The endocrine system during sepsis

Thyroid Profile in the First Three Months after Starting Treatment in Children with Newly Diagnosed Cancer

BACKGROUND

Thyroid hormone anomalies during childhood might affect neurological development, school performance and quality of life, as well as daily energy, growth, body mass index and bone development. Thyroid dysfunction (hypo- or hyperthyroidism) may occur during childhood cancer treatment, although its prevalence is unknown. The thyroid profile may also change as a form of adaptation during illness, which is called euthyroid sick syndrome (ESS). In children with central hypothyroidism, a decline in FT4 of >20% has been shown to be clinically relevant. We aimed to quantify the percentage, severity and risk factors of a changing thyroid profile in the first three months of childhood cancer treatment.

METHODS

In 284 children with newly diagnosed cancer, a prospective evaluation of the thyroid profile was performed at diagnosis and three months after starting treatment.

RESULTS

Subclinical hypothyroidism was found in 8.2% and 2.9% of children and subclinical hyperthyroidism in 3.6% and in 0.7% of children at diagnosis and after three months, respectively. ESS was present in 1.5% of children after three months. In 28% of children, FT4 concentration decreased by ≥20%.

CONCLUSIONS

Children with cancer are at low risk of developing hypo- or hyperthyroidism in the first three months after starting treatment but may develop a significant decline in FT4 concentrations. Future studies are needed to investigate the clinical consequences thereof.

Sepsis and Septic Shock - Basics of diagnosis, pathophysiology and clinical decision making

Sepsis and septic shock are major causes of mortality among hospitalized patients. The sepsis state is due to dysregulated host response to infection, leading to inflammatory damage to nearly every organ system. Early recognition of sepsis and appropriate treatment with antibiotics, fluids, and vasopressors is essential to reducing organ system injury and mortality. This review summarizes the current understanding of the epidemiology, pathophysiology, diagnosis, and treatment of sepsis and septic shock.

Free Thyroxine Determination in the Emergency Department Is a Predictor of Acute Pancreatitis Evolution

OBJECTIVE

The aim of this study was to determine the prevalence and type of thyroid hormone levels alterations in patients with acute pancreatitis (AP) and analyze if variations are useful AP progression predictors.

METHODS

Three groups of patients were analyzed: AP patients (n = 90), abdominal pain patients (n = 30), and healthy control subjects (n = 40). Usual blood parameters for AP diagnosis and prognosis, thyroid-stimulating hormone (or thyrotropin), FT4 (free thyroxine), FT3 (free triiodothyronine), and TT3 (total triiodothyronine) levels were analyzed.

RESULTS

Thyroid hormone level alterations were detected only within the AP group (41% of total cases), being the reduction in T3 levels the most frequently detected deviation (15.6% of FT3 and 8.3% of TT3 cases). Alterations were not influenced by age or sex. Free thyroxine average values were also significantly higher in the AP group, compared with the healthy control group (P = 0.0005), resulting as independent predictors of both severity and mortality. Mortality in this group was 50%, with deceased patients showing FT4 levels above the reference limit.

CONCLUSIONS

Our results show that FT4 level determination during the initial clinical evaluation of patients admitted to the emergency service with AP can be included as a severity indicator to help determine the differential care of these cases.

Reduced Insulin Resistance Contributes to the Beneficial Effect of Protein Tyrosine Phosphatase-1B Deletion in a Mouse Model of Sepsis

Hyperglycemia is a common feature of septic patients and has been associated with poor outcome and high mortality. In contrast, insulin has been shown to decrease mortality and to prevent the incidence of multiorgan failure but is often associated with deleterious hypoglycemia. Protein Tyrosine Phosphatase 1B (PTP1B) is a negative regulator of both insulin signaling and NO production, and has been shown to be an aggravating factor in septic shock. To evaluate the potential therapeutic effect of PTP1B blockade on glucose metabolism and insulin resistance in an experimental model of sepsis, we assessed the effect of PTP1B gene deletion in a cecal ligation and puncture (CLP) model of sepsis. PTP1B gene deletion significantly limited CLP-induced insulin resistance, improved AMP-activated protein kinase signaling pathway and Glucose Transporter 4 translocation, and decreased inflammation. These effects were associated with a reduction of sepsis-induced endothelial dysfunction/impaired NO production and especially of insulin-mediated dilatation. This modulation of insulin resistance may contribute to the beneficial effect of PTP1B blockade in septic shock, especially in terms of inflammation and cardiac metabolism.

[Adrenalitis]

Inflammation of the adrenal glands is caused by autoimmunopathies or infections and can induce adrenal insufficiency. Autoimmune lymphocytic adrenalitis is often combined with other autoimmune diseases and the most frequent cause of Addison's disease; however, it only becomes clinically apparent when more than 90 % of the adrenal cortex has been destroyed. Histological features are characterized by lymphoplasmacytic inflammation leading to an increased destruction of adrenocortical tissue but less severe courses can also occur. The second most frequent form of adrenalitis is adrenal tuberculosis, showing typical granulomatous findings that are nearly always caused by spreading from a tuberculous pulmonary focus. Other bacterial as well as viral infections, such as Epstein-Barr virus (EBV), cytomegalovirus (CMV) and others, generally affect the adrenal glands only in patients with immunodeficiency disorders. In these infections, the adrenal cortex and medulla are frequently involved to roughly the same extent. Although surgical specimens from inflammatory adrenal lesions are extremely rare, the various forms of adrenalitis play an important role in the post-mortem examination of the adrenal glands for clarification of unclear causes of death (e.g. death during an Addisonian crisis).

Incorporating bolus and infusion pharmacokinetics into the ICING insulin model

The ICING model has been successfully used to guide clinical decisions on insulin administration in critical illness. However, insulin pharmacokinetics in the ICING model can be improved to better describe both intravenous (IV) bolus and infusion insulin administration. Patient data from 217 Dynamic Insulin Sensitivity and Secretion Tests (DISST) and 36 Intravenous Glucose Tolerance Tests (IVGTT) from independent dietary intervention studies was used to fit model parameters to a model structure that conforms to known behaviour. The DISST tests measured both endogenous and exogenous IV insulin bolus responses, while the IVGTT measured exogenous IV insulin infusion dynamics. Unidentifiable parameters were given physiologically justified values, with knowledge on relative insulin clearance rates used to constrain parameter values. The resulting whole-cohort description was able to simultaneously describe both IV bolus and infusion dynamics, and improves ICING model descriptive capability. Improved infusion dynamics will allow better description of subcutaneous insulin, the insulin administration route favoured in outpatient care of diabetes.

Nonthyroidal illness syndrome in off-pump coronary artery bypass surger

OBJECTIVE

It is well known that coronary artery bypass grafting (CABG) is often the cause of non-thyroidal illness syndrome (NTIS). Non-thyroidal illness syndrome (NTIS) is a state characterized by low levels of tri-iodo-thyronine (T3) and high levels of reverse T3 (rT3), with normal or low levels of thyroxin (T4) and normal, low-normal, or low levels of thyroid-stimulating hormone (TSH). Today, there are two main techniques of CABG: CABG with the use of cardiopulmonary bypass (on-pump coronary artery bypass - ONCAB) and CABG without the use of cardiopulmonary bypass (off-pump coronary artery bypass OPCAB), or 'beating-heart surgery.' The OPCAB technique is considered to be less invasive. We prospectively investigated the influence of these surgical techniques on the occurrence of NTIS.

METHODS

Serum levels of free fractions of thyroid hormones (FT3 and FT4) and TSH were analyzed in 70 consecutive patients subjected to CABG surgery, using the ONCAB technique in 36 patients and OPCAB technique in 34 patients. The measurements of hormone levels were performed prior to surgery and 12 hours and 14 days after surgery.

RESULTS

The basic, the early, and the late postoperative serum levels of FT3 (p=0.458, p=0.632, p=0.869, respectively), FT4 (p=0.664, p=0.301, p=0.417, respectively), and TSH (p=0.249, p=0.058, p=0.324, respectively) were similar in both groups. The levels of FT3 and TSH were significantly lower 12 hours after surgery (p<0.0001, p<0.0001, respectively), and the FT4 levels rose at the same time (p<0.0001). The third measurement showed the return of all investigated parameters back to physiological levels, although they were still not precisely within the initial values.

CONCLUSION

NTIS occurs significantly in patients subjected to CABG. Although the OPCAB technique is considered to be less invasive, its impact on the occurrence of NTIS does not differ significantly from the ONCAB technique.

Insulin Control of Blood Glucose and GLUT4 Expression in the Skeletal Muscle of Septic Rats

BACKGROUND

Insulin resistance is common in septic patients. The level at which the serum glucose should be maintained using insulin infusions for optimal utilization by skeletal muscles is not yet established.

OBJECTIVE

The objective of the present study was to compare glucose transporter 4 (GLUT4) mRNA and GLUT4 expression and glucose utilization at the recommended glucose levels of 6-8 mmol/L (110-140 mg/dL) and 8-10 mmol/L (140-180 mg/dL) in septic rats.

SUBJECTS AND METHODS

This was a prospective randomized study using 44 Sprague-Dawley rats (260-330 g). Rats were anaesthetized with gaseous diethyl ether. Catheters were implanted into the jugular vein and artery. Following a laparotomy, rats in the experimental group (n = 36) were rendered septic by standard caecal ligation and puncture (CLP) and intraperitoneal lipopolysaccharide (LPS) infusion (O111:[B4], 1 mg/kg). Control animals (n = 8) underwent laparotomy, but no caecal ligation or puncture and no LPS injection. Four experimental groups were studied: sham-operated control, sepsis treated with fluid maintenance only, sepsis treated with fluid and insulin infusion controlling blood glucose concentration at 6-8 mmol/L and sepsis treated with fluid and insulin infusion controlling blood glucose concentration at 8-10 mmol/L. Hyperinsulinaemic-euglycaemic clamp experiment was done before fluid maintenance and insulin treatment to calculate average glucose infusion rate.

RESULTS

All septic rats were markedly hyperglycaemic compared with sham-operated controls two hours after operation. Glucose infusion rate during hyperinsulinaemic-euglycaemic clamp experiment was slower in septic rats, suggesting that they were insulin resistant. At the 12th and 24th hour, skeletal muscle was taken to observe pathological change and analyse the GLUT4 mRNA and GLUT4 levels. There were more inflammatory cells, less GLUT4 mRNA and GLUT4 expression in the skeletal muscles of septic rats. Insulin increased the expression of GLUT4 mRNA and GLUT4 in the skeletal muscle of septic rats. Among all septic rats, the expression of GLUT4 mRNA and GLUT4 was more in the 8-10 mmol/L group.

CONCLUSION

Blood glucose concentration of 8-10 mmol/L results in more glucose utilization than 6-8 mmol/L in the skeletal muscle of septic rats during insulin therapy.

Pancreatic digestive enzyme blockade in the small intestine prevents insulin resistance in hemorrhagic shock

Hemorrhagic shock is associated with metabolic defects, including hyperglycemia and insulin resistance, but the mechanisms are unknown. We recently demonstrated that reduction of the extracellular domain of the insulin receptor by degrading proteases may lead to a reduced ability to maintain normal plasma glucose values. In shock, transfer of digestive enzymes from the lumen of the intestine into the systemic circulation after breakdown of the intestinal mucosal barrier causes inflammation and organ dysfunction. Suppression of the digestive enzymes in the lumen of the intestine with protease inhibitors is effective in reducing the level of the inflammatory reactions. To determine the degree to which blockade of digestive enzymes affects insulin resistance in shock, rats were exposed to acute hemorrhagic shock (mean arterial pressure of 30 mmHg for 2 h) at which time all shed blood volume was returned. Digestive proteases in the intestine were blocked with a serine protease inhibitor (tranexamic acid in polyethylene glycol and physiological electrolyte solution), and the density of the insulin receptor was measured with immunohistochemistry in the mesentery microcirculation. The untreated rat without enzyme blockade had significantly attenuated levels of insulin receptor density as compared with control and treated rats. Blockade of the digestive proteases after 60 min of hypotension in the lumen of the small intestine led to a lesser decrease in insulin receptor density compared with controls without protease blockade. Glucose tolerance test indicates a significant increase in plasma glucose levels 2 h after hemorrhagic shock, which are reduced to control values in the presence of protease inhibition in the lumen of the intestine. The transient reduction of the plasma glucose levels after an insulin bolus is significantly attenuated after shock but is restored when digestive enzymes in the lumen of the intestine are blocked. These results suggest that in hemorrhagic shock elevated microvascular extracellular digestive enzyme activity causes insulin receptor dysfunction, hyperglycemia, and reduced ability to regulate blood glucose values.

Oxytocin affects nitric oxide and cytokine production by sepsis-sensitized macrophages

BACKGROUND/AIM

Oxytocin (OXT) secretion during cecal ligation puncture (CLP)-induced sepsis has not yet been examined. Although immune properties have been attributed to OXT, its effect on CLP-sensitized macrophages has never been investigated. We analyzed OXT secretion during CLP and its effect in CLP-sensitized macrophage cultures.

METHODS

Male Wistar rats were decapitated 4, 6 or 24 h after CLP surgery or sham operation and blood, brain and neurohypophyses were collected for OXT measurements. In another set of animals we studied the effect of OXT on nitrite, tumor necrosis factor (TNF-α), interleukin (IL)-1β and IL-10 production of peritoneal macrophages harvested at 6 and 24 h after CLP.

RESULTS

In the early phase of sepsis (4-6 h), OXT levels increased in plasma and decreased in hypothalamus and neurohypophysis. In the late phase (24 h), plasma and neurohypophyseal levels remained basal. In the paraventricular, the OXT content remained low, but in the supraoptic increased. Macrophages of the early phase of sepsis pretreated with OXT and stimulated with lipopolysaccharide showed decreased nitrite, TNF-α and IL-1β levels, but no alteration in IL-10 production. In the late phase, they showed reduction only on IL-1β.

CONCLUSIONS

OXT secretion during sepsis may represent a neuroendocrine response contributing to the overall host response to infection by decreasing the proinflammatory response and oxidative stress.

Anesthesia with propofol induces insulin resistance systemically in skeletal and cardiac muscles and liver of rats

Hyperglycemia together with hepatic and muscle insulin resistance are common features in critically ill patients, and these changes are associated with enhanced inflammatory response, increased susceptibility to infection, muscle wasting, and worsened prognosis. Tight blood glucose control by intensive insulin treatment may reduce the morbidity and mortality in intensive care units. Although some anesthetics have been shown to cause insulin resistance, it remains unknown how and in which tissues insulin resistance is induced by anesthetics. Moreover, the effects of propofol, a clinically relevant intravenous anesthetic, also used in the intensive care unit for sedation, on insulin sensitivity have not yet been investigated. Euglycemic hyperinsulinemic clamp study was performed in rats anesthetized with propofol and conscious unrestrained rats. To evaluate glucose uptake in tissues and hepatic glucose output [(3)H]glucose and 2-deoxy[(14)C]glucose were infused during the clamp study. Anesthesia with propofol induced a marked whole-body insulin resistance compared with conscious rats, as reflected by significantly decreased glucose infusion rate to maintain euglycemia. Insulin-stimulated tissue glucose uptake was decreased in skeletal muscle and heart, and hepatic glucose output was increased in propofol anesthetized rats. Anesthesia with propofol induces systemic insulin resistance along with decreases in insulin-stimulated glucose uptake in skeletal and heart muscle and attenuation of the insulin-mediated suppression of hepatic glucose output in rats.

Disturbances of the hypothalamic-pituitary-adrenal axis and plasma electrolytes during experimental sepsis

Background

Sepsis continues to be a poorly understood syndrome with a high mortality rate. While we are beginning to decipher the intricate interplay of the inflammatory response during sepsis, the precise regulation of the hypothalamic-pituitary-adrenal (HPA) axis and its impact on electrolyte homeostasis during sepsis remains incompletely understood.

Methods

Sepsis was induced in adult male Sprague-Dawley rats by cecal ligation and puncture (CLP). Plasma samples were obtained as a function of time (6-48 hrs) after CLP and compared with healthy animals (neg ctrl). Samples were analyzed for adrenocorticotropin (ACTH), corticosterone, and aldosterone levels, as well as concentrations of sodium (Na⁺), potassium (K⁺), chloride (Cl^-), and magnesium (Mg²⁺).

Results

ACTH levels were found to be significantly reduced 6-24 hrs after CLP in comparison to baseline levels and displayed gradual recovery during the later course (24-48 hrs) of sepsis. Plasma corticosterone concentrations exhibited a bell-shaped response, peaking between 6 and 12 hrs followed by rapid decline and concentrations below negative control levels 48 hrs after injury. Aldosterone levels in septic animals were continuously elevated between 6 and 48 hrs. Whereas plasma Na⁺ levels were found to be persistently elevated following CLP, levels of K⁺, Cl^- and Mg²⁺ were significantly reduced as a function of time and gradually recovered during the later course of sepsis.

Conclusions

CLP-induced sepsis resulted in dynamic changes of ACTH, corticosterone, and aldosterone levels. In addition, electrolyte levels showed significant disturbances after CLP. These electrolyte perturbations might be evoked by a downstream effect or a dysfunctional HPA-axis response during sepsis and contribute to severe complications during sepsis.

Novel regulators of the systemic response to lipopolysaccharide

Our understanding of the role that host genetic factors play in the initiation and severity of infections caused by gram-negative bacteria is incomplete. To identify novel regulators of the host response to lipopolysaccharide (LPS), 11 inbred murine strains were challenged with LPS systemically. In addition to two strains lacking functional TLR4 (C3H/HeJ and C57BL/6J(TLR4-/-)), three murine strains with functional TLR4 (C57BL/6J, 129/SvImJ, and NZW/LacJ) were found to be relatively resistant to systemic LPS challenge; the other six strains were classified as sensitive. RNA from lung, liver, and spleen tissue was profiled on oligonucleotide microarrays to determine if unique transcripts differentiate susceptible and resistant strains. Gene expression analysis identified the Hedgehog signaling pathway and a number of transcription factors (TFs) involved in the response to LPS. RNA interference-mediated inhibition of six TFs (C/EBP, Cdx-2, E2F1, Hoxa4, Nhlh1, and Tead2) was found to diminish IL-6 and TNF-α production by murine macrophages. Mouse lines with targeted mutations were used to verify the involvement of two novel genes in innate immunity. Compared with wild-type control mice, mice deficient in the E2F1 transcription factor were found to have a reduced inflammatory response to systemic LPS, and mice heterozygote for Ptch, a gene involved in Hedgehog signaling, were found to be more responsive to systemic LPS. Our analysis of gene expression data identified novel pathways and transcription factors that regulate the host response to systemic LPS. Our results provide potential sepsis biomarkers and therapeutic targets that should be further investigated in human populations.

Brain interstitial fluid TNF-alpha after subarachnoid hemorrhage

OBJECTIVE

TNF-alpha is an inflammatory cytokine that plays a central role in promoting the cascade of events leading to an inflammatory response. Recent studies have suggested that TNF-alpha may play a key role in the formation and rupture of cerebral aneurysms, and that the underlying cerebral inflammatory response is a major determinate of outcome following subrarachnoid hemorrhage (SAH).

METHODS

We studied 14 comatose SAH patients who underwent multimodality neuromonitoring with intracranial pressure (ICP) and cerebral microdialysis as part of their clinical care. Continuous physiological variables were time-locked every 8h and recorded at the same point that brain interstitial fluid TNF-alpha was measured in brain microdialysis samples. Significant associations were determined using generalized estimation equations.

RESULTS

Each patient had a mean of 9 brain tissue TNF-alpha measurements obtained over an average of 72h of monitoring. TNF-alpha levels rose progressively over time. Predictors of elevated brain interstitial TNF-alpha included higher brain interstitial fluid glucose levels (beta=0.066, p<0.02), intraventricular hemorrhage (beta=0.085, p<0.021), and aneurysm size >6mm (beta=0.14, p<0.001). There was no relationship between TNF-alpha levels and the burden of cisternal SAH; concurrent measurements of serum glucose, or lactate-pyruvate ratio.

INTERPRETATION

Brain interstitial TNF-alpha levels are elevated after SAH, and are associated with large aneurysm size, the burden of intraventricular blood, and elevation brain interstitial glucose levels.

Nuclear factor-kappaB decoy oligodeoxynucleotides ameliorate impaired glucose tolerance and insulin resistance in mice with cecal ligation and puncture-induced sepsis

OBJECTIVE

Insulin-resistant hyperglycemia is commonly observed in septic patients and may actually lead to some of adverse outcomes. We examined the changes in insulin signaling and glucose uptake regulation in sepsis and the involvement of the nuclear factor-kappaB pathway.

DESIGN

Controlled animal study.

SETTING

University research laboratory.

SUBJECTS

One hundred fifty-four BALB/c mice (8-12 wks of age).

INTERVENTIONS

The following four experimental groups were studied: sham-operated control, cecal ligation and puncture-induced sepsis, sepsis + nuclear factor-kappaB decoy oligodeoxynucleotide treatment, and sepsis + scrambled decoy oligodeoxynucleotide treatment.

MEASUREMENTS AND MAIN RESULTS

Septic mice were markedly hyperinsulinemic with apparently normal blood glucose levels in the fasted state, suggesting they are insulin-resistant. In fact, glucose clearance in response to insulin was markedly impaired in septic mice. They had impaired GLUT4 membrane translocation resulting from impaired insulin signaling as indicated by the decreased amount of insulin receptor substrate protein and the reduced activation of phosphatidylinositol 3-kinase and Akt. Interestingly, injection of nuclear factor-kappaB decoy oligodeoxynucleotide into the skeletal muscle dramatically improved all of the changes, including glucose clearance and insulin signaling. We also found that the Cbl-associated protein to TC10 pathway, another pathway regulating GLUT4 translocation, was up-regulated in septic mice in a nuclear factor-kappaB-dependent manner. This pathway may be one of the compensatory mechanisms to translocate GLUT4 because silencing of the individual components of the pathway with small interfering RNAs further reduced GLUT4 translocation in muscles of septic mice.

CONCLUSIONS

In sepsis, skeletal muscle GLUT4 translocation is impaired as a result of the reduced phosphatidylinositol 3-kinase/Akt pathway associated with insulin receptor substrate down-regulation through nuclear factor-kappaB activation.

Bench-to-bedside review: Beta-adrenergic modulation in sepsis

Sepsis, despite recent therapeutic progress, still carries unacceptably high mortality rates. The adrenergic system, a key modulator of organ function and cardiovascular homeostasis, could be an interesting new therapeutic target for septic shock. β-Adrenergic regulation of the immune function in sepsis is complex and is time dependent. However, β₂ activation as well as β₁ blockade seems to downregulate proinflammatory response by modulating the cytokine production profile. β₁ blockade improves cardiovascular homeostasis in septic animals, by lowering myocardial oxygen consumption without altering organ perfusion, and perhaps by restoring normal cardiovascular variability. β-Blockers could also be of interest in the systemic catabolic response to sepsis, as they oppose epinephrine which is known to promote hyperglycemia, lipid and protein catabolism. The role of β-blockers in coagulation is less clear cut. They could have a favorable role in the septic pro-coagulant state, as β₁ blockade may reduce platelet aggregation and normalize the depressed fibrinolytic status induced by adre-nergic stimulation. Therefore, β₁ blockade as well as β₂ activation improves sepsis-induced immune, cardiovascular and coagulation dysfunctions. β₂ blocking, however, seems beneficial in the metabolic field. Enough evidence has been accumulated in the literature to propose β- adrenergic modulation, β₁ blockade and β₂ activation in particular, as new promising therapeutic targets for septic dyshomeostasis, modulating favorably immune, cardiovascular, metabolic and coagulation systems.

Effects of vasopressin in septic shock

Septic shock continues to be one of the leading causes of death in the intensive care unit today. The confluence of many factors contributes to the deterioration of patients' condition in septic shock. Increased levels of nitric oxide, in part, mediate the cardiovascular effects of septic shock. Nitric oxide is major mediator of vasodilation and hypotension as well as myocardial depression. It also contributes to decreased production and release of endogenous vasopressin. Vasopressin effects are actualized by stimulation of V1, V2, and V3 receptors located in various parts of the body. The response is dose dependent. Endogenous vasopressin and angiotensin II act synergistically to preserve and restore blood pressure levels. Decreased circulating vasopressin contributes to adrenal insufficiency via hypothalamic-pituitary-adrenal axis suppression and increased catecholamine resistance to vasopressors. Exogenous vasopressin supplementation in physiologic doses has been shown to improve blood pressure levels and decrease vasopressor needs in patients with septic shock.

Death due to late-presenting congenital diaphragmatic hernia in a 2-year-old child

Congenital diaphragmatic hernia (CDH) is classically regarded as a neonatal defect presenting with respiratory distress; however, not all CDH will present in this manner. Unlike newborn deaths related to CDH, where the mechanism of death is respiratory in nature, the mechanism of death in late-presenting CDH is not always due to respiratory compromise. In this case report, we present a death occurring in a 2 1/2-year-old child who presented to the emergency department with complaints of abdominal pain and emesis, and then rapidly decompensated and died. Autopsy revealed a CDH, with herniation of abdominal contents into the left thoracic cavity, with associated gastric volvulus, necrosis, and rupture.

[The euthyroid sick syndrome in severe acute illness]

OBJECTIVE

To describe euthyroid sick syndrome (ESS) and its different clinical variants in severe acute illness.

DESIGN

This prospective cohort study examined hormone results and outcome for patients admitted to our intensive care unit (ICU).

METHODS

In this heterogeneous group of 108 patients from our ICU we analyzed the prevalence of ESS and its influence on mortality and sought to determine if any thyroid indicators had a prognostic value.

RESULTS

The prevalence of ESS was similar to that described by other authors (68.5% for ESS type I, 15.7% for type II and 1.9% for type III). Patients developed thyroid alterations on their third day of hospitalization and those with ESS type II had a higher mortality rate. The only thyroid indicator with prognostic value was a reverse triiodothyronine (rT3) value exceeding 0.61 ng/mL.

CONCLUSION

Severe acute illness induced the thyroid alterations known as ESS. Type I had the highest prevalence, but type II was correlated with a higher mortality rate. The only thyroid indicator with a prognostic value was rT3.

Diabetes mellitus and anesthesia

Diabetes mellitus is an extremely common condition with specific associated comorbidity. Its incidence is rising. Diabetic patients have more perioperative complications than nondiabetic patients. These complications may be related to the presence of organ damage secondary to the diabetes, rather than the defects in carbohydrate metabolism themselves, or to perioperative hyperglycemia. Several new drugs are available for the treatment of diabetes, and these are associated with specific and significant side effects, and varying lengths of action with which the anesthetist should be familiar. Few data are available regarding recommendations for fasting in the presence of these newer drugs. In the postoperative period and during cardiac surgery, hyperglycemia has been shown to be detrimental, and should probably be sought and managed aggressively. The incidence of intraoperative hyperglycemia in noncardiac surgery patients is not as well-defined, nor are the effects of aggressive management.

Innate immune system regulation of nuclear hormone receptors in metabolic diseases

The immune system modulates a number of biological processes to properly defend against pathogens. Here, we review how crosstalk between nuclear hormone receptors and the innate immune system may influence multiple biological functions during an immune response. Although nuclear hormone receptor repression of innate immune responses and inflammation has been well studied, a number of new studies have identified repression of nuclear hormone receptor signaling by various innate immune responses. IFN regulatory factor 3, a key transcription factor involved in the induction of antiviral genes, may play a role in mediating such crosstalk between the innate immune response and nuclear receptor-regulated metabolism. This crosstalk mechanism is now implicated in the pathogenesis of atherosclerosis and Reye's syndrome and could provide an explanation for other pathogen-associated metabolic and developmental disorders.

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 immune system as a regulator of thyroid hormone activity

It has been known for decades that the neuroendocrine system can both directly and indirectly influence the developmental and functional activity of the immune system. In contrast, far less is known about the extent to which the immune system collaborates in the regulation of endocrine activity. This is particularly true for immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis. Although thyroid-stimulating hormone (TSH) can be produced by many types of extra-pituitary cells--including T cells, B cells, splenic dendritic cells, bone marrow hematopoietic cells, intestinal epithelial cells, and lymphocytes--the functional significance of those TSH pathways remains elusive and historically has been largely ignored from a research perspective. There is now, however, evidence linking cells of the immune system to the regulation of thyroid hormone activity in normal physiological conditions as well as during times of immunological stress. Although the mechanisms behind this are poorly understood, they appear to reflect a process of local intrathyroidal synthesis of TSH mediated by a population of bone marrow cells that traffic to the thyroid. This hitherto undescribed cell population has the potential to microregulate thyroid hormone secretion leading to critical alterations in metabolic activity independent of pituitary TSH output, and it has expansive implications for understanding mechanisms by which the immune system may act to modulate neuroendocrine function during times of host stress. In this article, the basic underpinnings of the hematopoietic-thyroid connection are described, and a model is presented in which the immune system participates in the regulation of thyroid hormone activity during acute infection.