The Endocrine Response to Critical Illness: Update and Implications for Emergency Medicine

Free and bound cortisol, corticosterone, and metabolic adaptations during the early inflammatory response to an intramammary lipopolysaccharide challenge in dairy cows

Glucocorticoids, particularly cortisol and corticosterone, are key homeostatic regulators during metabolic and endocrine adaptations including inflammatory responses. Besides the established response of total cortisol (TC) concentrations during inflammatory processes in dairy cows, we investigated changes of corticosterone, free cortisol (FC), and serum albumin as the main protein of unspecific cortisol binding, in response to an intramammary lipopolysaccharide (LPS) challenge. Furthermore, we evaluated relationships of glucocorticoid responses with concomitant alterations of metabolites and their endocrine regulators, insulin and glucagon. Blood samples of 10 multiparous Holstein dairy cows (26.8 ± 3.4 d in milk, previous lactation yield: 7,601 ± 938 kg; mean ± SD) were obtained every 30 min up to 5 h after the LPS instillation, and rectal temperature and heart rate were measured in parallel. Corticosterone was measured by enzyme immunoassay, TC by radioimmunoassay, and the proportion of FC by ultrafiltration. A mixed model was used to evaluate differences within the investigated parameters among selected time points (0, 3.5, and 5 h relative to the intramammary LPS administration). Rectal temperature increased up to 41.6 ± 0.1°C at 5 h after the LPS application. Concentrations of TC and corticosterone increased until 3.5 h, and the proportion of FC relative to TC more than doubled until 3.5 h after LPS administration. Serum albumin concentration was reduced at 5 h compared with initial values, whereas concentrations of insulin, glucagon, and glucose were increased after 5 h compared with 0 h. In conclusion, the stimulation of the immune system by the intramammary LPS administration is accompanied by distinct metabolic and endocrine changes. Corticosterone and TC concentrations react similarly in response to the LPS challenge and earlier compared with metabolic adaptations. The increased need of active cortisol is covered by both increased secretion and a higher percentage of FC.

[Stress adaptive effects after traumatic brain injury]

Neuroendocrine dysfunction, in particular impaired synthesis of anterior pituitary hormones, is a common complication of traumatic brain injury. Deficiency of tropic pituitary hormones entails a hypofunction of the related peripheral endocrine glands and can be accompanied by persistent endocrine and metabolic disorders. In particular, the hypophyseal mechanisms are the key ones in implementation of most stress effects. Adequate implementation of these mechanisms largely determines a favorable outcome in the acute stage of disease. Traumatic brain injury (as well as any significant injury) initiates a stress response that can not develop in full in the case of pituitary gland failure. It is logical to suppose that the course of the acute phase of stress in the presence of hypopituitarism is different to a certain extent from the typical course, which inevitably affects certain adaptation elements. In this review, we analyzed the adaptive effects of stress after traumatic brain injury.

Urgent Thyroid-Stimulating Hormone Testing in Emergency Medicine: A Useful Tool?

BACKGROUND

Thyroid-stimulating hormone (TSH) has recently been introduced among the tests available to the Emergency Department (ED) of our hospital.

OBJECTIVE

To evaluate the prevalence of TSH-level-dependent thyroid dysfunction and to assess the usefulness of urgent TSH testing in a series of emergency patients.

METHODS

We planned a single-center observational cross-sectional clinical study. We divided patients in groups according to their thyroid status using defined TSH decision levels. Previously diagnosed history of thyroid dysfunction and newly diagnosed thyroid dysfunctions were differentiated. Further, we analyzed the subset of emergency patients affected by atrial fibrillation (AF) due to the role of hyperthyroidism in AF pathogenesis. For each TSH request, we made a retrospective chart review to assess the usefulness of the test based on clinical efficacy and management efficiency indicators.

RESULTS

The present study showed that, although the overall thyroid dysfunction rate was higher than in the general population, only a few newly diagnosed thyroid dysfunctions were found with limited clinical utility. We categorized urgent TSH requests as useful and not useful, by retrospective evaluation, and we identified and compared the main TSH testing clinical indications in the two groups.

CONCLUSION

We found a positive impact of urgent TSH determination in emergency decision-making. Nevertheless, a stronger clinical impact could be achieved by improving request appropriateness and by targeting TSH testing to some clinical indications identified by the study. The work was considered a quality-improvement project by the Hospital Committee for Quality Management.

Thyroid hormone replacement for nephrotic syndrome patients with euthyroid sick syndrome: a meta-analysis

OBJECTIVE

To assess the efficacy of thyroid hormone replacement therapy for nephrotic syndrome (NS) patients associated with euthyroid sick syndrome (ESS).

MATERIALS AND METHODS

The Cochrane library, ISI, Ovid, PubMed, Chinese Biomedicine Database were searched, and reference list of relevant articles were selected. Randomized controlled trials (RCTs) or quasi-RCTs with thyroid hormone replacement on NS patients associated with ESS were included in this analysis.

RESULTS

Six trials (329 participants) were included. Meta-analysis showed that thyroid hormone replacement therapy can significantly increase the completely remission rate [OR = 3.04, 95% confidence interval (CI): 3.04-1.88, p < 0.00001] and total response rate (OR = 4.63, 95% CI: 2.46-8.71, p < 0.00001) of NS patients associated with ESS. No side effect was observed during the follow-up period. There was no obvious publication bias in the mete-analysis studies.

CONCLUSIONS

Thyroid hormone replacement therapy significantly increases the remission of ESS in patients with NS.

The current state in the evaluation and treatment of ARdS and SIRS

Trauma, the number one cause of death until the fourth decade of life, causes an inflammatory response. This response in its extreme is associated with the development of the systemic inflammatory state, adult respiratory distress syndrome, multi-organ failure, and death. The inflammatory response is mediated via multiple pathways- the inflammatory-cytokine, immunologic, coagulation and endocrine pathways. It is countered by producing antiinflammatory mediators. This reaction is altered in elderly patients. Knowledge of the patient's prior medical problems and the differential diagnosis for the possible causes of the current condition should help direct the surgical intervention and supportive care in an attempt to stabilize the patient. With the improvement of monitoring and diagnostic technologies, understanding the significance of the inflammatory pathways in trauma patients will decrease morbidity and mortality in this group of patients.

The diagnosis and investigation of adrenal insufficiency in adults

There is considerable variation in the methods used to diagnose and investigate adrenal insufficiency in clinical practice. These include a range of adrenocorticotropin (ACTH) stimulation and other dynamic testing protocols, serum cortisol cut-off values for diagnosis and tests used for differential diagnosis. With the introduction of modern cortisol and ACTH assays, the interpretation of tests used for diagnosis and differential diagnosis has become more complex and requires local validation. This review examines the basis of normal hypothalamic-pituitary-adrenal axis function and adrenal insufficiency states based upon an evidence base accumulated over the past four decades. The role of the laboratory in the differential diagnosis and interpretation based upon assay methodology is discussed. The accurate identification of patients who may benefit from corticosteroid replacement in special settings such as critical illness is challenging and will be explored.

Current perioperative treatment of patients with type 1 and type 2 diabetes

Diabetes mellitus is rapidly increasing, diabetic patients are likely to undergo surgical procedures more than non-diabetic patients, the hospital stay of diabetic patients is longer, and diabetic patients have increased mortality and morbidity. The correct treatment of diabetic patients in the perioperative period is crucial to improve clinical outcomes. Diabetic patients must be carefully evaluated for cardiovascular risk, keeping in mind micro- and macroangiopathic diabetic complications. Metabolic control deserves great attention because hyperglycemia is related to increased complications and worse outcomes. Insulin infusion regimens to achieve near normoglycemia must be implemented in surgical and critically ill patients.