Distinct T-helper cell responses to Staphylococcus aureus bacteremia reflect immunologic comorbidities and correlate with mortality.

BACKGROUND: The dysregulated host immune response that defines sepsis varies as a function of both the immune status of the host and the distinct nature of the pathogen. The degree to which immunocompromising comorbidities or immunosuppressive medications affect the immune response to infection is poorly understood because these patients are often excluded from studies about septic immunity. The objectives of this study were to determine the immune response to a single pathogen (Staphylococcus aureus) among a diverse case mix of patients and to determine whether comorbidities affect immune and clinical outcomes. METHODS: Blood samples were drawn from 95 adult inpatients at multiple time points after the first positive S. aureus blood culture. Cox proportional hazards modeling was used to determine the associations between admission neutrophil counts, admission lymphocyte counts, cytokine levels, and 90-day mortality. A nested case-control flow cytometric analysis was conducted to determine T-helper type 1 (Th1), Th2, Th17, and regulatory T-cell (Treg) subsets among a subgroup of 28 patients. In a secondary analysis, we categorized patients as either having immunocompromising disorders (human immunodeficiency virus and hematologic malignancies), receiving immunosuppressive medications, or being not immunocompromised. RESULTS: Higher neutrophil-to-lymphocyte count ratios and higher Th17 cytokine responses relative to Th1 cytokine responses early after infection were independently associated with mortality and did not depend on the immune state of the patient (HR 1.93, 95% CI 1.17-3.17, p = 0.01; and HR 1.13, 95% CI 1.01-1.27, p = 0.03, respectively). On the basis of flow cytometric analysis of CD4 T-helper subsets, an increasing Th17/Treg response over the course of the infection was most strongly associated with increased mortality (HR 4.41, 95% CI 1.69-11.5, p < 0.01). This type of immune response was most common among patients who were not immunocompromised. In contrast, among immunocompromised patients who died, a decreasing Th1/Treg response was most common. CONCLUSIONS: The association of both increased Th17 responses and increased neutrophil counts relative to lymphocyte counts with mortality suggests that an overwhelming inflammatory response is detrimental. However, the differential responses of patients according to immune state suggest that immune status is an important clinical indicator that should be accounted for in the management of septic patients, as well as in the development of novel immunomodulatory therapies.

Comparison of Two Lidocaine Administration Techniques on Perceived Pain From Bedside Procedures: A Randomized Clinical Trial.

BACKGROUND: Lidocaine is used to alleviate procedural pain but paradoxically increases pain during injection. Pain perception can be modulated by non-noxious stimuli such as temperature or touch according to the gate control theory of pain. We postulated that lidocaine dripped onto the skin prior to injection would cool or add the sensation of touch at the skin surface to reduce pain perception from the procedure. METHODS: A randomized clinical trial of patients referred to the procedure service from February 2011 through March 2015 was conducted. All patients received 1% subcutaneous lidocaine injection. Patients randomized to the intervention group had approximately 1 to 2 ml of lidocaine squirted onto the skin surface prior to subcutaneous lidocaine injection. Patients were blinded to the details of the intervention and were surveyed by a blinded investigator to document the primary outcome (severity of pain from the procedure) using a visual analog scale. RESULTS: A total of 481 patients provided consent and were randomized to treatment. There was a significant improvement in the primary outcome of procedural pain (control, 16.6 ± 24.8 mm vs 12.2 ± 19.4 mm; P = .03) with the intervention group as assessed by using the visual analog scale score. Pain scores were primarily improved for peripherally inserted central catheters (control, 18.8 ± 25.6 mm vs 12.2 ± 18.2 mm; P = .02) upon subgroup analysis. CONCLUSIONS: Bedside procedures are exceedingly common. Data regarding the severity of procedural pain and strategies to mitigate it are important for the informed consent process and patient satisfaction. Overall, pain reported from common bedside procedures is low, but pain can be further reduced with the addition of lidocaine onto the skin surface to modulate pain perception. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01330134; URL: www.clinicaltrials.gov.

Experimental Lung Injury Reduces Krüppel-like Factor 2 to Increase Endothelial Permeability via Regulation of RAPGEF3-Rac1 Signaling.

RATIONALE: Acute respiratory distress syndrome (ARDS) is caused by widespread endothelial barrier disruption and uncontrolled cytokine storm. Genome-wide association studies (GWAS) have linked multiple genes to ARDS. Although mechanosensitive transcription factor Krüppel-like factor 2 (KLF2) is a major regulator of endothelial function, its role in regulating pulmonary vascular integrity in lung injury and ARDS-associated GWAS genes remains poorly understood. OBJECTIVES: To examine KLF2 expression in multiple animal models of acute lung injury and further elucidate the KLF2-mediated pathways involved in endothelial barrier disruption and cytokine storm in experimental lung injury. METHODS: Animal and in vitro models of acute lung injury were used to characterize KLF2 expression and its downstream effects responding to influenza A virus (A/WSN/33 [H1N1]), tumor necrosis factor-α, LPS, mechanical stretch/ventilation, or microvascular flow. KLF2 manipulation, permeability measurements, small GTPase activity, luciferase assays, chromatin immunoprecipitation assays, and network analyses were used to determine the mechanistic roles of KLF2 in regulating endothelial monolayer integrity, ARDS-associated GWAS genes, and lung pathophysiology. MEASUREMENTS AND MAIN RESULTS: KLF2 is significantly reduced in several animal models of acute lung injury. Microvascular endothelial KLF2 is significantly induced by capillary flow but reduced by pathologic cyclic stretch and inflammatory stimuli. KLF2 is a novel activator of small GTPase Ras-related C3 botulinum toxin substrate 1 by transcriptionally controlling Rap guanine nucleotide exchange factor 3/exchange factor directly activated by cyclic adenosine monophosphate, which maintains vascular integrity. KLF2 regulates multiple ARDS GWAS genes related to cytokine storm, oxidation, and coagulation in lung microvascular endothelium. KLF2 overexpression ameliorates LPS-induced lung injury in mice. CONCLUSIONS: Disruption of endothelial KLF2 results in dysregulation of lung microvascular homeostasis and contributes to lung pathology in ARDS.

Sequential Organ Failure Assessment Score Modified for Recent Infection in Patients With Hematologic Malignant Tumors and Severe Sepsis.

BACKGROUND: Baseline health status influences outcomes of severe sepsis. OBJECTIVE: To determine if recent infection is a marker of poor health in patients with hematologic malignant tumors and severe sepsis by modifying the Sequential Organ Failure Assessment (SOFA) score to account for infection. METHODS: Medical records of the first 50 patients with hematologic malignant tumors and severe sepsis admitted from September 1, 2009 to September 1, 2014, were reviewed to derive a modified SOFA score. The predictive accuracy of the modified score was compared with that of the unmodified score and the Acute Physiology and Chronic Health Evaluation (APACHE) II score for the 196 subsequent patients. RESULTS: The area under the receiver operator characteristic curve was 0.73 (95% CI, 0.66-0.80) for the modified score, 0.68 (95% CI, 0.61-0.76) for the unmodified score, and 0.65 (95% CI, 0.58-0.73) for the APACHE II score. The modified score was better for discriminating survivors from nonsurvivors than the unmodified score (P = .005) and the APACHE II score (P = .04). After adjustments for the modified score and age, only increased days from hospital to intensive care unit admission was significantly associated with 30-day mortality. CONCLUSION: Modifying the SOFA score to account for infections before admission to the intensive care unit improved the prognostic usefulness of the scores for patients with hematologic malignant tumors and severe sepsis.

Validation of a Method to Identify Immunocompromised Patients with Severe Sepsis in Administrative Databases.

RATIONALE: Immunocompromised patients are at high risk for developing severe sepsis. Currently, there are no validated strategies for identifying this group of patients in large administrative databases. OBJECTIVES: We set out to define and validate a method that could be used to identify immunocompromised patients with severe sepsis in administrative databases. METHODS: Patients were categorized as immunocompromised based on the presence of International Classification of Diseases, 9th revision discharge diagnosis codes and medication data. We validated this strategy by comparing the discriminatory ability of the search algorithm to that of manual chart review. MEASUREMENTS AND MAIN RESULTS: We identified 4,438 patients at a single academic center with severe sepsis using a definition applied to administrative data described by Angus and colleagues. There were 1,185 (26.7%) who were categorized as immunocompromised based on our novel administrative data search strategy. Compared with identification by medical record review, the new administrative data search strategy had positive and negative predictive values of 94.4% (95% confidence interval [CI], 88.8-97.7%) and 94.3% (95% CI, 91.0-96.6%). The sensitivity and specificity were 87.4% (95% CI, 80.6-92.5%) and 97.6% (95% CI, 95.0-99.9%). CONCLUSIONS: Patients who are immunosuppressed are a large subgroup of those with severe sepsis. Following its validation as a search strategy using other large databases, and its adaptation for International Classification of Diseases, 10th revision, this novel method may allow researchers to account for a patient's immune state when examining outcomes.

A comparison of initial monotherapy with norepinephrine versus vasopressin for resuscitation in septic shock.

BACKGROUND: Early goal-directed therapy is a time-sensitive therapeutic algorithm with a tiered approach to target hypoperfusion and cardiovascular collapse within the first 6 hours of septic shock. The Surviving Sepsis Campaign guidelines recommend norepinephrine or dopamine as the initial vasoactive agent for resuscitation in septic shock, reserving the administration of vasopressin as adjunctive therapy. OBJECTIVE: To determine whether vasopressin was noninferior to norepinephrine as the initial vasopressor to achieve a mean arterial pressure (MAP) goal in the first 6 hours of shock onset. METHODS: This retrospective cohort study evaluated adults who received monotherapy with either norepinephrine or vasopressin as initial vasoactive therapy for the management of septic shock. Patients were excluded if the treatment arm was not monotherapy, if they were admitted to a cardiology or cardiothoracic surgery service, or if they lacked a comparator-based 1:1 frequency matching. RESULTS: A total of 130 patients were included, 65 in each treatment arm. The proportion of patients who achieved a goal MAP in the vasopressin group was 63% (95% CI 51%-75%) and was 67.7% (95% CI 56%-79%) in the norepinephrine group. This observed difference between goal MAP attainment did not exceed the predefined noninferiority margin of -25% (CI for 4.7% difference -21.2% to 12%), suggesting noninferiority of vasopressin. No significant difference was identified between vasopressin and norepinephrine for final mean (SD) MAP achieved (75 [9.6] and 76.0 [8.2] mm Hg, respectively; p = 0.06) or the mean total change from baseline MAP to goal (14.1 [8.4] and 15.1 [9.1] mm Hg, respectively; p = 0.6). CONCLUSIONS: Vasopressin was noninferior to norepinephrine for the achievement of a MAP goal in the first 6 hours from onset of septic shock. Further prospective analysis is warranted; however, the results are useful for consideration of alternative vasopressors in the setting of drug shortages.

Conventional transbronchial needle aspiration decreases the rate of surgical sampling of intrathoracic lymphadenopathy.

BACKGROUND: Previous studies have suggested a decreased need for the surgical biopsy of intrathoracic lymph nodes (LNs) due to improved diagnostic rates utilizing transbronchial needle aspiration (TBNA) with endobronchial ultrasound and endoscopic ultrasound. The goal of this study was to determine whether conventional TBNA using combined cytologic and histologic analysis of tissue specimens impacted the rates of surgical diagnostic biopsies of patients with intrathoracic lymphadenopathy. METHODS: Retrospective review at a single academic center. All mediastinal and hilar tissue samples submitted for pathologic analysis over an 8.4-year period were analyzed. Patients were categorized into a "before" group and an "after" group based on two different time periods. The before group underwent only cytologic analysis of Wang needle (19-gauge or 21-gauge) aspirates. The after group had cytologic analysis of aspirates as well as histologic analysis of needle "core" (19 gauge) biopsy specimens. The groups were compared for the rate of intrathoracic LNs sampled by surgical means vs TBNA and the number of times that TBNA averted the need for a surgical diagnostic procedure. RESULTS: The success of TBNA increased significantly in the after group compared to that in the before group. The yield for the successful sampling of mediastinal and hilar LNs increased from 53 to 91% (p < 0.001) in the before group vs the after group. TBNA averted a surgical biopsy in 35% of the before cases compared to 66% of the after cases (p < 0.001). CONCLUSIONS: Conventional TBNA using large-bore needles with both cytology and surgical pathology evaluation decreases the need for surgical sampling of the mediastinum to diagnose thoracic lymphadenopathy.