Risk factors for nosocomial gastrointestinal bleeding and use of acid-suppressive medication in non-critically ill patients

BACKGROUND

It is unknown whether there exist certain subsets of patients outside of the intensive care unit in whom the risk of nosocomial gastrointestinal bleeding is high enough that prophylactic use of acid-suppressive medication may be warranted.

OBJECTIVE

To identify risk factors for nosocomial gastrointestinal bleeding in a cohort of non-critically ill hospitalized patients, develop a risk scoring system, and use this system to identify patients most likely to benefit from acid suppression.

DESIGN

Cohort study.

PATIENTS

Adult patients admitted to an academic medical center from 2004 through 2007. Admissions with a principal diagnosis of gastrointestinal bleeding or a principal procedure code for cardiac catheterization were excluded.

MAIN MEASURES

Medication, laboratory, and other clinical data were obtained through electronic data repositories maintained at the medical center. The main outcome measure-nosocomial gastrointestinal bleeding occurring outside of the intensive care unit-was ascertained via ICD-9-CM coding and confirmed by chart review.

KEY RESULTS

Of 75,723 admissions (median age = 56 years; 40 % men), nosocomial gastrointestinal bleeding occurred in 203 (0.27 %). Independent risk factors for bleeding included age > 60 years, male sex, liver disease, acute renal failure, sepsis, being on a medicine service, prophylactic anticoagulants, and coagulopathy. Risk of bleeding increased as clinical risk score derived from these factors increased. Acid-suppressive medication was utilized in > 50 % of patients in each risk stratum. Our risk scoring system identified a high risk group in whom the number-needed-to-treat with acid-suppressive medication to prevent one bleeding event was < 100.

CONCLUSIONS

In this large cohort of non-critically ill hospitalized patients, we identified several independent risk factors for nosocomial gastrointestinal bleeding. With further validation at other medical centers, the risk model derived from these factors may help clinicians to direct acid-suppressive medication to those most likely to benefit.

Estimated nursing workload for the implementation of ventilator bundles

BACKGROUND

Ventilator-associated pneumonia is a common healthcare-associated infection with high attributable morbidity and mortality. Prevention strategies, including prevention bundles, have been widely adopted across the USA. However, the nursing resources required to implement these bundles, and their effect on other aspects of intensive care unit patient care, are unknown.

METHODS

We conducted a survey of all critical care nurses at our institution to determine the time required, and impact of, a prevention bundle at our hospital.

RESULTS

Nurses estimated that the standard ventilator bundle requires a median of 115 min (IQR: 74-182) per patient per day. Although the majority of nurses did not perceive that other patient care tasks were delayed by these prevention activities, this was not universal; 29% (95% CI 21% to 39%) of respondents reported that other patient care tasks were sometimes delayed because time was allocated to ventilator bundle activities.

CONCLUSIONS

Our estimates may serve as potentially important inputs for cost-effectiveness and decision analyses related to intensive care unit prevention activities. Further research should include direct observations about nursing time allocation related to prevention activities.

Proton-pump inhibitor use is associated with low serum magnesium concentrations

Although case reports link proton-pump inhibitor (PPI) use and hypomagnesemia, no large-scale studies have been conducted. Here we examined the serum magnesium concentration and the likelihood of hypomagnesemia (<1.6 mg/dl) with a history of PPI or histamine-2 receptor antagonist used to reduce gastric acid, or use of neither among 11,490 consecutive adult admissions to an intensive care unit of a tertiary medical center. Of these, 2632 patients reported PPI use prior to admission, while 657 patients were using a histamine-2 receptor antagonist. PPI use was associated with 0.012 mg/dl lower adjusted serum magnesium concentration compared to users of no acid-suppressive medications, but this effect was restricted to those patients taking diuretics. Among the 3286 patients concurrently on diuretics, PPI use was associated with a significant increase of hypomagnesemia (odds ratio 1.54) and 0.028 mg/dl lower serum magnesium concentration. Among those not using diuretics, PPI use was not associated with serum magnesium levels. Histamine-2 receptor antagonist use was not significantly associated with magnesium concentration without or with diuretic use. The use of PPI was not associated with serum phosphate concentration regardless of diuretic use. Thus, we verify case reports of the association between PPI use and hypomagnesemia in those concurrently taking diuretics. Hence, serum magnesium concentrations should be followed in susceptible individuals on chronic PPI therapy.

Sustained effectiveness of a primary-team-based rapid response system

OBJECTIVE

Laws and regulations require many hospitals to implement rapid-response systems. However, the optimal resource intensity for such systems is unknown. We sought to determine whether a rapid-response system that relied on a patient's usual care providers, not a critical-care-trained rapid-response team, would improve patient outcomes.

DESIGN, SETTING, AND PATIENTS

An interrupted time-series analysis of over a 59-month period.

SETTING

Urban, academic hospital.

PATIENTS

One hundred seven-one thousand, three hundred forty-one consecutive adult admissions.

INTERVENTION

In the intervention period, patients were monitored for predefined, standardized, acute, vital-sign abnormalities or marked nursing concern. If these criteria were met, a team consisting of the patient's existing care providers was assembled.

MEASUREMENTS AND MAIN RESULTS

The unadjusted risk of unexpected mortality was 72% lower (95% confidence interval 55%-83%) in the intervention period (absolute risk: 0.02% vs. 0.09%, p < .0001). The unadjusted in-hospital mortality rate was not significantly lower (1.9% vs. 2.1%, p = .07). After adjustment for age, gender, race, season of admission, case mix, Charlson Comorbidity Index, and intensive care unit bed capacity, the intervention period was associated with an 80% reduction (95% confidence interval 63%-89%, p < .0001) in the odds of unexpected death, but no significant change in overall mortality [odds ratio 0.91 (95% confidence interval 0.82-1.02), p = .09]. Analyses that also adjusted for secular time trends confirmed these findings (relative risk reduction for unexpected mortality at end of intervention period: 65%, p = .0001; for in-hospital mortality, relative risk reduction = 5%, p = .2).

CONCLUSIONS

A primary-team-based implementation of a rapid response system was independently associated with reduced unexpected mortality. This system relied on the patient's usual care providers, not an intensive care unit based rapid response team, and may offer a more cost-effective approach to rapid response systems, particularly for systems with limited intensivist availability.

Intensivist time allocation: economic and ethical issues surrounding how intensivists use their time

Intensivists' time is a fundamentally constrained resource. Many factors can put intensivists under conditions in which demands for their time outstrip the amount of time available. The importance of intensivist time strain is increasing both because demand for intensivists exceeds supply and because the roles that intensivists are being asked to take on are constantly expanding. There is strong evidence that time strain affects the decisions that intensivists make; evidence about whether it impacts patient outcomes is mixed. In deciding how to allocate their time, intensivists face many challenges. This article highlights two of these challenges: (1) How should intensivists approach two common scheduling-related issues (24/7 intensive care unit coverage and long blocks of service time that promote continuity but sacrifice weekends off) and balance these issues with the very real workforce concern of accelerated professional burnout? (2) What are the hidden financial impacts of intensivist participation in quality improvement programs, given current reimbursement systems?

Initial management of septic patients with hyperglycemia in the noncritical care inpatient setting

BACKGROUND

Previous research on the management of hyperglycemia in patients with sepsis has focused primarily on those with established organ failure in the critical care setting. The impact of hyperglycemia and glycemic control in patients with infection before developing severe sepsis or shock remains undefined.

METHODS

This observational, prospective, cohort study investigated the relationship between initial 72-hour time-weighted mean glucose concentrations and in-hospital mortality, intensive care unit transfer, and hospital length of stay in a cohort of patients with an acute infection who were admitted from the emergency department to a non-intensive care unit hospital ward. We used multivariate regression models adjusted for age, diabetes, and disease severity.

RESULTS

A total of 1849 patients were included, of whom 29% had diabetes. In the 1310 nondiabetic patients, we observed hyperglycemia using time-weighted glucose concentrations: 121 to 150 mg/dL (n=204, 16%), 151 to 180 mg/dL (n=32, 2.4%), and greater than 180 mg/dL (n=21, 1.6%). Insulin treatment was infrequent in nondiabetic patients, with 9%, 13%, and 29% of nondiabetic patients in these ranges receiving insulin, respectively. As patient glucose values increased, in-hospital mortality increased in nondiabetic patients, with odds ratios (ORs) of 4.4 (95% confidence interval [CI], 1.8-11), 10.0 (95% CI, 2.5-40), and 9.3 (95% CI, 1.9-44.0). Conversely, hyperglycemia did not confer an increased risk of adverse outcomes in diabetic patients. Likewise, increased risk for unplanned intensive care unit admission from the floor demonstrated ORs of 2.2 (95% CI, 1.1-4.3), 2.0 (95% CI, 0.45-8.9), and 6.3 (95% CI, 1.9-20.6) in nondiabetic patients, whereas no increased risk was found in diabetic patients.

CONCLUSIONS

In this cohort of acutely infected patients without established severe sepsis or shock, higher glucose concentrations within the first 72 hours in the nondiabetic population were associated with worse hospital outcomes and were less likely to be treated with insulin compared with diabetic patients.

Lectican proteoglycans, their cleaving metalloproteinases, and plasticity in the central nervous system extracellular microenvironment

The extracellular matrix (ECM) in the central nervous system actively orchestrates and modulates changes in neural structure and function in response to experience, after injury, during disease, and with changes in neuronal activity. A component of the multi-protein, ECM aggregate in brain, the chondroitin sulfate (CS)-bearing proteoglycans (PGs) known as lecticans, inhibit neurite outgrowth, alter dendritic spine shape, elicit closure of critical period plasticity, and block target reinnervation and functional recovery after injury as the major component of a glial scar. While removal of the CS chains from lecticans with chondroitinase ABC improves plasticity, proteolytic cleavage of the lectican core protein may change the conformation of the matrix aggregate and also modulate neural plasticity. This review centers on the roles of the lecticans and the endogenous metalloproteinase families that proteolytically cleave lectican core proteins, the matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs), in neural plasticity. These extracellular metalloproteinases modulate structural neural plasticity-including changes in neurite outgrowth and dendritic spine remodeling-and synaptic plasticity. Some of these actions have been demonstrated to occur via cleavage of the PG core protein. Other actions of the proteases include cleavage of non-matrix substrate proteins, whereas still other actions may occur directly at the cell surface without proteolytic cleavage. The data convincingly demonstrate that metalloproteinases modulate physiological and pathophysiological neural plasticity.

Red cell distribution width improves the simplified acute physiology score for risk prediction in unselected critically ill patients

Introduction

Recently, red cell distribution width (RDW), a measure of erythrocyte size variability, has been shown to be a prognostic marker in critical illness. The aim of this study was to investigate whether adding RDW has the potential to improve the prognostic performance of the simplified acute physiology score (SAPS) to predict short- and long-term mortality in an independent, large, and unselected population of intensive care unit (ICU) patients.

Methods

This observational cohort study includes 17,922 ICU patients with available RDW measurements from different types of ICUs. We modeled the association between RDW and mortality by using multivariable logistic regression, adjusting for demographic factors, comorbidities, hematocrit, and severity of illness by using the SAPS.

Results

ICU-, in-hospital-, and 1-year mortality rates in the 17,922 included patients were 7.6% (95% CI, 7.2 to 8.0), 11.2% (95% CI, 10.8 to 11.7), and 25.4% (95% CI, 24.8 to 26.1). RDW was significantly associated with in-hospital mortality (OR per 1% increase in RDW (95%CI)) (1.14 (1.08 to 1.19), P < 0.0001), ICU mortality (1.10 (1.06 to 1.15), P < 0.0001), and 1-year mortality (1.20 (95% CI, 1.14 to 1.26); P < 0.001). Adding RDW to SAPS significantly improved the AUC from 0.746 to 0.774 (P < 0.001) for in-hospital mortality and 0.793 to 0.805 (P < 0.001) for ICU mortality. Significant improvements in classification of SAPS were confirmed in reclassification analyses. Subgroups demonstrated robust results for gender, age categories, SAPS categories, anemia, hematocrit categories, and renal failure.

Conclusions

RDW is a promising independent short- and long-term prognostic marker in ICU patients and significantly improves risk stratification of SAPS. Further research is needed the better to understand the pathophysiology underlying these effects.

Red cell distribution width and mortality in newly hospitalized patients

OBJECTIVE

Previous studies suggest that red cell distribution width, a measure of erythrocyte size variability, may predict long-term mortality, particularly in cardiovascular disease. Less research has focused on the prognostic utility of red cell distribution width in an acutely hospitalized population.

METHODS

We performed a secondary analysis of prospectively collected data on 74,784 consecutive hospitalized adults with red cell distribution width measured on admission. The primary outcome of interest was in-hospital mortality; a secondary outcome was unplanned transfer to the intensive care unit. We calculated multivariable logistic models adjusted for age, gender, race, and comorbid conditions.

RESULTS

The overall in-hospital mortality rate was 1.3% (95% confidence interval [CI], 1.2-1.4). As red cell distribution width increased, so did mortality, from 0.2% (lowest red cell distribution width decile) to 4.4% (highest red cell distribution width decile). Unadjusted red cell distribution width significantly discriminated between hospital survivors and nonsurvivors (area under the curve 0.74). In multivariate analyses, for every 1% increment in red cell distribution width at the time of admission, the odds for in-hospital mortality increased by 24% (odds ratio 1.24; 95% CI, 1.20-1.27); findings were robust across comorbidity subgroups. The rate of unplanned intensive care unit transfer was 7.0% (95% CI, 6.8-7.2) and in unadjusted analyses increased more than 2-fold from 4.5% in the lowest to 11.6% in the highest red cell distribution width decile. This relationship was significantly confounded but remained significant in multivariate analysis (odds ratio 1.04 per 1% red cell distribution width increment; 95% CI, 1.03-1.06).

CONCLUSION

Red cell distribution width strongly and independently predicted in-hospital mortality in this large cohort of hospitalized patients. It also was associated with acute decompensation among patients on the general ward, but to a lesser degree. The mechanisms underlying these findings are unknown.

The association of lactate and vasopressor need for mortality prediction in survivors of cardiac arrest

BACKGROUND

Currently there are few tools available for clinicians to predict outcomes in cardiac arrest survivors. Our objective was to determine if the combination of simple clinical parameters (initial blood lactate and vasopressor use) can predict outcome in post-cardiac arrest patients.

METHODS

The design was a retrospective medical record review. The study was carried on in two urban, tertiary-care, university teaching hospitals. As for patients, inclusion criteria were: 1) age ≥18 years; 2) non-traumatic out-of-hospital cardiac arrest with return of spontaneous circulation; 3) lactic acid measured within one hour of return of circulation. No interventions was performed.

RESULTS

Patients were divided into groups based on two variables: 1) vasopressor status (receipt of vasopressors vs. no vasopressors); and 2) initial blood lactate (categories defined as lactate <5 mmol/L, lactate 5 to 10 mmol/L, lactate ≥10 mmol/L); 128 out-of-hospital cardiac arrest patients met study inclusion criteria. Overall mortality was 71% (95%CI 63-79%). Patients who received vasopressors had significantly higher mortality rates compared to patients who did not receive vasopressors (80% vs. 52%; P=0.002). A stepwise increase in mortality is associated with increasing lactate levels (39% lactate <5 mmol/L, 67% lactate 5 mmol/L to10 mmol/L, and 92% lactate ≥10 mmol/L; P<0.001). The AUC for our model was 0.82.

CONCLUSION

The combination of two clinical parameters, vasopressor need and lactic acid levels, is an accurate severity of illness classification system and can predict mortality in patients following out-of-hospital cardiac arrest. Prospective validation of these variables in post-cardiac arrest is needed.

Diabetes is not associated with increased mortality in emergency department patients with sepsis

STUDY OBJECTIVE

Despite its high prevalence, the influence of diabetes on outcomes of emergency department (ED) patients with sepsis remains undefined. Our aim is to investigate the association of diabetes and initial glucose level with mortality in patients with suspected infection from the ED.

METHODS

Three independent, observational, prospective cohorts from 2 large US tertiary care centers were studied. We included patients admitted to the hospital from the ED with suspected infection. We investigated the association of diabetes and inhospital mortality within each cohort separately and then overall with logistic regression and generalized estimating equations adjusted for age, sex, disease severity, and sepsis syndrome. We also tested for an interaction between diabetes and hyperglycemia/hypoglycemia.

RESULTS

A total of 7,754 patients were included. The mortality rate was 4.3% (95% confidence interval [CI] 3.9% to 4.8%) and similar in diabetic and nondiabetic patients (4.1% versus 4.4%; absolute risk difference 0.4%; 95% CI -0.7% to 1.4%). There was no significant association between diabetes and mortality in adjusted analysis (odds ratio [OR] overall 0.85; 95% CI 0.71 to 1.01). Diabetes significantly modified the effect of hyperglycemia and hypoglycemia with mortality; initial glucose levels greater than 200 mg/dL were associated with higher mortality in nondiabetic patients (OR 2.1; 95% CI 1.4 to 3.0) but not in diabetic patients (OR 1.0; 95% CI 0.2 to 4.7), whereas glucose levels less than 100 mg/dL were associated with higher mortality mainly in the diabetic population (OR 2.3; 95% CI 1.6 to 3.3) and to a lesser extent in nondiabetic patients (OR 1.1; 95% CI 1.03 to 1.14).

CONCLUSION

We found no evidence for a harmful association of diabetes and mortality in patients across different sepsis severities. High initial glucose levels were associated with adverse outcomes in the nondiabetic population only. Further investigation is warranted to determine the mechanism for these effects.

The signal transducer and activator of transcription 6 gene (STAT6) increases the propensity of patients with atopic dermatitis toward disseminated viral skin infections

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with increased susceptibility to recurrent skin infections.

OBJECTIVE

We sought to determine why a subset of patients with AD have an increased risk of disseminated viral skin infections.

METHODS

Human subjects with AD with a history of eczema herpeticum (EH) and various control groups were enrolled. Vaccinia virus (VV) expression was measured by means of PCR and immunofluorescent staining in skin biopsy specimens from each study group after incubation with VV. Transgenic mice with a constitutively active signal transducer and activator of transcription 6 gene (STAT6) were characterized for response to VV skin inoculation. Genotyping for 10 STAT6 single nucleotide polymorphisms (SNPs) was performed in a white patient sample (n = 444).

RESULTS

VV gene and protein expression were significantly increased in the skin of patients with EH compared with other subject groups after incubation with VV in vitro. Antibody neutralization of IL-4 and IL-13 resulted in lower VV replication in patients with a history of EH. Mice that expressed a constitutively active STAT6 gene compared with wild-type mice had increased mortality and satellite lesion formation after VV skin inoculation. Significant associations were observed between STAT6 SNPs and EH (rs3024975, rs841718, rs167769, and rs703817) and IFN-γ production. The strongest association was observed for a 2-SNP haplotype (patients with AD with a history of EH vs patients with AD without a history of EH, 24.9% vs 9.2%; P = 5.17 × 10(-6)).

CONCLUSION

The STAT6 gene increases viral replication in the skin of patients with AD with a history of EH. Further genetic association studies and functional investigations are warranted.

Commentary: Is the glass half empty? Code blue training in the modern era

Skilled management of cardiopulmonary resuscitation, or responding to a "code blue," is widely considered an important training objective during internal medicine residency. Gaining proficiency in managing a code blue typically depends on event-based experiential learning. In this issue of Academic Medicine, Mickelsen and colleagues report their use of schedule-based stochastic simulation estimates matched with observed code blue data to model the number of annual opportunities a first-year resident has to participate in code blue events. Their data offer compelling evidence that trainees in 2008 had much less opportunity (83% less) to participate in code blue events than did their predecessors in 2002. Mickelsen and coinvestigators speculate that this reduction could be attributable to quality improvement initiatives that may have reduced the total number of code blue situations, as well as to duty hours restrictions that reduced the residents' overall availability to participate. The authors of this commentary discuss the general influence of secular trends on educational needs, and they describe possible strategies to compensate for less "in-the-field" exposure by maximizing the "learning yield per event" and using simulation training methods. Finally, the authors consider the question of whether code blue training remains an appropriate goal for general medicine trainees in the face of evolving trends in health care systems.

Human atopic dermatitis complicated by eczema herpeticum is associated with abnormalities in IFN-γ response

BACKGROUND

The basis for increased susceptibility of patients with atopic dermatitis (AD) to develop disseminated viral skin infections such as eczema herpeticum (AD with a history of eczema herpeticum, ADEH(+)) is poorly understood.

OBJECTIVE

We sought to determine whether subjects with AD prone to disseminated viral skin infections have defects in their IFN responses.

METHODS

GeneChip profiling was used to identify differences in gene expression of PBMCs from patients with ADEH(+) compared with patients with AD without a history of eczema herpeticum (ADEH(-)) and nonatopic controls. Key differences in protein expression were verified by enzyme-linked immunosorbent spot assay and/or ELISA. Clinical relevance was further demonstrated by a mouse model of disseminated viral skin infection and genetic association analysis for genetic variants in IFNG and IFNGR1 and ADEH among 435 cases and controls.

RESULTS

We demonstrate by global gene expression analysis selective transcriptomic changes within the IFN superfamily of PBMCs from subjects with ADEH(+) reflecting low IFN-γ and IFN-γ receptor gene expression. IFN-γ protein production was also significantly lower in patients with ADEH(+) (n = 24) compared with patients with ADEH(-) (n = 20) and nonatopic controls (n = 20). IFN-γ receptor knockout mice developed disseminated viral skin infection after epicutaneous challenge with vaccinia virus. Genetic variants in IFNG and IFNGR1 single nucleotide polymorphisms (SNPs) were significantly associated with ADEH (112 cases, 166 controls) and IFN-γ production: a 2-SNP (A-G) IFNGR1 haplotype (rs10457655 and rs7749390) showed the strongest association with a reduced risk of ADEH+ (13.2% ADEH(+) vs 25.5% ADEH(-); P = .00057).

CONCLUSION

Patients with ADEH(+) have reduced IFN-γ production, and IFNG and IFNGR1 SNPs are significantly associated with ADEH(+) and may contribute to an impaired immune response to herpes simplex virus.

Acid-suppressive medication use and the risk for nosocomial gastrointestinal tract bleeding

BACKGROUND

Acid-suppressive medications are increasingly prescribed for noncritically ill hospitalized patients, although the incidence of nosocomial gastrointestinal (GI) tract bleeding (GI bleeding) and magnitude of potential benefit from this practice are unknown. We aimed to define the incidence of nosocomial GI bleeding outside of the intensive care unit and examine the association between acid-suppressive medication use and this complication.

METHODS

We conducted a pharmacoepidemiologic cohort study of patients admitted to an academic medical center from 2004 through 2007, at least 18 years of age, and hospitalized for 3 or more days. Admissions with a primary diagnosis of GI bleeding were excluded. Acid-suppressive medication use was defined as any order for a proton pump inhibitor or histamine-2-receptor antagonist. The main outcome measure was nosocomial GI bleeding. A propensity matched generalized estimating equation was used to control for confounders.

RESULTS

The final cohort included 78,394 admissions (median age, 56 years; 41% men). Acid-suppressive medication was ordered in 59% of admissions, and nosocomial GI bleeding occurred in 224 admissions (0.29%). After matching on the propensity score, the adjusted odds ratio for nosocomial GI bleeding in the group exposed to acid-suppressive medication relative to the unexposed group was 0.63 (95% confidence interval, 0.42-0.93). The number needed to treat to prevent 1 episode of nosocomial GI bleeding was 770.

CONCLUSIONS

Nosocomial GI bleeding outside of the intensive care unit was rare. Despite a protective effect of acid-suppressive medication, the number needed to treat to prevent 1 case of nosocomial GI bleeding was relatively high, supporting the recommendation against routine use of prophylactic acid-suppressive medication in noncritically ill hospitalized patients.

Specificity protein 1 is pivotal in the skin's antiviral response

BACKGROUND

Previous studies have found specificity protein (Sp) 1 transcription factor in the viral replication machinery and postulated that Sp1 was required for viral replication in host cells.

OBJECTIVES

We investigated the role of Sp1 in the skin's antiviral responses from the perspective of host defense and its biological relevance in patients with atopic dermatitis and a history of eczema herpeticum (ADEH(+)).

METHODS

Small interfering RNA duplexes were used to knock down Sp1 in keratinocytes. The expression of vaccinia virus (VV), herpes simplex virus 1, and other genes were evaluated by real-time PCR, or combined with Western blot and immunohistofluorescence staining. A total of 106 human subjects participated in this study.

RESULTS

Both VV and herpes simplex virus 1 replication were enhanced in Sp1 knocked-down keratinocytes. Sp1 gene expression was significantly decreased in ADEH(+) subjects compared with patients with atopic dermatitis without a history of eczema herpeticum and nonatopic subjects (P < .0001) and inversely correlated with VV DNA copy number in human skin explants incubated with VV in vitro (partial correlation r = -0.256; P = .009). Gene profiling revealed that the antiviral genes, double-stranded RNA-dependent protein kinase (PKR) and 2'5'-oligoadenylate synthetase 2 (OAS2), were significantly downregulated in Sp1-silenced keratinocytes. Gene expression of PKR and OAS2 was also significantly decreased in skin biopsies from ADEH(+) subjects compared with patients with atopic dermatitis without a history of eczema herpeticum and nonatopic subjects. IFN-γ augmented the antiviral capacity of Sp1-silenced keratinocytes.

CONCLUSION

Specificity protein 1 knockdown enhances viral replication in keratinocytes by downregulating gene expression of PKR and OAS2. Sp1 deficiency in ADEH(+) patients may contribute to their increased propensity to disseminated skin viral infections. IFN-γ augmentation may be a potential treatment for ADEH(+) patients.

Human factors in resuscitation: Lessons learned from simulator studies

Medical algorithms, technical skills, and repeated training are the classical cornerstones for successful cardiopulmonary resuscitation (CPR). Increasing evidence suggests that human factors, including team interaction, communication, and leadership, also influence the performance of CPR. Guidelines, however, do not yet include these human factors, partly because of the difficulties of their measurement in real-life cardiac arrest. Recently, clinical studies of cardiac arrest scenarios with high-fidelity video-assisted simulations have provided opportunities to better delineate the influence of human factors on resuscitation team performance. This review focuses on evidence from simulator studies that focus on human factors and their influence on the performance of resuscitation teams. Similar to studies in real patients, simulated cardiac arrest scenarios revealed many unnecessary interruptions of CPR as well as significant delays in defibrillation. These studies also showed that human factors play a major role in these shortcomings and that the medical performance depends on the quality of leadership and team-structuring. Moreover, simulated video-taped medical emergencies revealed that a substantial part of information transfer during communication is erroneous. Understanding the impact of human factors on the performance of a complex medical intervention like resuscitation requires detailed, second-by-second, analysis of factors involving the patient, resuscitative equipment such as the defibrillator, and all team members. Thus, high-fidelity simulator studies provide an important research method in this challenging field.

Identifying infected emergency department patients admitted to the hospital ward at risk of clinical deterioration and intensive care unit transfer

OBJECTIVES

An important challenge faced by emergency physicians (EPs) is determining which patients should be admitted to an intensive care unit (ICU) and which can be safely admitted to a regular ward. Understanding risk factors leading to undertriage would be useful, but these factors are not well characterized.

METHODS

The authors performed a secondary analysis of two prospective, observational studies of patients admitted to the hospital with clinically suspected infection from an urban university emergency department (ED). Inclusion criteria were as follows: adult ED patient (age 18 years or older), ward admission, and suspected infection. The primary outcome was transfer to an ICU within 48 hours of admission. Using multiple logistic regression, independent predictors of early ICU transfer were identified, and the area under the curve for the model was calculated.

RESULTS

Of 5,365 subjects, 93 (1.7%) were transferred to an ICU within 48 hours. Independent predictors of ICU transfer included respiratory compromise (odds ratio [OR] = 2.5, 95% confidence interval [CI] = 1.4 to 4.3), congestive heart failure (CHF; OR = 2.2, 95% CI = 1.4 to 3.6), peripheral vascular disease (OR = 2.0, 95% CI = 1.1 to 3.7), systolic blood pressure (sBP) < 100 mm Hg (OR = 1.9, 95% CI = 1.2 to 2.9), heart rate > 90 beats/min (OR = 1.8, 95% CI = 1.1 to 2.8), and creatinine > 2.0 (OR = 1.8, 95% CI = 1.1 to 2.8). Cellulitis was associated with a lower likelihood of ICU transfer (OR = 0.33, 95% CI = 0.15 to 0.72). The area under the curve for the model was 0.73, showing moderate discriminatory ability.

CONCLUSIONS

  In this preliminary study, independent predictors of ICU transfer within 48 hours of admission were identified. While somewhat intuitive, physicians should consider these factors when determining patient disposition.

Iatrogenic gastric acid suppression and the risk of nosocomial Clostridium difficile infection

BACKGROUND

The incidence and severity of Clostridium difficile infections are increasing. Acid-suppressive therapy has been suggested as a risk factor for C difficile, but this remains controversial.

METHODS

We conducted a pharmacoepidemiologic cohort study, performing a secondary analysis of data collected prospectively on 101 796 discharges from a tertiary care medical center during a 5-year period. The primary exposure of interest was acid suppression therapy, classified by the most intense acid suppression therapy received (no acid suppression, histamine(2)-receptor antagonist [H(2)RA] therapy, daily proton pump inhibitor [PPI], and PPI more frequently than daily).

RESULTS

As the level of acid suppression increased, the risk of nosocomial C difficile infection increased, from 0.3% (95% confidence interval [CI], 0.21%-0.31%) in patients not receiving acid suppressive therapy to 0.6% (95% CI, 0.49%-0.79%) in those receiving H(2)RA therapy, to 0.9% (95% CI, 0.80%-0.98%) in those receiving daily PPI treatment, and to 1.4% (1.15%-1.71%) in those receiving more frequent PPI therapy. After adjustment for comorbid conditions, age, antibiotics, and propensity score-based likelihood of receipt of acid-suppression therapy, the association persisted, increasing from an odds ratio of 1 (no acid suppression [reference]) to 1.53 (95% CI, 1.12-2.10) (H(2)RA), to 1.74 (95% CI, 1.39-2.18) (daily PPI), and to 2.36 (95% CI, 1.79-3.11) (more frequent PPI). Similar estimates were found with a matched cohort analysis and with nested case-control techniques.

CONCLUSIONS

Increasing levels of pharmacologic acid suppression are associated with increased risks of nosocomial C difficile infection. This evidence of a dose-response effect provides further support for the potentially causal nature of iatrogenic acid suppression in the development of nosocomial C difficile infection.

Iatrogenic gastric acid suppression and the risk of nosocomial Clostridium difficile infection

BACKGROUND

The incidence and severity of Clostridium difficile infections are increasing. Acid-suppressive therapy has been suggested as a risk factor for C difficile, but this remains controversial.

METHODS

We conducted a pharmacoepidemiologic cohort study, performing a secondary analysis of data collected prospectively on 101 796 discharges from a tertiary care medical center during a 5-year period. The primary exposure of interest was acid suppression therapy, classified by the most intense acid suppression therapy received (no acid suppression, histamine(2)-receptor antagonist [H(2)RA] therapy, daily proton pump inhibitor [PPI], and PPI more frequently than daily).

RESULTS

As the level of acid suppression increased, the risk of nosocomial C difficile infection increased, from 0.3% (95% confidence interval [CI], 0.21%-0.31%) in patients not receiving acid suppressive therapy to 0.6% (95% CI, 0.49%-0.79%) in those receiving H(2)RA therapy, to 0.9% (95% CI, 0.80%-0.98%) in those receiving daily PPI treatment, and to 1.4% (1.15%-1.71%) in those receiving more frequent PPI therapy. After adjustment for comorbid conditions, age, antibiotics, and propensity score-based likelihood of receipt of acid-suppression therapy, the association persisted, increasing from an odds ratio of 1 (no acid suppression [reference]) to 1.53 (95% CI, 1.12-2.10) (H(2)RA), to 1.74 (95% CI, 1.39-2.18) (daily PPI), and to 2.36 (95% CI, 1.79-3.11) (more frequent PPI). Similar estimates were found with a matched cohort analysis and with nested case-control techniques.

CONCLUSIONS

Increasing levels of pharmacologic acid suppression are associated with increased risks of nosocomial C difficile infection. This evidence of a dose-response effect provides further support for the potentially causal nature of iatrogenic acid suppression in the development of nosocomial C difficile infection.

Vaccinia virus-specific molecular signature in atopic dermatitis skin

BACKGROUND

Eczema vaccinatum (EV), a disseminated viral skin infection, is a life-threatening complication of vaccinia virus (VV) inoculation in patients with atopic dermatitis (AD) and is thought to be associated with a defective innate immune response. However, the precise mechanism or mechanisms and key factor or factors of EV are unknown.

OBJECTIVE

Given that patients with psoriasis, another inflammatory skin disorder, are not susceptible to EV, we compared the global transcriptional response of skin to VV in healthy subjects, patients with psoriasis, and patients with AD, focusing on AD-specific genes. We hypothesized that differences in the transcriptional response to VV between patients with AD and patients with psoriasis or healthy subjects would identify a defective pathway or pathways that might be associated with the development of EV.

METHODS

Gene expression profiling of sham-treated and VV-treated unaffected skin explants from patients with AD (n = 12), patients with psoriasis (n = 12), or healthy subjects (n = 13) were generated with U133_Plus2 (54,613 probe sets) GeneChips and analyzed with the GCOS_1.4/SAM_2.1/MAPPFinder_2.0 pipeline.

RESULTS

Sixty-seven genes were significantly affected by VV in AD skin but not in psoriatic and healthy skin. Genes associated with defense response, response to wounding, and immune response were the most affected by VV in AD skin. All genes in these ontologies were downregulated, including the innate immunity genes leukotriene B(4) receptor (LTB4R), orosomucoid 1 (ORM1), coagulation factor II (thrombin) receptor (F2R), complement component 9 (C9), and LPS-binding protein (LBP). These findings were confirmed by means of real-time PCR and validated by means of PubMatrix analysis. ORM1, Toll-like receptor 4 (TLR4), and NLR family pyrin domain containing 1 (NLRP1) genes were also linked to AD severity.

CONCLUSION

This study identified groups of innate immunity genes that are associated with the aberrant response of AD skin to VV and represent potential targets for EV pathogenesis.

IL-4 regulates skin homeostasis and the predisposition toward allergic skin inflammation

IL-4 promotes the development of Th2 cells and allergic inflammation. In atopic dermatitis lesions, IL-4 decreases the expression of multiple genes associated with innate defense, including genes in the epidermal differentiation complex (EDC) that regulate epidermal barrier function. However, it is not clear whether IL-4 also contributes to homeostatic control of EDC genes. In this report, we demonstrate that expression of EDC genes and barrier function is increased in the absence of endogenous IL-4. Mice that express a constitutively active Stat6 (Stat6VT) are prone to the development of allergic skin inflammation and have decreased expression of EDC genes. IL-4 deficiency protects Stat6VT transgenic mice from the development of allergic skin inflammation and decreased recovery time in barrier function following skin irritation, with a concomitant increase in EDC gene expression. These data suggest that IL-4 plays an important role in regulating epidermal homeostasis and innate barrier function.