Clinical predictors of adverse outcome in severe sepsis patients with lactate 2-4 mM admitted to the hospital

Quick Sequential Organ Failure Assessment Score, Lactate, and Neutrophil-Lymphocyte Ratio Help in Diagnosis and Mortality Prediction during Golden Hour of Sepsis in Emergency Department

Introduction

Sepsis is a life-threatening condition with a very narrow golden period in which confirmatory diagnosis may change the outcome dramatically. No confirmatory biomarker is available till date for early diagnosis of sepsis. This study aimed to evaluate the combined and independent role of quick sequential organ failure assessment (qSOFA) score, lactate, and neutrophil-lymphocyte ratio (NLR) in diagnosis and mortality prediction in early sepsis.

Methods

This was a hospital-based, single-center, prospective cohort study conducted in a tertiary care institute, Karnataka, India. Three hundred adult sepsis patients were recruited during 10-month period, and demographic data, qSOFA score, lactate, NLR, and culture samples were collected in ED within 1 h of admission. Outcome groups (survivor and nonsurvivor) were statistically analyzed with relative frequencies (%), median, mean ± standard deviation with 95% confidence interval (CI), univariate, bivariate, and multivariate logistic regression analysis, and Receiver -operating characteristic curve (ROC) curve to test the predictive ability of initial levels of three biomarkers.

Results

Sepsis was more prevalent among middle-aged male patients. Male gender (odds ratio [OR], 6.9; 95% CI: 1.61-30.1), qSOFA (OR, 154; 95% CI: 15-1565), and lactate (OR, 1.36; 95% CI: 22-833) show 97% (area under the curve) predictive accuracy of the model for sepsis on bivariate and multivariate logistic regression analysis. A significant rise in NLR was a poor outcome indicator on univariate analysis (P = 0.773).

Conclusion

All three biomarkers are good outcome predictors whereas qSOFA and lactate have diagnostic significance in early sepsis. These markers can be used for patient triaging, minimizing culture report dependence for treatment and ultimately the outcome.

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

Background

Arterial lactate (AL) level is an important predictor of patient prognosis. AL and peripheral venous lactate (PVL) in blood gas analysis have a low concordance rate, and PVL cannot be used as a substitute for AL. However, if the AL range can be predicted from PVL, PVL may be an alternative method for predicting patient prognosis, and the risk of arterial puncture complications with AL may be reduced. This could be a safe and rapid test method.

Methods

This was a retrospective observational study of 125 cases in which blood gas analysis was performed on both arterial and venous blood with an infectious disease in an emergency department. Spearman’s rank correlation coefficient (r) and Bland–Altman analyses were performed. Sensitivity, specificity, and area under the curve (AUC) were calculated for PVL to predict AL < 2 mmol/L or < 4 mmol/L.

Results

The median [interquartile range] AL and PVL were 1.82 [1.25–2.46] vs. 2.08 [1.57–3.28], respectively, r was 0.93 (p < 0.0001), and a strong correlation was observed; however, Bland–Altman analysis showed disagreement. When AL < 2 mmol/L was used as the outcome, AUC was 0.970, the PVL cutoff value was 2.55 mmol/L, sensitivity was 85.71%, and specificity was 96.05%. If PVL < 2 mmol/L was the outcome, the sensitivity for AL < 2mmol/L was 100%, and for PVL levels ≥ 3 mmol/L, the specificity was 100%. When AL < 4 mmol/L was used as the outcome, AUC was 0.967, the PVL cutoff value was 3.4 mmol/L, sensitivity was 100%, and specificity was 85.84%. When PVL < 3.5 mmol/L was the outcome, the sensitivity for AL < 4 mmol/L was 100%, and for PVL levels ≥ 4 mmol/L, the specificity was 93.81%.

Conclusions

This study revealed that PVL and AL levels in the same critically ill patients did not perfectly agree with each other but were strongly correlated. Furthermore, the high accuracy for predicting AL ranges from PVL levels explains why PVL levels could be used as a substitute for AL level ranges.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12245-022-00410-y.

Prognosis and Risk Factors of Sepsis Patients in Chinese ICUs: A Retrospective Analysis of a Cohort Database

BACKGROUND

Sepsis-3 proposed a new definition of septic shock that excluded patients without hyperlactacidemia. The data from China might help to elucidate the prognosis of this special patient group.

OBJECTIVE

To study the clinical prognosis and factors affecting patients with sepsis based on data from Chinese intensive care units (ICUs).

METHODS

We conducted a retrospective, multicentre observational study in a larger Chinese cohort from January 1, 2014 to August 31, 2015. The patients were divided into four groups according to the presence or absence of hypotension/vasopressor delivery and hyperlactacidemia after fluid resuscitation. Descriptive statistics for the clinical characteristics were presented. The differences between groups were assessed. A survival curve was then plotted using the Kaplan-Meier method. Finally, to better understand the risk factors for the 28-day hospital mortality rates, Cox regression analysis was performed.

RESULTS

In total, 1,194 patients with sepsis were included: 282 with hypotension and hyperlactacidemia, 250 with hypotension but without hyperlactacidemia, 161 with hyperlactacidemia but without hypotension, and 501 without hypotension and hyperlactacidemia. The 28-day mortality rates of the four groups were 48.2%, 43.2%, 26.1%, and 24.8%, respectively. Age, the Acute Physiology And Chronic Health Evaluation (APACHE) II score, hyperlactacidemia, hypotension, intra-abdominal infection, and cancer increased the risk of the 28-day mortality, while soft tissue infection and coming from the operating room were associated with a decreased risk of mortality.

CONCLUSIONS

Patients with hypotension but without hyperlactacidemia in the ICU also show a high 28-day mortality, and some clinical factors may affect their prognosis and must be treated carefully in the future.

Utility of the Lactate/Albumin Ratio as a Predictor for Mortality in Necrotizing Fasciitis Patients

Background

The lactate/albumin (L/A) ratio has been proposed as a prognostic marker because the ratio is associated with multiple organ failure and mortality in critically ill patients. We aimed to investigate the clinical utility of the L/A ratio as a good prognostic indicator of mortality in a cohort of necrotizing fasciitis patients.

Method

This retrospective study was conducted in two tertiary hospitals in Taiwan between 2015 and 2020. We reviewed adult patients with measured serum lactate and albumin on the emergency department (ED) arrival to evaluate the prognostic performance of the lactate and lactate/albumin (L/A) ratio for outcome prediction.

Result

Of the 262 NF patients, 20 (7.63%) died in the hospital. The area under the receiver operating characteristic curve (AUROC) value of the L/A ratio (0.76, 95% confidence interval [CI] 0.69–0.81, P < 0.01) was higher than lactate alone (0.71, 95% CI 0.65–0.74 P < 0.01) for predicting in-hospital mortality. The optimal cutoff of the L/A ratio was 1.61. The AUROC value of the L/A ratio was better than lactate alone regardless of normal lactate level. The cutoff of L/A ratio and hypoalbuminemia showed further discriminative value for in-hospital mortality even in patients with normal lactate levels.

Conclusion

The prognostic performance of the L/A ratio was superior to a single measurement of lactate for predicting in-hospital mortality and intensive care unit (ICU) lengths in necrotizing fasciitis patients. Aggressive intervention and intensive care were necessary for high-risk NF patients upon ED arrival.

A Prediction Model for Assessing Prognosis in Critically Ill Patients with Sepsis-associated Acute Kidney Injury

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is a common problem in critically ill patients and is associated with high morbidity and mortality. Early prediction of the survival of hospitalized patients with SA-AKI is necessary, but a reliable and valid prediction model is still lacking.

METHODS

We conducted a retrospective cohort analysis based on a training cohort of 2,066 patients enrolled from the Multiparameter Intelligent Monitoring in Intensive Care Database III (MIMIC III) and a validation cohort of 102 patients treated at Nanfang Hospital of Southern Medical University. Least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression analysis were used to identify predictors for survival. Areas under the ROC curves (AUC), the concordance index (C-index), and calibration curves were used to evaluate the efficiency of the prediction model (SAKI) in both cohorts.

RESULTS

The overall mortality of SA-AKI was approximately 18%. Age, admission type, liver disease, metastatic cancer, lactate, BUN/SCr, admission creatinine, positive culture, and AKI stage were independently associated with survival and combined in the SAKI model. The C-index in the training and validation cohorts was 0.73 and 0.72. The AUC in the training cohort was 0.77, 0.72, and 0.70 for the 7-day, 14-day, and 28-day probability of in-hospital survival, respectively, while in the external validation cohort, it was 0.83, 0.73, and 0.67. SAPSII and SOFA scores showed poorer performance. Calibration curves demonstrated a good consistency.

CONCLUSIONS

Our SAKI model has predictive value for in-hospital mortality of SA-AKI in critically ill patients and outperforms generic scores.

What Is the Utility of Measuring Lactate Levels in Patients with Sepsis and Septic Shock?

Elevations in blood lactate concentrations have been studied in sepsis and other disease states for decades and are well known to be associated with increased mortality. Many studies have also demonstrated the prognostic accuracy of serial lactate levels, and some have suggested that lactate clearance may be a useful therapeutic target for resuscitation. Lactate measurements have therefore gained an increasingly prominent role in sepsis definitions, screening protocols, management guidelines, and quality measures over the past two decades. The heavy emphasis on lactate monitoring, however, has also generated controversy and concerns. Lactate is not specific to infection and its frequent use for sepsis screening and diagnosis may therefore trigger unnecessary broad-spectrum antibiotic use in some patients. Because hyperlactatemia does not always reflect fluid-responsive hypoperfusion, titrating resuscitation to lactate clearance can also lead to unnecessary fluid and volume overload. More broadly, there is a lack of high-quality evidence demonstrating that initial and serial lactate monitoring leads to better patient-centered outcomes. Indeed, a recent randomized controlled trial comparing resuscitation strategies based on lactate clearance versus normalizing capillary refill time showed no benefit and potential harm with lactate-guided therapy. In this article, we review the basic pathobiology of lactate metabolism and delineate why the traditional paradigm that hyperlactatemia reflects tissue hypoxia is overly simplistic and incomplete. We then review the evidence behind the diagnostic, prognostic, and therapeutic uses of lactate monitoring and place this in the context of evolving sepsis diagnosis and management guidelines.

Association of Positive Fluid Balance at Discharge After Sepsis Management With 30-Day Readmission

IMPORTANCE

Although early fluid administration has been shown to lower sepsis mortality, positive fluid balance has been associated with adverse outcomes. Little is known about associations in non-intensive care unit settings, with growing concern about readmission from excess fluid accumulation in patients with sepsis.

OBJECTIVE

To evaluate whether positive fluid balance among non-critically ill patients with sepsis was associated with increased readmission risk, including readmission for heart failure.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter retrospective cohort study was conducted between January 1, 2012, and December 31, 2017, among 57 032 non-critically ill adults hospitalized for sepsis at 21 hospitals across Northern California. Kaiser Permanente Northern California is an integrated health care system with a community-based population of more than 4.4 million members. Statistical analysis was performed from January 1 to December 31, 2019.

EXPOSURES

Intake and output net fluid balance (I/O) measured daily and cumulatively at discharge (positive vs negative).

MAIN OUTCOMES AND MEASURES

The primary outcome was 30-day readmission. The secondary outcomes were readmission stratified by category and mortality after living discharge.

RESULTS

The cohort included 57 032 patients who were hospitalized for sepsis (28 779 women [50.5%]; mean [SD] age, 73.7 [15.5] years). Compared with patients with positive I/O (40 940 [71.8%]), those with negative I/O (16 092 [28.2%]) were older, with increased comorbidity, acute illness severity, preexisting heart failure or chronic kidney disease, diuretic use, and decreased fluid administration volume. During 30-day follow-up, 8719 patients (15.3%) were readmitted and 3639 patients (6.4%) died. There was no difference in readmission between patients with positive vs negative I/O (HR, 1.00; 95% CI, 0.95-1.05). No association was detected between readmission and I/O using continuous, splined, and quadratic function transformations. Positive I/O was associated with decreased heart failure-related readmission (HR, 0.80 [95% CI, 0.71-0.91]) and increased 30-day mortality (HR, 1.23 [95% CI, 1.15-1.31]).

CONCLUSIONS AND RELEVANCE

In this large observational study of non-critically ill patients hospitalized with sepsis, there was no association between positive fluid balance at the time of discharge and readmission. However, these findings may have been limited by variable recording and documentation of fluid intake and output; additional studies are needed to examine the association of fluid status with outcomes in patients with sepsis to reduce readmission risk.

Utility of modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score in distinguishing necrotizing from non-necrotizing soft tissue infections

Background

We conducted this study to promote a modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score and evaluate the utility in distinguishing necrotizing fasciitis (NF) from other soft-tissue infections.

Method

A retrospective cohort study of hospitalized patients with NF diagnosed by surgical finding was conducted in two tertiary hospital in southern Taiwan between January 2015 and January 2020. Another group was matched by controls with non-necrotizing soft tissue infections based on time, demographics, and immune status. Data such as infectious location, comorbidities, and laboratory findings were recorded and compared. Logistics regression were used to determine the association with NF after adjustment for confounders and MLRINEC score was developed by then. Receiver operating curve (ROC) and the area under the curve (AUC) were used to evaluate its discriminating ability.

Result

A total of 303 patients were included; 101 in NF group and 202 in non-NF group. We added serum lactate and comorbid liver disease to the original LRINEC score and re-defined the cut-off values for 3 variables to develop the MLRINEC score. The cut-off value for MLRINEC score was 12 points with corresponding sensitivity of 91.8% and a specificity of 88.4%, and the area under ROC (AUC) was 0.893 (95% CI, 0.723 to 0.948; p < 0.01).

Conclusion

MLRINEC score shows a high sensitivity and specificity in distinguishing NF from non-necrotizing soft-tissue infections. Patients with a MLRINEC score > 12 points should be highly suspected of presence of necrotizing fasciitis.

Significance of body temperature in elderly patients with sepsis

Background

Elderly patients have a blunted host response, which may influence vital signs and clinical outcomes of sepsis. This study was aimed to investigate whether the associations between the vital signs and mortality are different in elderly and non-elderly patients with sepsis.

Methods

This was a retrospective observational study. A Japanese multicenter sepsis cohort (FORECAST, n = 1148) was used for the discovery analyses. Significant discovery results were tested for replication using two validation cohorts of sepsis (JAAMSR, Japan, n = 624; SPH, Canada, n = 1004). Patients were categorized into elderly and non-elderly groups (age ≥ 75 or < 75 years). We tested for association between vital signs (body temperature [BT], heart rate, mean arterial pressure, systolic blood pressure, and respiratory rate) and 90-day in-hospital mortality (primary outcome).

Results

In the discovery cohort, non-elderly patients with BT < 36.0 °C had significantly increased 90-day mortality (P = 0.025, adjusted hazard ratio 1.70, 95% CI 1.07–2.71). In the validation cohorts, non-elderly patients with BT < 36.0 °C had significantly increased mortality (JAAMSR, P = 0.0024, adjusted hazard ratio 2.05, 95% CI 1.29–3.26; SPH, P = 0.029, adjusted hazard ratio 1.36, 95% CI 1.03–1.80). These differences were not observed in elderly patients in the three cohorts. Associations between the other four vital signs and mortality were not different in elderly and non-elderly patients. The interaction of age and hypothermia/fever was significant (P < 0.05).

Conclusions

In septic patients, we found mortality in non-elderly sepsis patients was increased with hypothermia and decreased with fever. However, mortality in elderly patients was not associated with BT. These results illuminate the difference in the inflammatory response of the elderly compared to non-elderly sepsis patients.

The utility of point of care serum lactate in predicting serious adverse outcomes among critically ill adult patients at urban emergency departments of tertiary hospitals in Tanzania

Background

Elevated serum lactate levels have been shown in numerous studies to be associated with serious adverse events, including mortality. Point of care lactate level is increasingly available in resource-limited emergency department (ED) settings. However, little is known about the predictive ability of for serious adverse events.

Aim of the study

We aimed to describe the utility of serum lactate level as a predictor of 24-h serious adverse events among adult patients presenting at the Emergency Medicine Department (EMD) of Muhimbili National Hospital (MNH) and MUHAS Academic Medical Center (MAMC).

Methods

This was a prospective observational study involving adult patients presenting to the EMD-MNH and MAMC from 1 September 2018 and 31 October 2018. Eligible patients with at least one lactate level test drawn while in the ED were examined in terms of their demographics, relevant clinical characteristics, and any serious adverse event (SAE) within 24 h of arrival. The sensitivity and specificity of lactate level to predict outcomes of interest were determined using the best cut-off point constructed from AUROC to see how well lactate level could discriminate which patients would have adverse events in the next 24 h. Categorical and continuous variables were compared with the chi-square test and two-sample t test, respectively.

Results

We screened 2057 (20.9%) out of 9828 patients who presented during study period, and enrolled 387 (18.8%). The overall median age was 54 years (interquartile range 40–68 years) and 206 (53.2%) were male. Using local triaging system, a total of 322 (83.2%) was triaged as an emergency category. The mean lactate level was 3.2 ± 3.6 mmol/L, 65 (16.8%) patients developed at least one SAE, with 42 (11%) who required ICU/HDU, 37 (10%) needed ventilator support, 10 (3%) required inotropes, and 9 (2%) developed cardiac arrest. The overall 24-h mortality was 28 (7%). The AUC of serum lactate level for overall 24-h mortality was 0.801 (95%CI, 0.7–0.9, P ≤ 0.001). At the optimal cutoff value (3.8 mmol/L), lactate level had a sensitivity and specificity for 24-h mortality of 64% and 85%, respectively. Mortality of the high-lactate level group (³3.8 mmol/L) was significantly higher than that of the low-lactate level group (< 3.8 mmol/L), 23.8% vs. 2.9%, respectively (95%CI 3.8–17.2, p < 0.001), with the relative risk of mortality in the high-lactate level group being 8.1 times higher compared to the low-lactate level group.

Conclusion

The utility of lactate level in predicting mortality was similar to that seen in high-resource settings. A serum lactate level of ³3.8 mmol/L predicted 24-h serious adverse events in unselected patients seen in the high-acuity area of our ED. Incorporating serum lactate level in ED in lower- and middle-income countries (LMICs) can help identify patients at risk of developing serious adverse events.

Lactate on emergency department arrival as a predictor of in-hospital mortality in necrotizing fasciitis: a retrospective study

Background

Hyperlactatemia is known to be associated with adverse outcome in critical illness. In this study, we attempted to identify if hyperlactatemia on emergency department (ED) arrival is a reliable predictor for in-hospital mortality in necrotizing fasciitis (NF) patients.

Method

A prospective cohort study of hospitalized patients with NF was conducted in two tertiary teaching hospitals in Taiwan between March 2010 and March 2018. Blood samples were collected in the ED upon arrival, and the lactate levels were determined. Sequential organ failure assessment (SOFA) scores were calculated during the first 24 h after admission. All collected data were statistically analyzed.

Result

Of the 707 NF patients, 40 (5.66%) died in the hospital. The median (interquartile range) blood lactate level in all NF patients was 3.6 mmol/l (2.2–4.8). The blood lactate level upon ED arrival was significantly associated with mortality (odds ratio [OR] = 1.35; 95% confidence interval [CI], 1.30–1.46; P < 0.001), even after adjustment for age and SOFA score (OR = 1.27; P < 0.001). Multivariate regression analysis showed that a high blood lactate level (OR = 1.17; 95% CI, 1.07–1.29; P = 0.001) and a high SOFA score (OR = 1.15; 95% CI, 1.11–1.20; P < 0.001) were independent risk factors for in-hospital mortality in NF. Blood lactate achieved an area under-the-receiver-operating-characteristic curve (AUC) of 0.79 (P < 0.001) for predicting mortality that was similar to that of SOFA score (AUC = 0.82; P < 0.001). Blood lactate displayed a sensitivity of 62% and a specificity of 86% in predicting mortality at the optimal cutoff value of 5.80 mmol/l.

Conclusion

In necrotizing fasciitis patients, hyperlactatemia on ED arrival is independently associated with in-hospital mortality. NF patients with hyperlactatemia on ED arrival should be closely monitored for signs of deterioration and consider early and aggressive intervention to prevent mortality.

Outcomes and factors influencing outcomes of critically ill HIV-positive patients in a tertiary care center in South India

The incidence of (Human immune deficiency) HIV in India has fallen by 58% since the onset of the HIV epidemic. As of 2016 there are 2.1 million people living in India with HIV and only 49% of the adults with HIV are on ART (1). The HIV infected individuals may require intensive care due to various reasons. This study attempts to look at the outcomes of these patients admitted in the intensive care unit and the predictors of these outcomes.

Mortality is Greater in Septic Patients With Hyperlactatemia Than With Refractory Hypotension

BACKGROUND

In septic patients, it is uncertain whether isolated hyperlactatemia (lactate ≥4 mmol/L without refractory hypotension) can be used to diagnose septic shock and whether mortality rate differs from that of isolated refractory hypotension (refractory to 1000 mL or greater fluid bolus).

AIMS

To compare baseline characteristics, treatments, and outcomes of participants enrolled into the Australian Resuscitation in Sepsis Evaluation (ARISE) trial according to the presence of isolated hyperlactatemia or isolated refractory hypotension.

PATIENTS

Cohort of 1,332 ARISE participants with sepsis and either isolated hyperlactatemia or isolated refractory hypotension.

METHODS

We performed a secondary analysis of the ARISE data, constructing a propensity score model to discriminate between hyperlactatemia and isolated refractory hypotension. We analyzed 90-day all-cause mortality using a generalized linear model and inverse propensity score weighting. We modeled length of intensive care unit (ICU) and hospital stay using time to event analyses incorporating mortality as a competing risk.

RESULTS

There were 478 participants (35.9%) with isolated hyperlactatemia and 854 (64.1%) with isolated refractory hypotension. They had similar median (interquartile range) ages (66.2 [54.2, 76.3] years vs. 65.2 [50.9, 75.5] years) and similar sources of infection. However, isolated hyperlactatemia participants had higher mean (standard deviation) baseline APACHE II scores (isolated hyperlactatemia 16.2 [6.4]) vs. 14.5 [6.4] for isolated refractory hypotension; P < 0.001). Isolated hyperlactatemia participants had a 1.7 times higher risk of 90-day mortality (propensity-weighted risk ratio; 95% confidence intervals [CI] 1.2, 2.5, P = 0.003). They were less likely to be discharged alive from ICU and hospital (propensity weighted sub-hazard ratio 0.77 (95% CI 0.64, 0.92; P < 0.005) and 0.79 (95% CI 0.66, 0.95; P = 0.01), respectively).

CONCLUSIONS

ARISE trial participants with isolated hyperlactatemia had worse adjusted 90-day mortality than those with isolated refractory hypotension. In septic patients, isolated hyperlactatemia may define greater illness severity and worse outcomes than isolated refractory hypotension.

Evaluation of a novel 5-group classification system of sepsis by vasopressor use and initial serum lactate in the emergency department

Prognostication in sepsis is limited by disease heterogeneity, and measures to risk-stratify patients in the proximal phases of care lack simplicity and accuracy. Hyperlactatemia and vasopressor dependence are easily identifiable risk factors for poor outcomes. This study compares incidence and hospital outcomes in sepsis based on initial serum lactate level and vasopressor use in the emergency department (ED). In a retrospective analysis of a prospectively identified dual-center ED registry, patients with sepsis were categorized by ED vasopressor use and initial serum lactate level. Vasopressor-dependent patients were categorized as dysoxic shock (lactate >4.0 mmol/L) and vasoplegic shock (≤4.0 mmol/L). Patients not requiring vasopressors were categorized as cryptic shock major (lactate >4.0 mmol/L), cryptic shock minor (>2.0 and ≤4.0 mmol/L), and sepsis without lactate elevation (≤2.0 mmol/L). Of 446 patients included, 4.9% (n = 22) presented in dysoxic shock, 11.7% (n = 52) in vasoplegic shock, 12.1% (n = 54) in cryptic shock major, 30.9% (n = 138) in cryptic shock minor, and 40.4% (n = 180) in sepsis without lactate elevation. Group mortality rates at 28 days were 50.0, 21.1, 18.5, 12.3, and 7.2%, respectively. After adjusting for potential confounders, odds ratios for mortality at 28 days were 15.1 for dysoxic shock, 3.6 for vasoplegic shock, 3.8 for cryptic shock major, and 1.9 for cryptic shock minor, when compared to sepsis without lactate elevation. Lactate elevation is associated with increased mortality in both vasopressor dependent and normotensive infected patients presenting to the emergency department (ED). Cryptic shock mortality (normotension + lactate >4 mmol/L) is equivalent to vasoplegic shock mortality (vasopressor requirement + lactate <4 mmol/L) in our population. The odds of normotensive, infected patients decompensating is three to fourfold higher with hyperlactemia. The proposed Sepsis-3 definitions exclude an entire group of high-risk ED patients. A simple classification in the ED by vasopressor requirement and initial lactate level may identify high-risk subgroups of sepsis. This study may inform prognostication and triage decisions in the proximal phases of care.

Sepsis in Internal Medicine wards: current knowledge, uncertainties and new approaches for management optimization

Sepsis represents a global health problem in terms of morbidity, mortality, social and economic costs. Although usually managed in Intensive Care Units, sepsis showed an increased prevalence among Internal Medicine wards in the last decade. This is substantially due to the ageing of population and to multi-morbidity. These characteristics represent both a risk factor for sepsis and a relative contra-indication for the admission to Intensive Care Units. Although there is a lack of literature on the management of sepsis in Internal Medicine, the outcome of these patients seems to be gradually improving. This is due to Internists' increased adherence to guidelines and "bundles". The routine use of SOFA score helps physicians in the definition of septic patients, even if the optimal score has still to come. Point-of-care ultrasonography, lactates, procalcitonin and beta-d-glucan are of help for treatment optimization. The purpose of this narrative review is to focus on the management of sepsis in Internal Medicine departments, particularly on crucial concepts regarding diagnosis, risk assessment and treatment. Key Messages Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. The prevalence of sepsis is constantly increasing, affecting more hospital patients than any other disease. At least half of patients affected by sepsis are admitted to Internal Medicine wards. Adherence to guidelines, routine use of clinical and lab scores and point-of-care ultrasonography are of help for early recognition of septic patients and treatment optimization.

Reconsidering lactate as a sepsis risk biomarker

Objectives

There has been renewed interest in lactate as a risk biomarker in sepsis and septic shock. However, the ability of the odds ratio (OR) and change in the area under the receiver operator characteristic curve (AUC-ROC) to assess biomarker added-value has been questioned.

Design, setting and participants

A sepsis cohort was identified from the ICU database of an Australian tertiary referral hospital using APACHE III diagnostic codes. Demographic information, APACHE III scores, 24-hour post-admission patient lactate levels, and hospital mortality were accessed.

Measurements and main results

Hospital mortality was modelled using a base predictive logistic regression model and sequential addition of admission lactate, lactate clearance ([lactate^admission—lactate^final]/lactate^admission), and area under the lactate-time curve (LTC). Added-value was assessed using lactate index OR; AUC-ROC difference (base-model versus lactate index addition); net (mortality) reclassification index (NRI; range -2 to +2); and net benefit (NB), the number of true positives per patient adjusted for the number of false positives. The data set comprised 717 patients with mean(SD) age and APACHE III score 61.1(16.5) years and 68.3(28.2) respectively; 59.2% were male. Admission lactate was 2.3(2.5) mmol/l; with lactate of ≥ 4 mmol/L (37% hospital mortality) in 17% and patients with lactate < 4 mmol/L having 18% hospital mortality. The admission base-model had an AUC-ROC = 0.81 with admission lactate OR = 1.127 (95%CI: 1.038, 1.224), AUC-ROC difference of 0.0032 (-0.0037, 0.01615; P = 0.61), and NRI 0.240(0.030, 0.464). The over-time model had an AUC-ROC = 0.86 with (i) clearance OR = 0.771, 95%CI: 0.578, 1.030; P = 0.08; AUC-ROC difference 0.001 (-0.003, 0.014; P = 0.78), and NRI 0.109(-0.193, 0.425) and (ii) LTC OR = 0.997, 95%CI: 0.989, 1.005, P = 0.49; AUC-ROC difference 0.004 (-0.002, 0.004; P = 0.34), and NRI 0.111(-0.222, 0.403). NB was not incremented by any lactate index.

Conclusions

Lactate added-value assessment is dependent upon the performance of the underlying predictive model and should incorporate risk reclassification and net benefit measures.

The Effects of red Blood Cell Transfusion on Tissue Oxygenation and the Microcirculation in the Intensive Care Unit: A Systematic Review

The transfusion of red blood cells (RBCs) is a common intervention in intensive care unit (ICU) patients, yet the benefits are far from clear in patients with moderate anemia (eg, hemoglobin (Hb) levels of 7-10 g/dL). Determining which of these patients benefit, and how to even define benefit, from transfusion is challenging. As the intended physiological benefit underpinning RBC transfusion is to improve tissue oxygenation, several studies utilizing a wide range of assessment techniques have attempted to study the effects of transfusion on tissue oxygenation and microcirculatory function. The objective of this systematic review was to determine whether RBC transfusion improves tissue oxygenation/microcirculatory indices in the ICU population, and to provide an introduction to the techniques used in these studies. Eligible studies published between January 1996 and February 2017 were identified from searches of PubMed, Embase, Cinahl, ScienceDirect, Web of Science, and The Cochrane Library. Seventeen studies met inclusion criteria, though there was significant heterogeneity in study design, patient population, assessment techniques and outcomes reported. Overall, the majority of studies (11 of 17) concluded that transfusion did not generally improve tissue oxygenation or microcirculation. Inter-individual effects were highly variable, however, and closer review of sub-groups available in 9 studies revealed that patients with abnormal tissue oxygenation or microcirculatory indices prior to transfusion had improvement in these indices with transfusion, irrespective of assessment method. This finding suggests a new strategy for future trials in the ICU: utilizing tissue oxygenation/microcirculatory parameters to determine the need for transfusion rather than largely arbitrary hemoglobin concentrations.

Sepsis Definitions: The Search for Gold and What CMS Got Wrong

On October 1, 2015, the United States Centers for Medicare and Medicaid Services (CMS) issued a core measure addressing the care of septic patients. These core measures are controversial among healthcare providers. This article will address that there is no gold standard definition for sepsis, severe sepsis or septic shock and the CMS-assigned definitions for severe sepsis and septic shock are premature and inconsistent with evidence-based definitions.

Prognostic value of plasma lactate levels in a retrospective cohort presenting at a university hospital emergency department

OBJECTIVES

The prognostic value of lactate in the setting of an emergency department (ED) has not been studied extensively. The goal of this study was to assess 28-day mortality in ED patients in whom lactate was elevated (≥4.0 mmol/L), <4.0 mmol/L or not determined and to study the impact of the underlying cause of hyperlactatemia, that is, type A (tissue hypoxia) or type B (non-hypoxia), on mortality.

DESIGN

Retrospective study.

SETTING

A secondary and tertiary referral centre in the Netherlands.

MATERIALS AND METHODS

All internal medicine patients with hyperlactatemia (≥4.0 mmol/L) at the ED between January 2011 and October 2014 were included in this study. Samples of patients with lactate levels <4.0 mmol/L and of patients in whom no lactate was measured were included as a reference.

RESULTS

In 1144 of 19 822 patients (5.8%), lactate was measured. Hyperlactatemia (n=197) was associated with a higher 28-day mortality than in those with lactate <4.0 mmol/L (40.6% vs 18.5%; p<0.001) and in those without lactate measurements (9.5%). Type A hyperlactatemia, present in 84% of those with hyperlactatemia, was associated with higher mortality than type B hyperlactatemia (45.8% vs 12.5%, p=0.001).

CONCLUSIONS

This study demonstrates that the prognostic value of lactate depends largely on the underlying cause and the population in whom lactate has been measured. Prospective studies are required to address the true added value of lactate at the ED.

Pitfalls in the Treatment of Sepsis

Sepsis is a challenging, dynamic, pathophysiology requiring expertise in diagnosis and management. Controversy exists as to the most sensitive early indicators of sepsis and sepsis severity. Patients presenting to the emergency department often lack complete history or clinical data that would point to optimal management. Awareness of these potential knowledge gaps is important for the emergency provider managing the septic patient. Specific areas of management including the initiation and management of mechanical ventilation, the appropriate disposition of the patient, and consideration of transfer to higher levels of care are reviewed.

Effects of Shenfu Injection in the Treatment of Septic Shock Patients: A Multicenter, Controlled, Randomized, Open-Label Trial

The effect of Shenfu on biochemical parameters and survival during resuscitation in patients with septic shock was examined. This was a multicenter, controlled, randomized, open-label trial carried out in 210 patients with septic shock from seven medical centers in China. They were randomized to Shenfu or saline. The primary outcome was lactate clearance. The secondary outcomes were shock index normalization, dose of vasopressors, ICU stay, hospital stay, and mortality. A total of 199 patients completed the trial. Blood pressure, heart rate, and other routine lab tests showed no difference between the groups. Lactate levels and lactate clearance were similar between the two groups. Hospital and ICU stay were similar between the two groups. When considering all patients, the 7- and 28-day mortality were similar between the two groups, but when considering only patients with lactate levels ≥4.5 mmol/L, the Shenfu group showed a better 7-day survival than the control group (7 days: 83.3% versus 54.5%, P = 0.034; 28 days: 72.7% versus 47.6%, P = 0.092). Shenfu may improve the 7-day survival in patients with impaired lactate clearance (≥4.5 mmol/L), but the mechanism for this effect is unclear. Additional studies are necessary to characterize the hemodynamic changes after Shenfu infusion. This trial is registered with ChiCTR-TRC-11001369.

Does Infection Site Matter? A Systematic Review of Infection Site Mortality in Sepsis

PURPOSE

Sepsis treatment protocols emphasize source control with empiric antibiotics and fluid resuscitation. Previous reviews have examined the impact of infection site and specific pathogens on mortality from sepsis; however, no recent review has addressed the infection site. This review focuses on the impact of infection site on hospital mortality among patients with sepsis.

METHODS

The PubMed database was searched for articles from 2001 to 2014. Studies were eligible if they included (1) one or more statistical models with hospital mortality as the outcome and considered infection site for inclusion in the model and (2) adult patients with sepsis, severe sepsis, or septic shock. Data abstracted included stage of sepsis, infection site, and raw and adjusted effect estimates. Nineteen studies were included. Infection sites most studied included respiratory (n = 19), abdominal (n = 19), genitourinary (n = 18), and skin and soft tissue infections (n = 11). Several studies found a statistically significant lower mortality risk for genitourinary infections on hospital mortality when compared to respiratory infections.

CONCLUSION

Based on studies included in this review, the impact of infection site in patients with sepsis on hospital mortality could not be reliably estimated. Misclassification among infections and disease states remains a serious possibility in studies on this topic.

High incidence of adverse events during intra-hospital transport of critically ill patients and new related risk factors: a prospective, multicenter study in China

BACKGROUND

The aim of the present study was to investigate the incidence of adverse events (AEs) during intra-hospital transport (IHT) of critically ill patients and evaluate the risk factors associated with these events.

METHODS

This prospective multicenter observational study was performed in 34 intensive care units in China during 20 consecutive days from 5 November to 25 November 2012. All consecutive patients who required IHT for diagnostic testing or therapeutic procedures during the study period were included. All AEs that occurred during IHT were recorded. The incidence of AEs was defined as the rate of transports with at least one AE. The statistical analysis included a description of demographic and clinical characteristics of the cohort as well as identification of risk factors for AEs during IHT by univariate and multivariate logistic regression analyses.

RESULTS

In total, 441 IHTs of 369 critically ill patients were analyzed. The overall incidence of AEs was 79.8% (352 IHTs). The proportion of equipment- and staff-related adverse events was 7.9% (35 IHTs). The rate of patient-related adverse events (P-AEs) was 79.4% (349 IHTs). The rates of vital sign-related P-AEs and arterial blood gas analysis-related P-AEs were 57.1% (252 IHTs) and 46.9% (207 IHTs), respectively. The incidence of critical P-AEs was 33.1% (146 IHTs). The rates of vital sign-related critical P-AEs and arterial blood gas analysis-related critical P-AEs were 22.9% (101 IHTs) and 15.0% (66 IHTs), respectively. All data collected in our study were considered potential risk factors. In the multivariate analysis, predictive factors for P-AEs were pH, partial pressure of carbon dioxide in arterial blood, lactate level, glucose level, and heart rate before IHT. Furthermore, the Acute Physiology and Chronic Health Evaluation II score, partial pressure of oxygen in arterial blood, lactate level, glucose level, heart rate, respiratory rate, pulse oximetry, and sedation before transport were independent influential factors for critical P-AEs during IHT.

CONCLUSIONS

The incidence of P-AEs during IHT of critically ill patients was high. Risk factors for P-AEs during IHT were identified. Strategies are needed to reduce their frequency.

TRIAL REGISTRATION

Chinese Clinical Trial Register identifier ChiCTR-OCS-12002661. Registered 5 November 2012.

Lactic Acidosis in Sepsis: It's Not All Anaerobic: Implications for Diagnosis and Management

Increased blood lactate concentration (hyperlactatemia) and lactic acidosis (hyperlactatemia and serum pH < 7.35) are common in patients with severe sepsis or septic shock and are associated with significant morbidity and mortality. In some patients, most of the lactate that is produced in shock states is due to inadequate oxygen delivery resulting in tissue hypoxia and causing anaerobic glycolysis. However, lactate formation during sepsis is not entirely related to tissue hypoxia or reversible by increasing oxygen delivery. In this review, we initially outline the metabolism of lactate and etiology of lactic acidosis; we then address the pathophysiology of lactic acidosis in sepsis. We discuss the clinical implications of serum lactate measurement in diagnosis, monitoring, and prognostication in acute and intensive care settings. Finally, we explore treatment of lactic acidosis and its impact on clinical outcome.