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Biomedical subjects

Emanuel P Rivers

Publications and source records attributed to Emanuel P Rivers.

18 recordsLinked to original sources

Severe sepsis and septic shock: review of the literature and emergency department management guidelines.

Severe sepsis and septic shock are as common and lethal as other acute life-threatening conditions that emergency physicians routinely confront such as acute myocardial infarction, stroke, and trauma. Recent studies have led to a better understanding of the pathogenic mechanisms and the development of new or newly applied therapies. These therapies place early and aggressive management of severe sepsis and septic shock as integral to improving outcome. This independent review of the literature examines the recent pathogenic, diagnostic, and therapeutic advances in severe sepsis and septic shock for adults, with particular relevance to emergency practice. Recommendations are provided for therapies that have been shown to improve outcomes, including early goal-directed therapy, early and appropriate antimicrobials, source control, recombinant human activated protein C, corticosteroids, and low tidal volume mechanical ventilation.

Adrenal Cortex Hormones↗

Early goal-directed therapy in severe sepsis and septic shock revisited: concepts, controversies, and contemporary findings.

Studies of acute myocardial infarction, trauma, and stroke have been translated into improved outcomes by earlier diagnosis and application of therapy at the most proximal stage of hospital presentation. Most therapies for these diseases are instituted prior to admission to an ICU; this approach to the sepsis patient has been lacking. In response, a trial comparing early goal-directed therapy (EGDT) vs standard care was performed using specific criteria for the early identification of high-risk sepsis patients, verified definitions, and a consensus-derived protocol to reverse the hemodynamic perturbations of hypovolemia, vasoregulation, myocardial suppression, and increased metabolic demands. Five years after the EGDT publication, there has been much discussion generated with regard to the concepts of EGDT, as well as debate fueled regarding diagnostic and therapeutic interventions. However, during this time period further investigations by the primary investigators and others have brought additional contemporary findings. EGDT modulates some of the components of inflammation, as reflected by improved organ function. The end points used in the EGDT protocol, the outcome results, and the cost-effectiveness have subsequently been externally validated, revealing similar or even better findings than those from the original trial. Although EGDT is faced with challenges, a coordinated approach to sepsis management is necessary to duplicate the progress in outcomes seen in patients with conditions such as acute myocardial infarction, stroke, and trauma.

Algorithms↗

Early and innovative interventions for severe sepsis and septic shock: taking advantage of a window of opportunity.

The pathogenic, diagnostic and therapeutic landscape of sepsis is no longer confined to the intensive care unit: many patients from other portals of entry to care, both outside and within the hospital, progress to severe disease. Approaches that have led to improved outcomes with other diseases (e.g., acute myocardial infarction, stroke and trauma) can now be similarly applied to sepsis. Improved understanding of the pathogenesis of severe sepsis and septic shock has led to the development of new therapies that place importance on early identification and aggressive management. This review emphasizes approaches to the early recognition, diagnosis and therapeutic management of sepsis, giving the clinician the most contemporary and practical approaches with which to treat these patients.

Anti-Bacterial Agents↗

Clinical manifestations of disordered microcirculatory perfusion in severe sepsis.

Microcirculatory dysfunction plays a pivotal role in the development of the clinical manifestations of severe sepsis. Prior to the advent of new imaging technologies, clinicians had been limited in their ability to assess the microcirculation at the bedside. Clinical evidence of microcirculatory perfusion has historically been limited to physical examination findings or surrogates that could be derived from global parameters of oxygen transport. This review explores: (1) the clinical manifestations of severe sepsis that can be linked to microcirculatory dysfunction; (2) the relationship between conventional hemodynamic parameters and microcirculatory blood flow indices; (3) the incorporation of microcirculatory function into the definition of 'shock' in the sepsis syndrome; (4) the role of the microcirculation in oxygen transport; and (5) the potential impact of novel sepsis therapies on microcirculatory flow. Although the study of the microcirculation has long been the domain of basic science, newly developed imaging technologies, such as orthogonal polarization spectral imaging, have now given us the ability to directly visualize and analyze microcirculatory blood flow at the bedside, and see the microcirculatory response to therapeutic interventions. Disordered microcirculatory flow can now be associated with systemic inflammation, acute organ dysfunction, and increased mortality. Using new technologies to directly image microcirculatory blood flow will help define the role of microcirculatory dysfunction in oxygen transport and circulatory support in severe sepsis.

Hemodynamics↗

Central venous-arterial carbon dioxide difference as an indicator of cardiac index.

OBJECTIVE: The mixed venous-arterial (v-a) pCO(2) difference has been shown to be inversely correlated with the cardiac index (CI). A central venous pCO(2), which is easier to obtain, may provide similar information. The purpose of this study was to examine the correlation between the central venous-arterial pCO(2) difference and CI. DESIGN: Prospective, cohort study. SETTING: Intensive care unit of an urban tertiary care hospital. PATIENTS AND PARTICIPANTS: Eighty-three consecutive intensive care unit patients. MEASUREMENTS: Simultaneous blood gases from the arterial, pulmonary artery (PA), and central venous (CV) catheters were obtained. At the same time point, cardiac indices were measured by the thermodilution technique (an average of three measurements). The cardiac indices obtained by the venous-arterial differences were compared with those determined by thermodilution. RESULTS: The correlation (R(2)) between the mixed venous-arterial pCO(2) difference and cardiac index was 0.903 (p <0.0001), and the correlation between the central venous-arterial pCO(2) difference and cardiac index was 0.892 (p <0.0001). The regression equations for these relationships were natural log (CI)=1.837-0.159 (v-a) CO(2) for the PA and natural log (CI)=1.787-0.151 (v-a) CO(2) for the CV (p <0.0001 for both). The root-mean-squared error for the PA and CV regression equations were 0.095 and 0.101, respectively. CONCLUSION: Venous-arterial pCO(2) differences obtained from both the PA and CV circulations inversely correlate with the cardiac index. Substitution of a central for a mixed venous-arterial pCO(2) difference provides an accurate alternative method for calculation of cardiac output.

Adult↗

Critical care medicine training and certification for emergency physicians.

Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine and critical care medicine. Critical care is a continuum that includes out-of-hospital, emergency department (ED), and ICU care teams. Both emergency medicine and critical care medicine require expertise in treating life-threatening acute illness, with many critically ill patients often presenting first to the ED. Increased patient volumes and acuity have resulted in longer ED lengths of stay and more critical care delivery in the ED. However, the majority of critical care medicine fellowships do not accept emergency medicine residents, and those who do successfully complete a fellowship do not have access to a US certification examination in critical care medicine. Despite these barriers, interest in critical care medicine training among emergency physicians is increasing. Dual emergency medicine- and critical care medicine-trained physicians will not only help alleviate the intensivist shortage but also strengthen critical care delivery in the ED and facilitate coordination at the ED-ICU interface. We therefore propose that all accreditation bodies work cooperatively to create a route to critical care medicine certification for emergency physicians who complete a critical care fellowship.

Certification↗

Critical care medicine training and certification for emergency physicians.

Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine and critical care medicine. Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine (EM) and critical care medicine (CCM). Critical care is a continuum that includes prehospital, emergency department (ED), and intensive care unit (ICU) care teams. Both EM and CCM require expertise in treating life-threatening acute illness, with many critically ill patients often presenting first to the ED. Increased patient volumes and acuity have resulted in longer ED lengths of stay and more critical care delivery in the ED. However, the majority of CCM fellowships do not accept EM residents, and those who successfully complete a fellowship do not have access to a U.S. certification exam in CCM. Despite these barriers, interest in CCM training among EM physicians is increasing. Dual EM/CCM-trained physicians not only will help alleviate the intensivist shortage but also will strengthen critical care delivery in the ED and facilitate coordination at the ED-ICU interface. We therefore propose that all accreditation bodies work cooperatively to create a route to CCM certification for emergency physicians who complete a critical care fellowship.

Certification↗

Early lactate clearance is associated with improved outcome in severe sepsis and septic shock.

OBJECTIVE: Serial lactate concentrations can be used to examine disease severity in the intensive care unit. This study examines the clinical utility of the lactate clearance before intensive care unit admission (during the most proximal period of disease presentation) as an indicator of outcome in severe sepsis and septic shock. We hypothesize that a high lactate clearance in 6 hrs is associated with decreased mortality rate. DESIGN: Prospective observational study. SETTING: An urban emergency department and intensive care unit over a 1-yr period. PATIENTS: A convenience cohort of patients with severe sepsis or septic shock. INTERVENTIONS: Therapy was initiated in the emergency department and continued in the intensive care unit, including central venous and arterial catheterization, antibiotics, fluid resuscitation, mechanical ventilation, vasopressors, and inotropes when appropriate. MEASUREMENTS AND MAIN RESULTS: Vital signs, laboratory values, and Acute Physiology and Chronic Health Evaluation (APACHE) II score were obtained at hour 0 (emergency department presentation), hour 6, and over the first 72 hrs of hospitalization. Therapy given in the emergency department and intensive care unit was recorded. Lactate clearance was defined as the percent decrease in lactate from emergency department presentation to hour 6. Logistic regression analysis was performed to determine independent variables associated with mortality. One hundred and eleven patients were enrolled with mean age 64.9 +/- 16.7 yrs, emergency department length of stay 6.3 +/- 3.2 hrs, and overall in-hospital mortality rate 42.3%. Baseline APACHE II score was 20.2 +/- 6.8 and lactate 6.9 +/- 4.6 mmol/L. Survivors compared with nonsurvivors had a lactate clearance of 38.1 +/- 34.6 vs. 12.0 +/- 51.6%, respectively (p =.005). Multivariate logistic regression analysis of statistically significant univariate variables showed lactate clearance to have a significant inverse relationship with mortality (p =.04). There was an approximately 11% decrease likelihood of mortality for each 10% increase in lactate clearance. Patients with a lactate clearance> or =10%, relative to patients with a lactate clearance <10%, had a greater decrease in APACHE II score over the 72-hr study period and a lower 60-day mortality rate (p =.007). CONCLUSIONS: Lactate clearance early in the hospital course may indicate a resolution of global tissue hypoxia and is associated with decreased mortality rate. Patients with higher lactate clearance after 6 hrs of emergency department intervention have improved outcome compared with those with lower lactate clearance.

Biomarkers↗

Targeted resuscitation strategies after injury.

PURPOSE OF REVIEW: The management of the traumatically injured patient has evolved during the past half century despite continually high morbidity and mortality rates. The management of the trauma victim requires timely intervention and damage control in an attempt to maintain normal hemodynamic parameters and adequate systemic perfusion. There is a fine balance between oxygen delivery and consumption, and when this is perturbed, oxygen debt may ensue. The presence of ongoing oxygen debt is rather deleterious, resulting in an inflammatory cascade that can lead to multisystem organ dysfunction. The rapid identification and restoration of oxygen debt are central to the resuscitation of the critically ill patient, be it the result of sepsis or trauma. RECENT FINDINGS: Resuscitation end points have evolved that allow the physician to more rapidly identify a perturbation between oxygen delivery and consumption. Moreover, end points allow uniformity in gauging the adequacy of resuscitation: preventing under- and overresuscitation and serving as a basis to compare outcome measures in resuscitation trials. Recent technologic advances have allowed a greater wealth of clinical data that can be obtained via less invasive means. Examples of this include esophageal Doppler monitoring, sublingual capnography, orthogonal polarization spectral imaging, and lithium dilution cardiac output determinations. These devices can be used in concert with more traditional resuscitation end points (ie, lactate and base deficit) to maximize oxygen delivery and correct tissue dysoxia. In addition, the management of hemorrhagic shock is continuing to evolve and challenge the dogmatic practices of normotensive resuscitation. SUMMARY: This review addresses (1) resuscitation end points to optimize cardiac function, (2) resuscitation end points to assess the microcirculation, (3) recent developments in the management of hypotensive hemorrhagic shock, and (4) the translation of early goal-directed therapy from septic shock to use in trauma. Past findings are reflected on and direction for future investigation and clinical practice based on recent clinical advances is provided.

Acidosis↗

Prevalence of elevated troponin I in end-stage renal disease patients receiving hemodialysis.

OBJECTIVES: Patients with end-stage renal disease (ESRD) who are receiving hemodialysis have an increased incidence of atherosclerotic heart disease. Currently, there is considerable controversy regarding the significance of elevated cardiac troponin I (cTnI) levels in patients with ESRD. The objective of this study was to examine the prevalence of elevated cTnI levels in asymptomatic patients with ESRD on hemodialysis. METHODS: This was a prospective cohort study at an urban hospital outpatient dialysis center. Serum was collected pre- and postdialysis from patients on dialysis at this center over a two-week period. Samples were batched and analyzed for cTnI using the Asxym fluorescent antibody test. An elevated cTnI level was defined as >0.8 ng/dL. RESULTS: Predialysis cTnI levels ranged from <0.1 to 0.7 ng/dL, and postdialysis cTnI levels ranged from <0.1 to 0.6 ng/dL. None of the patients had a cTnI level >0.8 ng/dL. CONCLUSIONS: cTnI levels are not falsely elevated in patients with ESRD on hemodialysis. In a patient with ESRD, myocardial injury should be suspected if his or her cTnI level is >0.8 ng/dL.

Adult↗

Whole body oxygen consumption and critical oxygen delivery in response to prolonged and severe carbon monoxide poisoning.

BACKGROUND: Carbon monoxide (CO) poisoning remains the leading cause of death by poisoning in the world. One of the major proposed mechanisms for CO toxicity is the binding of CO to cytochrome oxidase and interference with cellular oxygen utilization but evidence for this is inconclusive. AIM OF STUDY: This study examined the effects of prolonged CO exposure on the dynamics of whole body oxygen consumption (VO(2)) and oxygen delivery (DO(2)) in an attempt to observe if CO exposure results in a defect of oxygen utilization defect as determined by a reduction in VO(2) during the course of poisoning prior to reaching the point where VO(2) is directly dependent on DO(2). This critical level of DO(2) (DO(2)crit) produced by CO poisoning was compared to historical values produced by other insults, which decrease global body DO(2). METHODS: Five small dogs were ventilated for 2 h with 0.25% CO and room air followed by 0.5% CO until death. Cardiac index (Q), DO(2), VO(2), oxygen extraction ratio (OER), and systemic lactate were measured every 15 min until death. RESULTS: Carboxyhemoglobin (COHb) levels increased linearly over 2.5 h to values above 80% until death. VO(2) remained constant and not significantly different from baseline below a COHb of 80%. At COHb levels above 80%, VO(2) precipitously dropped. Similarly lactate levels were not significantly elevated from baseline until VO(2) dropped. DO(2) decreased by 78% (from 23+/-6 ml/kg/min to 5+/-4 ml/kg/min) over time despite an increase in Q by 58% until levels of COHb were above 80%. OER increased from 19+/-5% to 50+/-11% until death. The calculated DO(2)crit was 10.7+/-4 ml/min/kg, which is not significantly different from values ranging from 7 to 13 ml/min/kg reported in the literature due to other insults, which reduce DO(2). CONCLUSION: In this canine model of prolonged CO exposure, no gradual reduction in VO(2) or increase in systemic lactate prior to reaching DO(2)crit was noted. In addition, CO exposure does not appear to change the DO(2)crit. The combination of these findings does not support the theory that CO produces a whole body intracellular defect in oxygen utilization.

Animals↗

The prevalence of latex-specific IgE in patients presenting to an urban emergency department.

STUDY OBJECTIVE: Since the first report of immediate hypersensitivity to latex was documented in 1979, latex allergy has been increasingly recognized as a medical problem in patient populations. However, there are no data available regarding the seroprevalence of latex sensitization in patients presenting to the emergency department. The overall aim of this study was to determine the prevalence of latex IgE seropositivity (L-IgE) in ED patients. METHODS: We measured latex-specific IgE antibodies among a convenience sample of 1,027 patients using the AlaSTAT assay. We also measured serum IgE antibodies specific for 12 common inhalant allergens using the AlaTOP Microplate Allergy Screen assay. Demographic data were collected. Two questions related to latex allergy were queried. Descriptive statistics are presented. Point estimates and 95% confidence intervals (CIs) were calculated for each seroprevalence test. Odds ratios (ORs) and 95% CIs were used to assess the relationship between sex, race, and seropositivity to inhalant allergens and L-IgE. RESULTS: The participation rate was 90% (1,027). The mean age of the patients was 46.9 years, 47.6% (489) were male, and 13.9% (143) were white. Eighty-four (8.2%; 95% CI 6.5% to 10.0%) had positive L-IgE results, and 23.8% (20) of patients with positive L-IgE results were classified as having strongly positive results. Bivariate analyses showed that being nonwhite (OR 4.7; 95% CI 1.5 to 15.1) and being seropositive for inhalant allergens (OR 7.4; 95% CI 4.2 to 13.1) were associated with L-IgE. CONCLUSION: The prevalence of latex sensitization in our sampling is substantial and higher than previously estimated in the general adult population. The clinical significance of seropositivity requires further evaluation.

Adult↗

Critical care and emergency medicine.

The changing landscape of health care has resulted in an increase in the delivery of critical care in the emergency department. Although the emergency department duration is brief compared with the total length of hospitalization, physiologic determinants of outcome may be established before ICU admission. The care provided during the emergency department stay for critically ill patients has been shown to significantly impact the progression of organ failure and mortality. Despite these trends, formal critical care training for emergency physicians is limited. The need to maximize patient throughput in frequently overcrowded emergency departments hinders the provision of optimal care to the critically ill patient. Methodologies should be developed to examine the quality of patient care and objectively measure the impact of clinical interventions. The potential to improve outcome through educational initiatives and resource allocation should not be viewed as a burden of delivering a higher level of care in this setting but as a significant opportunity to effectively mitigate the socioeconomic consequences.

Critical Care↗