Emergency department lactate is associated with mortality in older adults admitted with and without infections

Cost-effectiveness analysis of early point-of-care lactate testing in the emergency department

PURPOSE

To determine the cost-effectiveness of implementing a point-of-care (POC) Lactate Program in the emergency department (ED) for patients with suspected sepsis to identify patients who can benefit from early resuscitation.

MATERIALS AND METHODS

We constructed a cost-effectiveness model to examine an ED with 30 000 patients annually. We evaluated a POC lactate program screening patients with suspected sepsis for an elevated lactate ≥4 mmol/L. Those with elevated lactate levels are resuscitated and their lactate clearance is evaluated by serial POC lactate measurements. The POC Lactate Program was compared with a Usual Care Strategy in which all patients with sepsis and an elevated lactate are admitted to the intensive care unit. Costs were estimated from the 2014 Medicare Inpatient and National Physician Fee schedules, and hospital and industry estimates.

RESULTS

In the base-case, the POC Lactate Program cost $39.53/patient whereas the Usual Care Strategy cost $33.20/patient. The screened patients in the POC arm resulted in 1.07 quality-adjusted life years for an incremental cost-effectiveness ratio of $31 590 per quality-adjusted life year gained, well below accepted willingness-to-pay-thresholds.

CONCLUSIONS

Implementing a POC Lactate Program for screening ED patients with suspected sepsis is a cost-effective intervention to identify patients responsive to early resuscitation.

Prognostic value of neglected biomarker in sepsis patients with the old and new criteria: predictive role of lactate dehydrogenase

OBJECTIVES

This study examined the pH, lactate dehydrogenase (LDH), and heart rate values on the first day of hospitalization in patients with a prediagnosis of sepsis and biomarkers that may predict mortality.

METHODS

Patients hospitalized in an emergency intensive care unit with a diagnosis of systemic inflammatory response syndrome were classified as having sepsis (n = 28), septic shock (n = 8), or severe sepsis (n = 8) according to International Sepsis Guidelines (old criteria). Forty-four patients were classified as having sepsis (n = 4), septic shock (n = 30), or infection (n = 10) according to The Third International Consensus Definitions for Sepsis and Septic Shock (new criteria). The effects of these patients' laboratory values on survival between groups were compared. Significant values were evaluated by χ² automatic interaction detection analysis.

RESULTS

When the patients were categorized according to the new classification criteria, there was an increase in the number of septic shock patients and a decrease in the number of sepsis patients. In addition, 10 patients were removed from the sepsis category. There was a significant difference between ex and discharged patients in terms of heart rate, pH, sodium bicarbonate, lactate, and LDH (P= .007, P= .002, P= .034, P= .009, and P= .002, respectively). Based on a χ² automatic interaction detection analysis of the significant values, pH, LDH, and heart rate were prominent predictors of prognosis.

CONCLUSIONS

Systemic pH, LDH, and heart rate values may be used to determine the best time to discharge patients from intensive care to other, more affordable hospital units.

Blood Lactate Is a Useful Indicator for the Medical Emergency Team

Lactate has been thoroughly studied and found useful for stratification of patients with sepsis, in the Intensive Care Unit, and trauma care. However, little is known about lactate as a risk-stratification marker in the Medical Emergency Team- (MET-) call setting. We aimed to determine whether the arterial blood lactate level at the time of a MET-call is associated with increased 30-day mortality. This is an observational study on a prospectively gathered cohort at a regional secondary referral hospital. All MET-calls during the two-year study period were eligible. Beside blood lactate, age and vital signs were registered at the call. Among the 211 calls included, there were 64 deaths (30.3%). Median lactate concentration at the time of the MET-call was 1.82 mmol/L (IQR 1.16–2.7). We found differences between survivors and nonsurvivors for lactate and oxygen saturation, a trend for age, but no significant correlations between mortality and systolic blood pressure, respiratory rate, and heart rate. As compared to normal lactate (<2.44 mmol/L), OR for 30-day mortality was 3.54 (p < 0.0006) for lactate 2.44–5.0 mmol/L and 4.45 (p < 0.0016) for lactate > 5.0 mmol/L. The present results support that immediate measurement of blood lactate in MET call patients is a useful tool in the judgment of illness severity.

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.

Short-term prognostic factors in the elderly patients seen in emergency departments due to infections

OBJECTIVES

To analyse factors associated with short-term mortality in elderly patients seen in emergency departments (ED) for an episode of infectious disease.

MATERIALS AND METHODS

A prospective, observational, multicentre, analytical study was carried out on patients aged 75years and older who were treated in the ED of one of the eight participating hospitals. An assessment was made of 26 independent variables that could influence mortality at 30days. They covered epidemiological, comorbidity, functional, clinical and analytical factors. Multivariate logistic regression analysis was performed.

RESULTS

The study included 488 consecutive patients, 92 (18.9%) of whom died within 30days of visiting the ED. Three variables were significantly associated with higher mortality: severe functional dependence, with Barthel index ≤60 [odds ratio (OR) 8,92; 95% confidence interval (CI): 4.98-15.98, P=.003], systolic blood pressure <90mmHg [OR 7.34; 95%CI: 4.39-12.26, P=.005] and serum lactate >4mmol/l [OR 21.14; 95%CI: 8.94-49.97, P=.001]. The area under the curve for the model was 0.971 (95%CI: 0.951-0.991; P<.001).

CONCLUSIONS

Several factors evaluated in an initial assessment in the ED, including the level of functional dependence, systolic blood pressure and, especially, serum lactate, were found to determine a poor short-term prognosis in the elderly patients who presented with an episode of an infectious disease.

The accuracy and timeliness of a Point Of Care lactate measurement in patients with Sepsis

BACKGROUND

The aims of this study were to a) compare the lactate measurement of a Point of Care (POC) handheld device to near patient blood gas analysers, and b) determine the differential reporting times between the analysers.

METHODS

A two-staged study; method comparison and prospective observational stages, was conducted. For the first stage, blood samples were analysed on the i-STAT handheld device and the near patient blood gas analysers (GEM 4000 and OMNI S). Results were compared using Pearson correlation coefficient and Bland-Altman tests. For the second stage, we examined the differential reporting times of the POC device compared to the near patient blood gas analysers in two Scottish hospitals. Differential reporting times were assessed using Mann-Whitney test and descriptive statistics were reported with quartiles.

RESULTS

Highly significant Pearson correlation coefficients (0.999 and 0.993 respectively) were found between i-STAT and GEM 4000 and OMNI S. The Bland-Altman agreement method showed bias values of -0.03 and -0.24, between i-STAT and GEM 4000 and OMNI S respectively. Median time from blood draw to i-STAT lactate results was 5 min (Q1-Q3 5-7). Median time from blood draw to GEM 4000 lactate results was 10 min (Q1-Q3 7.75-13). Median time from blood draw to OMNIS lactate results was 11 min (Q1-Q3 8-22). The i-STAT was significantly quicker than both the GEM 4000 and the OMNIS (each p-value < 0.001). In addition, 18 of our study samples were sent to the central laboratory for analysis due to a defect in the lactate module of OMNI S. The median time for these samples from blood draw to availability of the central laboratory results at the clinical area was 133 min.

CONCLUSIONS

The POC handheld device produced accurate, efficient and timely lactate measurements with the potential to influence clinical decision making sooner.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

High serum lactate level may predict death within 24 hours

BACKGROUND

Unexpected death within 24 hours of admission is a real challenge for the clinician in the emergency room. How to diagnose these patients and the right approach to prevent sudden death with 24 hours is still an enigma. The aims of our study were to find the independent factors that may affect the clinical outcome in the first 24 hours of admission to the hospital.

METHODS

We performed a retrospective study defining unexpected death within 24 hours of admission in our Department of Medicine in the last 6 years. We found 43 patients who died within 24 hours of admission, and compared their clinical and biochemical characteristics to 6055 consecutive patients who were admitted in that period of time and did not die within the first 24 hours of admission. The parameters that were used include gender, age, temperature, clinical and laboratory criteria for SIRS, arterial blood lactate, and arterial blood pH.

RESULTS

Most of the patients who died within 24 hours had sepsis with SIRS. These patients were older (78.6±14.7 vs. 65.2±20.2 years [p<.0001]), had higher lactate levels (8.0±4.8 vs. 2.1±1.8mmol/L [p<.0001]), and lower pH (7.2±0.2 vs. 7.4±0.1 [p<.0001]). Logistic regression analysis found that lactate was the strongest independent parameter to predict death within 24 hours of admission (OR 1.366 [95% CI 1.235-1.512]), followed by old age (OR 1.048 [95% CI 1.048-1.075] and low arterial blood pH (OR 0.007 [CI <0.001-0.147]). When gender was analyzed, pH was not an independent variable in females (only in males).

CONCLUSIONS

The significant independent variable that predicted death within 24 hours of admission was arterial blood lactate level on admission. Older age was also an independent variable; low pH affected only males, but was a less dominant variable. We suggest use of arterial blood lactate level on admission as a bio-marker in patients with suspected sepsis admitted to the hospital for risk assessment and prediction of death within 24 hours of admission.

Physician documentation of sepsis syndrome is associated with more aggressive treatment

Introduction

Timely recognition and treatment of sepsis improves survival. The objective is to examine the association between recognition of sepsis and timeliness of treatments.

Methods

We identified a retrospective cohort of emergency department (ED) patients with positive blood cultures from May 2007 to January 2009, and reviewed vital signs, imaging, laboratory data, and physician/nursing charts. Patients who met systemic inflammatory response syndrome (SIRS) criteria and had evidence of infection available to the treating clinician at the time of the encounter were classified as having sepsis. Patients were dichotomized as RECOGNIZED if sepsis was explicitly articulated in the patient record or if a sepsis order set was launched, or as UNRECOGNIZED if neither of these two criteria were met. We used median regression to compare time to antibiotic administration and total volume of fluid resuscitation between groups, controlling for age, sex, and sepsis severity.

Results

SIRS criteria were present in 228/315 (72.4%) cases. Our record review identified sepsis syndromes in 214 (67.9%) cases of which 118 (55.1%) had sepsis, 64 (29.9%) had severe sepsis, and 32 (15.0%) had septic shock. The treating team contemplated sepsis (RECOGNIZED) in 123 (57.6%) patients. Compared to the UNRECOGNIZED group, the RECOGNIZED group had a higher use of antibiotics in the ED (91.9 vs.75.8%, p=0.002), more patients aged 60 years or older (56.9 vs. 33.0%, p=0.001), and more severe cases (septic shock: 18.7 vs. 9.9%, severe sepsis: 39.0 vs.17.6%, sepsis: 42.3 vs.72.5%; p<0.001). The median time to antibiotic (minutes) was lower in the RECOGNIZED (142) versus UNRECOGNIZED (229) group, with an adjusted median difference of −74 minutes (95% CI [−128 to −19]). The median total volume of fluid resuscitation (mL) was higher in the RECOGNIZED (1,600 mL) compared to the UNRECOGNIZED (1,000 mL) group. However, the adjusted median difference was not statistically significant: 262 mL (95% CI [ −171 to 694 mL]).

Conclusion

Patients whose emergency physicians articulated sepsis syndrome in their documentation or who launched the sepsis order set received antibiotics sooner and received more total volume of fluid. Age <60 and absence of fever are factors associated with lack of recognition of sepsis cases.

Lactate clearance as a marker of mortality in pediatric intensive care unit

OBJECTIVE

To correlate lactate clearance with Pediatric Intensive Care Unit (PICU) mortality.

METHODS

45 (mean age 40.15 mo, 60% males) consecutive admissions in the PICU were enrolled between May 2012 to June 2013. Lactate clearance (Lactate level at admission - level 6 hr later x 100 / lactate level at admission) in first 6 hours of hospitalization was correlated to in-hospital mortality and PRISM score.

RESULTS

Twelve out of 45 patients died. 90% died among those with delayed/poor clearance (clearance <30%) compared to 8.5% in those with good clearance (clearance >30%) (P<0.001). Lactate clearance <30% predicted mortality with sensitivity of 75%, specificity of 97%, positive predictive value of 90%, and negative predictive value of 91.42%. Predictability was comparable to PRISM score >30.

CONCLUSION

Lactate clearance at six hours correlates with mortality in the PICU.

Peripheral venous lactate at admission is associated with in-hospital mortality, a prospective cohort study

BACKGROUND

The prognostic value of blood lactate as a predictor of adverse outcome in the acutely ill patient is unclear. The aim of this study was to investigate if a peripheral venous lactate measurement, taken at admission, is associated with in-hospital mortality in acutely ill patients with all diagnosis. Furthermore, we wanted to investigate if the test improves a triage model in terms of predicting in-hospital mortality.

METHODS

We retrieved a cohort of 2272 adult patients from a prospectively gathered acute admission database. We performed regression analysis to evaluate the association between the relevant covariates and the outcome measure: in-hospital mortality.

RESULTS

Lactate as a continuous variable was a risk for in-hospital mortality with an odds ratio (OR) of 1.40 [95% confidence interval (CI) 1.25-1.57, P<0.0001]. OR for in-hospital mortality increased with increasing lactate levels from 2.97 (95% CI 1.55-5.72, P<0.001) for lactate between 2 mmol/l and 4 mmol/l, to 7.77 (95% CI 3.23-18.66, P<0.0001) for lactate>4 mmol/l. If the condition was non-compensated (i.e. pH<7.35), OR for in-hospital mortality increased to 19.99 (7.26-55.06, P<0.0001). Patient with a blood lactate at 4 mmol/l or more had a risk of in-hospital mortality equivalent to the patients in the most urgent triage category.

CONCLUSION

We found elevated admission peripheral venous lactate to be independently associated with in-hospital mortality in the acutely ill patient admitted to the emergency department. Patients with a lactate>4 mmol/l at hospital admission should be considered triaged to the most urgent triage category.

Incidence and impact of skin mottling over the knee and its duration on outcome in critically ill patients

PURPOSE

Skin mottling is frequent and can be associated with an increased mortality rate in ICU patients with septic shock. Its overall incidence in ICU and its impact on outcome is unknown. We aimed to assess the incidence of skin mottling over the knee among all critically ill patients admitted in ICU and its role on their outcome.

METHODS

An observational study over a 1-year period in a 15-bed medical ICU of a teaching hospital. Skin mottling over the knee was prospectively and qualitatively assessed by trained nurses.

RESULTS

Incidence of skin mottling was 29% (230 of 791 patients) in overall, and 49% (32 of 65 patients) in the subset of patients admitted for septic shock. Skin mottling was present on the day on admission in 65% of patients and persisted more than 6 h in 59% of cases. In-ICU mortality was 8% in patients without mottling, 30% in patients with short skin mottling and 40% in patients with persistent skin mottling (p < 0.01 between all groups). In the overall population, skin mottling over the knee was associated with in-ICU mortality independently from SAPS II (aOR 3.29 [95% CI, 2.08-5.19], p < 0.0001). Among patients with skin mottling over the knee, persistence of skin mottling remained associated with increased in-ICU mortality independently of organ dysfunctions at the mottling onset (OR 2.77 [95% CI, 1.34-5.72], p = 0.004).

CONCLUSIONS

Skin mottling is frequent in the general population of patients admitted in ICU. Occurrence and persistence of skin mottling are independently associated with in-ICU mortality.

Lactate clearance is a useful biomarker for the prediction of all-cause mortality in critically ill patients: a systematic review and meta-analysis*

OBJECTIVES

Lactate clearance has been widely investigated for its prognostic value in critically ill patients. However, the results are conflicting. The present study aimed to explore the diagnostic accuracy of lactate clearance in predicting mortality in critically or acutely ill patients.

DATA SOURCES

Databases of Medline, Embase, Scopus, and Web of Knowledge were searched from inception to June 2013.

STUDY SELECTION

Studies investigating the prognostic value of lactate clearance were defined as eligible. The searched item consisted of terms related to critically ill patients and terms related to lactate clearance.

DATA EXTRACTION

The following data were extracted: the name of the first author, publication year, subjects and setting, mean age of study population, sample size, male percentage, mortality of study cohort, definition of clearance, and the initial lactate level. Relative risk was reported to estimate the predictive value of lactate clearance on mortality rate, with relative risk less than 1 indicating that lactate clearance was a protective factor. Meta-analysis of diagnostic accuracy of lactate clearance in predicting mortality was performed by using hierarchical summary receiver operating characteristic model.

DATA SYNTHESIS

A total of 15 original articles were included in the study. Because of the significant heterogeneity across studies (I = 61.4%), random-effects model was used to pool relative risks. The pooled relative risk for mortality was 0.38 (95% CI, 0.29-0.50). The overall sensitivity and specificity for lactate clearance to predict mortality were 0.75 (95% CI, 0.58-0.87) and 0.72 (95% CI, 0.61-0.80), respectively. The diagnostic performance improved slightly when meta-analysis was restricted to ICU patients, with sensitivity and specificity of 0.83 (95% CI, 0.67-0.92) and 0.67 (95% CI, 0.59-0.75), respectively.

CONCLUSION

Our study demonstrates that lactate clearance is predictive of lower mortality rate in critically ill patients, and its diagnostic performance is optimal for clinical utility.

High plasma levels of high mobility group box 1 is associated with the risk of sepsis in severe blunt chest trauma patients: a prospective cohort study

Background

High mobility group box 1 (HMGB1) is a late mediator of systemic inflammation. Extracellular HMGB1 play a central pathogenic role in critical illness. The purpose of the study was to investigate the association between plasma HMGB1 concentrations and the risk of poor outcomes in patients with severe blunt chest trauma.

Methods

The plasma concentrations of HMGB1 in patients with severe blunt chest trauma (AIS ≥ 3) were measured by a quantitative enzyme-linked immunosorbent assay at four time points during seven days after admission, and the dynamic release patterns were monitored. The biomarker levels were compared between patients with sepsis and non-sepsis, and between patients with multiple organ dysfunction syndrome (MODS) and non-MODS. The related factors of prognosis were analyzed by using multivariate logistic regression analysis. The short-form 36 was used to evaluate the quality of life of patients at 12 months after injury.

Results

Plasma HMGB1 levels were significantly higher both in sepsis and MODS group on post-trauma day 3, 5, and 7 compared with the non-sepsis and non-MODS groups, respectively. Multivariate analysis showed that HMGB1 levels and ISS were independent risk factors for sepsis and MODS in patients with severe blunt chest trauma.

Conclusions

Plasma HMGB1 levels were significantly elevated in patients with severe blunt chest trauma. HMGB1 levels were associated with the risk of poor outcome in patients with severe blunt chest trauma. Daily HMGB1 levels measurements is a potential useful tool in the early identification of post-trauma complications. Further studies are needed to determine whether HMGB1 intervention could prevent the development of sepsis and MODS in patients with severe blunt chest trauma.

Implementation of risk stratified antibiotic therapy for neutropenic fever: what are the risks?

BACKGROUND

A new national guideline for the management of febrile patients with severe neutropenia uses a risk stratification score to tailor treatment.

AIMS

To evaluate the implementation of this guideline in a metropolitan teaching hospital.

METHODS

A protocol was developed for implementation of the national guidelines for patients with neutropenic fever or at risk because of recent chemotherapy. Medical records of all patients presenting with fever to the haematology and oncology service for 3 months in 2011 were audited. Patients with a neutrophil count between 0.5 and 1.0 × 10(9) /L were classified as borderline neutropenia.

RESULTS

Eighty-one episodes of fever were treated on the protocol. Forty-three per cent of patients were neutropenic. Uptake of the policy was low (35%) despite concerted efforts. The sensitivity and specificity of the Multinational Association for Supportive Care in Cancer score was 86% and 24% respectively. The readmission rate with fever was 19.2%. Median time to antibiotics was 60 min. Outcomes were similar for the neutropenic fever and borderline groups. Increasing treatment complexity was the major barrier to implementation.

CONCLUSIONS

The majority of presentations with cancer and fever following chemotherapy do not have neutropenia but have similar outcomes when treated on the same pathway. The utility of the Multinational Association for Supportive Care in Cancer score was limited by uptake and specificity. Reducing time to antibiotics administration and readmission rates were identified as priorities. Implementation was labour-intensive and faced significant barriers. Prioritisation of evidence for translation requires attention to local priorities and implementation complexity. These results argue for a single sepsis guideline with treatment of cancer as a high-risk group.

Etiology and therapeutic approach to elevated lactate levels

Lactate levels are commonly evaluated in acutely ill patients. Although most often used in the context of evaluating shock, lactate levels can be elevated for many reasons. While tissue hypoperfusion may be the most common cause of elevation, many other etiologies or contributing factors exist. Clinicians need to be aware of the many potential causes of lactate level elevation as the clinical and prognostic importance of an elevated lactate level varies widely by disease state. Moreover, specific therapy may need to be tailored to the underlying cause of elevation. The present review is based on a comprehensive PubMed search between the dates of January 1, 1960, to April 30, 2013, using the search term lactate or lactic acidosis combined with known associations, such as shock, sepsis, cardiac arrest, trauma, seizure, ischemia, diabetic ketoacidosis, thiamine, malignancy, liver, toxins, overdose, and medication. We provide an overview of the pathogenesis of lactate level elevation followed by an in-depth look at the varied etiologies, including medication-related causes. The strengths and weaknesses of lactate as a diagnostic/prognostic tool and its potential use as a clinical end point of resuscitation are discussed. The review ends with some general recommendations on the management of patients with elevated lactate levels.

Even mild hyperlactatemia is associated with increased mortality in critically ill patients

Introduction

The clinical significance of elevation of lactate levels within the reference range is not well studied. The objective of this study was to determine the best cutoff threshold for serum lactate within the reference range (0.01 to 2.00 mM) that best discriminated between survivors and nonsurvivors of critical illness and to examine the association between relative hyperlactatemia (lactate above the identified threshold) and mortality.

Methods

This was a retrospective cohort study of adult patients admitted to the medical-surgical intensive care unit (ICU) of a tertiary care academic center. Youden index was calculated to identify the best lactate cutoff threshold that discriminated between survivors and nonsurvivors. Patients with lactate above the identified threshold were defined as having relative hyperlactatemia. Multivariate logistic regression, adjusting for baseline variables, was performed to determine the relationship between the above two ranges of lactate levels and mortality. In addition, a test of interaction was performed to assess the effect of selected subgroups on the association between relative hyperlactatemia and hospital mortality.

Results

During the study period, 2,157 patients were included in the study with mean lactate of 1.3 ± 0.4 mM, age of 55.1 ± 20.3 years, and acute physiology and chronic health evaluation (APACHE) II score of 22.1 ± 8.2. Vasopressors were required in 42.4%. Lactate of 1.35 mM was found to be the best cutoff threshold for the whole cohort. Relative hyperlactatemia was associated with increased hospital mortality (adjusted odds ratio (aOR), 1.60, 95% confidence interval (CI) 1.29 to 1.98), and ICU mortality (aOR, 1.66; 95% CI, 1.26 to 2.17) compared with a lactate level of 0.01 to 1.35 mM. This association was consistent among all examined subgroups.

Conclusions

Relative hyperlactatemia (lactate of 1.36 to 2.00 mM) within the first 24 hours of ICU admission is an independent predictor of hospital and ICU mortality in critically ill patients.

Association between a geriatric trauma resuscitation protocol using venous lactate measurements and early trauma surgeon involvement and mortality risk

OBJECTIVES

To investigate whether implementing a geriatric resuscitation protocol that uses lactate-guided therapy with early trauma surgeon involvement is associated with lower mortality through the early recognition of occult hypoperfusion (OH).

DESIGN

Prospective cohort study.

SETTING

Level I trauma center.

PARTICIPANTS

All hemodynamically stable individuals with blunt trauma aged 65 and older admitted to the Level I trauma center from October 1, 2008, through December 31, 2011 (n = 1,998).

MEASUREMENTS

Mortality over time (according to quarter) was analyzed using an adjusted logarithmic regression model stratified according to the presence of OH. OH was defined as lactate of 2.5 mM or greater.

RESULTS

Overall mortality was 3.9% (n = 78). Admission venous lactate was collected in 73.5% of participants, of whom 20.5% had OH (n = 301). In participants with OH, a significant decrease in mortality was observed over time (adjusted coefficient of determination (R(2) ) = 0.66, P = .002). A smaller yet significant decrease in mortality rates in participants with normal perfusion status was also observed (adjusted R(2) = 0.55, P = .01).

CONCLUSION

Early identification and treatment of OH in elderly adults with trauma using venous lactate-guided therapy coupled with early trauma surgeon involvement was associated with significantly lower mortality. A protocol that uses lactate-guided therapy with early trauma surgeon involvement should be followed to improve the care of elderly adults with trauma.

Serum lactate is a prognostic indicator in patients with hip fracture

BACKGROUND AND PURPOSE

Serum lactate has been shown to be an indicator of adverse clinical outcomes in patients admitted secondary to general trauma or sepsis. We retrospectively investigated whether admission serum venous lactate can predict in-hospital mortality in patients with hip fractures.

METHOD AND RESULTS

Over a 38-month period the admission venous lactate of 807 patients with hip fractures was collated. Mean age was 82 years. The overall in-hospital mortality for this cohort was 9.4%. Mortality was not influenced by the fracture pattern or the type of surgery - be it internal fixation or arthroplasty (p = 0.7). A critical threshold of 3 mmol/L with respect to the influence of venous lactate level on mortality was identified. Mortality rate in those with a lactate level of less than 3 mmol/L was 8.6% and 14.2% for those whose level was 3 mmol/L or greater. A 1 mmol/L increase in venous lactate was associated with a 1.2 (1.02-1.41) increased risk of in-hospital mortality. Patients with a venous lactate of 3 mmol/L or higher had twice the odds of death in hospital compared to matched individuals. There was no statistically significant difference in ASA distribution between those with a lactate of less than or greater than 3 mmol/L.

CONCLUSIONS

Patients with an elevated venous lactate following hip trauma should be identified as being at increased risk of death and may benefit from targeted medical therapy.

Multicenter observational study of the development of progressive organ dysfunction and therapeutic interventions in normotensive sepsis patients in the emergency department

OBJECTIVES

Progressive organ dysfunction is the leading cause of sepsis-associated mortality; however, its incidence and management are incompletely understood. Sepsis patients with moderately impaired perfusion (serum lactate 2.0 to 3.9 mmol/L) who are not in hemodynamic shock ("preshock" sepsis patients) may be at increased risk for progressive organ dysfunction and increased mortality. The objectives of this study were to: 1) quantify the occurrence of progressive organ dysfunction among preshock sepsis patients, 2) examine if there were baseline differences in demographic and physiologic parameters between preshock sepsis patients who experienced progressive organ dysfunction and those who did not, and 3) examine if intravenous (IV) fluid administered in the emergency department (ED) differed between these two groups of patients.

METHODS

This was a prospective, observational study in four urban EDs targeting the preshock sepsis population, defined as adults (18 years or older) with suspected infection, serum lactate between 2.0 and 3.9 mmol/L, and without hypotension (systolic blood pressure [sBP] < 90 mm Hg or mean arterial pressure [MAP] < 70 mm Hg) or requiring mechanical ventilation at ED presentation. The primary composite outcome was progressive organ dysfunction, defined as a rise in the Sequential Organ Failure Assessment (SOFA) score of ≥1, vasopressor use, mechanical ventilation use within 72 hours after ED presentation, or in-hospital death. The secondary outcomes were any intensive care unit (ICU) admission, and total ICU and hospital lengths of stay (LOS).

RESULTS

Among 94 preshock sepsis patients, the primary composite outcome occurred in 24 of 94 (26%). In patients with the primary outcome, 22 of 24 (92%) experienced a rise in SOFA score of ≥1, five of 24 (21%) received vasopressor agents, and seven of 24 (30%) required mechanical ventilation. There were no baseline demographic or physiologic parameter differences between patients who met the primary outcome versus those who did not, while patients with the primary outcome had a higher average SOFA score at admission (2.4 vs. 1.3, p = 0.011) and at all subsequent time points. Median IV fluid volume administered to all preshock sepsis patients during their ED stay was 1,225 mL (interquartile range [IQR] = 712 to 2,000 mL) and did not differ significantly between patients with (1,150 mL, IQR = 469 to 2,000 mL) or without (1,250 mL, IQR = 750 to 2,000 mL) the primary outcome (p = 0.73). Patients with progressive organ dysfunction or death were more likely to be admitted to an ICU (50% vs. 20%, p < 0.01) and have an increased median hospital LOS (6 days vs. 3 days, p = 0.005), compared to those without progressive organ dysfunction.

CONCLUSIONS

Over one-quarter of preshock sepsis patients developed progressive organ dysfunction with associated increased resource use. Demographic and physiologic parameters were unable to differentiate patients with progressive organ dysfunction, while the initial SOFA score was increased in patients meeting the outcome. Overall, these patients received relatively little IV fluid therapy during their ED stays. Further research to determine if more aggressive therapy can prevent progressive organ dysfunction in this population is warranted.

Improving risk classification of critical illness with biomarkers: a simulation study

PURPOSE

Optimal triage of patients at risk for critical illness requires accurate risk prediction, yet few data on the performance criteria required of a potential biomarker to be clinically useful exists.

MATERIALS AND METHODS

We studied an adult cohort of nonarrest, nontrauma emergency medical services encounters transported to a hospital from 2002 to 2006. We simulated hypothetical biomarkers increasingly associated with critical illness during hospitalization and determined the biomarker strength and sample size necessary to improve risk classification beyond a best clinical model.

RESULTS

Of 57,647 encounters, 3121 (5.4%) were hospitalized with critical illness and 54,526 (94.6%) without critical illness. The addition of a moderate-strength biomarker (odds ratio, 3.0, for critical illness) to a clinical model improved discrimination (c statistic, 0.85 vs 0.8; P<.01) and reclassification (net reclassification improvement, 0.15; 95% confidence interval, 0.13-0.18) and increased the proportion of cases in the highest-risk category by +8.6% (95% confidence interval, 7.5%-10.8%). Introducing correlation between the biomarker and physiological variables in the clinical risk score did not modify the results. Statistically significant changes in net reclassification required a sample size of at least 1000 subjects.

CONCLUSIONS

Clinical models for triage of critical illness could be significantly improved by incorporating biomarkers, yet substantial sample sizes and biomarker strength may be required.

Venous lactate levels can be used to identify patients with poor outcome following community-onset norovirus enteritis

BACKGROUND

Norovirus enteritis (NVE) can be fatal in frail patients. High blood lactate levels indicate hypoperfusion and predict mortality in many infectious diseases. The objective was to determine the frequency and association with mortality of elevated lactate levels in patients with community-onset NVE.

METHODS

A retrospective cohort study was performed. All hospitalized adult patients with community-onset NVE verified by polymerase chain reaction during the period August 2008 to June 2009 were included. Vital signs and venous lactate on arrival, co-morbid conditions, and time of death were registered. The outcome measure was 30-day all-cause mortality.

RESULTS

Eighty-two patients with a median age of 77 y (interquartile range (IQR) 53-86 y) were included, of whom 47 (57%) were female and 49 (60%) had at least 1 major co-morbid condition. Lactate levels were above the upper limit of normal (ULN; 1.6 mmol/l) in 45 patients (55%). The overall 30-day mortality rate was 7% (6/82). Mortality was 18% (5/28) with lactate ≥ 2.4 mmol/l (> 50% above the ULN) on admission compared to 2% (1/54) with lactate < 2.4 mmol/l (p < 0.05). Patients who died had a higher median lactate level compared to survivors: 4.5 (IQR 2.7-7.9) mmol/l vs 1.7 (IQR 1.3-2.5) mmol/l, respectively (p < 0.01). The adjusted odds ratio for death within 30 days for a 1 mmol/l increase in lactate was 2.5 (95% confidence interval 1.003-6.3, p = 0.049).

CONCLUSIONS

We observed a high proportion of patients with elevated lactate levels in community-onset NVE. Lactate elevation could predict mortality. Measurement of blood lactate may be a valuable tool in the clinical management of patients with a suspected norovirus infection.

Cardiac troponin I does not independently predict mortality in critically ill patients with severe sepsis

OBJECTIVE

Patients with sepsis often have elevated cardiac troponin I even in the absence of coronary artery disease. The prognostic value of cardiac troponins in critically ill patients with sepsis remains debatable. Our objective was to evaluate the prognostic value of cardiac troponin I in critically ill patients with severe sepsis.

METHODS

In this retrospective study, we included patients with severe sepsis who had troponin assayed within 12 h of admission to intensive care over a 6 year period. Patients who had myocardial infarction at intensive care admission in the setting of sepsis were excluded. Included patients were classified into two groups based on their serum troponin I levels: low troponin group (troponin ≤ 0.1 µg/L) and elevated troponin group (troponin > 0.1 µg/L). The primary outcome of interest was hospital mortality. The secondary outcome measures included intensive care mortality, intensive care and hospital length of stay.

RESULTS

A total of 382 patients were admitted to intensive care with sepsis. Of these, 293 patients were included in analyses. There was a statistically significant difference in hospital (15% vs 36.1%; P < 0.01) and intensive care (11% vs 25%; P < 0.01) mortality, but not in intensive care and hospital duration of stay. Logistic regression analysis revealed temperature, simplified acute physiology score II and serum lactate to be independent predictors of hospital mortality. Cardiac troponin I was not an independent predictor of hospital mortality.

CONCLUSION

Critically ill patients with severe sepsis who had elevated troponin had increased hospital and intensive care mortality. However, cardiac troponin I did not independently predict hospital mortality.

Blood lactate as a predictor for in-hospital mortality in patients admitted acutely to hospital: a systematic review

BACKGROUND

Using blood lactate monitoring for risk assessment in the critically ill patient remains controversial. Some of the discrepancy is due to uncertainty regarding the appropriate reference interval, and whether to perform a single lactate measurement as a screening method at admission to the hospital, or serial lactate measurements. Furthermore there is no consensus whether the sample should be drawn from arterial, peripheral venous, or capillary blood. The aim of this review was: 1) To examine whether blood lactate levels are predictive for in-hospital mortality in patients in the acute setting, i.e. patients assessed pre-hospitally, in the trauma centre, emergency department, or intensive care unit. 2) To examine the agreement between arterial, peripheral venous, and capillary blood lactate levels in patients in the acute setting.

METHODS

We performed a systematic search using PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL up to April 2011. 66 articles were considered potentially relevant and evaluated in full text, of these ultimately 33 articles were selected.

RESULTS AND CONCLUSION

The literature reviewed supported blood lactate monitoring as being useful for risk assessment in patients admitted acutely to hospital, and especially the trend, achieved by serial lactate sampling, is valuable in predicting in-hospital mortality. All patients with a lactate at admission above 2.5 mM should be closely monitored for signs of deterioration, but patients with even lower lactate levels should be considered for serial lactate monitoring. The correlation between lactate levels in arterial and venous blood was found to be acceptable, and venous sampling should therefore be encouraged, as the risk and inconvenience for this procedure is minimal for the patient. The relevance of lactate guided therapy has to be supported by more studies.

Diagnostic pitfalls at admission in patients with acute superior mesenteric artery occlusion

BACKGROUND

Acute superior mesenteric artery (SMA) occlusion leads to acute intestinal ischemia and is associated with high mortality. Early diagnosis is often missed, and confounding factors leading to diagnostic delays need to be highlighted.

OBJECTIVES

To identify potential diagnostic laboratory pitfalls at admission in patients with acute SMA occlusion.

METHODS

Fifty-five patients with acute SMA occlusion were identified from the in-hospital register during a 4-year period, 2005-2009.

RESULTS

The median age was 76 years; 78% were women. The occlusion was embolic in 53% and thrombotic in 47% of patients. At admission, troponin I was above the clinical decision level (> 0.06 μg/L) for acute ischemic myocardial injury in 9/19 (47%) patients with embolic occlusion. Elevated pancreas amylase and normal plasma lactate were found in 12/45 and 13/27, respectively. A troponin I (TnI) above the clinical decision level was associated with a high frequency of referrals from the general surgeon to a specialist in internal medicine (p = 0.011) or a cardiologist (p = 0.024). The diagnosis was established after computed tomography angiography in 98% of the patients. The overall in-hospital mortality rate was 33%. Attempting intestinal revascularization (n = 43; p < 0.001), with a 95% frequency rate of completion control of the vascular procedure, was associated with a higher survival rate, whereas referral to the cardiologist was associated with a higher mortality rate (p = 0.018).

CONCLUSION

Elevated TnI was common in acute SMA occlusion, and referral to the cardiologist was found to be associated with adverse outcome. Elevated pancreas amylase and normal plasma lactate values are also potential pitfalls at admission in patients with acute SMA occlusion.