Etomidate, Adrenal Insufficiency and Mortality Associated With Severity of Illness: A Meta-Analysis.

PURPOSE: Etomidate causes adrenal insufficiency. Yet in critically ill patients, it is controversial whether it increases mortality rates above that of comparator anesthetic induction agents. We postulated that etomidate would increase relative mortality rates correspondingly to the severity of illness as defined by SAPS or APACHE scores. MATERIALS AND METHODS: A literature search was performed on Pub Med, SCOPUS, and Cochrane Reviews for human studies, regardless of language, between 1983 and February 2020. The search strategy used keywords, "etomidate," "adrenal insufficiency," "glucocorticoid," and "intensive care." Both authors reviewed electronic data search titles, abstracts and extracted data, which were checked by the other reviewer. Primary outcome was 28-day survival. Secondary outcome was adrenal insufficiency. RESULTS: There were 29 trials of etomidate versus comparators in 8584 patients. Etomidate was associated with adrenal insufficiency (risk ratio (rr) = 1·54, 95% CI; 1·42, 1·67, p < 0.001) and increased overall relative mortality rates (rr = 1.09, CI;1.04,1.16, p = 0.001). Meta-regression showed that with etomidate there was a continuous progressive relative risk of mortality associated with increasing severity of illness (predefined in each article by standard critical illness scores). In those patients who had a predicted mortality rate > the median for this analysis (predicted mortality 44%) the relative mortality rate (rr) = 1.20, Ci;1.12,1.29, p < 0.001, the absolute risk difference (rd) = 0.08, CI;0.05,0.11, p < 0.0001 and the number needed to harm (1/rd) was 12.5. In those with a calculated predicted mortality <44% there was no increase in relative mortality rate. CONCLUSIONS: Whereas etomidate causes adrenal insufficiency, it was not shown to increase mortality in many analyzed here in ICU settings. However, etomidate associated relative mortality rates increased progressively and correlated with the severity of critical illness scores. Intensivists should anticipate the need for glucocorticoid supplementation after etomidate in those with severe critical illness and in those with acute deterioration of vital signs.

Including Relative Adrenal Insufficiency in Definition and Classification of Acute-on-Chronic Liver Failure.

BACKGROUND & AIMS: Relative adrenal insufficiency (RAI) is defined by insufficient production of cortisol relative to organ demand. RAI is observed frequently in hospitalized patients with cirrhosis, but there is disagreement over the clinical effects of RAI in these patients. We evaluated the prevalence and the clinical effects of RAI in hospitalized patients with cirrhosis. METHODS: We performed a prospective study of 160 patients admitted to a hospital in Italy for acute decompensation of cirrhosis from May 2011 through September 2016. Patients were followed up until death, liver transplantation, or a maximum of 90 days. Serum and salivary levels of cortisol were measured before and after a 1-hour Short Synacthen Test. A diagnosis of RAI was given to patients with an increase in serum cortisol of less than 9 µg/dL, after Synacthen administration, in patients with baseline serum levels of cortisol less than 35 µg/dL. We collected blood samples before the Synacthen test and analyzed them for blood cell counts, liver and renal function, levels of C-reactive protein, and lipid profiles (total cholesterol, high-density lipoprotein cholesterol, apolipoprotein-A1). RESULTS: A diagnosis of RAI was made for 78 patients (49%). Age (odds ratio [OR], 0.95; P = .030), number of leukocytes (OR, 3.10; P = .006), and levels of high-density lipoprotein cholesterol (OR, 0.30; P = .039) were associated independently with RAI. Patients with RAI had a significantly higher risk of developing bacterial infections (hazard ratio [HR], 1.60; P = .038), sepsis (HR, 2.95; P = .001), septic shock (HR, 4.94; P = .038), new organ failures (HR, 2.45; P = .014), and acute-on-chronic liver failure (HR, 2.27; P = .037) than patients without RAI. RAI was associated independently with death within 90 days of diagnosis (subdistribution HR, 4.83; P = .001). Patients with RAI and mild renal dysfunction or hepatic encephalopathy had no significant difference in cumulative incidence of 28-day mortality vs patients with acute-on-chronic liver failure grade 1 (25% vs 22%). CONCLUSIONS: We found RAI to occur in almost half of patients admitted to a hospital for acute decompensation of cirrhosis. RAI was associated with a deficit of substrates for steroidogenesis and an increase in markers of inflammation. Patients with RAI have a high risk of developing sepsis, septic shock, organ failure, and death within 90 days. RAI has similar prognostic value to nonrenal organ failures.

Corticosteroid receptor rebalancing alleviates critical illness-related corticosteroid insufficiency after traumatic brain injury by promoting paraventricular nuclear cell survival via Akt/CREB/BDNF signaling.

BACKGROUND: We previously found that high-dose methylprednisolone increased the incidence of critical illness-related corticosteroid insufficiency (CIRCI) and mortality in rats with traumatic brain injury (TBI), whereas low-dose hydrocortisone but not methylprednisolone exerted protective effects. However, the receptor-mediated mechanism remains unclear. This study investigated the receptor-mediated mechanism of the opposite effects of different glucocorticoids on the survival of paraventricular nucleus (PVN) cells and the incidence of CIRCI after TBI. METHODS: Based on controlled cortical impact (CCI) and treatments, male SD rats (n = 300) were randomly divided into the sham, CCI, CCI + GCs (methylprednisolone 1 or 30 mg/kg/day; corticosterone 1 mg/kg/day), CCI + methylprednisolone+RU486 (RU486 50 mg/kg/day), and CCI + corticosterone+spironolactone (spironolactone 50 mg/kg/day) groups. Blood samples were collected 7 days before and after CCI. Brain tissues were collected on postinjury day 7 and processed for histology and western blot analysis. RESULTS: We examined the incidence of CIRCI, mortality, apoptosis in the PVN, the receptor-mediated mechanism, and downstream signaling pathways on postinjury day 7. We found that methylprednisolone and corticosterone exerted opposite effects on the survival of PVN cells and the incidence of CIRCI by activating different receptors. High-dose methylprednisolone increased the nuclear glucocorticoid receptor (GR) level and subsequently increased cell loss in the PVN and the incidence of CIRCI. In contrast, low-dose corticosterone but not methylprednisolone played a protective role by upregulating mineralocorticoid receptor (MR) activation. The possible downstream receptor signaling mechanism involved the differential effects of GR and MR on the activity of the Akt/CREB/BDNF pathway. CONCLUSION: The excessive activation of GR by high-dose methylprednisolone exacerbated apoptosis in the PVN and increased CIRCI. In contrast, refilling of MR by corticosterone protects PVN neurons and reduces the incidence of CIRCI by promoting GR/MR rebalancing after TBI.

Cosyntropin testing does not predict response to glucocorticoids in community-acquired pneumonia in a randomized controlled trial.

OBJECTIVE: Glucocorticoids have been shown to improve outcome in community-acquired pneumonia (CAP). However, glucocorticoids have potential side-effects, and treatment response may vary. It is thus crucial to select patients with high likelihood to respond favourably. In critical illness, cosyntropin testing is recommended to identify patients in need for glucocorticoids. We investigated whether cosyntropin testing predicts treatment response to glucocorticoids in CAP. DESIGN: Predefined secondary analysis of a randomized controlled trial. PATIENTS: Hospitalized patients with CAP. MEASUREMENTS: We performed 1 µg cosyntropin tests in a randomized trial comparing prednisone 50 mg for 7 days to placebo. We investigated whether subgroups based on baseline and stimulated cortisol levels responded differently to glucocorticoids with regard to time to clinical stability (TTCS) and other outcomes by inclusion of interaction terms into statistical models. RESULTS: A total of 326 patients in the prednisone and 309 patients in the placebo group were evaluated. Neither basal cortisol nor a Δcortisol <250 nmol/L after stimulation nor the combination of basal cortisol and Δcortisol predicted treatment response as measured by TTCS (all P for interaction >0.05). Similarly, we found no effect modification with respect to mortality, rehospitalization, antibiotic treatment duration or CAP-related complications (all P for interaction >0.05). However, glucocorticoids had a stronger effect on shortening length of hospital stay in patients with a baseline cortisol of ≥938 nmol/L (P for interaction = 0.015). CONCLUSIONS: Neither baseline nor stimulated cortisol after low-dose cosyntropin testing at a dose of 1 µg predicted glucocorticoid responsiveness in mild to moderate CAP. A treatment decision for or against adjunct glucocorticoids in CAP should not be made depending on cortisol values or cosyntropin testing results.

[Critical illness - related corticosteroid insufficiency in patients after cardiac surgery and cardiologic emergencies].

Critical illness - related corticosteroid insufficiency (CIRCI) is associated with elevated level of circulating biomarkers of inflammation, pro - coagulant effects, deterioration of systemic inflammatory response syndrome (SIRS) and, consequently, prolonged in - hospital stay and increased mortality of intensive care patients. Incidence of CIRCI widely varies depending on specific patient's population and applied diagnostic thresholds being as high as 30% among postoperative patients on inotropes. CIRCI is a complex clinical and pathophysiological condition with substantial influence on immediate survival and prognosis. Clinical impact of CIRCI as well as pathogenetically based therapy arouse keen interest of intensive care specialists and clinical pathologists. The specific issues of CIRCI in patients after cardiac surgery and cardiology emergencies remain largely under - recognized, so further scrutinization is needed.

Critical illness-related corticosteroid insufficiency (CIRCI) in paediatric patients: a diagnostic and therapeutic challenge.

Critical illness-related corticosteroid insufficiency or CIRCI is characterized by acute and life-threatening disfunction of hypothalamic-pituitary-adrenal (HPA) axis observed among intensive care unit- staying patients.It is associated with increased circulating levels of biological markers of inflammation and coagulation, morbidity, length of ICU stay, and mortality.Several mechanisms are involved in CIRCI pathogenesis: reduced CRH-stimulated ACTH release, peripheral resistance to glucocorticoids, altered cortisol synthesis, impaired cortisol-free fraction and bioavailability.Diagnostic and therapeutic management of this condition in children is still debated, probably because of the lack of agreement among intensive care specialists and endocrinologists regarding diagnostic criteria and prevalence of CIRCI in paediatric age.In the present narrative review, we focused on definition of CIRCI in paediatric age and we advise on how to diagnose and treat this poorly understood condition, based on current literature data.

SNARE-ing the Reason for Post-Cardiac Surgery Critical Illness-Related Corticosteroid Insufficiency.

Critical illness-related corticosteroid insufficiency (CIRCI) can cause hemodynamic instability in neonates after congenital heart surgery with manifestations that increase morbidity and potential mortality. We retrospectively reviewed neonates who underwent cardiac surgery between August 2018 and July 2020 at a freestanding children's hospital, had next-generation sequencing performed, and had their cortisol levels drawn as standard clinical care after cardiac surgery. The groups were defined as CIRCI (with a cortisol level ≤ 4.5 mcg/dL) and non-CIRCI (level > 4.5 mcg/dL). The CIRCI group (n = 8) had a 100% incidence of heterozygous gene mutation on STX1A with splicing or loss of function, and this mutation was not found in the non-CIRCI group (n = 8). Additional gene mutations were found in the CIRCI group on RAB6A, ABCA3, SIDT2, and LILRB3, with no incidence in the non-CIRCI group. Three additional mutations were found across the CIRCI group in INPPL1 and FAM189A2 (both splicing and missense), with 12-25% of patients in the non-CIRCI group also displaying these mutations. Novel genetic abnormalities were seen in neonates with symptoms of CIRCI with potential cardiac implications from a gene mutation for STX1A. Compounding effects of additional gene mutations need to be confirmed and explored for potential predisposition to hemodynamic instability during times of stress.

Corticosteroids in sepsis and community-acquired pneumonia.

Sepsis and septic shock, which are often caused by pneumonia, impact millions of people every year. Despite adequate antibiotic therapy, mortality remains high, up to 45% in septic shock, which is characterized by an inappropriate, excessive immune response of the host. Moreover, critical illness-related corticosteroid insufficiency often coexists. Against this background, several trials and meta-analyses evaluated corticosteroid therapy as adjuvant therapy with heterogeneous results. Indeed, before 2000, high-dosage, short courses of corticosteroid treatment resulted in no benefit on mortality and a higher rate of adverse events. After 2000, thanks to a deeper understanding of the pathophysiology, low-dosage with longer courses of treatment were tested. With this regimen, a faster decrease in inflammation and faster resolution of shock, with a low rate of mild adverse events, was demonstrated although no clear effect on mortality was shown. To date, guidelines on sepsis and septic shock and guidelines on severe community-acquired pneumonia suggest corticosteroid use in selected patients. Furthermore, by utilizing latent class analysis, phenotypes of sepsis patients who benefit the most from corticosteroid treatment were recently identified. Future research should be guided by a precision medicine approach to identify adequate dosage and duration of corticosteroid treatment for appropriate patients. This article is freely available.

Profiling endogenous adrenal function during veno-venous ECMO support in COVID-19 ARDS: a descriptive analysis.

Background: Prolonged critical illness is often accompanied by an impairment of adrenal function, which has been frequently related to conditions complicating patient management. The presumed connection between hypoxia and the pathogenesis of this critical- illness- related corticosteroid insufficiency (CIRCI) might play an important role in patients with severe acute respiratory distress syndrome (ARDS). Since extracorporeal membrane oxygenation (ECMO) is frequently used in ARDS, but data on CIRCI during this condition are scarce, this study reports the behaviour of adrenal function parameters during oxygenation support with veno-venous (vv)ECMO in coronavirus disease 2019 (COVID-19) ARDS. Methods: A total of 11 patients undergoing vvECMO due to COVID-19 ARDS at the Medical University of Vienna, who received no concurrent corticosteroid therapy, were retrospectively included in this study. We analysed the concentrations of cortisol, aldosterone, and angiotensin (Ang) metabolites (Ang I-IV, Ang 1-7, and Ang 1-5) in serum via liquid chromatography/tandem mass spectrometry before, after 1 day, 1 week, and 2 weeks during vvECMO support and conducted correlation analyses between cortisol and parameters of disease severity. Results: Cortisol concentrations appeared to be lowest after initiation of ECMO and progressively increased throughout the study period. Higher concentrations were related to disease severity and correlated markedly with interleukin-6, procalcitonin, pH, base excess, and albumin during the first day of ECMO. Fair correlations during the first day could be observed with calcium, duration of critical illness, and ECMO gas flow. Angiotensin metabolite concentrations were available in a subset of patients and indicated a more homogenous aldosterone response to plasma renin activity after 1 week of ECMO support. Conclusion: Oxygenation support through vvECMO may lead to a partial recovery of adrenal function over time. In homogenous patient collectives, this novel approach might help to further determine the importance of adrenal stress response in ECMO and the influence of oxygenation support on CIRCI.

The Development of a Protocol for Critical Illness-Related Corticosteroid Insufficiency (CIRCI) at a Tertiary Hospital.

Objectives: The diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) remains a challenge. This initiative aimed to develop a protocol for the diagnosis and management of CIRCI which will facilitate informed decision-making among clinicians through consensus-building among a multi-disciplinary team. Methodology: This was a single-center, qualitative study which utilized the modified Delphi method, consisting of a sequential iterative process with two rounds of voting. A cut-off value of 70% was set as the threshold for reaching consensus. Results: The protocol on the diagnosis and management of CIRCI was approved after two rounds of voting, with all the components reaching 83.3%-100% agreement. This protocol on CIRCI provided a framework for the clinical approach to refractory shock. It was advocated that all cases of probable CIRCI should immediately be started on hydrocortisone at 200 mg/day. The definitive diagnosis of CIRCI is established through a random serum cortisol <10 mcg/dL or increase in cortisol of <9 mcg/dL at 60 minutes after a 250 mcg ACTH stimulation test in patients with indeterminate random cortisol levels. Conclusion: The presence of refractory shock unresponsive to fluid resuscitation and vasopressors should warrant the clinical suspicion for the existence of CIRCI and should trigger a cascade of management strategies.

Factors Associated With Dietary Behaviour Among Patients With Type 2 Diabetes Mellitus in Rural Indonesia.

Background: Type 2 Diabetes Mellitus (T2DM) is one of the fastest-growing diseases and most serious major health problems worldwide. Few studies have focused on the association of social support with diabetes-related dietary behaviour. Objective: To examine the relationship between social support and dietary behaviour among patients with diabetes in a rural area of Indonesia. Methodology: This was a descriptive cross-sectional study that included 120 physically healthy patients above 18 years old with T2DM for at least 6 months. Data analysis was done using a stepwise regression model. Results: The mean age was 61.97 years (SD = 7.85, range = 52-74); 86.7% of the participants were females. Social support (ß = 0.272, p = <0.001), diabetes medications (ß = 0.169, p = 0.003), duration of diabetes (ß = 0.118, p = 0.0047), and presence of diabetes complications (ß = 0.197, p = 0.008) were significant predictors of dietary behaviour and accounted for 34.2% of the variance. Conclusions: Social support, diabetes medications, presence of diabetes complications, and duration of diabetes were associated with improved dietary behaviour. Therefore, social support should be considered when designing dietary interventions for patients with type 2 diabetes mellitus.

Decreased maximal cortisol secretion rate in patients with cirrhosis: Relation to disease severity.

BACKGROUND & AIMS: Hepatic enzymes play a major role in the metabolic elimination of cortisol, and reduced rates of cortisol clearance have been consistently observed in patients with chronic liver disease. It is less clear whether there are concomitant abnormalities of adrenocortical function in patients with cirrhosis. In the present study, we sought to assess adrenocortical function in patients with cirrhosis using measures of free cortisol appearance and elimination rates that are independent of serum concentrations of cortisol binding proteins. METHODS: Post hoc analysis used computer-assisted numerical and modelling methods with serial total and free cortisol concentration data to obtain rates of free cortisol appearance and elimination. Rate parameters were obtained in 114 patients with chronic liver disease, including Child-Pugh (CP) ≤8 (n = 53) and CP >8 (n = 61). RESULTS: Maximal cortisol secretion rate (CSRmax) was significantly decreased (p = 0.01) in patients with cirrhosis with CP >8 (0.28 nM/s; 95% CI 0.24-0.34) compared with those with CP ≤8 (0.39 nM/s; 95% CI 0.33-0.46), and CSRmax was negatively correlated with CP score (r = -0.19, p = 0.01). Free cortisol elimination rate was significantly (p = 0.04) decreased in the CP >8 group (0.16 ± 0.20 min-1) compared with that in the CP ≤8 group (0.21 ± 0.21 min-1), and free cortisol elimination rates were negatively correlated with CP score (r = -0.23, p = 0.01). A significant correlation between CSRmax and free cortisol elimination rate (r = 0.88, p <0.001) was observed. CONCLUSIONS: CSRmax and free cortisol elimination rates were significantly reduced according to severity of cirrhosis. In contrast to stimulated total cortisol concentrations, CSRmax estimates were independent of cortisol-binding protein concentrations. Results provide additional evidence of subnormal adrenocortical function in patients with cirrhosis. LAY SUMMARY: We applied numerical analytic methods to characterise adrenocortical function in patients with varying stages of chronic liver disease. We found that patients with more severe cirrhosis have decreased rate of free cortisol elimination and decreased maximal cortisol secretion rate, which is a measure of adrenocortical function. In contrast to conventional measures of adrenocortical function, those obtained using numerical methods were not affected by variation in corticosteroid binding globulin and albumin concentrations. We conclude that patients with cirrhosis demonstrate measurable abnormalities of adrenocortical function, evidence of which supports aspects of the hepatoadrenal syndrome hypothesis.

Bile acids and glucocorticoid metabolism in health and disease.

Glucocorticoids are regulators of stress response essential for survival. Liver disease can alter this homeostatic mechanism in patients with liver cirrhosis - a finding that might mirror the controversially discussed condition of critical illness related corticosteroid insufficiency. Underlying mechanisms might be shared molecular pathways in both bile acid as well as glucocorticoid metabolism at the level of synthesis, catabolism or the hypothalamus and the pituitary gland. Molecular links include the farnesoid X receptor FXR or the G protein-coupled bile acid receptor TGR5 expressed in the liver and the adrenals. In this review we sum up knowledge on the regulation of adrenal gland function and steroidogenesis, focussing on bile acids and potential alterations under cholestatic conditions, depict molecular links between glucocorticoid and bile acid metabolism and discuss the difficulties of assessment of adrenal function in humans in general and more specifically in liver diseases.

[Advances in the research of severe burn-related corticosteroid insufficiency].

Despite considerable advances in diagnosis and treatment of the critical illness-related corticosteroid insufficiency (CIRCI), it is still not clear that whether it is common in severe burn patients or not, and how clinical diagnosis, treatment, and research progress. Severe burn is a systemic disease involving the damage of multiple organs of the whole body. The course of the disease is relatively long, and there often exists persistent inflammation, immunosuppression, and catabolism. On the basis of CIRCI study, the epidemiological evidence, possible mechanism, suspicious clinical manifestations, diagnosis and treatment of severe burn-related corticosteroid insufficiency (SBRCI) were briefly reviewed in this article in order to help clinical diagnosis and treatment of SBRCI.

Relative Adrenal Insufficiency in Patients with Alcoholic Hepatitis.

BACKGROUND/AIMS: Alcoholic hepatitis (AH) is an acute hepatic inflammation associated with high morbidity and mortality. Treatment with steroids is known to decrease short-term mortality in severe AH patients. Hence, we hypothesize that adrenal insufficiency can be associated with severe AH and affects prognosis. The aim of this study was (1) to evaluate relative adrenal insufficiency (RAI) in patients with AH and (2) to Compare RAI with the severity of AH. METHODS: Newly diagnosed cases of AH hospitalized in SMS Medical College and Hospital, Department of Gastroenterology were, enrolled. All patients of AH were classified as mild and severe AH on the basis of Maddrey discriminant function (DF). After baseline serum cortisol, 25 IU ACTH (Adreno Corticotrophic Hormone) was injected intramuscularly and blood sample was collected after 1 h and assessed for serum cortisol. RAI was defined as <7 µg increase in the cortisol level from baseline. RAI was compared with severity of AH. RESULTS: Of 120 patients of AH, 58 patients fulfilled the inclusion criteria, in which 48 patients were diagnosed as severe AH and 10 patients were diagnosed as mild AH. In patients with severe AH, the baseline mean serum cortisol level was significantly high as compared with mild AH; 26 patients (54.16 %) of 48 patients with severe AH showed RAI (P ≤ 0.001).Whereas in patients with mild AH, none of patients showed RAI. RAI also showed negative correlation with DF. There was no difference in RAI with respect to acute kidney injury (AKI). CONCLUSION: RAI is a common entity in patients with severe AH, and it is related with the severity of disease.

Serum Cortisol Level in Indian Patients with Severe Sepsis/Septic Shock.

BACKGROUND: The relationship between cortisol level and sepsis is not known in Indian patients of severe sepsis/septic shock. AIMS: The study was done to determine the optimal range of cortisol levels, defining the adrenocortical response, and predicting the mortality, if possible, in the above type of patients. SETTINGS AND DESIGNS: The study was a single-centered prospective cohort study, conducted in a tertiary referral center, North India. MATERIALS AND METHODS: Sixty patients with severe sepsis (n = 30) and septic shock (n = 30) were recruited. Basal and postcosyntropin (1 µg)-stimulated cortisol levels were measured, and all patients were closely monitored with daily assessments of clinical and laboratory variables. Western diagnostic criteria were followed for defining adrenal insufficiency (AI). The end point was the survival assessed at day 28 or death, whichever came earlier. RESULTS: The mean basal (T0) and poststimulation (T30) cortisol levels were 31.77 ± 15.9 µg/dL and 37.58 ± 17.31 µg/dL, respectively. In all sepsis patients, 48.33% qualified as AI at T0 ≤ 24 µg/dL, 61.67% at delta cortisol (Δ = T30-T0) ≤7 µg/dL, and 78.33% at Δ ≤9 µg/dL. Using receiver operating characteristic curve, the area under the curve (AUC) was 0.4954, signifying poor prediction to death. CONCLUSIONS: Indians have completely different characteristics of cortisol levels in sepsis patients, in comparison to the Western data. They have higher range of basal cortisol levels, higher percentage of AI, and an inability to predict mortality with the cortisol levels. Hence, there is requirement of an international study to confirm the dichotomy of the results.

Glucocorticoid receptor density and binding affinity in healthy horses and horses with systemic inflammatory response syndrome.

BACKGROUND: Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis occurs in horses with systemic inflammatory response syndrome (SIRS). Peripheral resistance to glucocorticoids has not been investigated in horses. OBJECTIVE: To determine if glucocorticoid receptor (GR) function in horses can be measured using flow cytometry, and to use this information to evaluate HPA axis dynamics. ANIMALS: Eleven healthy adult horses in parts 1 and 2. Ten horses with SIRS and 10 age and sex matched controls in part 3. METHODS: Flow cytometry was used to evaluate GR density and binding affinity (BA) in 3 healthy horses in part 1. In part 2, exogenous ACTH was administered to eight healthy horses. Their cortisol response and GR properties were measured. In part 3, CBC, serum biochemistry, cortisol and ACTH, and GR properties were compared between controls without SIRS (n = 10) and horses with SIRS (n = 10), and between survivors and nonsurvivors (n = 4 and n = 6 respectively). RESULTS: Flow cytometry can be used to measure GR properties in equine PBMCs. No correlation was observed between plasma cortisol concentration and GR density or BA in healthy horses (r = -0.145, P = .428 and r = 0.046, P = .802 respectively). Nonsurvivors with SIRS had significantly decreased GR BA (P = .008). Horses with triglyceride concentration > 28.5 mg/dL had increased odds of nonsurvival (OR=117; 95% CI, 1.94-7,060). GR BA <35.79% was associated with nonsurvival (OR = 30.33; 95% CI, 0.96-960.5). CONCLUSIONS AND CLINICAL IMPORTANCE: Tissue resistance to glucocorticoids contributes to HPA axis dysfunction in adult horses with SIRS. These horses might benefit from treatment with exogenous glucocorticoids.

Three calculations of free cortisol versus measured values in the critically ill.

OBJECTIVES: To investigate the agreement between the calculated free cortisol levels according to widely applied Coolens and adjusted Södergård equations with measured levels in the critically ill. DESIGN AND METHODS: A prospective study in a mixed intensive care unit. We consecutively included 103 patients with treatment-insensitive hypotension in whom an adrenocorticotropic hormone (ACTH) test (250µg) was performed. Serum total and free cortisol (equilibrium dialysis), corticosteroid-binding globulin and albumin were assessed. Free cortisol was estimated by the Coolens method (C) and two adjusted Södergård (S1 and S2) equations. Bland Altman plots were made. RESULTS: The bias for absolute (t=0, 30 and 60min after ACTH injection) cortisol levels was 38, -24, 41nmol/L when the C, S1 and S2 equations were used, with 95% limits of agreement between -65-142, -182-135, and -57-139nmol/L and percentage errors of 66, 85, and 64%, respectively. Bias for delta (peak-baseline) cortisol was 14, -31 and 16nmol/L, with 95% limits of agreement between -80-108, -157-95, and -74-105nmol/L, and percentage errors of 107, 114, and 100% for C, S1 and S2 equations, respectively. CONCLUSIONS: Calculated free cortisol levels have too high bias and imprecision to allow for acceptable use in the critically ill.

Serum cortisol concentrations in horses with colic.

Few studies have evaluated cortisol concentrations in horses with colic. In humans with septic shock, high cortisol levels are associated with an increased risk of death. The objectives of this study were to compare the serum total cortisol concentrations (STCCs) in horses with colic to those without colic, and to assess whether the STCC relates to the pathological nature or outcome of the disease. STCCs were determined at presentation in horses with colic and in systemically healthy 'control' horses. Horses with colic were grouped based on clinical and clinico-pathological parameters at admission, treatment, lesion type and location, and outcome. Univariable and multivariable logistic regression were performed using two different outcome measures: (a) whether the horse had colic or not (yes vs. no), and (b) horse STCC (≥200 nmol/L vs. <200 nmol/L). Horses were more likely to have colic if they presented with high STCCs (≥200 nmol/L compared with <200 nmol/L). Horses with colic and with STCCs ≥200nmol/L were more likely to have moderate or severe colic signs (compared with mild colic) and heart rates >45 beats per min (compared with ≤45 beats per min). It was concluded that colic in horses is associated with elevated STCCs, and increased STCC in horses with colic appears to relate to the severity of the disease. STCCs may provide additional decision-making and prognostic information in horses with colic but further studies are required to avoid misinterpretations associated with the wide variation in STCCs.

The incidence of critical-illness-related-corticosteroid-insufficiency is associated with severity of traumatic brain injury in adult rats.

Traumatic brain injury (TBI) causes deleterious critical-illness-related-corticosteroid-insufficiency (CIRCI), leading to high mortality and morbidity. However, the incidence of CIRCI following different TBI severities is not fully defined. This study was designed to investigate mechanistically the effects of injury severity on corticosteroid response and the development of CIRCI in a rat model of experimentally controlled TBI. Adult male Wistar rats were randomly assigned to sham, mild injury, moderate injury or severe injury groups. TBI was induced using a fluid percussion device at magnitudes of 1.2-1.4 atm (mild injury), 2.0-2.2 atm (moderate injury), and 3.2-3.5 atm (severe injury). We first assessed the effects of injury severity on the mortality and CIRCI occurrence using electrical stimulation test to assess corticosteroid response. We also investigated a series of pathological changes in the hypothalamus, especially in the paraventricular nuclei (PVN), among different injury group including: apoptosis detected by a TUNEL assay, blood-brain-barrier (BBB) permeability assessed by brain water content and Evans Blue extravasation into the cerebral parenchyma, and BBB integrity evaluated by CD31 and Claudin-5 expression and transmission electron microscopy. We made the following observations. First, 6.7% of mild-injured, 13.3% of moderate-injured, and 68.8% of severe-injured rats developed CIRCI, with a peak incidence on post-injury day 7. Second, TBI-induced CIRCI is closely correlated with injury severity. As the injury severity rises both the incidence of CIRCI and mortality surge; Third, increased level of injury severity reduces the expression of endothelial tight junction protein, aggravate BBB permeability and exacerbate the ensuing neural apoptosis in the PVN of hypothalamus. These findings indicate that increased severity of TBI aggravate the incidence of CIRCI by causing damage to tight junctions of vascular endothelial cells and increasing neuronal apoptosis in the PVN of hypothalamus.