Clinical review: corticotherapy in sepsis

How Would You Resuscitate This Patient With Septic Shock? : Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Sepsis is a potentially life-threatening systemic dysregulatory response to infection, and septic shock occurs when sepsis leads to systemic vasodilation and subsequent tissue hypoperfusion. The Surviving Sepsis Campaign published updated guidelines in 2021 on the management of sepsis and septic shock. Here, in the context of a patient with septic shock, 2 critical care specialists discuss and debate conditional guideline recommendations on using lactate to guide resuscitation, the use of balanced crystalloids versus normal saline, and the use of corticosteroids.

Analysis of risk factors of fungal superinfections in viral pneumonia patients: A systematic review and meta-analysis

BACKGROUND

Infections with fungi, such as Aspergillus species, have been found as common complications of viral pneumonia. This study aims to determine the risk factors of fungal superinfections in viral pneumonia patients using meta-analysis.

OBJECTIVE

This study aims to determine the risk factors of fungal infection s in viral pneumonia patients using meta-analysis.

METHODS

We reviewed primary literature about fungal infection in viral pneumonia patients published between January 1, 2010 and September 30, 2020, in the Chinese Biomedical Literature, Chinese National Knowledge Infrastructure, Wanfang (China), Cochrane Central Library, Embase, PubMed, and Web of Science databases. These studies were subjected to an array of statistical analyses, including risk of bias and sensitivity analyses.

RESULTS

In this study, we found a statistically significant difference in the incidence of fungal infections in viral pneumonia patients that received corticosteroid treatment as compared to those without corticosteroid treatment (p < .00001). Additionally, regarding the severity of fungal infections, we observed significant higher incidence of invasive pulmonary aspergillosis (IPA) in patients with high Acute Physiology and Chronic Health Evaluation (APACHE) II scores (p < .001), tumors (p = .005), or immunocompromised patients (p < .0001).

CONCLUSIONS

Our research shows that corticosteroid treatment was an important risk factor for the development of fungal infection in patients with viral pneumonia. High APACHE II scores, tumors, and immunocompromised condition are also important risk factors of developing IPA. The diagnosis of fungal infection in viral pneumonia patients can be facilitated by early serum galactomannan (GM) testing, bronchoalveolar lavage fluid Aspergillus antigen testing, culture, and biopsy.

Review of Postoperative Care for Heart Transplant Recipients

The early postoperative management strategies after heart transplantation include optimizing the function of the denervated heart, correcting the causes of hemodynamic instability, and initiating and maintaining immunosuppressive therapy, allograft rejection surveillance, and prophylaxis against infections caused by immunosuppression. The course of postoperative support is influenced by the quality of allograft myocardial protection prior to implantation and reperfusion, donor-recipient heart size matching, surgical technique of orthotopic heart transplantation, and patient factors (eg, preoperative condition, immunologic compatibility, postoperative vasomotor tone, severity and reversibility of pulmonary vascular hypertension, pulmonary function, mediastinal blood loss, and end-organ perfusion). This review provides an overview of the early postoperative care of recipients and includes a brief description of the surgical techniques for orthotopic heart transplantation.

Glucocorticoid Treatment Strategies in Liver Failure

Liver failure is characterized by serious liver decompensation and high mortality. The activation of systemic immune responses and systemic inflammation are widely accepted as the core pathogenesis of liver failure. Glucocorticoids (GCs) are most regularly utilized to suppress excessive inflammatory reactions and immunological responses. GCs have been used in the clinical treatment of liver failure for nearly 60 years. While there has been no unanimity on the feasibility and application of GC treatment in liver failure until recently. The most recent trials have produced conflicting results when it comes to the dose and time for GC therapy of different etiology of liver failure. Our review outlines the issues and options in managing GC treatment in liver failure based on an investigation of the molecular mechanism that GC may give in the treatment.

Characterization of Systemic and Regional Hemodynamics and Vascular Dysfunction in Mice with Fecal Induced Peritonitis

Sepsis is associated with circulatory dysfunction contributing to disturbed blood flow and organ injury. Decreased organ perfusion in sepsis is attributed, in part, to the loss of vasoregulatory mechanisms. Identifying which vascular beds are most susceptible to dysfunction is important for monitoring the recovery of organ function and guiding interventions. This study aimed to investigate the development of vascular dysfunction as sepsis progressed to septic shock. Anesthetized C57Bl/6 mice were instrumented with a fiberoptic pressure sensor in the carotid artery for blood pressure measurements. In subgroups of mice, regional blood flow measurements were taken by positioning a perivascular flow probe around either the left carotid, left renal, or superior mesenteric arteries. Hemodynamic parameters and their responsiveness to bolus doses of vasoactive drugs were recorded prior to and continuously after injection of fecal slurry (1.3 mg/g body weight) for 4 h. Fecal slurry-induced peritonitis reduced mean arterial pressure (62.7 ± 2.4 mmHg vs. 37.5 ± 3.2 mmHg in vehicle and septic mice, respectively), impaired cardiac function, and eventually reduced organ blood flow (71.9%, 66.8%, and 65.1% in the superior mesenteric, renal, and carotid arteries, respectively). The mesenteric vasculature exhibited dysregulation before the renal and carotid arteries, and this underlying dysfunction preceded the blood pressure decline and impaired organ blood flow.

Hemodynamic dysfunction in neonatal sepsis

Cardiovascular disturbances are a frequent occurrence in neonatal sepsis. Preterm and term infants are particularly vulnerable due to the unique features of their cardiovascular function and reserve, compared to older children and adults. The clinical manifestations of neonatal sepsis are a product of the variable inflammatory pathways involved (warm vs. cold shock physiology), developmental state of the cardiovascular system, and hormonal responses. Targeted neonatal echocardiography has played an important role in advancing our knowledge, may help delineate specific hemodynamic phenotypes in real-time, and supports an individualized physiology-based management of sepsis-associated cardiovascular dysfunction. IMPACT: Cardiovascular dysfunction is a common sequela of sepsis. This review aims to highlight the pathophysiological mechanisms involved in hemodynamic disturbance in neonatal sepsis, provide insights from targeted neonatal echocardiography-based clinical studies, and suggest its potential incorporation in day-to-day management.

Fluid Resuscitation for Refractory Hypotension

Hypotension is a common occurrence, especially in anesthetized patients and in critical patients suffering from hypovolemia due to shock and sepsis. Hypotension can also occur in normovolemic animals, anesthetized or conscious, under conditions of vasodilation or decreased cardiac function. The main consequence of hypotension is decreased organ perfusion and tissue injury/dysfunction. In the human literature there is no consensus on what is the threshold value for hypotension, and ranges from < 80 to < 100 mmHg for systolic blood pressure and from < 50 to < 70 mmHg for mean arterial blood pressure have been referenced for intraoperative hypotension. In veterinary medicine, similar values are referenced, despite marked differences in normal arterial blood pressure between species and with respect to humans. Therapeutic intervention involves fluid therapy to normalize volemia and use of sympathomimetics to enhance cardiac function and regulate peripheral vascular resistance. Despite these therapeutic measures, there is a subset of patients that are seemingly refractory and exhibit persistent hypotension. This review covers the physiological aspects that govern arterial blood pressure control and blood flow to tissues/organs, the pathophysiological mechanisms involved in hypotension and refractory hypotension, and therapeutic considerations and expectations that include proper interpretation of cardiovascular parameters, fluid recommendations and therapy rates, use of sympathomimetics and vasopressors, and newer approaches derived from the human literature.

Hemoadsorption during Cardiopulmonary Bypass in Patients with Endocarditis Undergoing Valve Surgery: A Retrospective Single-Center Study

Background: Aim of this study was to evaluate the outcomes of endocarditis patients undergoing valve surgery with the Cytosorb^® hemoadsorption (HA) device during cardiopulmonary bypass. Methods: From 2009 until 2019, 241 patients had undergone valve surgery due to endocarditis at the Department of Cardiac Surgery, University Hospital of Basel. We compared patients who received HA during surgery (n = 41) versus patients without HA (n = 200), after applying inverse probability of treatment weighting. Results: In-hospital mortality, major adverse cardiac and cerebrovascular events and postoperative renal failure were similar in both groups. Demand for norepinephrine (88.4 vs. 52.8%; p = 0.001), milrinone (42.2 vs. 17.2%; p = 0.046), red blood cell concentrates (65.2 vs. 30.6%; p = 0.003), and platelets (HA vs. Control: 36.7 vs. 9.8%; p = 0.013) were higher in the HA group. In addition, a higher incidence of reoperation for bleeding (34.0 vs. 7.7 %; p = 0.011), and a prolonged length of in-hospital stay (15.2 (11.8 to 19.6) vs. 9.0 (7.1 to 11.3) days; p = 0.017) were observed in the HA group. Conclusions: No benefits of HA-therapy were observed in patients with infective endocarditis undergoing valve surgery.

Impact of corticosteroid treatment on clinical outcomes of influenza-associated ARDS: a nationwide multicenter study

Background

Corticosteroid treatment has been widely used in the treatment of septic shock, influenza, and ARDS, although some previous studies discourage its use in severe influenza patients. This multicenter retrospective cohort study conducted in the intensive care units (ICUs) of eight medical centers across Taiwan aims to determine the real-world status of corticosteroid treatment in patients with influenza-associated acute respiratory distress syndrome (ARDS) and its impact on clinical outcomes. Between October 2015 and March 2016, consecutive ICU patients with virology-proven influenza infections who fulfilled ARDS and received invasive mechanical ventilation were enrolled. The impact of early corticosteroid treatment (≥ 200 mg hydrocortisone equivalent dose within 3 days after ICU admission, determined by a sensitivity analysis) on hospital mortality (the primary outcome) was assessed by multivariable logistic regression analysis, and further confirmed in a propensity score-matched cohort.

Results

Among the 241 patients with influenza-associated ARDS, 85 (35.3%) patients receiving early corticosteroid treatment had similar baseline characteristics, but a significantly higher hospital mortality rate than those without early corticosteroid treatment [43.5% (37/85) vs. 19.2% (30/156), p < 0.001]. Early corticosteroid treatment was independently associated with increased hospital mortality in overall patients [adjusted odds ratio (95% CI) = 5.02 (2.39–10.54), p < 0.001] and in all subgroups. Earlier treatment and higher dosing were associated with higher hospital mortality. Early corticosteroid treatment was associated with a significantly increased odds of subsequent bacteremia [adjusted odds ratio (95% CI) = 2.37 (1.01–5.56)]. The analyses using a propensity score-matched cohort showed consistent results.

Conclusions

Early corticosteroid treatment was associated with a significantly increased hospital mortality in adult patients with influenza-associated ARDS. Earlier treatment and higher dosing were associated with higher hospital mortality. Clinicians should be cautious while using corticosteroid treatment in this patient group.

Chronopharmacology of glucocorticoids

Glucocorticoids influence a wide array of metabolic, anti-inflammatory, immunosuppressive, and cognitive signaling processes, playing an important role in homeostasis and preservation of normal organ function. Synthesis is regulated by the hypothalamic-pituitary-adrenal (HPA) axis of which cortisol is the primary glucocorticoid in humans. Synthetic glucocorticoids are important pharmacological agents that augment the anti-inflammatory and immunosuppressive properties of endogenous cortisol and are widely used for the treatment of asthma, Crohn's disease, and rheumatoid arthritis, amongst other chronic conditions. The homeostatic activity of cortisol is disrupted by the administration of synthetic glucocorticoids and so there is interest in developing treatment options that minimize HPA axis disturbance while maintaining the pharmacological effects. Studies suggest that optimizing drug administration time can achieve this goal. The present review provides an overview of endogenous glucocorticoid activity and recent advances in treatment options that have further improved patient safety and efficacy with an emphasis on chronopharmacology.

The pituitary gland prevents shock-associated death by controlling multiple inflammatory mediators

Bacterial infections cause a major burden of disease worldwide. Sepsis and septic shock are life-threatening complications of infections. The hypothalamic-pituitary-adrenal (HPA) axis initiates the release of endogenous glucocorticoids that modulate the host stress response and acute inflammation during septic shock. It is an ongoing controversial debate, if therapeutic manipulations of the HPA axis could benefit the clinical situation in the context of shock. Here, we have studied Long Evans rats with hypophysectomy followed by endotoxic shock. The shock-associated lethality was substantially higher in hypophysectomized rats as compared to control mice after cranial sham surgery (7-day survival rates: 27% vs. 89%). Fluorimetric bead-based assays were used to quantify the release of >20 cytokines and chemokines. The surgical removal of the pituitary gland resulted in greatly increased plasma concentrations of mediators such as IL-1α/IL-1β (10-12-fold), TNFα (19-fold), IL-6 (111-fold), IL-10 (10-fold) as well as the Th1 cytokines, Interferon-γ (8-fold), IL-12 (4-fold) and IL-18 (9-fold) after intra-peritoneal lipopolysaccharide (LPS) injections. In contrast, MIP-1α and Leptin were negatively associated with hypophysectomy. The Th2 cytokines, IL-4 and IL-13, as well as G-CSF, VEGF, IP-10 and RANTES were not significantly affected. The gene expression of the IL-6/IL-12 family cytokine, IL-27p28 was profoundly increased after pituitary gland removal followed by endotoxic shock. A dose-dependent reduction of LPS/TLR4-induced IL-27p28 release by glucococorticoids was observed in cultured rodent macrophages (C57BL/6J) as well as in vivo. This study reveals that the neuroendocrine influences of the HPA axis on the shock-associated inflammatory response are more selective and complex than previously known. These findings will be helpful to predict some of the consequences of therapeutic manipulations of the HPA in the context of sepsis and septic shock.

Definitions and pathophysiology of vasoplegic shock

Vasoplegia is the syndrome of pathological low systemic vascular resistance, the dominant clinical feature of which is reduced blood pressure in the presence of a normal or raised cardiac output. The vasoplegic syndrome is encountered in many clinical scenarios, including septic shock, post-cardiac bypass and after surgery, burns and trauma, but despite this, uniform clinical definitions are lacking, which renders translational research in this area challenging. We discuss the role of vasoplegia in these contexts and the criteria that are used to describe it are discussed. Intrinsic processes which may drive vasoplegia, such as nitric oxide, prostanoids, endothelin-1, hydrogen sulphide and reactive oxygen species production, are reviewed and potential for therapeutic intervention explored. Extrinsic drivers, including those mediated by glucocorticoid, catecholamine and vasopressin responsiveness of the blood vessels, are also discussed. The optimum balance between maintaining adequate systemic vascular resistance against the potentially deleterious effects of treatment with catecholamines is as yet unclear, but development of novel vasoactive agents may facilitate greater understanding of the role of the differing pathways in the development of vasoplegia. In turn, this may provide insights into the best way to care for patients with this common, multifactorial condition.

The Central Role of the Inflammatory Response in Understanding the Heterogeneity of Sepsis-3

In sepsis-3, in contrast with sepsis-1, the definition "systemic inflammatory response" has been replaced with "dysregulated host response", and "systemic inflammatory response syndrome" (SIRS) has been replaced with "sequential organ failure assessment" (SOFA). Although the definition of sepsis has changed, the debate regarding its nature is ongoing. What are the fundamental processes controlling sepsis-induced inflammation, immunosuppression, or organ failure? In this review, we discuss the heterogeneity of sepsis-3 and address the central role of inflammation in the pathogenesis of sepsis. An unbalanced pro- and anti-inflammatory response, inflammatory resolution disorder, and persistent inflammation play important roles in the acute and/or chronic phases of sepsis. Moreover, powerful links exist between inflammation and other host responses (such as the neuroendocrine response, coagulation, and immunosuppression). We suggest that a comprehensive evaluation of the role of the inflammatory response will improve our understanding of the heterogeneity of sepsis.

Guidelines for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in critically ill patients (Part I): Society of Critical Care Medicine (SCCM) and European Society of Intensive Care Medicine (ESICM) 2017

OBJECTIVE

To update the 2008 consensus statements for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in adult and pediatric patients.

PARTICIPANTS

A multispecialty task force of 16 international experts in Critical Care Medicine, endocrinology, and guideline methods, all of them members of the Society of Critical Care Medicine and/or the European Society of Intensive Care Medicine.

DESIGN/METHODS

The recommendations were based on the summarized evidence from the 2008 document in addition to more recent findings from an updated systematic review of relevant studies from 2008 to 2017 and were formulated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The strength of each recommendation was classified as strong or conditional, and the quality of evidence was rated from high to very low based on factors including the individual study design, the risk of bias, the consistency of the results, and the directness and precision of the evidence. Recommendation approval required the agreement of at least 80% of the task force members.

RESULTS

The task force was unable to reach agreement on a single test that can reliably diagnose CIRCI, although delta cortisol (change in baseline cortisol at 60 min of <9 µg/dl) after cosyntropin (250 µg) administration and a random plasma cortisol of <10 µg/dl may be used by clinicians. We suggest against using plasma free cortisol or salivary cortisol level over plasma total cortisol (conditional, very low quality of evidence). For treatment of specific conditions, we suggest using intravenous (IV) hydrocortisone <400 mg/day for ≥3 days at full dose in patients with septic shock that is not responsive to fluid and moderate- to high-dose vasopressor therapy (conditional, low quality of evidence). We suggest not using corticosteroids in adult patients with sepsis without shock (conditional recommendation, moderate quality of evidence). We suggest the use of IV methylprednisolone 1 mg/kg/day in patients with early moderate to severe acute respiratory distress syndrome (PaO₂/FiO₂ < 200 and within 14 days of onset) (conditional, moderate quality of evidence). Corticosteroids are not suggested for patients with major trauma (conditional, low quality of evidence).

CONCLUSIONS

Evidence-based recommendations for the use of corticosteroids in critically ill patients with sepsis and septic shock, acute respiratory distress syndrome, and major trauma have been developed by a multispecialty task force.

Corticosteroids in ARDS: The Never-Ending Story

This feature examines the impact of pharmacologic interventions on the treatment of the critically ill patient — an area of health care that has become increasingly complex. Recent advances in drug therapy (including evolving and controversial data) for adult intensive-care-unit patients will be reviewed and assessed in terms of clinical, humanistic, and economic outcomes.

CRH Affects the Phenotypic Expression of Sepsis-Associated Virulence Factors by Streptococcus pneumoniae Serotype 1 In vitro

Sepsis is a life-threatening health condition caused by infectious pathogens of the respiratory tract, and accounts for 28–50% of annual deaths in the US alone. Current treatment regimen advocates the use of corticosteroids as adjunct treatment with antibiotics, for their broad inhibitory effect on the activity and production of pro-inflammatory mediators. However, despite their use, corticosteroids have not proven to be able to reverse the death incidence among septic patients. We have previously demonstrated the potential for neuroendocrine factors to directly influence Streptococcus pneumoniae virulence, which may in turn mediate disease outcome leading to sepsis and septic shock. The current study investigated the role of Corticotropin-releasing hormone (CRH) in mediating key markers of pneumococcal virulence as important phenotypic determinants of sepsis and septic shock risks. In vitro cultures of serotype 1 pneumococcal strain with CRH promoted growth rate, increased capsule thickness and penicillin resistance, as well as induced pneumolysin gene expression. These results thus provide significant insights of CRH–pathogen interactions useful in understanding the underlying mechanisms of neuroendocrine factor's role in the onset of community acquired pneumonias (CAP), sepsis and septic shock.

Late-onset circulatory collapse of prematurity

Late-onset circulatory collapse (LCC) is a refractory hypotension occurring after the early neonatal period (>day 7), in very low-birthweight infants. Typically, infants stabilized within the early neonatal period develop sudden onset of circulatory collapse after the early neonatal period. The underlying pathophysiology of LCC is considered to be relative adrenal insufficiency, which is well known in Japan, but is not widely accepted in North America or Europe. The current increase in LCC in Japan suggests that the principal trigger is related to recent trends in neonatal medicine and/or newly introduced treatments for preterm infants, but the pathophysiology has not been fully elucidated. In this review, based on current knowledge regarding LCC, the pathophysiology is discussed.

Blinded randomised controlled trial of low-dose Adjuvant Steroids in Adults admitted to hospital with Pandemic influenza (ASAP): a trial 'in hibernation', ready for rapid activation

BACKGROUND

There are no completed randomised trials of the use of corticosteroids in patients with severe influenza infection. Corticosteroid use in influenza is widespread, non-systematic and marked by controversy. A recent meta-analysis of observational studies of adjuvant corticosteroids in influenza found an association with increased mortality but there were important concerns regarding the risks of bias.

OBJECTIVES

To (1) evaluate whether or not low-dose corticosteroids given as an adjunct to standard treatment is beneficial in patients who are hospitalised with severe pandemic influenza and (2) develop an 'off-the-shelf' clinical trial that is ready to be activated in a future pandemic.

DESIGN

Multicentre, pragmatic, blinded, randomised placebo-controlled trial.

SETTING

Thirty to 40 hospitals in the UK.

PARTICIPANTS

Adults (≥ 16 years) admitted to hospital with an influenza-like illness during a pandemic.

INTERVENTION

Five-day course of dexamethasone (Dexsol®, Rosemont Pharmaceuticals Ltd) 6 mg daily, started within 24 hours of admission.

MAIN OUTCOME MEASURE

Admission to Intensive Care Unit, or death, within 30 days of admission to hospital.

RESULTS

This trial has not yet been activated. It is currently set up with full ethics and regulatory approvals in place, ready for rapid activation at the onset of the next pandemic. Hurdles to setting up a pandemic trial include planning for pandemic-level pressures on UK NHS resources and co-enrolment of patients to multiple pandemic studies, ensuring adequate geographical distribution of participating sites, maintaining long-term low-level engagement with site investigators, addressing future trial-specific training needs of local investigators and resilience planning in trial management. Identified threats to trial delivery include changes to research capabilities or policies during the hibernation phase, lack of staff resources during a pandemic and the influence of media at the time of a pandemic. A mismatch in the approach to informed consent required by current regulations to that preferred by patients and the public was identified.

CONCLUSIONS

This study demonstrates that advance set-up of a trial to be conducted during a pandemic, with full regulatory approvals in place, is possible. Regular review during the hibernation phase will be required. This study serves as a model for the development of other 'off-the-shelf' trials as part of preparedness planning for public health emergencies.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN72331452. European Union Drug Regulating Authorities Clinical Trials number: 2013-001051-12.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 16. See the NIHR Journals Library website for further project information.

Impact of corticosteroids on experimental meningococcal sepsis in mice

Neisseria meningitidis is responsible for septicemia and meningitis with high fatality that is associated with an excessive inflammatory reaction particularly with hyperinvasive isolates of the clonal complex ST-11 (cc11). However, anti-inflammatory adjuvant treatment remains controversial and difficult to assess in patients. We addressed this topic in a well-defined experimental meningococcal infection in transgenic mice expressing the human transferrin. Mice were infected by intra-peritoneal challenge with bioluminescent serogroup C/cc11 strain. After 3h of infection mice were differentially treated every 6h by saline, amoxicillin alone or amoxicillin and dexamethasone (DXM). Infected mice were scored for clinical status, temperature and weight. Biological markers of inflammation were also quantified. Significant clinical improvement was observed in mice treated with amoxicillin and DXM compared to the two other groups. A significant reduction of the inflammatory reaction assessed by CRP and Lipocalin 2 (two acute phase proteins) was also observed with this treatment. DXM significantly increased blood levels of IL-10 at 6h post-infection. DXM/amoxicillin treated mice, compared to the two other groups, also showed lower levels of TNF-α and lower bacterial blood load assessed by serial dilutions of blood and bioluminescence dynamic imaging. Our results suggest that DXM, added to an appropriate antibiotic therapy, has a beneficial effect on experimental sepsis with a hyperinvasive meningococcal strain in transgenic mice expressing human transferrin. This is most likely due to the reduction of inflammatory response by an early induction of IL-10 cytokine. These data may allow better decision-making to use or not corticotherapy during meningococcal sepsis.

Brain-lung crosstalk: Implications for neurocritical care patients

Major pulmonary disorders may occur after brain injuries as ventilator-associated pneumonia, acute respiratory distress syndrome or neurogenic pulmonary edema. They are key points for the management of brain-injured patients because respiratory failure and mechanical ventilation seem to be a risk factor for increased mortality, poor neurological outcome and longer intensive care unit or hospital length of stay. Brain and lung strongly interact via complex pathways from the brain to the lung but also from the lung to the brain. Several hypotheses have been proposed with a particular interest for the recently described “double hit” model. Ventilator setting in brain-injured patients with lung injuries has been poorly studied and intensivists are often fearful to use some parts of protective ventilation in patients with brain injury. This review aims to describe the epidemiology and pathophysiology of lung injuries in brain-injured patients, but also the impact of different modalities of mechanical ventilation on the brain in the context of acute brain injury.

Glucocorticoids as an emerging pharmacologic agent for cardiopulmonary resuscitation

Although cardiac arrest (CA) constitutes a major health problem with dismal prognosis, no specific drug therapy has been shown to improve survival to hospital discharge. CA causes adrenal insufficiency which is associated with poor outcome and increased mortality. Adrenal insufficiency may manifest as an inability to increase cortisol secretion during and after cardiopulmonary resuscitation (CPR). Several studies suggest that glucocorticoids during and after CPR seem to confer benefits with respect to return of spontaneous circulation (ROSC) rates and long term survival. They have beneficial hemodynamic effects that may favor their use during CPR and in the early post-resuscitation period. Moreover, they have anti-inflammatory and anti-apoptotic properties that improve organ function by reducing ischemia/reperfusion (I/R) injury. However, glucocorticoid supplementation has shown conflicting results with regard to survival to hospital discharge and neurological outcome. The purpose of this article is to review the pathophysiology of hypothalamic-pituitary-adrenal (HPA) axis during CPR. Furthermore, this article reviews the effects of glucocorticoids use during CRP and the post-resuscitation phase.

Community-acquired pneumonia: identification and evaluation of nonresponders

Community acquired pneumonia (CAP) is a relevant public health problem, constituting an important cause of morbidity and mortality. It accounts for a significant number of adult hospital admissions and a large number of those patients ultimately die, especially the population who needed mechanical ventilation or vasopressor support. Thus, early identification of CAP patients and its rapid and appropriate treatment are important features with impact on hospital resource consumption and overall mortality. Although CAP diagnosis may sometimes be straightforward, the diagnostic criteria commonly used are highly sensitive but largely unspecific. Biomarkers and microbiological documentation may be useful but have important limitations. Evaluation of clinical response is also critical especially to identify patients who fail to respond to initial treatment since these patients have a high risk of in-hospital death. However, the criteria of definition of non-response in CAP are largely empirical and frequently markedly diverse between different studies. In this review, we aim to identify criteria defining nonresponse in CAP and the pitfalls associated with this diagnosis. We also aim to overview the main causes of treatment failure especially in severe CAP and the possible strategies to identify and reassess non-responders trying to change the dismal prognosis associated with this condition.

New insights into the anti-inflammatory mechanisms of glucocorticoids: an emerging role for glucocorticoid-receptor-mediated transactivation

Glucocorticoids are anti-inflammatory drugs that are widely used for the treatment of numerous (autoimmune) inflammatory diseases. They exert their actions by binding to the glucocorticoid receptor (GR), a member of the nuclear receptor family of transcription factors. Upon ligand binding, the GR translocates to the nucleus, where it acts either as a homodimeric transcription factor that binds glucocorticoid response elements (GREs) in promoter regions of glucocorticoid (GC)-inducible genes, or as a monomeric protein that cooperates with other transcription factors to affect transcription. For decades, it has generally been believed that the undesirable side effects of GC therapy are induced by dimer-mediated transactivation, whereas its beneficial anti-inflammatory effects are mainly due to the monomer-mediated transrepressive actions of GR. Therefore, current research is focused on the development of dissociated compounds that exert only the GR monomer-dependent actions. However, many recent reports undermine this dogma by clearly showing that GR dimer-dependent transactivation is essential in the anti-inflammatory activities of GR. Many of these studies used GR(dim/dim) mutant mice, which show reduced GR dimerization and hence cannot control inflammation in several disease models. Here, we review the importance of GR dimers in the anti-inflammatory actions of GCs/GR, and hence we question the central dogma. We summarize the contribution of various GR dimer-inducible anti-inflammatory genes and question the use of selective GR agonists as therapeutic agents.

Update on adrenal insufficiency in patients with liver cirrhosis

Liver cirrhosis is a major cause of mortality worldwide, often with severe sepsis as the terminal event. Over the last two decades, several studies have reported that in septic patients the adrenal glands respond inappropriately to stimulation, and that the treatment with corticosteroids decreases mortality in such patients. Both cirrhosis and septic shock share many hemodynamic abnormalities such as hyperdynamic circulatory failure, decreased peripheral vascular resistance, increased cardiac output, hypo-responsiveness to vasopressors, increased levels of proinflammatory cytokines [interleukine(IL)-1, IL-6, tumor necrosis factor-alpha] and it has, consequently, been reported that adrenal insufficiency (AI) is common in critically ill cirrhotic patients. AI may also be present in patients with stable cirrhosis without sepsis and in those undergoing liver transplantation. The term hepato-adrenal syndrome defines AI in patients with advanced liver disease with sepsis and/or other complications, and it suggests that it could be a feature of liver disease per se, with a different pathogenesis from that of septic shock. Relative AI is the term given to inadequate cortisol response to stress. More recently, another term is used, namely "critical illness related corticosteroid insufficiency" to define "an inadequate cellular corticosteroid activity for the severity of the patient's illness". The mechanisms of AI in liver cirrhosis are not completely understood, although decreased levels of high-density lipoprotein cholesterol and high levels of proinflammatory cytokines and circulatory endotoxin have been suggested. The prevalence of AI in cirrhotic patients varies widely according to the stage of the liver disease (compensated or decompensated, with or without sepsis), the diagnostic criteria defining AI and the methodology used. The effects of corticosteroid therapy on cirrhotic patients with septic shock and AI are controversial. This review aims to summarize the existing published information regarding AI in patients with liver cirrhosis.

Netherton's syndrome and lepromatous leprosy: a mere coincidence?

OBJECTIVES

Netherton's syndrome (NS) is a rare autosomal recessive condition, first described in 1958, which involves a complex immunological dysfunction, ichthyosiform dermatitis, and erythroderma, characteristic defects of the hair shaft and atopy. Recurrent bacterial infection in the skin of patients with NS is frequent.

METHODS

This paper represents the first case report of leprosy and concurrent NS.

DISCUSSION

This case merits discussion among doctors in endemic and non-endemic areas to evaluate the chronic use of systemic corticosteroids as a risk factor for leprosy. The present patient came from an endemic area of leprosy and was treated chronically with systemic corticosteroids for erythroderma. This treatment, along with the immunodeficiency related to the syndrome and caused by a genetic mutation in SPINK5, may be a facilitating factor for the infection.

Comparative analysis of hepatic CD14 expression between two different endotoxin shock model mice: relation between hepatic injury and CD14 expression

CD14 is a glycoprotein that recognizes gram-negative bacterial lipopolysaccharide (LPS) and exists in both membrane-bound and soluble forms. Infectious and/or inflammatory diseases induce CD14 expression, which may be involved in the pathology of endotoxin shock. We previously found that the expression of CD14 protein differs among the endotoxin shock models used, although the reasons for these differences are unclear. We hypothesized that the differences in CD14 expression might be due to liver injury, because the hepatic tissue produces CD14 protein. We investigated CD14 expression in the plasma and liver in the carrageenan (CAR)-primed and D-galN-primed mouse models of endotoxin shock. Our results showed that severe liver injury was not induced in CAR-primed endotoxin shock model mice. In this CAR-primed model, the higher mRNA and protein expression of CD14 was observed in the liver, especially in the interlobular bile duct in contrast to D-galN-primed-endotoxin shock model mice. Our findings indicated that the molecular mechanism(s) underlying septic shock in CAR-primed and D-galN-primed endotoxin shock models are quite different. Because CD14 expression is correlated with clinical observations, the CAR-primed endotoxin shock model might be useful for studying the functions of CD14 during septic shock in vivo.

Determining “In Control” Versus “Not in Control” Glucose Management of Medical/Surgical Community Hospital Patients

Purpose: To move beyond the correlation analysis between glucose statistics and patient outcome and to benchmark summary statistics calculated on all glucose values taken during an entire individual patient-stay. Method: The sample consisted of 141 patient-stays with multiple finger-stick blood glucose (BG) measurements resulting in 5,428 total BGs. Glucose control assessments of the BG profiles for each patient-stay were independently conducted by two endocrinologists. Summary statistics (mean, standard deviation, mean absolute glucose [MAG], percentage of hours of patient-stay with BG over threshold) were calculated for BG using patient-stay as the unit of analysis. Results: Produced numerical benchmarks for the mean (148mg/dL), SD (40mg/dL), MAG (6.2), and the percentage of patient-stay hours over 200mg/dL (10%). Specificity and sensitivity were high, ranging from 91% to 89% for specificity and from 90% to 81% for sensitivity. Conclusion: This study demonstrated that benchmarks developed on specific patient populations can be used to evaluate glycemic control in a straightforward, computationally simple system.

Hypocortisolism in noncomatose patients during the acute phase of subarachnoid hemorrhage

BACKGROUND

Hypopituitarism represents a common long-term complication of subarachnoid hemorrhage (SAH). The incidence of hypocortisolism may be higher during the acute phase of SAH. Although hypocortisolism may be harmful in critically ill SAH patients, data are still lacking. The primary objective of this study was to investigate the incidence of hypocortisolism during the acute phase of SAH (15 days). Secondary objectives included an analysis of the relationship between hypocortisolism and outcome and the computation of the cortisol-time secretion curve.

METHODS

Clinical data of a consecutive series of 26 noncomatose patients with aneurysmal SAH were collected prospectively. The sample size was calculated considering an expected proportion of hypocortisolism of 30%, a confidence level of 95%, and a total width of confidence interval of 0.35. The definition of hypocortisolism (as taken from a statement from the critical care medicine task forces) includes random total cortisol <10 μg/dL or a Δtotal serum cortisol <9 μg/dL after 1 μg of corticotrophin hormone.

RESULTS

Hypocortisolism was diagnosed in 11 patients (42.3%). Cortisol increment after stimulation test was always >9 μg/dl, suggesting a hypothalamic-pituitary impairment. Hypocortisolism was independently associated with a higher risk of poor outcome (P = .046) even after adjusting for age and Hunt and Hess grade. The cortisol-time secretion curve showed a peak at day 5 and a minimum at day 8. The peak at day 5 correlated with the risk of delayed cerebral ischemia (P = .001), and the cortisol concentration slope between days 1 and 8 correlated with the risk of poor outcome (P = .033).

CONCLUSIONS

Patients with SAH are at high risk of secondary hypocortisolism during the first 15 days after bleeding. Hypocortisolism independently increases the risk of poor outcome. The acute phase of hypothalamo-pituitary dysfunction, as reflected by an abnormal day-by-day cortisol secretion pattern, may affect the risk of delayed cerebral ischemia.

What is the role of steroids in pneumonia therapy?

PURPOSE OF REVIEW

This review evaluates the potential benefits as well as adverse effects from adjunctive therapy with systemic steroids in patients with pneumonia: either mild-to-moderate or severe, community-acquired or hospital-acquired, of bacterial or of viral origin (in particular H1N1 viral infection).

RECENT FINDINGS

Steroids potentially modulate the marked and persistent activation of the immune system in pneumonia. However, several recent randomized controlled trials and large prospective observational studies have repeatedly shown that steroids had no impact on survival, the clinical event of interest, but in severe pneumonia some studies pointed to potential harmful effect. In addition, adverse effects, namely hyperglycemia, superinfections, as well as increased length-of-stay, were frequent findings in the steroid-treated patients.

SUMMARY

According to the current evidence, there are no data to support the well tolerated use of systemic steroids as a standard of care in pneumonia, neither in mild-to-moderate and severe, nor in bacterial and viral infection. Clinical and basic research should work together to improve trial designs to identify reliable surrogate markers of outcome, in particular of mortality. This may improve the patient selection and facilitate the identification of subgroups that can benefit from adjunctive steroid therapy.

The role of the vagus nerve: modulation of the inflammatory reaction in murine polymicrobial sepsis

The particular importance of the vagus nerve for the pathophysiology of peritonitis becomes more and more apparent. In this work we provide evidence for the vagal modulation of inflammation in the murine model of colon ascendens stent peritonitis (CASP). Vagotomy significantly increases mortality in polymicrobial sepsis. This effect is not accounted for by the dilatation of gastric volume following vagotomy. As the stimulation of cholinergic receptors by nicotine has no therapeutic effect, the lack of nicotine is also not the reason for the reduced survival rate. In fact, increased septic mortality is a consequence of the absent modulating influence of the vagus nerve on the immune system: we detected significantly elevated serum corticosterone levels in vagotomised mice 24 h following CASP and a decreased ex vivo TNF-alpha secretion of Kupffer cells upon stimulation with LPS. In conclusion, the vagus nerve has a modulating influence in polymicrobial sepsis by attenuating the immune dysregulation.

Current pharmacological advances in the treatment of cardiac arrest

Cardiac arrest is defined as the sudden cessation of spontaneous ventilation and circulation. Within 15 seconds of cardiac arrest, the patient loses consciousness, electroencephalogram becomes flat after 30 seconds, pupils dilate fully after 60 seconds, and cerebral damage takes place within 90–300 seconds. It is essential to act immediately as irreversible damage can occur in a short time. Cardiopulmonary resuscitation (CPR) is an attempt to restore spontaneous circulation through a broad range of interventions which are early defibrillation, high-quality and uninterrupted chest compressions, advanced airway interventions, and pharmacological interventions. Drugs should be considered only after initial shocks have been delivered (when indicated) and chest compressions and ventilation have been started. During cardiopulmonary resuscitation, no specific drug therapy has been shown to improve survival to hospital discharge after cardiac arrest, and only few drugs have a proven benefit for short-term survival. This paper reviews current pharmacological treatment of cardiac arrest. There are three groups of drugs relevant to the management of cardiac arrest: vasopressors, antiarrhythmics, and other drugs such as sodium bicarbonate, calcium, magnesium, atropine, fibrinolytic drugs, and corticosteroids.

Endotoxin tolerance of adrenal gland: attenuation of corticosterone production in response to lipopolysaccharide and adrenocorticotropic hormone

OBJECTIVES

Reversible adrenal insufficiency frequently has been diagnosed in critically ill patients with sepsis who have either low basal cortisol levels or low cortisol responses to adrenocorticotropic hormone (ACTH) stimulation. It is generally accepted that a phenomenon called "endotoxin tolerance" contributes to immunosuppression during sepsis. The present study was to investigate whether endotoxin tolerance occurs in the adrenal gland, leading to hyporesponsiveness of adrenal gland during sepsis.

DESIGN

Controlled laboratory experiment.

SETTING

University research laboratory.

SUBJECTS

Sprague-Dawley male rats 200-250 g and primary isolated adrenal fasciculata-reticularis cells.

INTERVENTIONS

Rats received intra-arterial injection of purified lipopolysaccharide (0.5 mg/kg) through indwelling femoral arterial catheters, and 24 hrs later the adrenocortical sensitivity to exogenous ACTH (10 ng/kg) was detected. Primary fasciculata-reticularis cells were pretreated with lipopolysaccharide at 0.1-100 ng/mL or with ACTH at 0.01-10 ng/mL and then challenged, in fresh media, with 1 μg/mL lipopolysaccharide or 10 ng/mL ACTH.

MEASUREMENTS AND MAIN RESULTS

Toll-like receptor 4 was expressed in adrenal gland and primary fasciculata-reticularis cells. Plasma corticosterone response to ACTH was decreased in rats receiving preinjection of lipopolysaccharide. Lipopolysaccharide pretreatment caused a significant decrease in corticosterone production in response to subsequent ACTH and lipopolysaccharide stimulation in primary fasciculata-reticularis cells. Lipopolysaccharide pretreatment inhibited ACTH- and lipopolysaccharide-induced expression of steroid metabolizing enzymes. Lipopolysaccharide significantly decreased Toll-like receptor 4 and ACTH receptor expression.

CONCLUSIONS

Pre-exposure to lipopolysaccharide resulted in hyporesponsiveness to ACTH stimulation in rats. In vitro, lipopolysaccharide pretreatment impaired corticosterone production of fasciculata-reticularis cells in response to ACTH and lipopolysaccharide, which was associated with decreased expression of synthetic enzymes required for corticosterone production. Our results indicate that endotoxin tolerance of adrenal gland is one of the mechanisms for adrenocortical insufficiency during sepsis.

Vascular hyporesponsiveness to vasopressors in septic shock: from bench to bedside

PURPOSE

To delineate some of the characteristics of septic vascular hypotension, to assess the most commonly cited and reported underlying mechanisms of vascular hyporesponsiveness to vasoconstrictors in sepsis, and to briefly outline current therapeutic strategies and possible future approaches.

METHODS

Source data were obtained from a PubMed search of the medical literature with the following MeSH terms: Muscle, smooth, vascular/physiopathology; hypotension/etiology; shock/physiopathology; vasodilation/physiology; shock/therapy; vasoconstrictor agents.

RESULTS

Nitric oxide (NO) and peroxynitrite are crucial components implicated in vasoplegia and vascular hyporeactivity. Vascular ATP-sensitive and calcium-activated potassium channels are activated during shock and participate in hypotension. In addition, shock state is characterized by inappropriately low plasma glucocorticoid and vasopressin concentrations, a dysfunction and desensitization of alpha-receptors, and an inactivation of catecholamines by oxidation. Numerous other mechanisms have been individualized in animal models, the great majority of which involve NO: MEK1/2-ERK1/2 pathway, H(2)S, hyperglycemia, and cytoskeleton dysregulation associated with decreased actin expression.

CONCLUSIONS

Many therapeutic approaches have proven their efficiency in animal models, especially therapies directed against one particular compound, but have otherwise failed when used in human shock. Nevertheless, high doses of catecholamines, vasopressin and terlipressin, hydrocortisone, activated protein C, and non-specific shock treatment have demonstrated a partial efficiency in reversing sepsis-induced hypotension.

"Relative" adrenal insufficiency in critical illness

OBJECTIVE

To present a recommended approach to the problem of "relative" adrenal insufficiency (RAI) in the intensive care unit (ICU).

METHODS

We examine historical data that support the traditional concepts of adrenal insufficiency and the idea that the increase in cortisol secretion during stress is needed to survive the stress. The controversial use of treatment with glucocorticoids (GCs) in patients with sepsis and septic shock in the ICU (and thus survival benefit) is also briefly discussed.

RESULTS

During the past decade, the concept of RAI as the failure of cortisol secretion to increase in response to stress to sustain the patient through that stress has gained strength. In some studies, it has been suggested that as many as 75% of patients in an ICU setting have RAI. Experimental support for the concept is not possible because there is no clinically useful laboratory measure of GC action. Therefore, diagnosis is generally based on interpretation of the cosyntropin stimulation test.

CONCLUSION

The best clinical judgment should always guide interpretation of any test results, and sharp categorization of patients on the basis of a single cutoff criterion should be avoided. Overall, the concept of RAI has no clinical utility. In these cases, administration of GCs adds cost without benefit and with increased risk.

Has mortality from sepsis improved and what to expect from new treatment modalities: review of current insights

BACKGROUND

The incidence of sepsis is increasing continuously, making mortality rate reduction through improved intensive care unit (ICU) care and new treatment modalities a pressing issue. This study aimed to provide insight into the effects of modern ICU care on mortality trends from severe sepsis and to provide a quantitative review of the relative effectiveness of new treatment modalities in reducing deaths.

METHODS

Mortality data from severe sepsis were extracted from the control arms of several large randomized trials of sepsis treatment published within the last two decades. The effectiveness of recent treatment strategies was expressed as the number of patients it is necessary to treat by that method to save one life (number needed to treat: NNT).

RESULTS

Death from severe sepsis showed a decline from 44% to 35% between 1990 and 2000. The two most effective strategies in critically ill patients are early appropriate antibiotics (NNT 3; 95% confidence interval [CI] 2, 4) and early goal-directed therapy (NNT 6; 95% CI 4, 24). Infusion of recombinant human activated protein C is the most effective anticoagulant therapy (NNT 15; 95% CI 10, 27). Intensive insulin therapy is only moderately effective (NNT 27; 95% CI 15, 124).

CONCLUSIONS

The mortality rate from severe sepsis has decreased significantly with modernization of ICU care. New therapeutic strategies may reduce further the mortality rate. However, focused implementation of these new strategies in accordance with their relative effectiveness is needed before we can expect to see their true effect on mortality rates.

Tissue mRNA expression of the glucocorticoid receptor and its splice variants in fatal critical illness

BACKGROUND

Critical illness results in activation of the hypothalamic-pituitary-adrenal (HPA) axis, which might be accompanied by a peripheral adaptation in glucocorticoid sensitivity. Tissue sensitivity is determined by the active glucocorticoid receptor GRalpha, of which two splice variants involving the hormone-binding domain exist, GRbeta and GR-P.

OBJECTIVE

To study tissue mRNA expression of the GR and its splice variants in fatal critical illness.

DESIGN AND METHODS

We assessed mRNA expression of the GRalpha, GRbeta and GR-P variants in liver (n = 58) and muscle (n = 65) of patients who had died after intensive care, and had been randomized for insulin treatment. We analysed whether GR mRNA expression was associated with insulin treatment, cortisol levels and glucocorticoid treatment.

RESULTS

GRalpha and GR-P mRNA constituted 87 +/- 8% and 13 +/- 2%, respectively, of total GR mRNA in liver. GRbeta mRNA could only be amplified in five liver samples. All variants were present in most muscle samples (alpha = 96 +/- 11%, P = 3.9 +/- 0.4%, beta = 0.010 +/- 0.002%). GR expression was not associated with insulin therapy. A strong positive relationship was observed between the different GR variants in both liver and muscle (P < 0.001 for all). Serum cortisol levels were negatively associated with liver GRalpha and muscle GR-P expression (P < 0.05). mRNA expression of both liver GRalpha and GR-P, but not muscle GR, was substantially lower in patients who had received exogenous glucocorticoids (P < 0.01).

CONCLUSION

We demonstrate the presence of GRalpha and GR-P mRNA in liver and of GRalpha, GRbeta and GR-P mRNA in muscle, with no evidence for altered splicing in critical illness. In contrast to muscle GR, liver GR expression was substantially lower in patients receiving exogenous glucocorticoids.

Stratification is the key: inflammatory biomarkers accurately direct immunomodulatory therapy in experimental sepsis

OBJECTIVE

This study examined the effectiveness of prospective stratification to identify and target high-dose glucocorticoid therapy for subjects developing lethal sepsis.

DESIGN

Prospective, randomized, laboratory-controlled experiment.

SETTING

University research laboratory.

SUBJECTS

Adult female outbred CD-1 mice.

INTERVENTIONS

Mice (n = 88) were subjected to sepsis induced by cecal ligation and puncture (CLP). Mice were prospectively divided into two groups, predicted to die (P-DIE) or predicted to live (P-LIVE), based on plasma levels of interleukin (IL)-6 obtained 6 hours after CLP. Following stratification, dexamethasone (DEX, 2.5 mg/kg, two doses) was administered to half the animals in each group whereas the other half received saline.

MEASUREMENTS AND MAIN RESULTS

Without stratification, DEX conferred no benefit. In the P-DIE group, none of saline-treated mice lived whereas 40% of the DEX-treated mice survived. Of the nonsurvivors, 67% had death delayed by 24-48 hours compared with saline-treated mice. Twenty-four hours post-CLP, the lymphocyte count was higher in the P-DIE than in the P-LIVE mice regardless of treatment status, whereas the opposite trend was noted for neutrophils. Plasma cytokine and cytokine inhibitor levels in the saline-treated animals showed that levels in the P-DIE group were higher than those in the P-LIVE group (e.g., 60 vs. 10 ng/mL for IL-6 and 453 vs.129 ng/mL for IL-1 receptor antagonist). Interestingly, DEX therapy did not decrease 24 hours post-CLP circulating cytokines in either the P-DIE or the P-LIVE group.

CONCLUSIONS

Following CLP-induced sepsis, early and accurate survival prediction allows targeted immunosuppression that improves survival. Better survival occurred without suppression of the typical proinflammatory mediators, suggesting that the deaths were not mediated by excessive cytokine-driven inflammation. Nonspecific anti-inflammatory/immunosuppressive treatment administered to more rigorously defined cohorts may be more successful than mediator-specific drugs used indiscriminately.

Relative adrenal insufficiency in the preterm and term infant

Cortisol release in the face of illness or stress is vital for survival. Relative adrenal insufficiency occurs when a patient's cortisol response is inadequate for the degree of illness or stress. Numerous studies have documented the existence of relative adrenal insufficiency in critically ill adults, and its association with increased morbidity and mortality. There is increasing evidence that relative adrenal insufficiency may be an etiology for hemodynamic instability and hypotension in the critically ill newborn, but compared with the adult population, there is still a paucity of data in this population. Randomized controlled trials are needed to evaluate the efficacy and safety of glucocorticoids for the treatment of cardiovascular insufficiency due to relative adrenal insufficiency in ill preterm and term newborn infants.

Effects of steroids on reintubation and post-extubation stridor in adults: meta-analysis of randomised controlled trials

Introduction

The efficacy of steroid administration before planned tracheal extubation in critical care patients remains controversial with respect to the selection of patients most likely to benefit from this treatment.

Methods

We performed an extensive literature search for adult trials testing steroids versus placebo to prevent reintubation or laryngeal dyspnoea. Studies were evaluated on a five-point scale based on randomisation, double-blinding and follow-up. Our analysis included trials having a score three or higher with patients mechanically ventilated for at least 24 hours and treated with steroids before extubation, taking into account the time of their administration (early vs late) and if the population selected was at risk or not.

Results

Seven prospective, randomised, double-blinded trials, including 1846 patients, (949 of which received steroids) were selected. Overall, steroids significantly decreased the risk of reintubation (relative risk (RR) = 0.58, 95% confidence interval (CI) = 0.41 to 0.81; number-needed-to-treat (NNT) = 28, 95% CI = 20 to 61) and stridor (RR = 0.48, 95% CI = 0.26 to 0.87; NNT = 11, 95% CI = 8 to 42). The effect of steroids on reintubation and stridor was more pronounced for selected high-risk patients, as determined by a reduced cuff leak volume (RR = 0.38, 95% CI = 0.21 to 0.72; NNT = 9, 95% CI = 7 to 19; and RR = 0.40, 95% CI = 0.25 to 0.63; NNT = 5, 95% CI = 4 to 8, respectively). In contrast, steroid benefit was unclear when trials did not select patients for their risk of reintubation (RR = 0.67, 95% CI = 0.45 to 1.00; NNT = 44, 95% CI ≥ 26 to infinity) or stridor (RR = 0.56, 95% CI = 0.20 to 1.55).

Conclusions

The efficacy of steroids to prevent stridor and reintubation was only observed in a high-risk population, as identified by the cuff-leak test and when it was administered at least four hours before extubation. The benefit of steroids remains unclear when patients at high risk are not selected.

The adrenal cortex and life

The template for our understanding of the physiological role of the adrenal cortex was set by Hans Selye, who demonstrated its key involvement in the response to stress, of whatever origin, and who also introduced the terms glucocorticoid and mineralocorticoid. Despite this, from the late 1940s on there was certainly general awareness of the multiple actions of glucocorticoids, including effects on the thymus and immune system, cardiovascular system, water balance, and the CNS. For these reasons, and perhaps because in the early studies of the actions of individual steroids there was less clear-cut difference between them, there was some initial resistance to the use of these terms. Today they are universal and unchallenged. It can be argued that, with respect to the glucocorticoids, this term colours our perception of their physiological importance, and may be misleading. By taking evidence from disease states, emphasis is placed on extreme conditions that do not necessarily reveal normal physiology. In particular, evidence for the role of glucocorticoid regulation of gluconeogenesis and blood glucose in the normal subject or animal is inconclusive. Similarly, while highly plausible theories explaining glucocorticoid actions on inflammation or the immune system as part of normal physiology have been presented, direct evidence to support them is hard to find. Under extreme conditions of chronic stress, the cumulative actions of glucocorticoids on insulin resistance or immunocompromise may indeed seem to be actually damaging. Two well-documented and long recognized situations create huge variation in glucocorticoid secretion. These are the circadian rhythm, and the acute response to mild stress, such as handling, in the rat. Neither of these can be adequately explained by the need for glucocorticoid action, as we currently understand it, particularly on carbohydrate metabolism or on the immune system. Perhaps we should re-examine other targets at the physiological level. At the present time, some of these seem to be out of fashion.

Dexamethasone modulates Salmonella enterica serovar Typhimurium infection in vivo independently of the glucocorticoid-inducible protein annexin-A1

Salmonella enterica serovar Typhimurium (S. Typhimurium) infection causes an inflammatory response through activation of Toll-like receptor 4 by lipopolysaccharide. Dexamethasone, a glucocorticoid analogue, suppresses inflammatory responses by many mechanisms including inhibition of the lipopolysaccharide-induced production of proinflammatory mediators. There is little information on the effect of glucocorticoids on murine salmonellosis. In this study, we treated susceptible BALB/c mice by subcutaneous implantation of slow-release dexamethasone pellets before infection with S. Typhimurium. Dexamethasone promotes bacterial growth early in infection and induces a dose-dependent increase in bacterial growth within mouse livers and spleens. The bacterial load in organs from infected placebo-treated mice was lower than that in dexamethasone-treated mice. Glucocorticoids inhibit lipopolysaccharide-induced inflammation partially through the steroid-inducible protein annexin-A1 (ANXA1). Infection of wild-type and ANXA1 knock-out mice with S. Typhimurium led to similar organ bacterial loads. ANXA1 also did not affect the bacterial load in organs from infected dexamethasone-treated mice. This suggests that glucocorticoids, independently of ANXA1, accelerate S. Typhimurium growth in vivo in susceptible BALB/c mice.