The impact of red blood cell storage duration on tissue oxygenation in cardiac surgery

OBJECTIVE

Although storage alters red blood cells, several recent, randomized trials found no differences in clinical outcomes between patients transfused with red blood cells stored for shorter versus longer periods of time. The objective of this study was to see whether storage impairs the in vivo ability of erythrocytes to traverse the microcirculation and deliver oxygen at the tissue level.

METHODS

A subset of subjects from a clinical trial of cardiac surgery patients randomized to receive transfusions of red blood cells stored ≤10 days or ≥21 days were assessed for thenar eminence and cerebral tissue hemoglobin oxygen saturation (S_tO₂) via the use of near-infrared spectroscopy and sublingual microvascular blood flow via side-stream darkfield videomicroscopy.

RESULTS

Among 55 subjects, there was little change in the primary endpoint (thenar eminence S_tO₂ from before to after transfusion of one unit) and the change was similar in the 2 groups: +1.7% (95% confidence interval, -0.3, 3.8) for shorter-storage and +0.8% (95% confidence interval, -1.1, 2.9) for longer-storage; P = .61). Similarly, no significant differences were observed for cerebral S_tO₂ or sublingual microvascular blood flow. These parameters also were not different from preoperatively to 1 day postoperatively, reflecting the absence of a cumulative effect of all red blood cell units transfused during this period.

CONCLUSIONS

There were no differences in thenar eminence or cerebral S_tO₂, or sublingual microcirculatory blood flow, in cardiac surgery patients transfused with red blood cells stored ≤10 days or ≥21 days. These results are consistent with the clinical outcomes in the parent study, which also did not differ, indicating that storage may not impair oxygen delivery by red blood cells in this setting.

Utility of Chest Radiography in Emergency Department Patients Presenting with Syncope

Introduction

Syncope has myriad etiologies, ranging from benign to immediately life threatening. This frequently leads to over testing. Chest radiographs (CXR) are among these commonly performed tests despite their uncertain diagnostic yield. The objective is to study the distribution of normal and abnormal chest radiographs in patients presenting with syncope, stratified by those who did or did not have an adverse event at 30 days.

Methods

We performed a post-hoc analysis of a prospective cohort of consecutive patients presenting to an urban tertiary care academic medical center with a chief complaint of syncope from 2003–2006. The frequency and findings for each CXR were reviewed, as well as emergency department and hospital discharge diagnoses, and 30-day outcome.

Results

There were 575 total subjects, 39.7% were male, and the mean age was 57.2 (SD 24.6). Of the 575 subjects, 403 (70.1%) had CXRs performed, and 116 (20.2%) had an adverse event after their syncope. Of the 116 people who had an adverse event, 15 (12.9%) had a positive CXR, 81 (69.8%) had a normal CXR, and 20 (17.2%) did not have a CXR as part of the initial evaluation. Among the 459 people who did not have an adverse event, 3 (0.7%) had a positive CXR, 304 (66.2%) had a normal CXR, and 152 (33.1%) did not have a CXR performed. Fifteen of the 18 patients (83.4%) with an abnormal CXR had an adverse event. Eighty-one of the 385 patients (21.0%) with a normal CXR had an adverse event. Among those who had a CXR performed, an abnormal CXR was associated with increased odds of adverse event (OR: 18.77 (95% CI= [5.3–66.4])).

Conclusion

Syncope patients with abnormal CXRs are likely to experience an adverse event, though the majority of CXRs performed in the work up of syncope are normal.

Systematic Molecular Phenotyping: A Path Toward Precision Emergency Medicine?

Precision medicine is an emerging approach to disease treatment and prevention that considers variability in patient genes, environment, and lifestyle. However, little has been written about how such research impacts emergency care. Recent advances in analytical techniques have made it possible to characterize patients in a more comprehensive and sophisticated fashion at the molecular level, promising highly individualized diagnosis and treatment. Among these techniques are various systematic molecular phenotyping analyses (e.g., genomics, transcriptomics, proteomics, and metabolomics). Although a number of emergency physicians use such techniques in their research, widespread discussion of these approaches has been lacking in the emergency care literature and many emergency physicians may be unfamiliar with them. In this article, we briefly review the underpinnings of such studies, note how they already impact acute care, discuss areas in which they might soon be applied, and identify challenges in translation to the emergency department (ED). While such techniques hold much promise, it is unclear whether the obstacles to translating their findings to the ED will be overcome in the near future. Such obstacles include validation, cost, turnaround time, user interface, decision support, standardization, and adoption by end-users.

A Broad-Spectrum Infection Diagnostic that Detects Pathogen-Associated Molecular Patterns (PAMPs) in Whole Blood

Background

Blood cultures, and molecular diagnostic tests that directly detect pathogen DNA in blood, fail to detect bloodstream infections in most infected patients. Thus, there is a need for a rapid test that can diagnose the presence of infection to triage patients, guide therapy, and decrease the incidence of sepsis.

Methods

An Enzyme-Linked Lectin-Sorbent Assay (ELLecSA) that uses magnetic microbeads coated with an engineered version of the human opsonin, Mannose Binding Lectin, containing the Fc immunoglobulin domain linked to its carbohydrate recognition domain (FcMBL) was developed to quantify pathogen-associated molecular patterns (PAMPs) in whole blood. This assay was tested in rats and pigs to explore whether it can detect infections and monitor disease progression, and in prospectively enrolled, emergency room patients with suspected sepsis. These results were also compared with data obtained from non-infected patients with or without traumatic injuries.

Results

The FcMBL ELLecSA was able to detect PAMPS present on, or released by, 85% of clinical isolates representing 47 of 55 different pathogen species, including the most common causes of sepsis. The PAMP assay rapidly (< 1 h) detected the presence of active infection in animals, even when blood cultures were negative and bacteriocidal antibiotics were administered. In patients with suspected sepsis, the FcMBL ELLecSA detected infection in 55 of 67 patients with high sensitivity (> 81%), specificity (> 89%), and diagnostic accuracy of 0·87. It also distinguished infection from trauma-related inflammation in the same patient cohorts with a higher specificity than the clinical sepsis biomarker, C-reactive Protein.

Conclusion

The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections, even when blood cultures are negative and antibiotic therapy has been initiated. It may help to triage patients with suspected systemic infections, and serve as a companion diagnostic to guide administration of emerging dialysis-like sepsis therapies.

•

The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections.

•

The FcMBL ELLecSA distinguished infection from trauma-related inflammation.

•

It can detect infection even when blood cultures are negative and antibiotic therapy has been initiated.

Current diagnostics of sepsis using blood cultures and molecular diagnostic tests fail to detect bloodstream infections in most infected patients, whereas the inflammatory biomarkers of infection that have a higher sensitivity of detection, lack specificity in distinguishing infection from trauma-related inflammation. Therefore we have leveraged a broad-spectrum pathogen binding opsonin and developed a rapid test to directly diagnose the presence of infection in the blood to triage patients and guide antibiotic therapy.

Lactate Clearance in Septic Shock Is Not a Surrogate for Improved Microcirculatory Flow

BACKGROUND

Failure to normalize lactate is associated with poor outcomes in septic shock. It has been suggested that persistently elevated lactate may result from regional ischemia due to disturbed and/or heterogenous microcirculatory blood flow.

OBJECTIVES

The goal of this study was to determine if lactate clearance (LC) may serve as a surrogate marker for changes in microcirculatory blood flow in patients with septic shock.

METHODS

This was a prospective observational study performed within a previously published clinical trial of l-carnitine for the treatment of vasopressor-dependent septic shock. Intravital video microscopy was performed at enrollment and 12 hours later, and microcirculatory flow index (MFI) was assessed. Associations between enrollment MFI, lactate, and Sequential Organ Failure Assessment (SOFA) score were determined, in addition to associations between ∆MFI, LC, and ∆SOFA. A preplanned subgroup analysis of only patients with an elevated initial lactate was performed.

RESULTS

We enrolled a total of 31 patients, 23 with survival and sufficient quality videos both at enrollment and at 12 hours. ∆MFI, LC, and ∆SOFA were 0.1 (interquartile range [IQR] = 0 to 0.3), 18% (IQR = -10% to 46%), and -2 (IQR = -4 to 0). Both ∆MFI and LC were associated with ∆SOFA (β = -5.3, p = 0.01; and β = -3.5, 0.047), but not with each other, even in the subgroup of patients with an initially elevated lactate.

CONCLUSIONS

We observed no association between degree of LC and change in microcirculatory blood flow in patients with septic shock. These data suggest against the hypothesis that LC may be used as a surrogate marker of microcirculatory blood flow.

Patient-reported Outcomes from A National, Prospective, Observational Study of Emergency Department Acute Pain Management With an Intranasal Nonsteroidal Anti-inflammatory Drug, Opioids, or Both

OBJECTIVES

Patient compliance and satisfaction with analgesics prescribed after emergency department (ED) care for acute pain are poorly understood, largely because of the lack of direct patient follow-up with the ED provider. Our objective was to compare patient satisfaction with three analgesia regimens prescribed for post-ED care-a nasally administered nonsteroidal anti-inflammatory drug (NSAID), an opioid, or combination therapy-by collecting granular follow-up on analgesic use, pain scores, side effects, work activity levels, and overall satisfaction directly from patients.

METHODS

We designed a prospective registry linking ED assessment and analgesic management for acute pain of specific musculoskeletal or visceral etiologies with self-reported automated telephonic follow-up daily for the 4 days post-ED discharge. Patients were prescribed a specific NSAID (SPRIX, ketorolac tromethamine for nasal instillation) only, an oral opioid only, or both with the opioid clearly defined as rescue therapy, at the ED provider's discretion.

RESULTS

There were 824 evaluable subjects. Maximum pain scores improved day to day more effectively with a ketorolac-based approach. Self-reported rates of return to work and work effectiveness were higher with SPRIX than with opioids or combination therapy. Adverse effects of nausea, constipation, drowsiness, and abdominal pain were higher each day among patients taking an opioid; nasal irritation was more common with SPRIX. Overall satisfaction at the end of the follow-up period was higher with SPRIX-based treatment than with opioid monotherapy.

CONCLUSIONS

Automated telephonic follow-up of ED patients prescribed short-term analgesia is feasible. Ketorolac-based analgesia after an ED visit for many acute pain syndromes was associated with favorable patient outcomes and higher satisfaction than opioid-based therapy. SPRIX, an NSAID that is not available over the counter and has a novel delivery approach, may be useful for short-term post-ED outpatient analgesia.

Derivation and Validation of Predictive Factors for Clinical Deterioration after Admission in Emergency Department Patients Presenting with Abnormal Vital Signs Without Shock

INTRODUCTION

Strategies to identify high-risk emergency department (ED) patients often use markedly abnormal vital signs and serum lactate levels. Risk stratifying such patients without using the presence of shock is challenging. The objective of the study is to identify independent predictors of in-hospital adverse outcomes in ED patients with abnormal vital signs or lactate levels, but who are not in shock.

METHODS

We performed a prospective observational study of patients with abnormal vital signs or lactate level defined as heart rate ≥130 beats/min, respiratory rate ≥24 breaths/min, shock index ≥1, systolic blood pressure <90 mm/Hg, or lactate ≥4 mmole/L. We excluded patients with isolated atrial tachycardia, seizure, intoxication, psychiatric agitation, or tachycardia due to pain (ie: extremity fracture). The primary outcome was deterioration, defined as development of acute renal failure (creatinine 2× baseline), non-elective intubation, vasopressor requirement, or mortality. Independent predictors of deterioration after hospitalization were determined using logistic regression.

RESULTS

Of 1,152 consecutive patients identified with abnormal vital signs or lactate level, 620 were excluded, leaving 532 for analysis. Of these, 53/532 (9.9±2.5%) deteriorated after hospital admission. Independent predictors of in-hospital deterioration were: lactate >4.0 mmol/L (OR 5.1, 95% CI [2.1-12.2]), age ≥80 yrs (OR 1.9, CI [1.0-3.7]), bicarbonate <21 mEq/L (OR 2.5, CI [1.3-4.9]), and initial HR≥130 (OR 3.1, CI [1.5-6.1]).

CONCLUSION

Patients exhibiting abnormal vital signs or elevated lactate levels without shock had significant rates of deterioration after hospitalization. ED clinical data predicted patients who suffered adverse outcomes with reasonable reliability.

Mitochondrial Dysfunction, Depleted Purinergic Signaling, and Defective T Cell Vigilance and Immune Defense

T cell suppression in sepsis is a well-known phenomenon; however, the underlying mechanisms are not fully understood. Previous studies have shown that T cell stimulation up-regulates mitochondrial adenosine triphosphate (ATP) production to fuel purinergic signaling mechanisms necessary for adequate T cell responses. Here we show that basal mitochondrial ATP production, ATP release, and stimulation of P2X1 receptors represent a standby purinergic signaling mechanism that is necessary for antigen recognition. Inhibition of this process impairs T cell vigilance and the ability of T cells to trigger T cell activation, up-regulate mitochondrial ATP production, and stimulate P2X4 and P2X7 receptors that elicit interleukin 2 production and T cell proliferation. T cells of patients with sepsis lack this standby purinergic signaling system owing to defects in mitochondrial function, ATP release, and calcium signaling. These defects impair antigen recognition and T cell function and are correlated with sepsis severity. Pharmacological targeting of these defects may improve T cell function and reduce the risk of sepsis.

Cost-effectiveness of quantitative pretest probability intended to reduce unnecessary medical radiation exposure in emergency department patients with chest pain and dyspnea

OBJECTIVES

Quantitative pretest probability (qPTP) incorporated into a decision support tool with advice can reduce unnecessary diagnostic testing among patients with symptoms suggestive of acute coronary syndrome (ACS) and pulmonary embolism (PE), reducing 30-day costs without an increase in 90-day adverse outcomes. This study estimates long-term (beyond 90-day) costs and outcomes associated with qPTP. The authors hypothesized that qPTP reduces lifetime costs and improves outcomes in low-risk patients with symptoms suggestive of ACS and PE.

METHODS

This was a cost-effectiveness analysis of a multicenter, randomized controlled trial of adult emergency patients with dyspnea and chest pain, in which a clinician encountering a low-risk patient with symptoms suggestive of ACS or PE conducted either the intervention (qPTP for ACS and PE with advice) or the sham (no qPTP and no advice). Effect of the intervention over a patient's lifetime was assessed using a Markov microsimulation model. Short-term costs and outcomes were from the trial; long-term outcomes and costs were from the literature. Outcomes included lifetime transition to PE, ACS, and intracranial hemorrhage (ICH); mortality from cancer, ICH, PE, ACS, renal failure, and ischemic stroke; quality-adjusted life-years (QALYs); and total medical costs compared between simulated intervention and sham groups.

RESULTS

Markov microsimulation for a 40-year-old patient receiving qPTP found lifetime cost savings of $497 for women and $528 for men, associated with small gains in QALYs (2 and 6 days, respectively) and lower rates of cancer mortality in both sexes, but a reduction in ICH only in males. Sensitivity analysis for patients aged 60 years predicted that qPTP would continue to save costs and also reduce mortality from both ICH and cancer. Use of qPTP significantly reduced the lifetime probability of PE diagnosis, with lower probability of death from PE in both sexes aged 40 to 60 years. However, use of qPTP reduced the rate of ACS diagnosis and death from ACS at age 40, but increased the death rate from ACS at age 60 for both sexes.

CONCLUSIONS

Widespread use of a combined qPTP for both ACS and PE has the potential to decrease costs by reducing diagnostic testing, while improving most long-term outcomes in emergency patients with chest pain and dyspnea.

Age-related differences in biomarkers of acute inflammation during hospitalization for sepsis

The authors aimed to evaluate age-related differences in inflammation biomarkers during the first 72 h of hospitalization for sepsis. This was a secondary analysis of a prospective observational cohort of adult patients (n = 855) from 10 urban academic emergency departments with confirmed infection and two or more systemic inflammatory response syndrome criteria. Six inflammation-related biomarkers were analyzed-chemokine (CC-motif) ligand-23, C-reactive protein, interleukin-1 receptor antagonist, neutrophil gelatinase-associated lipocalin (NGAL), peptidoglycan recognition protein, and tumor necrosis factor receptor-1a (TNFR-1a)-measured at presentation and 3, 6, 12, 24, 48, or 72 h later. The median age was 56 (interquartile range, 43 - 72) years, and sepsis severity was 38% sepsis, 16% severe sepsis without shock, and 46% septic shock; the overall 30-day mortality was 12%. Older age was associated with higher sepsis severity: 41% of subjects aged 18 to 34 years had severe sepsis or septic shock compared with 71% for those aged 65 years or older (P < 0.001). In longitudinal models adjusting for demographics, comorbidities, and infection source, older age was associated with higher baseline values for chemokine (CC-motif) ligand-23, interleukin-1 receptor antagonist, NGAL, and TNFR-1a (all P < 0.05). However, older adults had higher mean values during the entire 72-h period only for NGAL and TNFR-1a and higher final 72-h values only for TNFR-1a. Adjustment or stratification by sepsis severity did not change the age-inflammation associations. Although older adults had higher levels of inflammation at presentation and an increased incidence of severe sepsis and septic shock, these age-related differences in inflammation largely resolved during the first 72 h of hospitalization.

Discharge diagnoses versus medical record review in the identification of community-acquired sepsis

INTRODUCTION

We evaluated the accuracy of hospital discharge diagnoses in the identification of community-acquired sepsis and severe sepsis.

METHODS

We reviewed 379 serious infection hospitalizations from 2003 to 2012 from the national population-based reasons for geographic and racial differences in stroke (REGARDS) cohort. Through manual review of medical records, we defined criterion-standard community-acquired sepsis events as the presence of a serious infection on hospital presentation with ≥2 systemic inflammatory response syndrome criteria. We also defined criterion-standard community-acquired severe sepsis events as sepsis with >1 sequential organ failure assessment organ dysfunction. For the same hospitalizations, we identified sepsis and severe sepsis events indicated by Martin et al. and Angus et al. International Classifications of Diseases 9th edition discharge diagnoses. We evaluated the diagnostic accuracy of the Martin and Angus criteria for detecting criterion-standard community-acquired sepsis and severe sepsis events.

RESULTS

Among the 379 hospitalizations, there were 156 community-acquired sepsis and 122 community-acquired severe sepsis events. Discharge diagnoses identified 55 Martin-sepsis and 89 Angus-severe sepsis events. The accuracy of Martin-sepsis criteria for detecting community-acquired sepsis were: sensitivity 27.6%; specificity 94.6%; positive predictive value (PPV) 78.2%; negative predictive value (NPV) 65.1%. The accuracy of the Angus-severe sepsis criteria for detecting community-acquired severe sepsis were: sensitivity 42.6%; specificity 86.0%; PPV 58.4%; NPV 75.9%. Mortality was higher for Martin-sepsis than community-acquired sepsis (25.5% versus 10.3%, P = 0.006), as well as for Angus-severe sepsis than community-acquired severe sepsis (25.5 versus 11.5%, P = 0.002). Other baseline characteristics were similar between sepsis groups.

CONCLUSIONS

Hospital discharge diagnoses show good specificity but poor sensitivity for detecting community-acquired sepsis and severe sepsis. While sharing similar baseline subject characteristics as cases identified by hospital record review, discharge diagnoses selected for higher mortality sepsis and severe sepsis cohorts. The epidemiology of a sepsis population may vary with the methods used for sepsis event identification.

Diagnosing appendicitis: evidence-based review of the diagnostic approach in 2014

Introduction

Acute appendicitis is the most common abdominal emergency requiring emergency surgery. However, the diagnosis is often challenging and the decision to operate, observe or further work-up a patient is often unclear. The utility of clinical scoring systems (namely the Alvarado score), laboratory markers, and the development of novel markers in the diagnosis of appendicitis remains controversial. This article presents an update on the diagnostic approach to appendicitis through an evidence-based review.

Methods

We performed a broad Medline search of radiological imaging, the Alvarado score, common laboratory markers, and novel markers in patients with suspected appendicitis.

Results

Computed tomography (CT) is the most accurate mode of imaging for suspected cases of appendicitis, but the associated increase in radiation exposure is problematic. The Alvarado score is a clinical scoring system that is used to predict the likelihood of appendicitis based on signs, symptoms and laboratory data. It can help risk stratify patients with suspected appendicitis and potentially decrease the use of CT imaging in patients with certain Alvarado scores. White blood cell (WBC), C-reactive protein (CRP), granulocyte count and proportion of polymorphonuclear (PMN) cells are frequently elevated in patients with appendicitis, but are insufficient on their own as a diagnostic modality. When multiple markers are used in combination their diagnostic utility is greatly increased. Several novel markers have been proposed to aid in the diagnosis of appendicitis; however, while promising, most are only in the preliminary stages of being studied.

Conclusion

While CT is the most accurate mode of imaging in suspected appendicitis, the accompanying radiation is a concern. Ultrasound may help in the diagnosis while decreasing the need for CT in certain circumstances. The Alvarado Score has good diagnostic utility at specific cutoff points. Laboratory markers have very limited diagnostic utility on their own but show promise when used in combination. Further studies are warranted for laboratory markers in combination and to validate potential novel markers.

Chronic Statin Use and Long-Term Rates of Sepsis: A Population-Based Cohort Study

PURPOSE

"Statins" have immunomodulatory and anti-inflammatory effects and may attenuate the risk of infections. We sought to determine the association between chronic statin use and long-term rates of sepsis events.

MATERIALS AND METHODS

We used data from 30 183 adult (≥45 years old) community-dwelling participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. The primary exposure was statin use. The primary outcome was hospitalization or emergency department treatment for sepsis. Using Cox proportional hazards models, we determined associations between statin use and first sepsis events, adjusting for patients demographics, health behaviors, chronic medical conditions, degree of medication adherence, baseline high-sensitivity C-reactive protein (hsCRP), and propensity for statin use.

RESULTS

Approximately one-third of participants reported statin use (n = 9475, 31.4%). During the 10-year follow-up period from 2003 to 2012, there were 1500 incident sepsis events. Statin use was not associated with rates of sepsis after multivariable adjustment for demographics, health behaviors, chronic medical conditions, medication adherence, abnormal hsCRP, and propensity for statin use, hazard ratio 0.93 (95% confidence interval: 0.81-1.06). Statin use was not similarly associated with rates of sepsis when stratified by propensity for statin use or medication adherence.

CONCLUSION

In the REGARDS cohort, statin use at baseline was not associated with rates of future sepsis events.

Diagnostic characteristics of a clinical screening tool in combination with measuring bedside lactate level in emergency department patients with suspected sepsis

BACKGROUND

Early identification of sepsis and initiation of aggressive treatment saves lives. However, the diagnosis of sepsis may be delayed in patients without overt deterioration. Clinical screening tools and lactate levels may help identify sepsis patients at risk for adverse outcomes.

OBJECTIVES

The objective was to determine the diagnostic characteristics of a clinical screening tool in combination with measuring early bedside point-of-care (POC) lactate levels in emergency department (ED) patients with suspected sepsis.

METHODS

This was a prospective, observational study set at a suburban academic ED with an annual census of 90,000. A convenience sample of adult ED patients with suspected infection were screened with a sepsis screening tool for the presence of at least one of the following: temperature greater than 38°C or less than 36°C, heart rate greater than 90 beats/min, respiratory rate greater than 20 breaths/min, or altered mental status. Patients meeting criteria had bedside POC lactate testing following triage, which was immediately reported to the treating physician if ≥2.0 mmol/L. Demographic and clinical information, including lactate levels, ED interventions, and final diagnosis, were recorded. Outcomes included presence or absence of sepsis using the American College of Chest Physicians/Society of Critical Care Medicine consensus conference definitions and intensive care unit (ICU) admissions, use of vasopressors, and mortality. Diagnostic test characteristics were calculated using 2-by-2 tables with their 95% confidence intervals (CIs). The association between bedside lactate and ICU admissions, use of vasopressors, and mortality was determined using logistic regression.

RESULTS

A total of 258 patients were screened for sepsis. Their mean (± standard deviation [SD]) age was 64 (±19) years; 46% were female, and 82% were white. Lactate levels were 2.0 mmol/L or greater in 80 (31%) patients. Patients were confirmed to meet sepsis criteria in 208 patients (81%). The diagnostic characteristics for sepsis of the combined clinical screening tool and bedside lactates were sensitivity 34% (95% CI = 28% to 41%), specificity 82% (95% CI = 69% to 90%), positive predictive value 89% (95% CI = 80% to 94%), and negative predictive value 23% (95% CI = 17% to 30%). Bedside lactate levels were associated with sepsis severity (p < 0.001), ICU admission (odds ratio [OR] = 2.01; 95% CI = 1.53 to 2.63), and need for vasopressors (OR = 1.54; 95% CI = 1.13 to 2.12).

CONCLUSIONS

Use of a clinical screening tool in combination with early bedside POC lactates has moderate to good specificity but low sensitivity in adult ED patients with suspected sepsis. Elevated bedside lactate levels are associated with poor outcomes.

Mitochondria are gate-keepers of T cell function by producing the ATP that drives purinergic signaling

T cells play a central role in host defense. ATP release and autocrine feedback via purinergic receptors has been shown to regulate T cell function. However, the sources of the ATP that drives this process are not known. We found that stimulation of T cells triggers a spike in cellular ATP production that doubles intracellular ATP levels in <30 s and causes prolonged ATP release into the extracellular space. Cell stimulation triggered rapid mitochondrial Ca(2+) uptake, increased oxidative phosphorylation, a drop in mitochondrial membrane potential (Δψm), and the accumulation of active mitochondria at the immune synapse of stimulated T cells. Inhibition of mitochondria with CCCP, KCN, or rotenone blocked intracellular ATP production, ATP release, intracellular Ca(2+) signaling, induction of the early activation marker CD69, and IL-2 transcription in response to cell stimulation. These findings demonstrate that rapid activation of mitochondrial ATP production fuels the purinergic signaling mechanisms that regulate T cells and define their role in host defense.

Hospital variations in severe sepsis mortality

This study sought to characterize variations in severe sepsis mortality between hospitals in the United States. Hospital discharge data (2012) were used from the University HealthSystem Consortium (UHC), a cooperative of US not-for-profit academic medical centers and affiliated hospitals. Discharge diagnosis codes were used to define severe sepsis as the presence of a serious infection with at least 1 organ dysfunction on hospital presentation. Expected mortality was determined from UHC risk adjustment mortality models. Among the 188 hospitals in the analysis, there were 256 509 patients with severe sepsis on admission. The median number of severe sepsis cases per hospital was 1202 (interquartile range [IQR] = 718-1940). Severe sepsis observed mortality (median = 8.6%; IQR = 6.8%-10.3%; range = 0.9%-18.2%) and observed-to-expected (O:E) mortality ratios (median = 0.91; IQR = 0.77-1.05; range = 0.16-1.95) varied across the hospitals. Variations in institutional severe sepsis observed mortality rates and O:E mortality ratios were observed in this national consortium of major medical centers.

A randomized trial of protocol-based care for early septic shock

BACKGROUND

In a single-center study published more than a decade ago involving patients presenting to the emergency department with severe sepsis and septic shock, mortality was markedly lower among those who were treated according to a 6-hour protocol of early goal-directed therapy (EGDT), in which intravenous fluids, vasopressors, inotropes, and blood transfusions were adjusted to reach central hemodynamic targets, than among those receiving usual care. We conducted a trial to determine whether these findings were generalizable and whether all aspects of the protocol were necessary.

METHODS

In 31 emergency departments in the United States, we randomly assigned patients with septic shock to one of three groups for 6 hours of resuscitation: protocol-based EGDT; protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions; or usual care. The primary end point was 60-day in-hospital mortality. We tested sequentially whether protocol-based care (EGDT and standard-therapy groups combined) was superior to usual care and whether protocol-based EGDT was superior to protocol-based standard therapy. Secondary outcomes included longer-term mortality and the need for organ support.

RESULTS

We enrolled 1341 patients, of whom 439 were randomly assigned to protocol-based EGDT, 446 to protocol-based standard therapy, and 456 to usual care. Resuscitation strategies differed significantly with respect to the monitoring of central venous pressure and oxygen and the use of intravenous fluids, vasopressors, inotropes, and blood transfusions. By 60 days, there were 92 deaths in the protocol-based EGDT group (21.0%), 81 in the protocol-based standard-therapy group (18.2%), and 86 in the usual-care group (18.9%) (relative risk with protocol-based therapy vs. usual care, 1.04; 95% confidence interval [CI], 0.82 to 1.31; P=0.83; relative risk with protocol-based EGDT vs. protocol-based standard therapy, 1.15; 95% CI, 0.88 to 1.51; P=0.31). There were no significant differences in 90-day mortality, 1-year mortality, or the need for organ support.

CONCLUSIONS

In a multicenter trial conducted in the tertiary care setting, protocol-based resuscitation of patients in whom septic shock was diagnosed in the emergency department did not improve outcomes. (Funded by the National Institute of General Medical Sciences; ProCESS ClinicalTrials.gov number, NCT00510835.).

Association of body mass index with increased cost of care and length of stay for emergency department patients with chest pain and dyspnea

BACKGROUND

High body mass index (BMI) increases the probability of indeterminate findings on diagnostic studies, length of stay, and cost of care for hospitalized patients. No study has examined the economic and operational impact of BMI in patients with chest complaints presenting to the emergency department (ED). The objective was to measure the association of BMI with the main outcomes of cost of care, length of stay (including time in the ED and time in the wards if admitted), and radiation exposure in patients presenting to the ED with chest pain and dyspnea.

METHODS AND RESULTS

This was a prospective, 4-center, outcomes study. Patients were adults with dyspnea and chest pain, nondiagnostic electrocardiograms, and no obvious diagnosis. Patients were followed for the main outcomes for 90 days. Outcomes that were stratified by BMI in 5 categories, underweight, normal weight, overweight, obese, and morbidly obese, were compared using the Kruskall-Wallis rank test, and the independent predictive value of BMI was tested with multivariate regressions. Compared with medical costs for normal weight patients, costs were 22% higher for overweight patients (P=0.077), 28% higher for obese patients (P=0.020), and 41% higher for morbidly obese patients (P=0.015). Morbidly obese patients without computerized tomographic scanning stayed in the hospital 34% longer than normal weight patients (P=0.073), and morbidly obese patients with computerized tomographic scanning stayed in the hospital 44% longer than normal weight patients (P=0.083). BMI was not a significant predictor of radiation exposure. Morbidly obese patients had the highest proportion (87%) of no significant cardiopulmonary diagnosis for 90 days after computerized tomographic pulmonary angiography.

CONCLUSIONS

BMI was associated with increases in cost of care and length of hospital stay for patients with chest pain and dyspnea. These results emphasize a need for specific protocols to manage morbidly obese patients presenting to the ED with chest pain and dyspnea. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT01059500.

Soluble adhesion molecules as markers for sepsis and the potential pathophysiological discrepancy in neonates, children and adults

Sepsis is a severe and life-threatening systemic inflammatory response to infection that affects all populations and age groups. The pathophysiology of sepsis is associated with aberrant interaction between leukocytes and the vascular endothelium. As inflammation progresses, the adhesion molecules that mediate these interactions become shed from cell surfaces and accumulate in the blood as soluble isoforms that are being explored as potential prognostic disease biomarkers. We critically review the studies that have tested the predictive value of soluble adhesion molecules in sepsis pathophysiology with emphasis on age, as well as the underlying mechanisms and potential roles for inflammatory shedding. Five soluble adhesion molecules are associated with sepsis, specifically, E-selectin, L-selectin and P-selectin, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. While increased levels of these soluble adhesion molecules generally correlate well with the presence of sepsis, their degree of elevation is still poorly predictive of sepsis severity scores, outcome and mortality. Separate analyses of neonates, children and adults demonstrate significant age-dependent discrepancies in both basal and septic levels of circulating soluble adhesion molecules. Additionally, a range of both clinical and experimental studies suggests protective roles for adhesion molecule shedding that raise important questions about whether these should positively or negatively correlate with mortality. In conclusion, while predictive properties of soluble adhesion molecules have been researched intensively, their levels are still poorly predictive of sepsis outcome and mortality. We propose two novel directions for improving clinical utility of soluble adhesion molecules: the combined simultaneous analysis of levels of adhesion molecules and their sheddases; and taking age-related discrepancies into account. Further attention to these issues may provide better understanding of sepsis pathophysiology and increase the usefulness of soluble adhesion molecules as diagnostic and predictive biomarkers.

Delirium risk prediction, healthcare use and mortality of elderly adults in the emergency department

OBJECTIVES

To create a risk prediction rule for delirium in elderly adults in the emergency department (ED) and to compare mortality and resource use of elderly adults in the ED with and without delirium.

DESIGN

Prospective observational study.

SETTING

Urban tertiary care ED.

PARTICIPANTS

Individuals aged 65 and older presenting for ED care (N = 700).

MEASUREMENTS

A trained research assistant performed a structured mental status assessment and attention tests, after which delirium was determined using the Confusion Assessment Method. Data were collected on participant demographics, comorbidities, medications, ED course, hospital and intensive care unit (ICU) admission, length of stay, hospital charges, 30-day rehospitalization, and mortality.

RESULTS

Nine percent of elderly study participants had delirium. Using logistic regression, a delirium prediction rule consisting of older age, prior stroke or transient ischemic attack, dementia, suspected infection, and acute intracranial hemorrhage was created had good predictive accuracy (area under the receiver operating characteristic curve = 0.77). Admitted participants with ED delirium had longer median lengths of stay (4 vs 2 days) and were more likely to require ICU admission (13% vs 6%) and to be discharged to a new long-term care facility (37% vs 9%) than those without. In all participants, ED delirium was associated with higher 30-day mortality (6% vs 1%) and 30-day readmission (27% vs 13%).

CONCLUSION

This risk prediction rule may help identify a group of individuals in the ED at high risk of developing delirium who should undergo screening, but it requires external validation. Identification of delirium in the ED may enable physicians to implement strategies to decrease delirium duration and avoid inappropriate discharge of individuals with acute delirium, improving outcomes.