Immunologic and hemodynamic effects of "low-dose" hydrocortisone in septic shock: a double-blind, randomized, placebo-controlled, crossover study

Regulation of renal sodium transporters during severe inflammation

Sepsis-associated acute renal failure is characterized by decreased GFR and tubular dysfunction. The pathogenesis of endotoxemic tubular dysfunction with failure in urine concentration and increased fractional sodium excretion is poorly understood. This study investigated the regulation of renal sodium transporters during severe inflammation in vivo and in vitro. Injection of high-dosage LPS reduced BP and GFR, increased fractional sodium excretion, and strongly decreased the expression of Na(+)/H(+)-exchanger, renal outer medullary potassium channel, Na(+)-K(+)-2Cl(-) co-transporter, epithelial sodium channel, and Na(+)/K(+)-ATPase in mice. Also, injection of TNF-alpha, IL-1beta, or IFN-gamma decreased renal function and expression of renal sodium transporters. LPS-induced downregulation of sodium transporters was not affected in cytokine-knockout mice. However, supplementary glucocorticoid treatment, which inhibited LPS-induced increase of tissue cytokine concentrations, attenuated LPS-induced renal dysfunction and downregulation of tubular sodium transporters. Injection of low-dosage LPS increased renal tissue cytokines and downregulated renal sodium transporters without arterial hypotension. In vitro, in cortical collecting duct cells, cytokines also decreased expression of renal outer medullary potassium channel, epithelial sodium channel, and Na(+)/K(+)-ATPase. Renal hypoperfusion by renal artery clipping did not influence renal sodium transporter expression, in contrast to renal ischemia-reperfusion injury, which depressed transporter expression. These findings demonstrate downregulation of renal sodium transporters that likely accounts for tubular dysfunction during inflammation. These data suggest that alteration of renal sodium transporters during LPS-induced acute renal failure is mediated by cytokines rather than renal ischemia. However, in a complex in vivo model of severe inflammation, the possible presence and influence of renal hypoperfusion and reperfusion on the expression of renal sodium transporters cannot be completely excluded.

Management of sepsis

Severe sepsis remains a common cause of death in surgical patients. Eradication of the septic source and supportive care has long been the mainstay of treatment. In recent years, however, early goal-directed therapy, tighter glucose control, administration of drotrecogin alfa (activated), and steroid replacement have produced improved morbidity and mortality. In the future, a better understanding of the pathophysiology of sepsis and clinical studies may further improve outcomes from severe sepsis.

The hypothalamic-pituitary-adrenal axis in critical illness

The hypothalamic-pituitary-adrenal response to stress is a dynamic process. The homeostatic corrections that have emerged in the course of human evolution to cope with the catastrophic events during critical illness involve a complex multisystem endeavor. Although the repertoire of endocrine changes has been probed in some detail, discerning the vulnerabilities and failures of this system is far more challenging. One of the most controversially debated topics in the current literature is the characterization and optimal treatment of allegedly inadequate adaptations of the hypothalamic-pituitary-adrenal axis during critical illness. This outline attempts to touch briefly some of the debated issues, stir the discussion, and thereby contribute to resolving the dispute.

Pharmacologic Support of the Failing Heart

Cardiovascular failure in critically ill patients carries a high mortality. Identification and treatment of the underlying etiology simultaneously with prompt therapy are indicated to avoid the consequences of prolonged shock. Physicians should assess patients using all available clinical, radiologic, and laboratory data to avoid the pitfalls associated with use of single measures of regional or global perfusion. Continued evidence of inadequate perfusion despite fluid resuscitation warrants consideration of placement of a pulmonary artery catheter or pharmacologic support of the cardiovascular system. Finally, the dynamic nature of physiology in critically ill patients requires constant patient reassessment and flexibility in treatment to tailor therapy individually as the pathologic state evolves.

[Diagnosis and therapy of sepsis. Guidelines of the German Sepsis Society Inc. and the German Interdisciplinary Society for Intensive and Emergency Medicine]

A recent survey conducted by the publicly funded Competence Network Sepsis (SepNet) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approximately 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approximately 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organization of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to the requirements of the Working Group of Scientific Medical Societies (AWMF).

Emerging drugs for the treatment of sepsis

Septic shock still places a major burden on the healthcare system, although recent years have been marked by the demonstration that corticosteroids and activated protein C may substantially improve survival in selected populations. This review discusses the current management of septic shock and the potential development of new therapeutics following impressive advances in the pathomechanisms of septic shock.

HLA-DR expression on monocytes and systemic inflammation in patients with ruptured abdominal aortic aneurysms

Introduction

Mortality from ruptured abdominal aortic aneurysms (RAAA) remains high. Severe systemic inflammation, leading to multi-organ failure, often occurs in these patients. In this study we describe the level of HLA-DR expression in a consecutive group of patients following surgery for RAAA and compare results between survivors and non-survivors. A similar comparison is made for IL-6 and IL-10 levels and Sequential Organ Failure Assessment (SOFA) scores.

Methods

This is a prospective observational study. Patients with RAAA were prospectively analysed. Blood samples were collected on days 1, 3, 5, 7, 10 and 14. The fraction of CD-14 positive monocytes expressing HLA-DR was measured by flow-cytometry. IL-6 and IL-10 levels were measured by ELISA.

Results

The study included 30 patients with a median age of 70 years, of which 27 (90%) were men. Six patients died from multiple organ failure, all other patients survived. The SOFA scores were significantly higher in non-survivors on days 1 through 14. HLA-DR expression on monocytes was significantly lower on days 3, 5, 7, 10 and 14 in non-survivors. IL-6 and IL-10 levels were significantly higher in non-survivors on day 1 and days 1 and 3, respectively.

Conclusion

HLA-DR expression on monocytes was decreased, especially in non-survivors. All patients with RAAA displayed a severe inflammatory and anti-inflammatory response with an increased production of IL-6 and IL-10. Poor outcome is associated with high levels of IL-6 and IL-10 and a high SOFA score in the first three days after surgery, while low levels of HLA-DR expression are observed from day three after RAAA repair.

Management of sepsis during the early "golden hours"

Severe sepsis and septic shock are common causes of morbidity and mortality. Interventions directed at specific endpoints, when initiated early in the "golden hours" of patient arrival at the hospital, seem to be promising. Early hemodynamic optimization, administration of appropriate antimicrobial therapy, and effective source control of infection are the cornerstones of successful management. In patients with vasopressor-dependent septic shock, provision of physiologic doses of replacement steroids may result in improved survival. Administration of drotrecogin alfa (activated), (activated protein C) has been shown to improve survival in patients with severe sepsis and septic shock who have a high risk of mortality. In this article we review the multi-modality approach to early diagnosis and intervention in the therapy of patients with severe sepsis and septic shock.

Adrenal insufficiency in patients with cirrhosis and septic shock: Effect of treatment with hydrocortisone on survival

Relative adrenal insufficiency is frequent in patients with severe sepsis and is associated with hemodynamic instability, renal failure, and increased mortality. This study prospectively evaluated the effects of steroids on shock resolution and hospital survival in a series of 25 consecutive patients with cirrhosis and septic shock (group 1). Adrenal function was evaluated by the short corticotropin test within the first 24 hours of admission. Patients with adrenal insufficiency were treated with stress doses of intravenous hydrocortisone (50 mg/6 h). Data were compared to those obtained from the last 50 consecutive patients with cirrhosis and septic shock admitted to the same intensive care unit in whom adrenal function was not investigated and who did not receive treatment with steroids (group 2). Incidence of adrenal insufficiency in group 1 was 68% (17 patients). Adrenal dysfunction was frequent in patients with advanced cirrhosis (Child C: 76% vs. Child B: 25%, P = .08). Resolution of septic shock (96% vs. 58%, P = .001), survival in the intensive care unit (68% vs. 38%, P = .03), and hospital survival (64% vs. 32%, P = .003) were significantly higher in group 1. The main causes of death in group 1 were hepatorenal syndrome or liver failure (7 of 9 patients). In contrast, refractory shock caused most of the deaths in group 2 (20 of 34 patients). In conclusion, relative adrenal insufficiency is very frequent in patients with advanced cirrhosis and septic shock. Hydrocortisone administration in these patients is associated with a high frequency of shock resolution and high survival rate.

Management of severe sepsis and septic shock: challenges and recommendations

Sepsis and related aspects has become an area of active and intense research, leading to important advances for an early diagnosis and appropriate management useful to improve patient outcome. The septic response is an extremely complex cascade of events, including proinflammatory, anti-inflammatory, humoral, cellular, and circulatory involvement. The pathophysiology of this syndrome, its various and changing clinical aspects, and the vast variety of therapeutic options available, not always of well-proved efficacy, make its management a goal difficult to achieve.

Regulation of renal glucose transporters during severe inflammation

Severe sepsis is accompanied by acute renal failure (ARF) with renal tubular dysfunction and glucosuria. In this study, we aimed to determine the regulation of renal tubular glucose transporters during severe experimental inflammation. Male C57BL/6J mice were injected with LPS or proinflammatory cytokines, and renal perfusion, glomerular filtration rate (GFR), fractional glucose excretion, and expression of tubular glucose transporters were determined. We found a decreased plasma glucose concentration with impaired renal tissue perfusion and GFR and increased fractional glucose excretion associated with decreased expression of SGLT2, SGLT3, and GLUT2 after LPS injection. Similar alterations were observed after application of TNF-alpha, IL-1beta, IL-6, or IFN-gamma. To clarify the role of proinflammatory cytokines, we performed LPS injections in knockout mice with deficiencies for TNF-alpha, IL-1 receptor type 1, IFN-gamma, or IL-6 as well as LPS injections in glucocorticoid-treated wild-type mice. LPS-induced alterations of glucose transporters also were present in single-cytokine knockout mice. In contrast, glucocorticoid treatment clearly attenuated LPS-induced changes in renal glucose transporter expression and improved GFR and fractional glucose excretion. LPS-induced decrease of renal perfusion was not improved by glucocorticoids, indicating a minor role of ischemia in the development of septic renal dysfunction. Our results demonstrate modifications of tubular glucose transporters during severe inflammation that are probably mediated by proinflammatory cytokines and account for the development of ARF with increased fractional glucose excretion. In addition, our findings provide an explanation why single anti-cytokine strategies fail in the therapy of septic patients and contribute to an understanding of the beneficial effects of glucocorticoids on septic renal dysfunction.

Hypothalamic pituitary adrenal function during critical illness: limitations of current assessment methods

CONTEXT

Activation of the hypothalamic-pituitary-adrenal (HPA) axis represents one of several important responses to stressful events and critical illnesses. Despite a large volume of published data, several controversies continue to be debated, such as the definition of normal adrenal response, the concept of relative adrenal insufficiency, and the use of glucocorticoids in the setting of critical illness.

OBJECTIVES

The primary objective was to review some of the modulating factors and limitations of currently used methods of assessing HPA function during critical illness and provide alternative approaches in that setting.

DESIGN

This was a critical review of relevant data from the literature with inclusion of previously published as well as unpublished observations by the author. Data on HPA function during three different forms of critical illnesses were reviewed: experimental endotoxemia in healthy volunteers, the response to major surgical procedures in patients with normal HPA, and the spontaneous acute to subacute critical illnesses observed in patients treated in intensive care units.

SETTING

The study was conducted at an academic medical center.

PATIENTS/PARTICIPANTS

Participants were critically ill subjects.

INTERVENTION

There was no intervention.

MAIN OUTCOME MEASURE

The main measure was to provide data on the superiority of measuring serum free cortisol during critical illness as contrasted to those of total cortisol measurements.

RESULTS

Serum free cortisol measurement is the most reliable method to assess adrenal function in critically ill, hypoproteinemic patients. A random serum free cortisol is expected to be 1.8 microg/dl or more in most critically ill patients, irrespective of their serum binding proteins. Because the free cortisol assay is not currently available for routine clinical use, alternative approaches to estimate serum free cortisol can be used. These include calculated free cortisol (Coolens' method) and determining the free cortisol index (ratio of serum cortisol to transcortin concentrations). Preliminary data suggest that salivary cortisol measurements might be another alternative approach to estimating the free cortisol in the circulation. When serum binding proteins (albumin, transcortin) are near normal, measurements of total serum cortisol continue to provide reliable assessment of adrenal function in critically ill patients, in whom a random serum total cortisol would be expected to be 15 microg/dl or more in most patients. In hypoproteinemic critically ill subjects, a random serum total cortisol level is expected to be 9.5 microg/dl or more in most patients. Data on Cosyntropin-stimulated serum total and free cortisol levels should be interpreted with the understanding that the responses in critically ill subjects are higher than those of healthy ambulatory volunteers. The Cosyntropin-induced increment in serum total cortisol should not be used as a criterion for defining adrenal function, especially in critically ill patients.

CONCLUSIONS

The routine use of glucocorticoids during critical illness is not justified except in patients in whom adrenal insufficiency was properly diagnosed or others who are hypotensive, septic, and unresponsive to standard therapy. When glucocorticoids are used, hydrocortisone should be the drug of choice and should be given at the lowest dose and for the shortest duration possible. The hydrocortisone dose (50 mg every 6 h) that is mistakenly labeled as low-dose hydrocortisone leads to excessive elevation in serum cortisol to values severalfold greater than those achieved in patients with documented normal adrenal function. The latter data should call into question the current practice of using such doses of hydrocortisone even in the adrenally insufficient subjects.

Decreased progression of postinjury lung dysfunction to the acute respiratory distress syndrome and multiple organ failure

BACKGROUND

Postinjury organ dysfunction is a result of unbridled systemic hyperinflammation. According to the two-event construct, patients are resuscitated into an early vulnerable window of systemic hyperinflammation (primed) in which a second otherwise innocuous event precipitates uncontrolled hyperinflammation, leading to secondary organ damage and dysfunction (activated). Recent efforts to decrease postinjury morbidity have focused on limiting the potential of second events and systemic inflammation. We hypothesized that the collective effects of recently implemented therapeutic strategies have resulted in decreased activation of the systemic inflammatory response relative to priming in recent years.

METHODS

Data were collected prospectively on trauma patients at risk for postinjury multiple organ failure (MOF). Inclusion criteria were age >15 years, trauma intensive care unit admission, Injury Severity Score >15 and survival >48 hours. Isolated head injuries and head injuries with an extracranial abbreviated injury score <2 were excluded. Daily physiologic and laboratory data were collected through surgical intensive care unit day 28, and clinical events were recorded thereafter until death or hospital discharge. Organ failure was characterized with the use of the Denver MOF Scale. Acute respiratory distress syndrome (ARDS) was defined according to the consensus definition.

RESULTS

Over a 6.5-year period 897 patients were studied; 271 (31%) developed ARDS, and 226 (25%) developed MOF. Early lung dysfunction, as a measure of systemic priming, did not change over the study period. In contrast, the incidence of ARDS and MOF decreased from 43% to 25% and 33% to 12%, respectively. The incidence of early MOF decreased from 22% to 7% over the study period.

CONCLUSIONS

Priming of the postinjury inflammatory response is an early event and is primarily influenced by the injury itself. Recent advances in postinjury care such as judicious blood transfusion, lung protective ventilation, treatment of adrenal insufficiency, and tight glucose control are known to attenuate systemic inflammation. Step-wise adoption of these therapies is coincident with a decrease in the destructive processes resulting in ARDS and MOF. The global effect is a decrease in activation of the systemic inflammatory response over recent years.

Low-dose hydrocortisone during severe sepsis: effects on microalbuminuria

OBJECTIVE

The aim of this study was to investigate the effect of low-dose hydrocortisone on glomerular permeability measured by the microalbuminuria to creatinine ratio (MACR) and on other markers of sepsis in severe septic patients.

DESIGN

Randomized prospective study.

SETTING

University intensive care unit.

PATIENTS

The study involved 40 patients with severe sepsis randomized into the hydrocortisone group (n = 20) and the standard therapy group (n = 20).

INTERVENTIONS

The hydrocortisone group received standard therapy plus a continuous infusion of hydrocortisone for 6 days, whereas the standard therapy group received only standard therapy.

MEASUREMENTS AND MAIN RESULTS

MACR, serum C-reactive protein, and procalcitonin concentrations were recorded every day from the day before the steroid therapy (T(0)) until the 6 days after (T(1), T(2), T(3), T(4), T(5), and T(6)). Concentrations in the hydrocortisone group and the standard therapy group were compared using Mann-Whitney test at each time. We also compared with Wilcoxon signed rank test the values determined in each group at T(0) with those at each subsequent time. Median MACR decreased from T(0) to T(6) in both patient groups; however, values were significantly lower in the hydrocortisone group from T(3) through to T(6). Median serum C-reactive protein also decreased from T(0) in both patient groups, with significantly lower values in the hydrocortisone group from T(3) through to T(6). There were no significant differences in procalcitonin between groups compared with baseline values or at any individual time point.

CONCLUSIONS

Low-dose hydrocortisone seems to reduce MACR and serum C-reactive protein but not procalcitonin in patients with severe sepsis. Further studies are needed to confirm these results and to understand the underlying molecular mechanisms.

Innate recognition of bacteria: potential therapeutic targets for bacterial sepsis

Sepsis is a paradoxical and complex disorder that results from an over-reaction of our innate immune system to bacterial infections. Although this disorder has been known since ancient times, the history of clinical research into novel therapies for sepsis has been disappointing. The inability to translate our findings to the clinic could be attributed to our lack of knowledge of the molecular mechanisms involved in sensing microbial pathogens. However, in the last decade, the innate immune sensors responsible for triggering this disease have been discovered. This review will examine mediators that have been targeted in the past, as well as in the present, and propose novel therapeutic interventions for the future.

Upregulation of human angiotensinogen (AGT) gene transcription by interferon-gamma: involvement of the STAT1-binding motif in the AGT promoter

Mechanisms to maintain blood pressure in the face of infection are critical to survival. The angiotensinogen (AGT) gene locus is an important component of this response. Thus the AGT gene, expressed predominantly by liver cells, is known to be a positive acute phase reactant. We have previously demonstrated activation of the AGT promoter in hepatocytes through the IL6/STAT3 signaling mechanism. We have now investigated whether IFN-gamma, a cytokine also induced in response to diverse infections, can regulate AGT gene expression, and have elucidated the molecular mechanism involved. IFN gamma treatment up-regulated AGT mRNA level and promoter activity in Hep3B hepatocytes. Sequential deletion of the promoter from the 5' side suggested the major IFN gamma responsive DNA element to be between -303 and -103. This region contained a candidate STAT1-binding site between -271 and -279. EMSA and chromatin immuno-precipitation (ChIP) assays confirmed that IFN-gamma treatment induced the binding of STAT1 to this element. Reporter constructs containing this AGT promoter derived element in a multimerized context but not a mutant version were responsive to IFN gamma. Moreover mutating this STAT1 element in the context of the wild-type AGT holo promoter reduced responsiveness to IFN gamma. In contrast to the clear synergism between dexamethasone and IL 6 in the upregulation of the AGT promoter (through interaction between GR and STAT3), the combination of IFN gamma with IL 6 or with dexamethasone did not further increase AGT promoter activity suggesting that the IFN gamma/STAT1 pathway represents a separate signaling mechanism. These data highlight the redundancy in cytokine-mediated host response pathways aimed at the maintenance of blood pressure during infection.

Neutrophils in development of multiple organ failure in sepsis

Multiple organ failure is a major threat to the survival of patients with sepsis and systemic inflammation. In the UK and in the USA, mortality rates are currently comparable with and projected to exceed those from myocardial infarction. The immune system combats microbial infections but, in severe sepsis, its untoward activity seems to contribute to organ dysfunction. In this Review we propose that an inappropriate activation and positioning of neutrophils within the microvasculature contributes to the pathological manifestations of multiple organ failure. We further suggest that targeting neutrophils and their interactions with blood vessel walls could be a worthwhile therapeutic strategy for sepsis.

Year in review 2005: Critical Care - resource management

During 2005 Critical Care published several original papers dealing with resource management. Emphasis was placed on sepsis, especially the coagulation cascade, prognosis and resuscitation. The papers highlighted important aspects of the pathophysiology of coagulation and inflammation in sepsis, as well as dealing with the proper use of newly developed compounds. Several aspects of prognosis in critically ill patients were investigated, focusing on biological markers and clinical indexes. Resuscitation received great attention, dealing with the effects of fluid infusion in hemodynamics and the lung. The information obtained can be used to address unknown effects of established therapies, to enlighten current clinical discussion on controversial topics, and to introduce novel medical resources and strategies. Future clinical work will rely heavily on these preclinical and laboratory data.

Associated inflammatory response in pneumonia: role of adjunctive therapy with glucocorticoids

PURPOSE OF REVIEW

This article reviews the potential use of glucocorticoids as adjunctive therapy in the management of patients with severe bacterial pneumonia or pulmonary infections of other etiologies.

RECENT FINDINGS

The importance of an adequate assessment of the inflammatory process and the appearance of inflammatory markers that correlate with the severity of pneumonia is underlined. A recent randomized clinical trial indicates that adjunctive treatment of severe community-acquired pneumonia with glucocorticoids reduces complications and improves survival. The role of glucocorticoids in other lung infections is also reviewed. The design of new compounds with similar anti-inflammatory properties to classical glucocorticoids but with significantly fewer side effects constitutes a specific challenge for the near future.

SUMMARY

Although adjunctive treatment with glucocorticoids in severe pneumonia is probably indicated, further randomized clinical trials are urgently needed to confirm the preliminary positive results. In this regard, a proper evaluation of the inflammatory response is likely to be essential for the accurate selection of the target population.

Circulating Cytokines, Chemokines, and Stress Hormones are Increased in Patients with Organ Dysfunction Following Liver Resection

BACKGROUND

Humoral mediators are potentially involved in the pathogenesis of postoperative complications following surgery. The aim of the present study is to evaluate the postoperative responses of circulating cytokines, chemokines, and stress hormones following liver resection, and their effects on postoperative infectious complications and organ dysfunction.

PATIENTS AND METHODS

Perioperative plasma concentrations of interleukin (IL)-6, IL-10, IL-4, IL-8, macrophage chemoattractant protein (MCP)-1, cortisol, macrophage migration inhibitory factor (MIF), and leptin were measured by immunoassays in 128 consecutive patients undergoing liver resection.

RESULTS

Forty-three patients had postoperative infection and 11 had infection-related organ dysfunction. Plasma levels of all mediators except for IL-4 increased postoperatively. Postoperative levels of IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin were significantly higher in patients with organ dysfunction than in those without organ dysfunction (P < 0.05). However, postoperative MIF levels were not affected by postoperative infection or organ dysfunction. Plasma levels of IL-6, IL-10, IL-8, and MCP-1 were positively correlated with operation time (P < 0.0001) or blood loss (P < 0.0001), and higher in patients with jaundiced liver (P < 0.05). In univariate logistic regression analyses, elevated IL-6, IL-10, IL-8, and MCP-1, advanced age, large volume of blood loss, long operation time, long hepatic ischemia time, and major liver resection were significantly correlated with postoperative infection (P < 0.05). In multivariate analyses, IL-6 and IL-10 were significant predisposing factors for postoperative infection (P < 0.05), and blood loss and IL-6 for organ dysfunction (P < 0.01).

CONCLUSIONS

These results suggest that IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin are released after liver resection in response to surgical stress and correlated with postoperative infection and organ dysfunction, and that of these circulating mediators, IL-6 and IL-10, have a close relationship to the complications.

Efficacy and safety of corticosteroids for persistent acute respiratory distress syndrome

BACKGROUND

Persistent acute respiratory distress syndrome (ARDS) is characterized by excessive fibroproliferation, ongoing inflammation, prolonged mechanical ventilation, and a substantial risk of death. Because previous reports suggested that corticosteroids may improve survival, we performed a multicenter, randomized controlled trial of corticosteroids in patients with persistent ARDS.

METHODS

We randomly assigned 180 patients with ARDS of at least seven days' duration to receive either methylprednisolone or placebo in a double-blind fashion. The primary end point was mortality at 60 days. Secondary end points included the number of ventilator-free days and organ-failure-free days, biochemical markers of inflammation and fibroproliferation, and infectious complications.

RESULTS

At 60 days, the hospital mortality rate was 28.6 percent in the placebo group (95 percent confidence interval, 20.3 to 38.6 percent) and 29.2 percent in the methylprednisolone group (95 percent confidence interval, 20.8 to 39.4 percent; P=1.0); at 180 days, the rates were 31.9 percent (95 percent confidence interval, 23.2 to 42.0 percent) and 31.5 percent (95 percent confidence interval, 22.8 to 41.7 percent; P=1.0), respectively. Methylprednisolone was associated with significantly increased 60- and 180-day mortality rates among patients enrolled at least 14 days after the onset of ARDS. Methylprednisolone increased the number of ventilator-free and shock-free days during the first 28 days in association with an improvement in oxygenation, respiratory-system compliance, and blood pressure with fewer days of vasopressor therapy. As compared with placebo, methylprednisolone did not increase the rate of infectious complications but was associated with a higher rate of neuromuscular weakness.

CONCLUSIONS

These results do not support the routine use of methylprednisolone for persistent ARDS despite the improvement in cardiopulmonary physiology. In addition, starting methylprednisolone therapy more than two weeks after the onset of ARDS may increase the risk of death. (ClinicalTrials.gov number, NCT00295269.).

Adrenal insufficiency in patients with cirrhosis, severe sepsis and septic shock

Patients with cirrhosis are susceptible to bacterial infection, which can result in circulatory dysfunction, renal failure, hepatic encephalopathy, and a decreased survival rate. Severe sepsis is frequently associated with adrenal insufficiency, which may lead to hemodynamic instability and a poor prognosis. We evaluated adrenal function using short corticotropin stimulation test (SST) in 101 critically ill patients with cirrhosis and severe sepsis. Adrenal insufficiency occurred in 51.48% of patients. The patients with adrenal insufficiency had a higher hospital mortality rate when compared with those with normal adrenal function (80.76% vs. 36.7%, P < .001). The cumulative rates of survival at 90 days were 15.3% and 63.2% for the adrenal insufficiency and normal adrenal function groups, respectively (P < .0001). The hospital survivors had a higher cortisol response to corticotropin (16.2 +/- 8.0 vs. 8.5 +/- 5.9 microg/dL, P < .001). The cortisol response to corticotropin was inversely correlated with various disease severity, Model for End-Stage Liver Disease, and Child-Pugh scores. Acute physiology, age, chronic health evaluation III score, and cortisol increment were independent factors to predict hospital mortality. Mean arterial pressure on the day of SST was lower in patients with adrenal insufficiency (60 +/- 14 vs. 74.5 +/- 13 mm Hg, P < .001), and a higher proportion of these patients required vasopressors (73% vs. 24.48%, P < .001). Mean arterial pressure, serum bilirubin, vasopressor dependency, and bacteremia were independent factors that predicted adrenal insufficiency. In conclusion, adrenal insufficiency is common in critically ill patients with cirrhosis and severe sepsis. It is related to functional liver reserve and disease severity and is associated with hemodynamic instability, renal dysfunction, and increased mortality.

Physiopathologie du choc septique

Antigen presentation to inflammatory cells via pattern recognition receptors leads to the synthesis of NF-kappaB and other cytokine transcriptional factors. Leukocytes in the blood bind to endothelial receptors, the expression of which is mediated by proinflammatory cytokines via leukocyte integrins; the leukocytes then migrate to the site of inflammation. Endothelial procoagulant activity during sepsis is partly responsible for the disseminated intravascular coagulation (DIVC) and tissue hypoperfusion that follow. The endothelium synthesizes numerous proinflammatory factors, including nitric oxide, which is responsible for the resistance acquired to endogenous catecholamines and for vasomotor paralysis. During sepsis, the autonomic nervous system activity decreases in favor of proinflammatory parasympathetic activity. Secretion of counterregulatory rather than proinflammatory hormones increases during sepsis. Organ dysfunctions may alter cell functions, essentially mitochondrial, as well as intertissue communication.

Association between Adrenal Insufficiency and Ventilator Weaning

RATIONALE

Adrenal insufficiency is a common disorder in critically ill patients with mechanical ventilation and is usually associated with higher mortality and poor clinical outcome.

OBJECTIVES

To determine whether stress dose corticosteroid supplementation can improve ventilator weaning and clinical outcome in patients with adrenal insufficiency.

METHODS

A prospective, randomized, placebo controlled, double-blinded study was conducted in the intensive care unit of a tertiary teaching hospital. A total of 93 mechanically ventilated patients were enrolled in the ventilator weaning trial. Adrenal function was assessed in all patients. Patients with adrenal insufficiency were randomized to the treatment group (50 mg intravenous hydrocortisone every 6 h) and the placebo group.

MEASUREMENTS AND MAIN RESULTS

The successful ventilator weaning percentage was significantly higher in the adequate adrenal reserve group (88.4%) and in the stress dose hydrocortisone treatment group (91.4%) than in the placebo group (68.6%). The weaning period was shorter in the hydrocortisone treatment group than in the placebo group. No significant adverse effects were observed in the corticosteroid treatment group.

CONCLUSIONS

For patients with respiratory failure, early identification of adrenal insufficiency and appropriate supplementation with stress dose hydrocortisone increase the success of ventilator weaning and shortens the weaning period.

Clinical review: a systematic review of corticosteroid use in infections

Traditional teaching suggests that corticosteroids should be avoided during acute infectious episodes for fear of compromising the immune response. However, the outcome benefit shown through steroid administration in early septic shock implies this paranoia may be misplaced. We therefore performed a systematic review of the literature to identify the current strength of evidence for the use of corticosteroids in specified infections, and to make appropriate graded recommendations.

Cortisol levels in patients with severe community-acquired pneumonia

OBJECTIVES

To evaluate cortisol levels and prevalence of adrenal insufficiency in patients with severe community-acquired pneumonia (CAP).

DESIGN AND SETTING

Retrospective cohort study in a 24-bed medical-surgical intensive care unit (ICU).

PATIENTS

Forty patients with severe CAP admitted to the ICU from March 2003 and May 2005.

MEASUREMENTS AND RESULTS

Random cortisol levels were measured up to 72 h after ICU admission. A threshold of 20 microg/dl was considered for the diagnosis of adrenal insufficiency. Median cortisol levels were 15.5 microg/dl (IQR 10.8-25.1), and 26 patients (65%) met the criteria for adrenal insufficiency. Other cutoff levels of cortisol were evaluated, and 30 patients (75%) had cortisol levels below 25 microg/dl and 19 (47.5%) had cortisol levels below 15 microg/dl. When only patients with septic shock (n=19) were evaluated, 12 (63%) had adrenal insufficiency.

CONCLUSIONS

Relative adrenal insufficiency occurs in a high proportion of patients with severe CAP. This finding highlights the importance of measuring cortisol levels and may help explain the potential benefits of hydrocortisone infusion in these patients.

Effect of low doses of corticosteroids in septic shock patients with or without early acute respiratory distress syndrome

OBJECTIVE

We investigated the efficacy of low doses of corticosteroids in septic shock patients with or without early acute respiratory distress syndrome (ARDS) by post hoc analysis of a previously completed clinical trial.

DESIGN

Retrospective analysis of a placebo-controlled, randomized, double-blind trial of low doses of corticosteroids in septic shock.

SETTING

Nineteen intensive care units in France.

PATIENTS

Among the 300 septic shock patients enrolled, we selected those meeting standard criteria for ARDS at inclusion.

INTERVENTIONS

Seven-day treatment with 50 mg of hydrocortisone every 6 hrs and 50 microg of 9-alpha-fludrocortisone once a day.

MEASUREMENTS AND MAIN RESULTS

There were 177 patients with ARDS (placebo, n = 92; corticosteroids, n = 85) including 129 (placebo, n = 67; corticosteroids, n = 62) nonresponders and 48 (placebo, n = 25; corticosteroids, n = 23) responders. In nonresponders, there were 50 deaths (75%) in the placebo group and 33 deaths (53%) in the steroid group (hazard ratio 0.57, 95% confidence interval 0.36-0.89, p = .013; relative risk 0.71, 95% confidence interval 0.54-0.94, p = .011). The number of days alive and off the ventilator was 2.6 +/- 6.6 in the placebo group and 5.7 +/- 8.6 in the steroid group (p = .006). There was no significant difference between groups in responders. There was no significant difference between groups in the two subsets of patients without ARDS. Adverse events rates were similar in the two groups.

CONCLUSIONS

This post hoc analysis shows that a 7-day treatment with low doses of corticosteroids was associated with better outcomes in septic shock-associated early ARDS nonresponders, but not in responders and not in septic shock patients without ARDS.

Relative Adrenal Failure in the ICU: An Identifiable Problem Requiring Treatment

Critically ill patients at some stage may develop adrenal insufficiency (AI). This article reviews the mechanisms, diagnosis criteria, consequences, and treatment of AI in various ICU conditions. Glucocorticoid insufficiency may be related to a decrease in glucocorticoid synthesis (ie, adrenal insufficiency) or to a reduced delivery of glucocorticoid to target tissues and cells. Diagnosis relies on clinical suspicion and ACTH test results. The length of cortisol replacement therapy should be at least 7 days and the adjunction of fludrocortisone is recommended.

Low-dose hydrocortisone improves shock reversal and reduces cytokine levels in early hyperdynamic septic shock

OBJECTIVES

To investigate the effect of low-dose hydrocortisone on time to shock reversal, the cytokine profile, and its relation to adrenal function in patients with early septic shock.

DESIGN

Prospective, randomized, double-blind, single-center study.

SETTING

Medical intensive care unit of a university hospital.

PATIENTS

Forty-one consecutive patients with early hyperdynamic septic shock.

INTERVENTIONS

After inclusion and a short adrenocorticotropic hormone test, all patients were randomized to receive either low-dose hydrocortisone (50-mg bolus followed by a continuous infusion of 0.18 mg/kg body of weight/hr) or matching placebo. After shock reversal, the dose was reduced to 0.06 mg/kg/hr and afterward slowly tapered. Severity of illness was estimated using Acute Physiology and Chronic Health Evaluation II score and Sequential Organ Failure Assessment score.

MEASUREMENTS AND MAIN RESULTS

Time to cessation of vasopressor support (primary end point) was significantly shorter in hydrocortisone-treated patients compared with placebo (53 hrs vs. 120 hrs, p < .02). This effect was more profound in patients with impaired adrenal reserve. Irrespective of endogenous steroid production, cytokine production was reduced in the treatment group with lower plasma levels of interleukin-6 and a diminished ex vivo lipopolysaccharide-stimulated interleukin-1 and interleukin-6 production. Interleukin-10 levels were unaltered. Adverse events were not more frequent in the treatment group.

CONCLUSIONS

Treatment with low-dose hydrocortisone accelerates shock reversal in early hyperdynamic septic shock. This was accompanied by reduced production of proinflammatory cytokines, suggesting both hemodynamic and immunomodulatory effects of steroid treatment. Hemodynamic improvement seemed to be related to endogenous cortisol levels, whereas immune effects appeared to be independent of adrenal reserve.

Cell adhesion molecules as a marker reflecting the reduction of endothelial activation induced by glucocorticoids

In vitro, steroids down-regulate the expression of cell adhesion molecules (CAMs) in endothelial cells stimulated by lipopolysaccharide. Low-dose hydrocortisone is a new treatment of patients with septic shock, a state that is characterized by an endothelial injury. The aim of the present study was to investigate whether the plasma levels of soluble CAMs, reflecting in vivo endothelial activation, could be modulated in patients with septic shock treated by hydrocortisone. This was a prospective and observational study conducted in the intensive care unit at a university hospital. The subjects included 40 patients with septic shock (American College of Chest Physicians Consensus Conference/Society of Critical Care Medicine definition); 45 healthy blood donors served as controls. The patients receiving the standard care ("reference group") during the first 6 months were compared with the patients receiving the hydrocortisone therapy ("hydrocortisone group") for the next 6 months. Measurements of sCAMs were performed on days 1 and 3 of the disease. On day 1, sE-selectin, sP-selectin, sVCAM-1, and sICAM-1 were significantly elevated in patients with septic shock compared with healthy donors. sE-selectin levels significantly decreased between days 1 and 3 in the "hydrocortisone group," whereas there was no significant change in the "reference group". Surprisingly, sICAM-1 levels significantly increased between days 1 and 3 only in patients treated by hydrocortisone. No significant changes were observed for sP-selectin and sVCAM-1 levels in the two groups. In patients with septic shock, glucocorticoids differently affected the pattern of evolution of sCAMs, with sE-selectin being decreased and sICAM-1 being increased. Expression of sP-selectin and sVCAM-1 was not affected.

Management of adrenal insufficiency in different clinical settings

Adrenal insufficiency is a rare disease, but its prevalence is increasing. The most frequent cause of primary adrenal insufficiency in western countries is autoimmune adrenalitis, whereas secondary adrenal insufficiency is most often caused by pituitary tumours and their treatment (e.g., surgery). Chronic glucocorticoid replacement consists of hydrocortisone 15-25 mg/day in divided doses and dose monitoring is largely based on clinical judgement. Fludrocortisone 0.05-0.2 mg/day is given for substitution in mineralocorticoid deficiency aiming at normotension, normokalaemia and a plasma renin activity in the upper normal range. It has recently been shown that, despite adequate glucocorticoid and mineralocorticoid replacement well being in patients with adrenal insufficiency is still impaired. Several studies have demonstrated that dehydroepiandosterone 25-50 mg/day p.o. may improve mood, fatigue, well-being and, in women, also sexuality, suggesting that dehydroepiandosterone should become part of the standard treatment regime. However, large Phase III trials of dehydroepiandosterone for adrenal insufficiency are still lacking and it has not yet been approved for the treatment of this disease. Patients with adrenal insufficiency are at risk of adrenal crisis, usually precipitated by major stress, such as severe infection or surgery. Early dose adjustments are required to cover the increased glucocorticoid demand in stress. Careful and repeated education of patients and their partners is the best strategy to avoid this life-threatening emergency. Some recent studies suggest that during sepsis some patients with intact adrenal function may develop transient relative adrenal insufficiency and benefit from administration of hydrocortisone plus fludrocortisone. However, the pathophysiology and diagnosis criteria of relative adrenal insufficiency and its treatment remain unsettled issues.

The immuno-inflammatory response to trauma

The systemic inflammatory response syndrome is a well recognized physiological entity being part of our homeostatic mechanisms. It represents the cascade of inflammatory reactions initiated in the immediate aftermath following trauma reflecting the state of alertness that our body undergoes in order to fight for survival. A variety of inflammatory mediators and cellular elements are involved during this process interacting amongst each other. This allows communication between the different organ systems and thus regulating local and systemic responses. We have just begun to characterize and quantify the immuno-inflammatory response to trauma and this has opened new horizons in the way we understand the pathophysiological response to injury. As our knowledge evolves new therapeutic agents and innovative treatment plans will be developed contributing to increased survival rates in patients with multiple injuries.

Glucocorticoids in the treatment of severe sepsis and septic shock

PURPOSE OF REVIEW

Septic shock remains one of the leading causes of death in intensive care units. In recent years, there is general use of low to moderate doses of corticosteroids in the treatment of septic shock. However, there are wide variations in the practical modality of this treatment, mainly with regard to patients' selection, treatment's dose, timing, route of administration, duration, and weaning. This review provides opinion-based guidelines for the use of corticosteroids in severe sepsis and septic shock.

RECENT FINDINGS

A summary of the latest understanding of the mechanisms of action of corticosteroids and the most recent observations in the clinical and biologic responses to corticosteroids in severe sepsis and septic shock is presented.

SUMMARY

In septic shock, intravenous hydrocortisone should be started immediately after a 250 microg corticotropin test, at a dose of 200-300 mg per day. When adrenal insufficiency is confirmed, treatment should be continued at full doses for 7 days. Otherwise, hydrocortisone should be stopped. It is worth considering adding enteral fludrocortisone at a dose of 50 microg per day for 7 days. In severe sepsis, despite growing evidence to support the use of a moderate dose of corticosteroids, the efficacy and safety of this treatment needs to be assessed in a large-scale study.

[Adrenal cortex and steroids. Supplementary therapy in the perioperative phase]

Since the publication of two case reports that are considered to represent the first clinical demonstration of iatrogenic adrenal insufficiency, it has been the generally accepted practice to cover steroid-treated patients undergoing surgery with glucocorticoids in the perioperative period. Both the inclusion criteria for the patients and the extent of the substitution pattern have been selected on an empirical rather than on a rational basis. Scientific advances over the past 50 years in the knowledge of the hypothalamic-pituitary-adrenal system's physiology and the molecular mechanism of action of its biologically active components are, for the most part, not reflected in current clinical practice and instead seem to be ignored. Clinical and experimental evidence suggests, however, that even glucocorticoid-treated patients undergoing surgery do not require maximum stress doses of hydrocortisone, which should be reserved for the treatment of sepsis. With regard to the broad spectrum of efficacy of glucocorticoids and their side effects, revision and modification of the historical regimen appear prudent.

Low-dose steroid therapy at an early phase of postoperative acute respiratory distress syndrome

BACKGROUND

The acute respiratory distress syndrome (ARDS) that develops after thoracic surgery is usually lethal. The use of corticosteroids to treat ARDS has been the subject of great controversy.

METHODS

Therefore we compared conventional therapy with early low-dose steroid therapy in the treatment of postoperative ARDS. Methylprednisolone was given daily as an intravenous push every 6 hours and was changed to a single oral dose or discontinued, with a loading dose of 2 mg/kg followed by 2 mg/kg per day.

RESULTS

Over 2.5 years, 523 major thoracic operations were performed with postoperative ARDS developing in 20 patients (3.8%), of which 8 were treated with conventional therapy and 12 with early low-dose steroid therapy. Early low-dose steroid therapy significantly reduced postoperative mortality, with 7 patients (58.3%) recovering without mechanical ventilation.

CONCLUSIONS

We believe this is the first clinical study of low-dose methylprednisolone at an early phase of postoperative ARDS. The beneficial effects of the use of early low-dose steroids in ARDS are consistent with the hypothesis that fibroproliferation is an early response to lung injury, which is inhibited by early low-dose steroid therapy without disturbing operative wound healing.

Treatment of severe acute respiratory syndrome

The best treatment strategy for severe acute respiratory syndrome (SARS) is still unknown. Ribavirin and corticosteroids were used extensively during the SARS outbreak. Ribavirin has been criticized for its lack of efficacy. Corticosteroids are effective in lowering the fever and reversing changes in the chest radiograph but have the caveat of encouraging viral replication. The effectiveness of corticosteroids has only been suggested by uncontrolled observations, and the role of these agents in therapy remains to be established by randomized controlled studies. Both ribavirin and corticosteroids have very significant side effects. The lopinavir/ritonavir combination has been shown to reduce the intubation rate and the incidence of adverse clinical outcomes when used with ribavirin. When patients deteriorate clinically despite treatment with ribavirin and corticosteroids, rescue treatment with convalescent plasma and immunoglobulin may be beneficial. Noninvasive positive pressure ventilation is a sound treatment for SARS patients with respiratory failure if administered with due precaution in the correct environment. Interferons and other novel agents may hold promise as useful anti-SARS therapies in the future. The experience with traditional Chinese medicine is encouraging, and its use as an adjuvant should be further investigated.

Improved diagnostic approaches to infection/sepsis detection

Sepsis is a major healthcare problem from the perspective of mortality and economics. Advances in diagnostic detection of infection and sepsis have been slow, but recent advances in both soluble biomarker detection and quantitative cellular measurements promise the availability of improved diagnostic techniques. Though the promise of cytokine measurements reaching clinical practice have not matured, procalcitonin levels are currently available in many countries and appear to offer enhanced diagnostic distinction between bacterial and viral etiologies. Cellular diagnostics is poised to enter clinical laboratory practice in the form of neutrophil CD64 measurements, which offer superior sensitivity and specificity to conventional laboratory assessment of sepsis. Neutrophil CD64 expression is negligible in the healthy state. However, it increases as part of the systemic response to severe infection or sepsis. The combination of cellular proteomics, as in the case of neutrophil CD64 quantification, and selected soluble biomarkers of the inflammatory response, such as procalcitonin or triggering receptor expressed on myeloid cells (TREM)-1, is predicted to remove the current subjectivity and uncertainty in the diagnosis and therapeutic monitoring of infection and sepsis.

Histocompatibility leukocyte antigen-D related expression is specifically altered and predicts mortality in septic shock but not in other causes of shock

Although the expression of monocyte histocompatibility leukocyte antigen (HLA)-DR has been shown to be decreased during human sepsis, its level of expression in other nonseptic critical conditions is unclear. The aim of this study was to compare the level of HLA-DR expression on circulating monocytes among patients with septic, hemorrhagic, and cardiogenic shocks and severe sepsis without shock. At admission, HLA-DR expression was exclusively decreased in patients with septic shock (n = 30; P < 0.001), whereas the expression was similar between the other studied groups: cardiogenic shock (n = 16), hemorrhagic shock (n = 11), severe sepsis without shock (n = 18), and healthy volunteers (n = 8). HLA-DR expression was not predictive for overall mortality, but at day 1, an HLA-DR expression of less than 14 of mean fluorescence intensity (that corresponds to 40% labeled monocytes) was predictive of mortality exclusively in patients with septic shock (odds ratio, 11.4 and 95% confidence interval, 1.7; 78.4; P < 0.008). Catecholamine infusion, mechanical ventilation, positive blood culture, and number of units of blood or plasma transfused did not correlate with decreased HLA-DR expression. Thus, the decrease in HLA-DR expression is specific to septic shock and is associated, in septic shock patients, with increased mortality risk.