remains a relevant factor in patients with a high injury severity.

Reasons for in-hospital delays to emergency surgical care in a resource-limited setting: Surgery versus anesthesiology perspective

Patients experience delays in emergency surgical care. Our 3-month mixed-methods observational prospective study examined the duration of in-hospital delays (IHDs) to emergency surgery at a tertiary hospital in Malawi and perceived reasons for such delay, assessing the correlation between surgery and anesthesia. Delays over two hours occurred in the majority, and almost 20% waited over twelve hours. However, we found no correlation between surgeons and anaesthetists in the perceived reasons for In-hospital delays to emergency surgical care.

Pentraxin 3 (PTX3) as a Predictor of Severity of Sepsis in Patients Admitted to an Intensive Care Unit: A Cross-Sectional Study From North India

Background: Sepsis is a common clinical syndrome in critical patients in the medical intensive care unit. Many scoring systems and biomarkers are introduced to detect unfavorable outcomes in sepsis patients. This study aims to identify pentraxin 3 (PTX3) as a predictor of sepsis in patients who are critically ill and admitted to intensive care units.

Materials and methods: This prospective observational survey purposively included 100 patients with sepsis identified by the Surviving Sepsis Campaign guidelines in the medical intensive care unit at one of the apex care centers in North India. Socio-demographic and clinical profiles were collected using a structured and validated checklist. Simple and multi-linear regression analyses were used to determine PTX3 as a predictor of sepsis.

Results: A total of 100 patients were prospectively observed. Among them, 61% were males, and 39% were females, with a mean age of 50.78 (±13.53) years. From nine potential predictors, lactate (95% CI: 1.048-1.890, B: 1.469, p < 0.001), procalcitonin (95% CI: 0.136-0.270, B: 0.203, p < 0.001), and SOFA (Sequential Organ Failure Assessment) scores (95% CI: 0.112-0.450, B: 0.281, p = 0.001) significantly predict the changes in PTX3 level (R-square: 0.842, adjusted R-square: 0.826) in patients.

Conclusions: PTX3 was found to correlate with the severity of sepsis as SOFA score and other markers like lactate, procalcitonin, and APACHE-II (Acute Physiology and Chronic Health Evaluation II) score.

Severe hyperlactatemia in unselected surgical patients: retrospective analysis of prognostic outcome factors

Background

Etiology of hyperlactatemia in ICU patients is heterogeneous—septic, cardiogenic or hemorrhagic shock seem to be predominant reasons. Multiple studies show hyperlactatemia as an independent predictor for ICU mortality. Only limited data exists about the etiology of hyperlactatemia and lactate clearance and their influence on mortality. The goal of this single-center retrospective study, was to evaluate the effect of severe hyperlactatemia and reduced lactate clearance rate on the outcome of unselected ICU surgical patients.

Methods

Overall, 239 surgical patients with severe hyperlactatemia (> 10 mmol/L) who were treated in the surgical ICU at the University Medical Center Freiburg between June 2011 and August 2017, were included in this study. The cause of the hyperlactatemia as well as the postoperative course and the patient morbidity and mortality were retrospectively analyzed. Lactate clearance was calculated by comparing lactate level 12 h after first measurement of > 10 mmol/L.

Results

The overall mortality rate in our cohort was 82.4%. Severe hyperlactatemia was associated with death in the ICU (p < 0.001). The main etiologic factor was sepsis (51.9%), followed by mesenteric ischemia (15.1%), hemorrhagic shock (13.8%) and liver failure (9.6%). Higher lactate levels at ICU admission were associated with increased mortality (p < 0.001). Lactate clearance after 12 h was found to predict ICU mortality (ANOVA p < 0.001) with an overall clearance of under 50% within 12 h. The median percentage of clearance was 60.3% within 12 h for the survivor and 29.1% for the non-survivor group (p < 0.001).

Conclusion

Lactate levels appropriately reflect disease severity and are associated with short-term mortality in critically ill patients. The main etiologic factor for surgical patients is sepsis. When elevated lactate levels persist more than 12 h, survival chances are low and the benefit of continued maximum therapy should be evaluated.

Elevated serum lactate levels and age are associated with an increased risk for severe injury in trauma team activation due to trauma mechanism

BACKGROUND

The identification of risk factors for severe injury is crucial in trauma triage and trauma team activation (TTA) depends on a sufficient triage. The aim of this study was to determine whether or not elevated serum lactate levels and age are risk factors for severe injury in TTA due to trauma mechanism.

METHODS

We conducted a retrospective cohort study in a single level one trauma center between September 2019 and May 2021 and analysed every TTA due to trauma mechanism. Primary endpoint of interest was the association of serum lactate as well as age with injury severity assessed by the injury severity score (ISS).

RESULTS

During the study period, we included 250 patients. Mean age was 43.3 years (Min.: 11, Max.: 90, SD: 18.7) and the initial lactate level was 1.7 mmol/L (SD: 0.95) with a mean ISS of 8.4 (SD: 8.99). The adjusted odds ratio (OR) for age > 65 being associated with an ISS > 16 is 9.7 (p < 0.001; 95% CI 4.01-25.58) and for lactate > 2.2 mmol/L being associated with an ISS > 16 is 6.29 (p < 0.001; 95% CI 2.93-13.48). A lactate level of > 4 mmol/L results in a 36-fold higher risk of severe injury with an ISS > 16 (OR 36.06; 95% CI 4-324.29).

CONCLUSION

This study identifies age (> 65) and lactate (> 2.2 mmol/L) as independent risk factors for severe injury in a TTA due to trauma mechanism. Existing triage protocols might benefit from congruous amendments.

Prediction of diagnosis and prognosis of COVID-19 disease by blood gas parameters using decision trees machine learning model: a retrospective observational study

The coronavirus disease 2019 (COVID-19) epidemic went down in history as a pandemic caused by corona-viruses that emerged in 2019 and spread rapidly around the world. The different symptoms of COVID-19 made it difficult to understand which variables were more influential on the diagnosis, course and mortality of the disease. Machine learning models can accurately assess hidden patterns among risk factors by analyzing large-datasets to quickly predict diagnosis, prognosis and mortality of diseases. Because of this advantage, the use of machine learning models as decision support systems in health services is increasing. The aim of this study is to determine the diagnosis and prognosis of COVID-19 disease with blood-gas data using the Chi-squared Automatic Interaction Detector (CHAID) decision-tree-model, one of the machine learning methods, which is a subfield of artificial intelligence. This study was carried out on a total of 686 patients with COVID-19 (n = 343) and non-COVID-19 (n = 343) treated at Erzincan-Mengücek-Gazi-Training and Research-Hospital between April 1, 2020 and March 1, 2021. Arterial blood gas values of all patients were obtained from the hospital registry system. While the total-accuracyratio of the decision-tree-model was 65.0% in predicting the prognosis of the disease, it was 68.2% in the diagnosis of the disease. According to the results obtained, the low ionized-calcium value (< 1.10 mM) significantly predicted the need for intensive care of COVID-19 patients. At admission, low-carboxyhemoglobin (< 1.00%), high-pH (> 7.43), low-sodium (< 135.0 mM), hematocrit (< 40.0%), and methemoglobin (< 1.30%) values are important biomarkers in the diagnosis of COVID-19 and the results were promising. The findings in the study may aid in the early-diagnosis of the disease and the intensive-care treatment of patients who are severe. The study was approved by the Ministry of Health and Erzincan University Faculty of Medicine Clinical Research Ethics Committee.

Lactate and Myocadiac Energy Metabolism

The myocardium is capable of utilizing different energy substrates, which is referred to as “metabolic flexibility.” This process assures ATP production from fatty acids, glucose, lactate, amino acids, and ketones, in the face of varying metabolic contexts. In the normal physiological state, the oxidation of fatty acids contributes to approximately 60% of energy required, and the oxidation of other substrates provides the rest. The accumulation of lactate in ischemic and hypoxic tissues has traditionally be considered as a by-product, and of little utility. However, recent evidence suggests that lactate may represent an important fuel for the myocardium during exercise or myocadiac stress. This new paradigm drives increasing interest in understanding its role in cardiac metabolism under both physiological and pathological conditions. In recent years, blood lactate has been regarded as a signal of stress in cardiac disease, linking to prognosis in patients with myocardial ischemia or heart failure. In this review, we discuss the importance of lactate as an energy source and its relevance to the progression and management of heart diseases.

Admission blood lactate levels of patients diagnosed with cerebrovascular disease effects on short- and long-term mortality risk

OBJECTIVE

Our study was carried out on patients admitted to the emergency ward with acute stroke symptoms that were subsequently diagnosed with cerebrovascular disease. We aimed to examine the relationship between these patients' admission lactate levels and their 1-, 3-, and 12-month mortality rates in order to evaluate the prognostic value of lactate levels.

METHODS

Our data were obtained retrospectively from 568 patients diagnosed with acute ischemic stroke at our emergency department between 1 January 2017 and 1 January 2018. Patient data were accessed via the hospital patient database. Included patients' files were assessed for examination and history taken at admission, comorbid diseases, demographic characteristics, treatments utilized, and laboratory results. Hyperlactatemia was defined as a lactate level of over 2 mmol/L. The relationship between lactate levels and survival was investigated. Patients' complication rates after discharge were assessed alongside their 1-, 3-, and 12-month mortality.

RESULTS

Our study assessed 568 patients. Out of these patients, 400 patients met our inclusion criteria and constituted the study population. These patients were separated into two groups according to their lactate levels. The hyperlactatemic group had a statistically significant increase in 1-, 3-, and 12-month mortality rates in comparison to the other group.

CONCLUSIONS

Our study found that hyperlactatemia was associated with a higher risk of 1-, 3-, and 12-month mortality, suggesting that it has predictive prognostic value. In the future, we believe that prospective observational studies and/or large-scale retrospective studies will be of great value in providing more insight into this topic.

Prospective evaluation of plasma lactate parameters for prognosticating dogs with shock

OBJECTIVE

To determine whether admission venous plasma lactate concentration, serially calculated lactate variables, or the Acute Patient Physiologic and Laboratory Evaluation (APPLE_fast ) score could discriminate hospital survivors from non-survivors in dogs presenting to the emergency department with clinical signs of shock.

DESIGN

Prospective case series performed over a 24-month period.

SETTING

Large urban private teaching hospital.

ANIMALS

Seventy-one dogs admitted to the ICU with initial peripheral venous plasma lactate concentration > 2.5 mmol/L and clinical and hemodynamic parameters consistent with shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Heart rate, systolic blood pressure, temperature, initial venous plasma lactate, and APPLE_fast score were recorded at admission. Lactate concentrations were serially recorded at predefined time points and used to calculate lactate variables, including lactime (time lactate > 2.5 mmol/L), lactate clearance ([lactate_initial - lactate_delayed ]/ lactate_initial × 100), and LAC_AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge. Overall survival rate was 61%. Admission plasma lactate did not differ between groups (P = 0.28). Lactime was shorter in survivors vs non-survivors (P = 0.03). Lactate clearance at hours (h) 1, 4, 10, and 16 was greater in survivors vs non-survivors (P < 0.05). Final plasma lactate clearance differed between groups (P < 0.05). LAC_AREA at time intervals 1 to 4 hours, 4 to 10 hours, 10 to 16 hours, and 16 to 24 hours was larger in non-survivors vs survivors (P < 0.05). Total LAC_AREA did not differ between groups (P = 0.51). Admission APPLE_fast was not different between survivors and non-survivors (P = 0.16).

CONCLUSIONS

While neither single APPLE_fast nor admission plasma lactate concentration could discriminate between hospital survivors and non-survivors, measures of lactate clearance can prognosticate survival in dogs with shock.

Shock index is better than conventional vital signs for assessing higher level of care and mortality in severe sepsis or shock

BACKGROUND

Conventional vital signs alone have limitations in determining the physiological status. Age-adjusted shock-index (SIPA), a comprehensive physiological variable, defined as the ratio of heart rate (HR) and systolic blood pressure (SBP) may be better at predicting hemodynamic stability and outcome than vital signs.

OBJECTIVES

To compare discriminatory power of SIPA against vital signs in assessing higher level of care (vasopressor use and mechanical ventilation) and early mortality in severe sepsis/septic shock.

METHODS

Prospective cohort study of 116children <14 years with severe sepsis/septic shock admitted at emergency department of a tertiary care hospital. Association between abnormal signs (raised heart-rate; HR, lower systolic blood-pressure; SBP, high SIPA) and higher level of care and early mortality at 0 and completed 6 hours (t0, t6) were assessed using univariate/multivariate analysis. Area-under-receiver-operating-characteristic curves (AUROC) of SIPA and conventional vital signs for outcome variables and their correlation with arterial lactate using Pearson's-coefficient were noted.

RESULTS

High SIPA was independently associated with higher level of care i.e. vasopressor use, mechanical ventilation (AUROC t0: 0.698, 0.730; AUROC t6; 0.733, 0.735) as well as early mortality (AUROC t0: 0.638; AUROC t6:0.721) at t0 and t6. At t0, only high SIPA (r² = 0.313) fairly correlated with arterial lactate (4.5 mmol/L). At t6, HR and SBP showed weak and SIPA (r² = 0.434) demonstrated moderate correlation with arterial lactate.

CONCLUSIONS

SIPA performs better than conventional vital-signs in recognising higher-level-of-care and early mortality.

Arterial lactate in traumatic brain injury - Relation to intracranial pressure dynamics, cerebral energy metabolism and clinical outcome

PURPOSE

High arterial lactate is associated with disturbed systemic physiology. Lactate can also be used as alternative cerebral fuel and it is involved in regulating cerebral blood flow. This study explored the relation of endogenous arterial lactate to systemic physiology, pressure autoregulation, cerebral energy metabolism, and clinical outcome in traumatic brain injury (TBI).

METHOD

A retrospective study including 115 patients (consent given) with severe TBI treated in the neurointensive care unit, Uppsala university hospital, Sweden, 2008-2018. Data from cerebral microdialysis, arterial blood gases, hemodynamics and intracranial pressure were analyzed the first ten days post-injury.

RESULTS

Arterial lactate peaked on day 1 post-injury (mean 1.7 ± 0.7 mM) and gradually decreased. Higher arterial lactate correlated with lower age (p-value < 0.05), higher Marshall score (p-value < 0.05) and higher arterial glucose (p-value < 0.001) in a multiple regression analysis. Higher arterial lactate was associated with poor pressure autoregulation (p-value < 0.01), but not to worse cerebral energy metabolism. Higher arterial lactate was also associated with unfavorable clinical outcome (p-value < 0.05).

CONCLUSIONS

High endogenous arterial lactate is a biomarker of poor systemic physiology and may disturb cerebral blood flow autoregulation.

Biochemical Effects of Routine Gonadectomy on Blood of Domestic Ferrets (Mustela putorius furo)

We studied domestic ferrets (Mustela putorius furo) to evaluate the physiologic effects of routine surgery. Standard plasma biochemistry panels and ¹H-NMR spectroscopy of heparinized whole blood were performed on samples taken 24 h prior to and immediately after surgery from female and male ferrets undergoing routine gonadectomy. Increases in plasma glucose, phosphorus, potassium, and creatine kinase concentrations associated with the duration of surgery were identified on plasma biochemistry panels. Whole-blood NMR spectra allowed us to identify 42 metabolites and one drug residue. Variations between pre- and postoperative metabolite concentrations were most pronounced for female ferrets, which underwent more prolonged surgery than males. Affected metabolites included organic acids and osmolytes (betaine, methylmalonate, <small>D</small>-lactate), fatty acids and lipids (2-hydroxy-3-methylbutyric acid), and amino acid groups (acetylglycine, alloisoleucine, leucine, and isoleucine). These findings indicate that ¹H-NMR spectroscopy of whole blood provides insight into metabolic perturbations in domestic ferrets undergoing surgery that are not detected in routine clinical chemistry panels.

Clinical guided computer tomography decisions are advocated in potentially severely injured trauma patients: a one-year audit in a level 1 trauma Centre with long pre-hospital times

BACKGROUND

The International Commission on Radiological Protection's (ICRP) justification principles state that an examination is justified if the potential benefit outweighs the risk for radiation harm. Computer tomography (CT) contributes 50% of the radiation dose from medical imaging, and in trauma patients, the use of standardized whole body CT (SWBCT) increases. Guidelines are lacking, and reviews conclude conflictingly regarding the benefit. We aimed to study the degree of adherence to ICRP's level three justification, the individual dose limitation principle, in our institution.

METHODS

This is a retrospective clinical audit. We included all 144 patients admitted with trauma team activation to our regional Level 1 trauma centre in 2015. Injuries were categorized according to the Abbreviated Injury Scale (AIS) codes. Time variables, vital parameters and interventions were registered. We categorized patients into trauma admission SWBCT, selective CT or no CT examination strategy groups. We used descriptive statistics and regression analysis of predictors for CT examination strategy.

RESULTS

The 144 patients (114 (79.2%) males) had a median age of 31 (range 0-91) years. 105 (72.9%) had at least one AIS ≥ 2 injury, 26 (18.1%) in more than two body regions. During trauma admission, at least one vital parameter was abnormal in 46 (32.4%) patients, and 73 (50.7%) underwent SWBCT, 43 (29.9%) selective CT and 28 (19.4%) no CT examination. No or only minor injuries were identified in 17 (23.3%) in the SWBCT group. Two (4.6%) in the selective group were examined with a complement CT, with no new injuries identified. A significantly (p < 0.001) lower proportion of children (61.5%) than adults (89.8%) underwent CT examination despite similar injury grades and use of interventions. In adjusted regression analysis, patients with a high-energy trauma mechanism had significantly (p = 0.028) increased odds (odds ratio = 4.390, 95% confidence interval 1.174-16.413) for undergoing a SWBCT.

CONCLUSION

The high proportion of patients with no or only minor injuries detected in the SWBCT group and the significantly lower use of CT among children, indicate that use of a selective CT examination strategy in a higher proportion of our patients would have approximated the ICRP's justification level three, the individual dose limitation principle, better.

Predictive Value of Point-of-care Lactate Measurement in Patients Meeting Level II and III Trauma Team Activation Criteria that Present to the Emergency Department: A Prospective Study

Background

The aim of this study was to investigate the utility of early point-of-care (POC) lactate levels to help predict injury severity and ultimate emergency department (ED) disposition for trauma patients meeting Level II and III activation criteria.

Methods

This was a blinded, prospective cohort study including a convenience sample of patients meeting our triage criteria for Level II or III team activation with stable vital signs. Bedside lactate samples were collected during the secondary survey. Clinical care/disposition was at the discretion of physicians who remained blinded to the bedside lactate result. An elevated lactate was defined as >2.0 mmol/L.

Results

Ninety-six patients were in the study group; mean age was 41 ± 17 years, 26% were female, 57% were Hispanic, and 60% admitted. We found no difference in initial mean POC lactate levels (mmol/L) for admitted versus discharged groups and Injury Severity Score (ISS) ≥9 versus ISS <9 groups (3.71 [95% confidence interval (CI): 3.1-4.4] vs. 3.85 [95% CI: 2.8-4.9]; P = 0.99 and 3.54 [95% CI: 2.7-4.4] vs. 3.89 [95% CI: 3.1-4.6]; P = 0.60, respectively). Performance characteristics of early elevated lactate levels were poor both to predict need for hospital admission (sensitivity = 77% [65%-87%]; specificity = 26% [13%-43%]; negative predictive value [NPV] = 43% [27%-61%]; and positive predictive value [PPV] = 62% [56%-67%]) and to identify patients with ISS scores ≥9 (sensitivity = 76% [59%-89%]; specificity = 24% [14%-37%]; NPV = 65% [47%-80%]; and PPV = 36% [30%-41%]).

Conclusions

For Level II/III, we found that early bedside lactate levels were not predictive of ISS ≥9 or the need for admission.

Level of Evidence

III (diagnostic test).

Shock Index-A Useful Noninvasive Marker Associated With Age-Specific Early Mortality in Children With Severe Sepsis and Septic Shock: Age-Specific Shock Index Cut-Offs

BACKGROUND

Aim of the study was to analyze the association of shock index (SI) from 0 to 6 hours with early mortality in severe sepsis/septic shock and to explore its age-specific cut-off values. To investigate association of change in SI over first 6 hours with early mortality.

METHODS

A prospective cohort study of children (<14 years) admitted in emergency department, tertiary care hospital with severe sepsis or septic shock, divided into 3 groups: group 1: 1 month to <1 year; group 2: 1 to <6 years; group 3: 6 to 12 years. Shock index (SI = heart rate/systolic blood pressure) measured at admission (X0) and hourly till 6 hours (X1-6). Primary outcome was death within 48 hours of admission. Area under receiver operating characteristic curves were constructed for SI (0-6). Optimal cut-offs of SI 0 and SI 6, maximizing both sensitivity and specificity were determined and positive and negative predictive values (PPV, NPV) were calculated.

RESULTS

From 2015 to 2016, 120 children were recruited. Septic shock was present at admission in 56.7% children. Early mortality was 50%. All hourly shock indices (SI 0-6) were higher among nonsurvivors in group 2 (P ≤ .03) and group 3 (P < .001). In group 1, SI after 2 hours was higher in nonsurvivors (P 2-6: ≤ .02). Area under receiver operating characteristic curves (95% CI) for SI at 0 hour was 0.72 (0.5-0.9), 0.66 (0.5-0.8), and 0.77 (0.6-0.9) and at 6 hours was 0.8 (0.6-1), 0.75 (0.6-0.9), and 0.8 (0.7-1) in 3 groups. The cut-off values of SI 0 (sensitivity; specificity; PPV; NPV) in 3 groups: 1.98 (77; 75; 67; 83), 1.50 (65; 65; 68; 63), and 1.25 (90; 67; 77; 83) and SI6: 1.66 (85; 80; 73; 89), 1.36 (73; 70; 73; 70), and 1.30 (74; 73; 78; 69). Improvement of SI over 6 hours was associated with better outcome. Children with higher SI at both time points had higher mortality than those with SI score below the cut-offs (P = .001).

CONCLUSIONS

Age-specific SI cut-off values may identify children at high risk of early mortality in severe sepsis/septic shock and allow for better targeted management.

Hyperlactatemia and the Importance of Repeated Lactate Measurements in Critically Ill Patients

Objective

The aim of the study was to describe the prevalence of hyperlactatemia and emphasis on repeated lactate measurements in critically ill patients, and the associated mortality.

Materials and methods

The study included 70 patients admitted in the Medical Intensive Care Unit at the Clinical Center, University of Sarajevo, in a 6-month period (July - December 2015). The following data were obtained: age, gender, reason for admission, Simplified Acute Physiology Score II, Acute Physiology and Chronic Health Evaluation, lactate concentrations upon admission, after 24 and 48 hours, and outcome (discharge from hospital or death).

Results

Upon admission,hyperlactatemia was present in 91.4% patients with a mean concentration of lactate 4.13 ±1.21 mmol/L. Lactate concentration at 48 hours was independently associated within creased in-hospital mortality (P = 0.018).

Conclusion

Persistent hyperlactatemia is associated with adverse outcome in critically ill patients. Lactate concentration at 48 hours is independently associated within creased in-hospital mortality and it represents a statistically significant predictive marker of fatal outcomes of patients. Blood lactate concentrations > 2.25 mmol/L should be used by clinicians to identify patients at higher risk of death.

The utility of abnormal initial arterial blood gas values in determining clinical futility of trauma cases with severe hemorrhage

BACKGROUND

Patients who experience trauma with severe hemorrhage requiring immediate surgery and massive blood transfusion often present with markedly abnormal laboratory values. These cases require valuable resources; however, little is known regarding prognostic factors that correlate with mortality. The purpose of this study was to determine whether abnormal initial arterial blood gas (ABG) pH, a marker for severe blood loss, could serve as a prognostic indicator for these patients.

METHODS

An IRB approved retrospective study was performed at LAC+USC Medical Center Level I Trauma Center. Data was collected from trauma patients with severe hemorrhage admitted between June 2015 and April 2016 who were immediately admitted to the OR following entry into the ER. Baseline variables of age, sex and mechanism of trauma were collected. The pH readings from the initial three ABG data were obtained, and mortality was determined for each patient.

RESULTS

We identified 247 patients, 84.2% of which were male. Ages ranged from 1 to 91years (average=38.4). Overall mortality was 13.8%. The average initial pH value for non-survivors (7.10±0.13) was significantly lower than for survivors (7.34±0.07) [p<0.001]. Among patients whose initial three ABG pH values averaged ≤7.15, the survival rate was 8.7%. Ten patients had any single recorded pH value≤6.91. The mortality rate among these patients was 90%.

CONCLUSIONS

Consideration should be given to initial pH values when resuscitating "red blanket" patients. However, the pH values alone cannot reliably be used to determine clinical futility in individual patients in the early period after injury.

Perioperative Hyperlactemia Is a Poor Predictor of Outcome in Patients Undergoing Surgery for Acute Type-A Aortic Dissection

OBJECTIVE

In patients presenting with acute type-A aortic dissection (aTAAD), lactic acid measurement is a frequently used analysis for diagnosis of acute ischemia, which may have a dismal prognosis. The aim of the current study was to determine the performance of perioperative arterial lactic acid measurements in predicting outcome in aTAAD patients.

DESIGN

Retrospective, observational study.

SETTING

Cardiothoracic surgery unit at a tertiary-level hospital.

PARTICIPANTS

The study involved 285 consecutive patients undergoing surgery for aTAAD.

INTERVENTIONS

Preoperative and postoperative lactic acid levels were measured and evaluated together with clinical data related to outcome, including in-hospital and 1-year mortality.

MEASUREMENTS AND MAIN RESULTS

Altogether, 37 patients (13%) died during the index hospital admission, and survival was 84.4 ± 2.2 at 1 year. Preoperative cardiac malperfusion (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.3-7.3) and cerebral malperfusion (OR 2.6; 95% CI 1.2-5.6) were associated significantly with poorer 1-year survival. The area under the curve (AUC) for in-hospital and 1-year mortality in relation to preoperative lactic acid levels was 0.684 and 0.673, respectively, corresponding to a lactic acid cut-off for in-hospital mortality of 2.75 mmol/L (sensitivity 56%; specificity 72%) and a cut-off for 1-year mortality of 2.85 mmol/L (sensitivity 48%; specificity 74%). The AUC for in-hospital and 1-year mortality in relation to lactic acid levels measured postoperatively on arrival at the intensive care unit was 0.582 and 0.498, respectively.

CONCLUSION

Although hyperlactemia in aTAAD indicates an increased risk of postoperative mortality, the sole use of lactic acid levels as a tool for accurate assessment of postoperative mortality is inadvisable due to its poor discriminatory performance.

Assessment of a portable lactate meter for field use in the white rhinoceros (<i>Ceratotherium simum</i>)

Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (−0.16), tight 95% limits of agreement (LOA) (−1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (−0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.

Survival analysis of hypotensive cats admitted to an intensive care unit with or without hyperlactatemia: 39 cases (2005-2011)

OBJECTIVE To examine the association between blood lactate concentration and survival to hospital discharge in critically ill hypotensive cats. DESIGN Retrospective case series. ANIMALS 39 cats admitted to an intensive care unit of a university veterinary hospital between January 2005 and December 2011 for which blood lactate concentration was recorded ≤ 1 hour before or after a Doppler-derived arterial blood pressure measurement ≤ 90 mm Hg (ie, hypotension) was obtained. PROCEDURES Medical records of each cat were reviewed to assess survival to hospital discharge, illness severity, duration of hospitalization, age, body weight, and PCV. Results were compared between hypotensive cats with and without hyperlactatemia (blood lactate concentration ≥ 2.5 mmol/L). RESULTS 6 of 39 (15%) hypotensive cats survived to hospital discharge. Twelve (31%) cats were normolactatemic (blood lactate concentration < 2.5 mmol/L), and 27 (69%) were hyperlactatemic. Hypotensive cats with normolactatemia had a higher blood pressure and higher survival rate than hypotensive cats with hyperlactatemia. Five-day Kaplan-Meier survival rates were 57% for normolactatemic cats and 17% for hyperlactatemic cats. Age, body weight, duration of hospitalization, PCV, and illness severity did not differ significantly between hypotensive cats with and without hyperlactatemia. CONCLUSIONS AND CLINICAL RELEVANCE Hypotensive, normolactatemic cats in an intensive care unit had a significantly greater chance of survival to hospital discharge than their hyperlactatemic counterparts. Blood lactate concentration may be a useful prognostic indicator for this patient population when used in conjunction with other clinical and laboratory findings.

The Revised Trauma Score plus serum albumin level improves the prediction of mortality in trauma patients

INTRODUCTION

The Revised Trauma Score (RTS) is used worldwide in prehospital practice and in the emergency department (ED) settings to triage trauma patients. The main purpose of this study was to evaluate the value of the RTS plus serum albumin (RTS-A) and to compare it with other existing trauma scores as well as to compare the predictive performance of the Trauma and Injury Severity Score with the RTS-A (TRISS-A) with the original TRISS.

METHODS

This was a single center, trauma registry based observational cohort study. Data were collected from consecutive patients with blunt or penetrating injuries who presented to the emergency department of a tertiary referral hospital, between January 2012 and June 2016. 3145 and 2447 patients were assigned to the derivation group and validation group, respectively. Main outcome was in-hospital mortality.

RESULTS

Among patients in the derivation group, the median [interquartile range] age was 59 [43-73] years, and 66.7% were male. The area under the receiver operating characteristic curves (AUC) of the RTS-A (0.948; 95% CI: 0.939-0.955) was higher than that of the RTS (0.919; 95% CI: 0.909-0.929). In patients with blunt trauma, the AUC of the TRISS-A (0.960; 95% CI: 0.952-0.967) was significantly higher than that of the original TRISS (0.949; 95% CI: 0.941-0.957).

CONCLUSION

The value of the RTS-A predicts the in-hospital mortality of trauma patients better than the RTS, and the TRISS-A is a better mortality predictor compared to the original TRISS in patients with blunt trauma.

Validation of a hand-held point of care device for lactate in adult and pediatric patients using traditional and locally-smoothed median and maximum absolute difference curves

BACKGROUND

Lactate is commonly used in septic patients and is a viable biomarker for trauma patients. Its pre-hospital use could assist triaging and managing patients with these conditions.

METHODS

We evaluated the analytical performance of the point-of-care (POC) StatStrip Xpress Lactate Meter (Nova Biomedical) and compared it to the ABL 800 (Radiometer). We measured lactate in 250 adult and 250 pediatric whole blood samples in 2 laboratories. The performance of the POC meter was assessed by traditional linear regression and Bland-Altman plots, and locally-smoothed (LS) median absolute difference and maximum absolute difference (MAD and MaxAD) curves.

RESULTS

The StatStrip was linear with acceptable reproducibility at clinically relevant concentrations. Correlation with the ABL800 showed a negative bias for both populations with slope, bias ±SD (% bias) of 0.78, -0.4±0.7 (-14.5%) in children and 0.80-0.3±0.6 (-13.3%) in adults. The proportional bias appeared more significant at concentrations >4mmol/l (36.0mg/dl). The StatStrip misclassified 7.6 and 8.8% pediatric and adult samples, respectively, to lower risk categories defined using guidelines driven cut-offs. The LS MAD curves identified one breakout, concentration where the LS MAD exceeds the total allowable error limit of 0.3mmol/l (2.7mg/dl), at lactate concentrations of 3.8 and 3.2mmol/l (34.2 and 28.8mg/dl) in the pediatric and adult curves, respectively. Breakthroughs, points at which the LS MaxAD curve exceeds the 95th percentile of MaxADs, occur at concentrations above 7.5mmol/l (67.6mg/dl) for both populations where the performance of the POC meter became erratic. We concluded that if serial lactate measurements are performed, the same method should be used for baseline and follow up measurements. The LS MAD and LS MaxAD curves allowed visual and quantitative mapping of the performance of the lactate POC meter over the range of concentrations measured.

CONCLUSIONS

This approach seems useful for the identification of points at which the performance of a POC meter differs significantly from a comparison method and thresholds of poor analytical performance.

Relationship Between Peak Lactate and Patient Outcome Following High-Risk Gastrointestinal Surgery: Influence of the Nature of Their Surgery: Elective Versus Emergency

OBJECTIVES

The association between hyperlactatemia and adverse outcome in patients admitted to ICUs following gastrointestinal surgery has not been reported. To explore the hypothesis that in a large cohort of gastrointestinal surgical patients, the peak serum lactate (in the first 24 hr) observed in patients admitted to ICU following surgery is associated with unadjusted and severity-adjusted acute hospital mortality and that the strength of association is greater in patients admitted following "emergency" surgery than in patients admitted following "elective" surgery.

DESIGN

A retrospective cohort study of all patients who had gastrointestinal surgery and were admitted directly to the ICU between 2008 and 2012.

SETTING

Two hundred forty-nine hospitals in the United Kingdom.

PATIENTS

One hundred twenty-one thousand nine hundred ninety patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Peak blood lactate in the first 24 hours of admission to critical care, acute hospital mortality, length of stay, and other variables routinely collected within the U.K. Intensive Care National Audit and Research Centre Case Mix Programme database. Elevated blood lactate was associated with increased risk of death and prolonged duration of stay, and the relationship was maintained once adjusted for confounding variables. The positive association between mortality and levels of blood lactate continued down into the "normal range," without evidence of a plateau. There was no difference in the extent to which hyperlactatemia was related to mortality between patients admitted following elective and emergency surgery.

CONCLUSIONS

These findings have implications for our understanding of the role of lactate in critically ill patients.

The value of blood lactate kinetics in critically ill patients: a systematic review

BACKGROUND

The time course of blood lactate levels could be helpful to assess a patient's response to therapy. Although the focus of published studies has been largely on septic patients, many other studies have reported serial blood lactate levels in different groups of acutely ill patients.

METHODS

We performed a systematic search of PubMed, Science Direct, and Embase until the end of February 2016 plus reference lists of relevant publications. We selected all observational and interventional studies that evaluated the capacity of serial blood lactate concentrations to predict outcome. There was no restriction based on language. We excluded studies in pediatric populations, experimental studies, and studies that did not report changes in lactate values or all-cause mortality rates. We separated studies according to the type of patients included. We collected data on the number of patients, timing of lactate measurements, minimum lactate level needed for inclusion if present, and suggested time interval for predictive use.

RESULTS

A total of 96 studies met our criteria: 14 in general ICU populations, five in general surgical ICU populations, five in patients post cardiac surgery, 14 in trauma patients, 39 in patients with sepsis, four in patients with cardiogenic shock, eight in patients after cardiac arrest, three in patients with respiratory failure, and four in other conditions. A decrease in lactate levels over time was consistently associated with lower mortality rates in all subgroups of patients. Most studies reported changes over 6, 12 or 24 hrs, fewer used shorter time intervals. Lactate kinetics did not appear very different in patients with sepsis and other types of patients. A few studies suggested that therapy could be guided by these measurements.

CONCLUSIONS

The observation of a better outcome associated with decreasing blood lactate concentrations was consistent throughout the clinical studies, and was not limited to septic patients. In all groups, the changes are relatively slow, so that lactate measurements every 1-2 hrs are probably sufficient in most acute conditions. The value of lactate kinetics appears to be valid regardless of the initial value.

Extremes of shock index predicts death in trauma patients

Context:

We noted a bimodal relationship between mortality and shock index (SI), the ratio of heart rate to systolic blood pressure.

Aims:

To determine if extremes of SI can predict mortality in trauma patients.

Settings and Designs:

Retrospective evaluation of adult trauma patients at a tertiary care center from 2000 to 2012 in the United States.

Materials and Methods:

We examined the SI in trauma patients and determined the adjusted mortality for patients with and without head injuries.

Statistical Analysis Used:

Descriptive statistics and multivariable logistic regression. Results: SI values demonstrated a U-shaped relationship with mortality. Compared with patients with a SI between 0.5 and 0.7, patients with a SI of <0.3 had an odds ratio for death of 2.2 (95% confidence interval [CI] 21.2–4.1) after adjustment for age, Glasgow Coma score, and injury severity score while patients with SI >1.3 had an odds ratio of death of 3.1. (95% CI 1.6–5.9). Elevated SI is associated with increased mortality in patients with isolated torso injuries, and is associated with death at both low and high values in patients with head injury.

Conclusion:

Our data indicate a bimodal relationship between SI and mortality in head injured patients that persists after correction for various co-factors. The distribution of mortality is different between head injured patients and patients without head injuries. Elevated SI predicts death in all trauma patients, but low SI values only predict death in head injured patients.

Lactate, a useful marker for disease mortality and severity but an unreliable marker of tissue hypoxia/hypoperfusion in critically ill patients

Early aggressive hemodynamic resuscitation using elevated plasma lactate as a marker is an essential component of managing critically ill patients. Therefore, measurement of blood lactate is recommended to stratify patients based on the need for fluid resuscitation and the risks of multiple organ dysfunction syndrome and death. Hyperlactatemia is common among critically ill patients, and lactate levels and their trend may be reliable markers of illness severity and mortality. Although hyperlactatemia has been widely recognized as a marker of tissue hypoxia/hypoperfusion, it can also result from increased or accelerated aerobic glycolysis during the stress response. Additionally, lactate may represent an important energy source for patients in critical condition. Despite its inherent complexity, the current simplified view of hyperlactatemia is that it reflects the presence of global tissue hypoxia/hypoperfusion with anaerobic glycolysis. This review of hyperlactatemia in critically ill patients focuses on its pathophysiological aspects and recent clinical approaches. Hyperlactatemia in critically ill patients must be considered to be related to tissue hypoxia/hypoperfusion. Therefore, appropriate hemodynamic resuscitation is required to correct the pathological condition immediately. However, hyperlactatemia can also result from aerobic glycolysis, unrelated to tissue dysoxia, which is unlikely to respond to increases in systemic oxygen delivery. Because hyperlactatemia may be simultaneously related to, and unrelated to, tissue hypoxia, physicians should recognize that resuscitation to normalize plasma lactate levels could be over-resuscitation and may worsen the physiological status. Lactate is a reliable indicator of sepsis severity and a marker of resuscitation; however, it is an unreliable marker of tissue hypoxia/hypoperfusion.

Validation of lactate clearance at 6 h for mortality prediction in critically ill children

Background and Aims:

To validate the lactate clearance (LC) at 6 h for mortality prediction in Pediatric Intensive Care Unit (PICU)-admitted patients and its comparison with a pediatric index of mortality 2 (PIM 2) score.

Design:

A prospective, observational study in a tertiary care center.

Materials and Methods:

Children <13 years of age, admitted to PICU were included in the study. Lactate levels were measured at 0 and 6 h of admission for clearance. LC and delayed or nonclearance group compared for in-hospital mortality and compared with PIM 2 score for mortality prediction.

Results:

Of the 140 children (mean age 33.42 months) who were admitted to PICU, 23 (16.42%) patients died. For LC cut-off (16.435%) at 6 h, 92 patients qualified for clearance and 48 for delayed or non-LC group. High mortality was observed (39.6%) in delayed or non-LC group as compared to clearance group (4.3%) (P = 0.000). LC cut-off of 16.435% at 6 h (sensitivity 82.6%, specificity 75.2%, positive predictive value 39.6%, and negative predictive value 95.7%) correlates with mortality. Area under receiver operating characteristic (ROC) for LC at 6 h for mortality prediction was 0.823 (P = 0.000). The area under ROC curve for expected mortality prediction by PIM 2 score at admission was 0.906 and at 12.3% cut-off of PIM 2 Score was related with mortality. The mean PIM 2 score was high in delayed or non-LC group (25.25%) compared to LC group (10.95%) (P = 0.004).

Conclusion:

LC cut-off <16.435% at 6 h was associated with high mortality.

The predictive value of initial serum lactate in trauma patients

Trauma patients require early assessment of injury severity. Trauma scores, although well validated, can be unwieldy in the emergency clinical setting. We sought to evaluate the prognostic value of initial serum lactate (ISL) for mortality, operative intervention (OI), and intensive care unit admission (ICUA) in trauma patients. We conducted an institutional review board-approved retrospective study. We reviewed all trauma patients between January 2007 and June 2012 in our prospectively maintained database. We included only adults whose ISL had been drawn within the first 35 min after arrival. We included only those patients whose interval between injury and arrival was within 24 h. Survivors and nonsurvivors were compared using logistic regression, Mann-Whitney U, and chi-square tests. Discriminating ability of ISL for mortality was assessed with receiver operating characteristic analysis. Our secondary outcomes (ICUA and OI) were evaluated with logistic regression test and receiver operating characteristic analysis. A total of 1,941 patients were included. Overall mortality was 6.2%. Median ISL was 32 mg/dL (interquartile range, 17 - 62) for nonsurvivors versus 21 mg/dL (interquartile range, 14 - 32) for survivors (P < 0.001). In multivariate analysis, ISL was a significant covariate for mortality (P = 0.015). The odds ratio was 1.010 (95% confidence interval, 1.002 - 1.019). The area under the curve was 0.63. The ISL was a significant covariate for OI (P = 0.033). The ISL did not reach significance for ICUA. The ISL is an easily measured, rapid, and inexpensive test that can help to quickly stratify injury severity in trauma patients. We have found that ISL, when used in strictly selected patients, can predict OI and mortality.

Clinical significance of lactate in acute cardiac patients

Lactate, as a metabolite of easy and quick assessment, has been studied over time in critically ill patients in order to evaluate its prognostic ability. The present review is focused on the prognostic role of lactate levels in acute cardiac patients (that is with acute coronary syndrome, cardiogenic shock, cardiac arrest, non including post cardiac surgery patients). In patients with ST-elevation myocardial infarction treated with mechanical revascularization, hyperlactatemia identified a subset of patients at higher risk for early death and in-hospital complications, being strictly related mainly to hemodynamic derangement. The prognostic impact of hyperlactatemia on mortality has been documented in patients with cardiogenic shock and in those with cardiac arrest even if there is no cut-off value of lactate to be associated with worse outcome or to guide resuscitation or hemodynamic management. Therapeutic hypothermia seems to affect per se lactate values which have been shown to progressively decrease during hypothermia. The mechanism(s) accounting for lactate levels during hypothemia seem to be multiple ranging from the metabolic effects of reduced temperatures to the hemodynamic effects of hypothermia (i.e., reduced need of vasopressor agents). Serial lactate measurements over time, or lactate clearance, have been reported to be clinically more reliable than lactate absolute value also in acute cardiac patients. Despite differences in study design, timing of lactate measurements and type of acute cardiac conditions (i.e., cardiogenic shock, cardiac arrest, refractory cardiac arrest), available evidence strongly suggests that higher lactate levels can be observed on admission in non-survivors and that higher lactate clearance is associated with better outcome.

Denver ED Trauma Organ Failure Score outperforms traditional methods of risk stratification in trauma

BACKGROUND

Early identification of trauma patients at risk for inhospital mortality may facilitate goal-directed resuscitation and secondary triage to improve outcomes. The objective of this study was to compare prognostic accuracies of the Denver Emergency Department (ED) Trauma Organ Failure (TOF) Score, ED Sequential Organ Failure Assessment (SOFA) score, and ED base deficit and ED lactate for inhospital mortality in adult trauma patients.

METHODS

Consecutive adult trauma patients from 2005 to 2008 from the Denver Health Trauma Registry were included. Prognostic accuracies of the Denver ED TOF Score, ED SOFA score, ED base deficit, and ED lactate for inhospital mortality were evaluated with receiver operating characteristic curves.

RESULTS

Of the 4355 patients, the median age was 37 years (interquartile range [IQR], 26-51 years), median Injury Severity Score was 9 (IQR, 4-16), and 81% had blunt mechanisms. In addition, 38% (1670 patients) were admitted to the intensive care unit with a median intensive care unit length of stay of 2.5 days (IQR, 1-8 days), and 3% (138 patients) died. The areas under the receiver operating characteristic curves for the Denver ED TOF, ED lactate, ED base deficit, and ED SOFA were 0.94 (95% confidence interval [CI], 0.94-0.96), 0.88 (95% CI, 0.85-0.91), 0.82 (95% CI, 0.78-0.86), and 0.78 (95% CI, 0.73-0.82), respectively.

CONCLUSIONS

The Denver ED TOF Score more accurately predicts inhospital mortality in adult trauma patients compared to the ED SOFA score, ED base deficit, or ED lactate. The Denver ED TOF Score may help identify patients early who are at risk for mortality, allowing for targeted resuscitation and secondary triage to improve outcomes.

Predictors of mortality and prehospital monitoring limitations in blunt trauma patients

This study aimed at determining predictors of in-hospital mortality and prehospital monitoring limitations in severely injured intubated blunt trauma patients. We retrospectively reviewed patients' charts. Prehospital vital signs, Injury Severity Score (ISS), initial Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), arterial blood gases, and lactate were compared in two study groups: survivors (n = 40) and nonsurvivors (n = 30). There were no significant differences in prehospital vital signs between compared groups. Nonsurvivors were older (P = 0.006), with lower initial GCS (P < 0.001) and higher ISS (P < 0.001), along with higher lactate (P < 0.001) and larger base deficit (BD; P = 0.006), whereas RTS (P = 0.001) was lower in nonsurvivors. For predicting mortality, area under the curve (AUC) was calculated: for lactate 0.82 (P < 0.001), for ISS 0.82 (P < 0.001), and for BD 0.69 (P = 0.006). Lactate level of 3.4 mmol/L or more was 82% sensitive and 75% specific for predicting in-hospital death. In a multivariate logistic regression model, ISS (P = 0.037), GCS (P = 0.033), and age (P = 0.002) were found to be independent predictors of in-hospital mortality. The AUC for regression model was 0.93 (P < 0.001). Increased levels of lactate and BD on admission indicate more severe occult hypoperfusion in nonsurvivors whereas vital signs did not differ between the groups.

The effect of ethanol on lactate and base deficit as predictors of morbidity and mortality in trauma

OBJECTIVE

The objective of this study was to assess the predictive value of lactate and base deficit in determining outcomes in trauma patients who are positive for ethanol.

METHODS

Retrospective cohort study of patients admitted to a level 1 trauma center between 2005 and 2014. Adult patients who had a serum ethanol, lactate, base deficit, and negative urine drug screen obtained upon presentation were included.

RESULTS

Data for 2482 patients were analyzed with 1127 having an elevated lactate and 1092 an elevated base deficit. In these subgroups, patients with a positive serum ethanol had significantly lower 72-hour mortality, overall mortality, and hospital length of stay compared with the negative ethanol group. Abnormal lactate (odds ratio [OR], 2.607; 95% confidence interval [CI], 1.629-4.173; P = .000) and base deficit (OR, 1.917; 95% CI, 1.183-3.105; P = .008) were determined to be the strongest predictors of mortality in the ethanol-negative patients. Injury Severity Score was found to be the lone predictor of mortality in patients positive for ethanol (OR, 1.104; 95% CI, 1.070-1.138; P = .000). Area under the curve and Youden index analyses supported a relationship between abnormal lactate, base deficit, and mortality in ethanol-positive patients when the serum lactate was greater than 4.45 mmol/L and base deficit was greater than -6.95 mmol/L.

CONCLUSIONS

Previously established relationships between elevated lactate, base deficit, and outcome do not remain consistent in patients presenting with positive serum ethanol concentrations. Ethanol skews the relationship between lactate, base deficit, and mortality thus resetting the threshold in which lactate and base deficit are associated with increased mortality.

Initial venous lactate levels in patients with isolated penetrating extremity trauma: a retrospective cohort study

INTRODUCTION

Elevated initial lactate levels have been shown to be associated with severe injury in trauma patients, but some patients who do not appear to be in shock also presented with elevated lactate levels. We hypothesized that in hemodynamically stable patients with isolated penetrating extremity trauma, initial lactate level does not predict clinically significant bleeding.

METHODS

A 5-year institutional database review was performed. Hemodynamically stable patients (HR < 101, SBP > 90) with isolated penetrating extremity trauma with an initial lactate sent were included. The exposure of interest was captured as a dichotomous variable by initial lactate level normal (N ≤ 2.2 mEq/L), elevated (E > 2.2 mEq/L). The primary outcome measurement was clinically significant bleeding, defined by need for intervention (operation, angioembolization, or transfusion) or laboratory evidence of bleeding (presenting Hg < 7 g/dL, or Hg decrease by >2 g/dL/24 h). Chi-squared and Mann-Whitney tests were used to compare variables.

RESULTS

A total of 132 patients were identified. There were no differences in demographics or mechanism of injury between the N (n = 43, 7%) and E (n = 89, 14%) groups. Median lactate levels were 1.6 (IQR 1.2-1.9) mEq/dL vs. 3.8 (IQR 2.8-5.2) in the N and E groups, p < 0.001. Lactate was elevated in 89 (67%) patients but was not associated with clinically significant bleeding (37% elevated vs. 39 % not elevated p = 0.82).

CONCLUSIONS

In hemodynamically stable patients with isolated penetrating trauma to the extremity, elevated initial venous lactate levels (>2.2 mEq/L) are not associated with bleeding or need for interventions. Clinical judgment remains the gold standard for evaluation and management of these patients.

Serum lactate as a predictor of early outcomes among trauma patients in Uganda

Background

Trauma is the leading cause of death in the developed world. Accurate assessment of severity of injuries is critical in informing treatment choices. Current models of assessing severity of injury are not without limitations. The objective of this study therefore was to determine the diagnostic accuracy of serum lactate assays in assessing injury severity and prediction of early outcomes among trauma patients.

Methods

This was a cross-sectional analytical study. Consecutive series of all eligible patients had a single venous blood sample drawn for lactate assay analysis (index test) and a concurrent Kampala Trauma Score (KTS) II value determination (reference test). Admitted patients were followed up to assess early outcomes (length of hospital stay and mortality).

Results

Out of the 502 trauma patients recruited, 108 (22%) were severely injured, 394 (78%) had non-severe injuries, and 183 were admitted. There was a significant difference between median (interquartile range (IQR)) lactate levels among the severely injured (4.3 (2.6, 6.6)) and the non-severely injured (2.4 (1.6, 3.5), p < 0.001). After a 72-h follow-up of the admitted patients, 102 (56%) were discharged, 61 (33%) remained in the hospital, 3 (2%) remained in the ICU, and 17 (3%) had died. The area under the receiver operator characteristic (ROC) curve was 0.75 for injury severity. Serum lactate ≥2.0 mmol/l had a hazard ratio of 1.10 (p < 0.001) for emergency department disposition, 4.33 (p = 0.06) for the 72-h non-discharge disposition, and 1.19 (p < 0.001) for 72-h mortality. Serum lactate ≥2.0 mmol/l at admission was useful in discriminating severe from non-severe injuries with a sensitivity of 88%, specificity of 38%, PPV of 30%, and NPV of 92%.

Conclusion

Hyperlactatemia in an emergency trauma patient suggests a high probability of severe injury.