Relative adrenal failure in intensive care: an identifiable problem requiring treatment?

Apelin-13 as a Potential Biomarker in Critical Illness

BACKGROUND

The adrenocortical system and copeptin as prognostic markers were intensively investigated in critical illness. The potential predictive power of apelin-13 as a biomarker is largely unknown. We aimed to investigate the prognostic role of apelin-13 in relation to free cortisol, aldosterone, CRH, and copeptin in critically ill patients.

METHODS

In this prospective observational study, 124 critically ill patients (64 men, 60 women, median age: 70 (59-78) years) were consecutively enrolled at the time of admission. All routinely available clinical and laboratory parameters were evaluated and correlated to hormonal changes.

RESULTS

Serum apelin-13 was 1161 (617-2967) pg/mL in non-survivors vs. 2477 (800-3531) pg/mL in survivors (p = 0.054). The concentrations of apelin-13 and CRH had strong positive correlations (r = 0.685, p < 0.001) and were significantly higher in surviving non-septic patients (Apelin-13 (pg/mL): 2286 (790-3330) vs. 818 (574-2732) p < 0.05; CRH (pg/mL) 201 (84-317) vs. 89 (74-233) p < 0.05). Apelin-13 and free cortisol were independent determinants of survival in the multivariate Cox regression analysis, while copeptin, CRH, or aldosterone were not.

CONCLUSIONS

Beyond free cortisol, serum apelin-13 may also help refine prognostic predictions in the early phase of critical illness, especially in non-septic patients.

Management of Decompensated Cirrhosis and Associated Syndromes

Patients with cirrhosis account for 3% of intensive care unit admissions with hospital mortality exceeding 50%; however, improvements in survival among patients with acutely decompensated cirrhosis and organ failure have been described when treated in specialized liver transplant centers. Acute-on-chronic liver failure is a distinct clinical syndrome characterized by decompensated cirrhosis associated with one or more organ failures resulting in a significantly higher short-term mortality. In this review, we will discuss the management of common life-threatening complications in the patient with cirrhosis that require intensive care management including neurologic, cardiovascular, gastrointestinal, pulmonary, and renal complications.

Relative adrenal insufficiency in cirrhotic patients with ascites (hepatoadrenal syndrome)

AIM

Relative adrenal insufficiency (RAI) has been reported in critically ill patients with cirrhosis. We evaluated the prevalence of RAI and its relationship to clinical course in non-septic cirrhosis patients with ascites.

METHODS

The study included 66 consecutive non-septic cirrhosis patients with ascites. RAI was defined by a delta cortisol lower than 9 μg/dL and/or a peak cortisol lower than 18 μg/dL.

RESULTS

Sixty-six patients with cirrhosis and ascites were studied. The mean Child-Turcotte-Pugh (CTP) and model for end stage liver disease (MELD) scores were 10.6 ± 1.9 and 21.5 ± 7.3, respectively. The prevalence of RAI in patients with cirrhosis and ascites was 47% (31/66). The prevalence of RAI in patients with and without spontaneous bacterial peritonitis, renal failure and type 1 hepatorenal syndrome (HRS) was comparable. Baseline hyponatremia was common in RAI (42% versus 17%, p = 0.026). There was a significant correlation of prevalence of RAI with prothrombin time, international normalized ratio, MELD scores and CTP class. During follow-up, there was no association between RAI and the risk to develop new infections, severe sepsis, type 1 HRS and death.

CONCLUSIONS

RAI is common in non-septic cirrhotic patients with ascites and its prevalence increases with severity of liver disease. However, it does not affect the short-term outcome in these patients.

Review: Endotoxin and the hypothalamo-pituitary-adrenal (HPA) axis

Endotoxin is considered to be a systemic (immunological) stressor eliciting a prolonged activation of the hypothalamo-pituitary-adrenal (HPA) axis. The HPA-axis response after an endotoxin challenge is mainly due to released cytokines (IL-1, IL-6 and TNF-α) from stimulated peripheral immune cells, which in turn stimulate different levels of the HPA axis. Controversy exists regarding the main locus of action of endotoxin on glucocorticoid secretion, since the effect of endotoxin on this neuro-endocrine axis has been observed in intact animals and after ablation of the hypothalamus; however, a lack of LPS effect has been described at both pituitary and adrenocortical levels. The resulting increase in adrenal glucocorticoids has well-documented inhibitory effects on the inflammatory process and on inflammatory cytokine release. Therefore, immune activation of the adrenal gland by endotoxin is thought to occur by cytokine stimulation of corticosteroid-releasing hormone (CRH) production in the median eminence of the hypothalamus, which, in turn stimulates the secretion of ACTH from the pituitary. Acute administration of endotoxin stimulates ACTH and cortisol secretion and the release of CRH and vasopressin (AVP) in the hypophysial portal blood. During repeated endotoxemia, tolerance of both immune and HPA function develops, with a crucial role for glucocorticoids in the modulation of the HPA axis. A single exposure to a high dose of LPS can induce a long-lasting state of tolerance to a second exposure of LPS, affecting the response of plasma TNF-α and HPA hormones. Although there are gender differences in the HPA response to endotoxin and IL-1, these responses are enhanced by castration and attenuated by androgen and estrogen replacement. Estrogens attenuate the endotoxin-induced stimulation of IL-6, TNF-α and IL-1ra release and subsequent activation in postmenopausal women. There appears to be a temporal and functional relation between the HPA-axis response to endotoxin and nitric oxide formation in the neuro-endocrine hypothalamus, suggesting a stimulatory role for nitric oxide in modulating the HPA response to immune challenges.

Relative adrenal insufficiency in severe acute variceal and non-variceal bleeding: influence on outcomes

BACKGROUND & AIMS

Relative adrenal insufficiency (RAI) is common in critical illness and in cirrhosis, and is related with worse outcomes. The prevalence of RAI may be different in variceal and non-variceal bleeding and whether it may influence outcomes in these settings is unclear. This study assesses RAI and its prognostic implications in cirrhosis with variceal bleeding and in peptic ulcer bleeding.

METHODS

Patients with severe bleeding (systolic pressure <100 mmHg and/or haemoglobin <8 g/L) from oesophageal varices or from a peptic ulcer were included. Adrenal function was evaluated within the first 24 h and RAI was diagnosed as delta cortisol <250 nmol/L after 250 μg of i.v. corticotropin.

RESULTS

Sixty-two patients were included, 36 had cirrhosis and variceal bleeding and 26 without cirrhosis had ulcer bleeding. Overall, 15 patients (24%) had RAI, 8 (22%) with variceal and 7 (24%) with ulcer bleeding. Patients with RAI had higher rate of bacterial infections. Baseline serum and salivary cortisol were higher in patients with RAI (P < 0.001) while delta cortisol was lower (P < 0.001). There was a good correlation between plasma and salivary cortisol (P < 0.001). The probability of 45-days survival without further bleeding was lower in cirrhotic patients with variceal bleeding and RAI than in those without RAI (25% vs 68%, P = 0.02), but not in non-cirrhotic patients with peptic ulcer bleeding with or without RAI (P = 0.75).

CONCLUSION

The prevalence of RAI is similar in ulcer bleeding and in cirrhosis with variceal bleeding. Cirrhotic patients with RAI, but not those with bleeding ulcers, have worse prognosis.

Dynamic pituitary-adrenal interactions in response to cardiac surgery

OBJECTIVES

To characterize the dynamics of the pituitary-adrenal interaction during the course of coronary artery bypass grafting both on and off pump. Since our data pointed to a major change in adrenal responsiveness to adrenocorticotropic hormone, we used a reverse translation approach to investigate the molecular mechanisms underlying this change in a rat model of critical illness.

DESIGN

CLINICAL STUDIES

Prospective observational study.

ANIMAL STUDIES

Controlled experimental study.

SETTING

CLINICAL STUDIES

Cardiac surgery operating rooms and critical care units.

ANIMAL STUDIES

University research laboratory.

SUBJECTS

CLINICAL STUDIES

Twenty, male patients.

ANIMAL STUDIES

Adult, male Sprague-Dawley rats.

INTERVENTIONS

CLINICAL STUDIES

Coronary artery bypass graft-both on and off pump.

ANIMAL STUDIES

Injection of either lipopolysaccharide or saline (controls) via a jugular vein cannula.

MEASUREMENTS AND MAIN RESULTS

CLINICAL STUDIES

Blood samples were taken for 24 hours from placement of the first venous access. Cortisol and adrenocorticotropic hormone were measured every 10 and 60 minutes, respectively, and corticosteroid-binding globulin was measured at the beginning and end of the 24-hour period and at the end of operation. There was an initial rise in both levels of adrenocorticotropic hormone and cortisol to supranormal values at around the end of surgery. Adrenocorticotropic hormone levels then returned toward preoperative values. Ultradian pulsatility of both adrenocorticotropic hormone and cortisol was maintained throughout the perioperative period in all individuals. The sensitivity of the adrenal gland to adrenocorticotropic hormone increased markedly at around 8 hours after surgery maintaining very high levels of cortisol in the face of "basal" levels of adrenocorticotropic hormone. This sensitivity began to return toward preoperative values at the end of the 24-hour sampling period.

ANIMAL STUDIES

Adult, male Sprague-Dawley rats were given either lipopolysaccharide or sterile saline via a jugular vein cannula. Hourly blood samples were subsequently collected for adrenocorticotropic hormone and corticosterone measurement. Rats were killed 6 hours after the injection, and the adrenal glands were collected for measurement of steroidogenic acute regulatory protein, steroidogenic factor 1, and dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 messenger RNAs and protein using real-time quantitative polymerase chain reaction and Western immunoblotting, respectively. Adrenal levels of the adrenocorticotropic hormone receptor (melanocortin type 2 receptor) messenger RNA and its accessory protein (melanocortin type 2 receptor accessory protein) were also measured by real-time quantitative polymerase chain reaction. In response to lipopolysaccharide, rats showed a pattern of adrenocorticotropic hormone and corticosterone that was similar to patients undergoing coronary artery bypass grafting. We were also able to demonstrate increased intra-adrenal corticosterone levels and an increase in steroidogenic acute regulatory protein, steroidogenic factor 1, and melanocortin type 2 receptor accessory protein messenger RNAs and steroidogenic acute regulatory protein, and a reduction in dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 and melanocortin type 2 receptor messenger RNAs, 6 hours after lipopolysaccharide injection.

CONCLUSIONS

Severe inflammatory stimuli activate the hypothalamic-pituitary-adrenal axis resulting in increased steroidogenic activity in the adrenal cortex and an elevation of cortisol levels in the blood. Following coronary artery bypass grafting, there is a massive increase in both adrenocorticotropic hormone and cortisol secretion. Despite a subsequent fall of adrenocorticotropic hormone to basal levels, cortisol remains elevated and coordinated adrenocorticotropic hormone-cortisol pulsatility is maintained. This suggested that there is an increase in adrenal sensitivity to adrenocorticotropic hormone, which we confirmed in our animal model of immune activation of the hypothalamic-pituitary-adrenal axis. Using this model, we were able to show that this increased adrenal sensitivity results from changes in the regulation of both stimulatory and inhibitory intra-adrenal signaling pathways. Increased understanding of the dynamics of normal hypothalamic-pituitary-adrenal responses to major surgery will provide us with a more rational approach to glucocorticoid therapy in critically ill patients.

Controversies surrounding critical illness-related corticosteroid insufficiency in animals

OBJECTIVES

To describe the controversies surrounding critical illness-related corticosteroid insufficiency (CIRCI) and the use of hydrocortisone in critically ill patients, and to present published diagnostic and therapeutic strategies in companion veterinary species.

ETIOLOGY

Critical illness-related corticosteroid insufficiency may be due to hypothalamic-pituitary-adrenal (HPA) axis dysfunction, alterations in cortisol-plasma protein binding, target cell enzymatic changes, changes in glucocorticoid receptor (GR) function, or a combination of these or other factors present during critical illness.

DIAGNOSIS

Appropriate tests to diagnose CIRCI are unknown. The diagnosis in people is currently based on response to treatment with hydrocortisone. There is currently no consensus on appropriate diagnostic feature(s) in veterinary species.

THERAPY

Low-dose hydrocortisone is the treatment of choice for patients with CIRCI.

PROGNOSIS

If the patient survives the critical illness, prognosis for resolution of CIRCI and hydrocortisone dependence is very good.

Free and total cortisol levels are useful prognostic markers in critically ill patients: a prospective observational study

OBJECTIVE

The role of cortisol in the prediction of mortality risk in critical illness is controversial in the literature. The aim of this study was to evaluate the prognostic value of cortisol concentrations in a mixed population of critically ill patients in medical emergencies.

DESIGN

In this prospective, observational study, measurement of total (TC) and free cortisol (FC) levels was made in the serum samples of 69 critically ill patients (39 males and 30 females, median age of 74 years) at admission (0 h) and 6, 24, 48, and 96 h after admission.

METHODS

Cortisol levels were determined using HPLC coupled high-resolution ESI-TOF mass spectrometry. The severity of disease was calculated by prognostic scores. Statistical analyses were performed using the SPSS 22.0 software.

RESULTS

The range of TC varied between 49.9 and 8797.8 nmol/l, FC between 0.4 and 759.9 nmol/l. The levels of FC at 0, 6, 24, and 48 h and TC at 0, 6 h were significantly elevated in non-survivors and correlated with the predicted mortality. The prognostic value of these cortisol levels was comparable with the routinely used mortality scores. In predictive models, FC at 6, 24, and 48 h proved to be an independent determinant of mortality.

CONCLUSIONS

The predictive values of FC in the first 2 days after admission and TC within 6 h are comparable with the complex, routinely used mortality scores in evaluating the prognosis of critically ill patients. The cortisol response probably reflects the severity of disease.

Adrenal response after trauma is affected by time after trauma and sedative/analgesic drugs

BACKGROUND

The adrenal response in critically ill patients, including trauma victims, has been debated over the last decade. The aim of this study was to assess the early adrenal response after trauma.

METHODS

Prospective, observational study of 50 trauma patients admitted to a level-1-trauma centre. Serum and saliva cortisol were followed from the accident site up to five days after trauma. Corticosteroid binding globulin (CBG), dehydroepiandrosterone (DHEA) and sulphated dehydroepiandrosterone (DHEAS) were obtained twice during the first five days after trauma. The effect of time and associations between cortisol levels and; severity of trauma, infusion of sedative/analgesic drugs, cardiovascular dysfunction and other adrenocorticotropic hormone (ACTH) dependent hormones (DHEA/DHEAS) were studied.

RESULTS

There was a significant decrease over time in serum cortisol both during the initial 24 h, and from the 2nd to the 5th morning after trauma. A significant decrease over time was also observed in calculated free cortisol, DHEA, and DHEAS. No significant association was found between an injury severity score ≥ 16 (severe injury) and a low (< 200 nmol/L) serum cortisol at any time during the study period. The odds for a serum cortisol < 200 nmol/L was eight times higher in patients with continuous infusion of sedative/analgesic drugs compared to patients with no continuous infusion of sedative/analgesic drugs.

CONCLUSION

Total serum cortisol, calculated free cortisol, DHEA and DHEAS decreased significantly over time after trauma. Continuous infusion of sedative/analgesic drugs was independently associated with serum cortisol < 200 nmol/L.

Endobiogeny: a global approach to systems biology (part 2 of 2)

ENDOBIOGENY AND THE BIOLOGY OF FUNCTIONS ARE BASED ON FOUR SCIENTIFIC CONCEPTS THAT ARE KNOWN AND GENERALLY ACCEPTED: (1) human physiology is complex and multifactorial and exhibits the properties of a system; (2) the endocrine system manages metabolism, which is the basis of the continuity of life; (3) the metabolic activity managed by the endocrine system results in the output of biomarkers that reflect the functional achievement of specific aspects of metabolism; and (4) when biomarkers are related to each other in ratios, it contextualizes one type of function relative to another to which is it linked anatomically, sequentially, chronologically, biochemically, etc.

A new pathological scoring method for adrenal injury in rats with severe acute pancreatitis

These studies investigated the appearance and function of adrenal glands in rats with severe acute pancreatitis (SAP) and established a new histopathological score to evaluate adrenal histopathological changes. Severe acute pancreatitis relied on retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. The damage of SAP was estimated by serum amylase, secretory phospholipase A2 and pancreatic histopathology. Light and electron microscopy of adrenal gland, and the levels of serum corticosterone were investigated. These results showed that the generally ascending trend of adrenal pathological score was inversely proportional to the generally descending trend of serum corticosterone levels, but parallel with the changes of pancreatic histopathology. Herein, the new adrenal histopathological score was effective in the evaluation of adrenal injury following SAP. It may indirectly reflect the variation of serum cortisol levels and the severity of pancreatitis to a certain extent.

Relative adrenal insufficiency in decompensated cirrhosis: Relationship to short-term risk of severe sepsis, hepatorenal syndrome, and death

The prevalence of relative adrenal insufficiency (RAI) in critically ill cirrhosis patients with severe sepsis is over 60% and associated features include poor liver function, renal failure, refractory shock, and high mortality. RAI may also develop in noncritically ill cirrhosis patients but its relationship to the clinical course has not yet been assessed. The current study was performed in 143 noncritically ill cirrhosis patients admitted for acute decompensation. Within 24 hours after hospitalization adrenal function, plasma renin activity, plasma noradrenaline and vasopressin concentration, and serum levels of nitric oxide, interleukin-6 and tumor necrosis factor alpha were determined. RAI was defined as a serum total cortisol increase <9 μg/dL after 250 μg of intravenous corticotropin from basal values <35 μg/dL. Patients were followed for 3 months. RAI was detected in 26% of patients (n = 37). At baseline, patients with RAI presented with lower mean arterial pressure (76 ± 12 versus 83 ± 14 mmHg, P = 0.009) and serum sodium (131 ± 7 versus 135 ± 5 mEq/L, P = 0.007) and higher blood urea nitrogen (32 ± 24 versus 24 ± 15 mg/dl, P = 0.06), plasma renin activity (7.1 ± 9.9 versus 3.4 ± 5.6 ng/mL*h, P = 0.03), and noradrenaline concentration (544 ± 334 versus 402 ± 316 pg/mL, P = 0.02). During follow-up, patients with RAI exhibited a higher probability of infection (41% versus 21%, P = 0.008), severe sepsis (27% versus 9%, P = 0.003), type-1 hepatorenal syndrome (HRS) (16% versus 3%, P = 0.002), and death (22% versus 7%, P = 0.01).

CONCLUSION

RAI is frequent in noncritically ill patients with acute decompensation of cirrhosis. As compared with those with normal adrenal function, patients with RAI have greater impairment of circulatory and renal function, higher probability of severe sepsis and type-1 HRS, and higher short-term mortality.

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.

Low dose adrenocorticotropic hormone test and adrenal insufficiency in critically ill acquired immunodeficiency syndrome patients

CONTEXT

Prevalence of adrenal insufficiency (AI) is not uncommon in HIV infected population. However, AI is rarely diagnosed in clinical practice because many patients have non-specific symptoms and signs. Critical illness in such patients further complicates the evaluation of adrenal function. A 1μgm ACTH test can be used for diagnosis, since it results in more physiological levels of ACTH. A serum cortisol of <18 μg/dL, 30 or 60-minutes after ACTH test has been accepted as indicative of AI, but many experts advocate the normal cortisol response should exceed 25 μg/dL, in critically ill patients.

AIM

To determine the prevalence of AI in critically ill AIDS patients, by using 1 μg ACTH test and also, to compare the diagnostic criteria for adrenal insufficiency between cortisol response of <18 μg/dL and <25 μg/dL.

SETTINGS AND DESIGN

This prospective study was done in the Department of Medicine.

MATERIALS AND METHODS

After taking blood for basal plasma cortisol from AIDS affected fifty adult men and women aged over 18 yrs, 1 μg ACTH was given intravenously, and blood samples were again collected at 30 and 60 minutes for plasma cortisol estimation.

STATISTICAL ANALYSIS

It was done by Mann-Whitney test.

RESULTS

Prevalence of AI was 74% (37 patients) and 92% (46 patients), when the peak stimulated cortisol level of <18 μg/dL and <25 μg/dL, respectively, was used.

CONCLUSION

AI is more prevalent in critically ill AIDS patients. Hence, this test can be performed for early intervention and better management.

Validation of a low-dose ACTH stimulation test in healthy adult horses

OBJECTIVE

To determine the lowest ACTH dose that would induce a maximum increase in serum cortisol concentration in healthy adult horses and identify the time to peak cortisol concentration.

DESIGN

Evaluation study.

ANIMALS

8 healthy adult horses.

PROCEDURES

Saline (0.9% NaCl) solution or 1 of 4 doses (0.02, 0.1, 0.25, and 0.5 μg/kg [0.009, 0.045, 0.114, and 0.227 μg/lb]) of cosyntropin (synthetic ACTH) were administered IV (5 treatments/horse). Serum cortisol concentrations were measured before and 30, 60, 90, 120, 180, and 240 minutes after injection of cosyntropin or saline solution; CBCs were performed before and 30, 60, 120, and 240 minutes after injection.

RESULTS

For all 4 doses, serum cortisol concentration was significantly increased, compared with the baseline value, by 30 minutes after administration of cosyntropin; no significant differences were detected among maximum serum cortisol concentrations obtained in response to administration of doses of 0.1, 0.25, and 0.5 μg/kg. Serum cortisol concentration peaked 30 minutes after administration of cosyntropin at a dose of 0.02 or 0.1 μg/kg, with peak concentrations 1.5 and 1.9 times, respectively, the baseline concentration. Serum cortisol concentration peaked 90 minutes after administration of cosyntropin at a dose of 0.25 or 0.5 μg/kg, with peak concentrations 2.0 and 2.3 times, respectively, the baseline concentration. Cosyntropin administration significantly affected WBC, neutrophil, and eosinophil counts and the neutrophil-to-lymphocyte ratio.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that in healthy horses, administration of cosyntropin at a dose of 0.1 μg/kg resulted in maximum adrenal stimulation, with peak cortisol concentration 30 minutes after cosyntropin administration.

Bone physiology and therapeutics in chronic critical illness

Modern medical practices allow patients to survive acute insults and be sustained by machinery and medicines for extended periods of time. We define chronic critical illness as a later stage of prolonged critical illness that requires tracheotomy. These patients have persistent elevations of inflammatory cytokines, diminished hypothalamic-pituitary function, hypercatabolism, immobilization, and malnutrition. The measurement of bone turnover markers reveals markedly enhanced osteoclastic bone resorption that is uncoupled from osteoblastic bone formation. We review the mechanisms by which these factors contribute to the metabolic bone disease of chronic critical illness and suggest potential therapeutics.

Dysfunctional pancreatic beta-cells of critical stress play a more prominent role in the development of stress diabetes in critically burned Korean subjects

The purposes of this study are to identify the predictive parameters for the development of stress-induced hyperglycemia and to investigate the glucose metabolic homeostasis in critically burned Korean subjects. We conducted a prospective cross-sectional study of adult patients with glucose management targeting fasting and postprandial blood glucose levels less than 140 and 200 mg/dL, respectively, in patients with unrecognized diabetes. Clinical and laboratory stress parameters and insulin secretory and sensitivity parameters were assessed. Stimulated C-peptide and 24-hour urinary free cortisol predicted new-onset stress diabetes requiring insulin therapy. The subjects requiring insulin therapy were leaner and more insulin sensitive than insulin-free subjects, without significance. Glycated hemoglobin, stimulated C-peptide, homeostasis model assessment of insulin resistance, and age had a significant influence on the mean daily dose of insulin. Our present data showed that Korean subjects with dysfunctional pancreatic beta-cells of critical stress are prone to become stress diabetic and require more insulin to control the hyperglycemia.

A prospective multicenter study of adrenal function in critically ill children

RATIONALE

Adrenal insufficiency is a clinical condition associated with fluid- and catecholamine-resistant hypotension.

OBJECTIVES

The objectives of this study were to determine the prevalence of adrenal insufficiency, risk factors and potential mechanisms for its development, and its association with clinically important outcomes in critically ill children.

METHODS

A prospective, cohort study was conducted from 2005 to 2008 in seven tertiary-care, pediatric intensive care units in Canada on patients up to 17 years of age with existing vascular access. Adrenocorticotropic hormone stimulation tests (1 microg) were performed and adrenocorticotropic hormone levels measured in all participants.

MEASUREMENTS AND MAIN RESULTS

A total of 381 patients had adrenal testing on admission. The prevalence of adrenal insufficiency was 30.2% (95% confidence interval, 25.9-35.1). Patients with adrenal insufficiency had higher baseline cortisol levels (28.6 microg/dl vs. 16.7 microg/dl, P < 0.001) and were significantly older (11.5 yr vs. 2.3 yr, P < 0.001) than those without adrenal insufficiency. Adrenal insufficiency was associated with an increased need for catecholamines (P < 0.001) and more fluid boluses (P = 0.026). The sensitivity and specificity of the low-dose adrenocorticotropic hormone stimulation test were 100% and 84%, respectively.

CONCLUSIONS

Adrenal insufficiency occurs in many disease conditions in critically ill children and is associated with an increased use of catecholamines and fluid boluses. It is likely multifactorial in etiology and is associated with high baseline cortisol levels. Further research is necessary to determine which of these critically ill children are truly cortisol deficient before any treatment recommendations can be made.

Relative adrenal insufficiency

PURPOSE OF REVIEW

This article will review the clinical presentation, diagnosis, and treatment of acute adrenal insufficiency and explore the concept of 'relative adrenal insufficiency' in the critically ill.

RECENT FINDINGS

Current dogma suggests that as many as 70% of patients in intensive care units with the clinical syndromes of sepsis or cardiogenic shock have 'relative adrenal insufficiency'. This article will explore how this concept came into being and why the concept has no clinical utility.

SUMMARY

This article will provide an approach to critically ill patients that will identify adrenal insufficiency when it is part of the pathophysiology of a given patient and, at the same time, prevent the unnecessary treatment of critically ill patients with high doses of glucocorticoids for 'stress' when adrenal insufficiency is not a factor in the illness.

A prospective study on the incidence and predictive factors of relative adrenal insufficiency in Korean critically-ill patients

This study was undertaken to evaluate the incidence and risk factors associated with relative adrenal insufficiency (RAI) in Korean critically-ill patients. All patients who were admitted to the Medical Intensive Care Unit (MICU) of Samsung Medical Center between January 1, 2006 and April 30, 2007 were prospectively evaluated using a short corticotropin stimulation test on the day of admission. RAI was defined as an increase in the serum cortisol level of <9 microg/dL from the baseline after administration of 250 microg of corticotropin. In all, 123 patients were recruited and overall the incidence of RAI was 44% (54/123). The presence of septic shock (P=0.001), the Simplified Acute Physiology Score (SAPS) II (P=0.003), the Sequential Organ Failure Assessment (SOFA) score (P=0.001), the mean heart rate (P=0.040), lactate levels (P=0.001), arterial pH (P=0.047), treatment with vasopressors at ICU admission (P=0.004), and the 28-day mortality (P=0.041) were significantly different between patients with and without RAI. The multivariate analysis showed that the SOFA score was an independent predictor of RAI in critically-ill patients (odd ratio=1.235, P=0.032). Our data suggest that RAI is frequently found in Korean critically-ill patients and that a high SOFA score is an independent predictor of RAI in these patients.

[Adrenal insufficiency in cirrhosis]

Cortisol is a pluripotent hormone that is vital in the host adaptation to stress. It is essential to maintain the normal vascular tone, endothelial integrity and vascular permeability. Consequently, the failure of an appropriate adrenal response in the setting of critical illness, alteration known as relative adrenal insufficiency, may have important clinical consequences. The diagnosis of this entity is not possible on clinical grounds and relies on the measurement of plasma cortisol levels prior and after adrenal stimulation with synthetic corticotrophin. Several studies performed in the general population have shown that relative adrenal insufficiency contributes to vascular hyporesponsiveness in septic shock and increases mortality. However, contradictory data exist regarding the effects of hydrocortisone administration in these patients. Moreover, recent studies indicate that relative adrenal insufficiency is very frequent in patients with advanced cirrhosis and septic shock and in fulminant hepatic failure. This chapter summarizes the main aspects of the physiopathology, diagnosis and treatment of this entity in patients with acute or chronic liver disease.

Pituitary-adrenal function in dogs with acute critical illness

OBJECTIVE

To evaluate pituitary-adrenal function in critically ill dogs with sepsis, severe trauma, and gastric dilatation-volvulus (GDV).

DESIGN

Cohort study.

ANIMALS

31 ill dogs admitted to an intensive care unit (ICU) at Washington State University or the University of Pennsylvania; all dogs had acute critical illness for < 48 hours prior to admission.

PROCEDURES

Baseline and ACTH-stimulated serum cortisol concentrations and baseline plasma ACTH concentrations were assayed for each dog within 24 hours after admission to the ICU. The change in cortisol concentrations (Delta-cortisol) was calculated for each dog. Morbidity and mortality data were recorded for each patient.

RESULTS

Overall, 17 of 31 (55%) acutely critically ill dogs had at least 1 biochemical abnormality suggestive of adrenal gland or pituitary gland insufficiency. Only 1 (3%) dog had an exaggerated response to ACTH stimulation. Dogs with Delta-cortisol < or = 83 nmol/L were 5.7 times as likely to be receiving vasopressors as were dogs with Delta-cortisol > 83 nmol/L. No differences were detected among dogs with sepsis, severe trauma, or GDV with respect to mean baseline and ACTH-stimulated serum cortisol concentrations, Delta-cortisol, and baseline plasma ACTH concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Biochemical abnormalities of the hypothalamic-pituitary-adrenal axis indicative of adrenal gland or pituitary gland insufficiency were common in critically ill dogs, whereas exaggerated responses to ACTH administration were uncommon. Acutely ill dogs with Delta-cortisol < or = 83 nmol/L may be more likely to require vasopressors as part of the treatment plan.

Endocrine issues in the pediatric intensive care unit

This article reviews selected issues of endocrine concerns in the pediatric intensive care unit, exclusive of diabetic ketoacidosis. The sympathoadrenergic arm of the neuroendocrine stress response is described, followed by discussions of two topics of particular current concern: critical illness hyperglycemia and relative adrenal insufficiency. A selected set of common scenarios encountered in the daily practice of intensive care follows.

Low-dose steroid therapy does not affect hemodynamic response in septic shock patients

PURPOSE

Several studies showed that low-dose steroid therapy (LDST) in patients with septic shock leads to a significantly shorter duration of shock and a decreased mortality. However, these results have been criticized. Our purpose was to evaluate the effects of LDST on time to shock reversal and mortality in septic shock.

MATERIALS AND METHODS

We retrospectively studied 203 patients with septic shock admitted to the intensive care unit of our tertiary hospital. A short corticotropin test was performed in all patients within 72 hours of septic shock onset. We performed a propensity score analysis through a logistic regression model with baseline relevant characteristics, and evaluated the influence of LDST on time to shock reversal and inhospital mortality.

RESULTS

One hundred twenty-four patients were treated with LDST (steroid group) and 79 without LDST (control group). Patients treated with steroids presented higher Simplified Acute Physiology Score II and maximum Sepsis-Related Organ Failure Assessment scores. Both groups presented similar baseline and stimulated cortisol values. The hazard ratio of remaining on shock adjusted by severity of illness, inadequate antibiotic, and propensity score was 1.15 (95% confidence interval 0.71-1.86) for patients treated with steroids. Inhospital mortality was 62% in the steroid group and 52% in the control group (P = .84). Logistic regression analysis with propensity score neither showed differences between steroid and control group in the inhospital mortality. Predictors of inhospital mortality were age, maximum Sepsis-Related Organ Failure Assessment score, and inadequate antibiotics.

CONCLUSION

In our study, treatment with low-dose steroid therapy was not associated to a reduction in time to shock reversal or mortality.

Diagnosis and treatment of adrenal insufficiency in the critically ill patient

The reported incidence of adrenal insufficiency varies greatly depending on the population of critically ill patients studied, the test and cutoff levels used, and the severity of illness. Several studies have shown increased mortality in patients with very low or very high baseline cortisol levels. Manifestations of adrenal insufficiency in the critically ill patient are numerous and nonspecific, so clinicians are urged to have a high index of suspicion and be alert to important diagnostic clues, such as hyponatremia, hyperkalemia, and hypotension, that are refractory to fluids and vasopressors without any clear causation. Multiple tests have been developed to diagnose adrenal insufficiency, but the most commonly used test in the intensive care unit is the adrenocorticotropic hormone (ACTH) stimulation test. The low-dose ACTH stimulation test has been shown to be more sensitive and specific than the high-dose test; however, the high-dose test is preferred since the low-dose test has not been validated. Although diagnosing adrenal insufficiency continues to be difficult in the critically ill patient, administration of high-dose corticosteroids, defined as methylprednisolone 30 mg/kg/day or more (or its equivalent), over a short period of time provides no overall benefit and may even be harmful; however, administration of low-dose corticosteroids for a longer duration decreases both the amount of the time that vasopressors are required and mortality at 28 days. Hydrocortisone 200-300 mg/day, administered in divided doses or as a continuous infusion, is the preferred corticosteroid in patients with septic shock and should be started as early as possible. For patients in whom the ACTH stimulation test cannot be given immediately, clinicians are urged to consider using dexamethasone until such time that the test can be administered, since, unlike hydrocortisone, it does not interfere with the cortisol test.

Hyperreninemic hypoaldosteronism syndrome, plasma concentrations of interleukin-6 and outcome in critically ill patients with liver cirrhosis

OBJECTIVE

To investigate the relation between the adrenal production of gluco- and mineralocorticoids, the inflammatory status and the outcome in critically ill patients with liver cirrhosis.

DESIGN

Prospective descriptive study.

SETTING

Medical intensive care unit (ICU) in a university hospital.

PATIENTS

Fifty consecutive patients with liver cirrhosis.

INTERVENTIONS

A corticotropin stimulation test within 12h following ICU admission. Plasma cortisol concentration was measured before and after the test. Renin and aldosterone concentrations, as well as interleukin-6 (IL-6) level to assess the pro-inflammatory status, were measured only before the test. Impaired adrenal function was defined as cortisol response to the test less than 9microg/dl. Hyperreninemic hypoaldosteronism syndrome was defined as basal renin over aldosterone ratio (RRA) higher than 2.

MEASUREMENTS AND RESULTS

Forty-one (82%) patients had impaired adrenal function, and 26 patients (52%) presented with RRA > 2. Patients with RRA > 2 exhibited greater disease severity and organ dysfunction scores at baseline, higher levels of serum renin and IL-6, and a greater ICU mortality rate, but risk-adjusted mortality rates were not different between the two groups. Renin and IL-6 plasma concentrations were positively correlated. Finally, in a Cox regression analysis, independent predictors of 30-day mortality were hyperreninemic hypoaldosteronism syndrome, IL-6 higher than 400pg/ml and severe renal failure.

CONCLUSIONS

Adrenal dysfunction was common in critically ill cirrhotic patients. Hyperreninemic hypoaldosteronism syndrome was related to a greater pro-inflammatory status and degree of acute organ failure, and was independently associated with a worse prognosis.

Endocrine aspects of critical illness

Metabolic disorders and endocrine changes are common and relevant in critically ill patients. Thereby, endocrinopathies, electrolyte or metabolic derangements may either pre-exist or develop, and left unattended, may lead to significant morbidity and mortality. The homeostatic corrections which have emerged in the course of human evolution to cope with the catastrophic events during critical illness involve a complex multisystem endeavour, of which the endocrine contribution is an integral component. Although the repertoire of endocrine changes has been probed in some detail, discerning the vulnerabilities and failures of this system is far more challenging. The ensuing endocrine topics illustrate some of the current issues reflecting attempts to gain an improved insight and clinical outcome for critical illness. Disturbances in glucose and cortisol homeostasis during critical illness are two controversially debated topics in the current literature. The term "hormokine" encompasses the cytokine like behaviour of hormones during inflammation and infections. The concept is based on an ubiquitous expression of calcitonin peptides during sepsis. Adrenomedullin, another member of the calcitonin peptide superfamily, was shown to complement and improve the current prognostic assessment in lower respiratory tract infections. Procalcitonin is the protopye of "hormokine" mediators circulating procalcitonin levels increase several 10,000-fold during sepsis improve the clinical assessment especially of respiratory tract infections and sepsis safely and markedly reduces antibiotic usage in non-bacterial respiratory tract infections and meningitis. Adrenomedullin, another member of the calcitonin peptide superfamily, was shown to complement and improve the current prognostic assessment in lower respiratory tract infections. Hormokines are not only biomarkers of infection. Hormokines are also pivotal inflammatory mediators. Like all mediators, their role during systemic infections is basically beneficial, possibly to combat invading microbes. Yet, with increasing levels they can become harmful for their host. Multiple mechanisms of action were proposed. In several animal models the modulation and neutralization of hormokines during infection was shown to improve survival and thus might open new treatment options for severe infections, especially of the respiratory tract.

Basal serum cortisol levels are not predictive of response to corticotropin but have prognostic significance in patients with septic shock

Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis of 68 patients with septic shock who underwent short corticotropin stimulation testing. RAI was defined as an increase in cortisol level <9 microgram/dL from baseline, and results showed that 48 patients (70.6%) had this insufficiency. According to the univariate analysis, the RAI group had significantly higher simplified acute physiology score II (SAPS II) and sequential organ failure assessment (SOFA) scores than the non-RAI group. The incidence of RAI was the same regardless of the basal serum cortisol level (p=0.447). The hospital mortality rate was 58.8% and was not significantly different between the RAI and non-RAI groups. However, a high basal serum cortisol level (> or =30 microgram/dL) was significantly associated with in-hospital mortality. In conclusion, our data suggest that basal serum cortisol levels are not predictive of serum cortisol response to corticotropin but have a significant prognostic value in patients with septic shock.

Effect of low doses of cosyntropin on serum cortisol concentrations in clinically normal dogs

OBJECTIVE

To determine the lowest of 5 doses of cosyntropin (1.0, 0.5, 0.1, 0.05, or 0.01 microg/kg) administered IV that stimulates maximal cortisol secretion in clinically normal dogs.

ANIMALS

10 clinically normal dogs.

PROCEDURES

5 dose-response experiments were performed in each of the dogs. Each dog received 5 doses of cosyntropin (1.0, 0.5, 0.1, 0.05, and 0.01 microg/kg) IV in random order (2-week interval between each dose). Serum samples for determination of cortisol concentrations were obtained before (baseline) and at 10, 20, 30, 40, 50, 60, 120, and 240 minutes after cosyntropin administration.

RESULTS

Compared with baseline values, mean serum cortisol concentration in the study dogs increased significantly after administration of each of the 5 cosyntropin doses. Mean peak serum cortisol concentration was significantly lower after administration of 0.01, 0.05, and 0.1 microg of cosyntropin/kg, compared with findings after administration of 0.5 and 1.0 microg of cosyntropin/kg. After administration of 0.5 and 1.0 microg of cosyntropin/kg, mean peak serum cortisol concentration did not differ significantly; higher doses of cosyntropin resulted in more sustained increases in serum cortisol concentration, and peak response developed after a longer interval.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of cosyntropin IV at a dose of 0.5 microg/kg induced maximal cortisol secretion in healthy dogs. Serum cortisol concentration was reliably increased in all dogs after the administration of each of the 5 doses of cosyntropin. These data should be useful in subsequent studies to evaluate the hypothalamic-pituitary-adrenal axis in healthy and critically ill dogs.

Acute adrenal crisis after orthopedic surgery for pathologic fracture

Background

Adrenal crisis after surgical procedure is a rare but potentially catastrophic life-threatening event. Its manifestations, such as hypotension, tachycardia, hypoxia, and fever mimic the other more common postoperative complications. Clinical outcome is dependent upon early recognition of the condition and proper management with exogenous steroid administration.

Case presentation

We report a 75-year-old man who presented with shock immediately after surgery for a femoral fracture from lung cancer metastasis. Anemia and severe hyponatremia were detected. Despite adequate fluid resuscitation, nonspecific symptoms including hypotension, tachycardia, hypoxia, fever and confusion occurred. Emergent CT revealed enlarged bilateral adrenal glands. Under the diagnosis of adrenal crisis due to metastatic infiltration of adrenal glands, the patient was treated with appropriate steroid replacement resulting in rapid improvement and recovery.

Conclusion

We describe a case of adrenal crisis caused by the lack of adrenal reserve based on metastatic involvement and surgical stress, the first published case of adrenal crisis after surgery for a pathologic fracture from lung cancer metastasis. Surgeons treating pathologic fractures should be aware of this complication and familiar with its appropriate therapy because of increasing opportunity to care patients with metastatic bone tumors due to recent advances in cancer treatment.

The hypothalamic-pituitary-adrenal axis in critical illness

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

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

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

Do we have reliable biochemical markers to predict the outcome of critical illness?

Current outcome prediction in critically ill patients relies on the art of clinical judgement and/or the science of prognostication using illness severity scores. The biochemical processes underlying critical illness have increasingly been unravelled. Several biochemical markers reflecting the process of inflammation, immune dysfunction, impaired tissue oxygenation and endocrine alterations have been evaluated for their predictive power in small subpopulations of critically ill patients. However, none of these parameters has been validated in large populations of unselected ICU patients as has been done for the illness severity and organ failure scores. A simple biochemical predictor of ICU mortality will probably remain elusive because the processes underlying critical illness are very complex and heterogeneous. Future prognostic models will need to be far more sophisticated.

Relative adrenal insufficiency among trauma patients in a community hospital

BACKGROUND

The integrity of the hypothalamic-pituitary-adrenal (HPA) axis is a major determinant of the host response to stress. Recent studies have proven that low doses of hydrocortisone and fludrocortisone can significantly reduce mortality in patients with relative adrenal insufficiency (RAI) without increasing adverse events.

STUDY DESIGN

This study was a retrospective chart review of patients in a community hospital who carried the diagnosis of both adrenal insufficiency and trauma.

RESULTS

Over a 16-month period, the incidence of RAI among severely injured patients (injury severity score >/= 13) was 3%. Only 1 patient had the classic electrolyte findings of adrenal insufficiency, but all had vasopressor-dependent hypotension. Our patients had an average intensive care unit day stay of 37 days and were not tested for RAI on average until day 20 of their intensive care unit stay. Random cortisol levels did not correlate with injury severity. Six patients (75%) had a positive hemodynamic response to steroids.

CONCLUSIONS

Relative adrenal insufficiency after trauma is rare. In RAI, clear signs and symptoms are usually absent. The clinical diagnostic clue may be the unexplained hypotension and the resistance to inappropriately high doses of inotropes and vasoactive agents. The hemodynamic profile often shows a hyperdynamic state of high cardiac output and a low systemic vascular resistance. Baseline serum cortisol levels did not correlate with injury severity scores in this group of patients, which suggests a defect in the HPA axis. An intensive care unit day stay of greater than or equal to 20 days, ventilator dependence/acute respiratory distress syndrome, and a hyperdynamic state mandates consideration of endocrine testing to exclude RAI. Physiologic doses of hydrocortisone can reverse this potentially life-threatening syndrome.

Adrenal infections

Adrenal infections are an important but under-recognized clinical entity. The adrenal gland can be infected by a myriad of pathogens including fungi, viruses, parasites, and bacteria. Infection can directly or indirectly cause tissue damage and alteration in endocrine function. Direct damage occurs via microbial replication and local production of toxic compounds, such as endotoxins. Indirect damage results from alterations in the regulation of a host's immunologic and endocrine mediators in response to damage by a microbe at a distant site. Variations in pathogen tropism, adrenal anatomy, and host immune integrity contribute to the progression of active disease and discernable adrenal dysfunction. Early recognition and intervention in the case of adrenal infection can significantly improve outcome, demonstrating the need for increased clinical suspicion in the appropriate clinical setting.

Serum cortisol levels in children with acute bacterial and aseptic meningitis

OBJECTIVE

To study serum cortisol levels in acute childhood meningitis with respect to the severity of illness and the outcome.

DESIGN

Prospective observational study.

SETTING

Pediatric services of a tertiary care teaching and referral hospital.

SUBJECTS

A total of 30 consecutive children, 2 months to 12 yrs of age, with suspected bacterial meningitis.

METHODS

Serum cortisol levels (by enzyme-linked immunosorbent assay) obtained at admission were correlated with clinical characteristics (including Glasgow Coma Scale and Pediatric Risk of Mortality scores) recorded at admission and with neurologic and hearing status 2 months after discharge using SPSS 10.0.

RESULTS

Mean +/- sd serum cortisol was 467 +/- 251 ng/dL in patients with bacterial (n = 16) and 319 +/- 159 ng/dL in aseptic meningitis (n = 14, p = .068). Glasgow coma scale score, systolic blood pressure, age, Pediatric Risk of Mortality, and cerebrospinal fluid protein were significant independent predictors of serum cortisol on stepwise multivariate regression analysis (each had an R change of >5%). Patients with neurologic or hearing sequelae had significantly higher median serum cortisol (450 ng/mL, n = 12) than those without sequelae (300 ng/mL, n = 17; p = .043 by Mann-Whitney U test). On multivariate logistic regression analysis, a serum cortisol of >/=420 ng/mL (odds ratio, 0.022; 95% confidence interval, 0.01-0.43) and systolic blood pressure (odds ratio, 1.35; 95% confidence interval, 1.04-1.74) were significant independent predictors of neurologic and hearing sequelae.

CONCLUSION

Low serum cortisol is uncommon in acute bacterial meningitis of nonmeningococcal pathogenesis. Very high levels are likely to be associated with sequelae.

Absolute and relative adrenal insufficiency in children with septic shock*

OBJECTIVE

Corticosteroid replacement improves outcome in adults with relative adrenal insufficiency and catecholamine-resistant septic shock. We evaluated the relationship of absolute and relative adrenal insufficiency to catecholamine-resistant septic shock in children.

DESIGN

Prospective cohort study.

SETTING

University hospital pediatric intensive care unit in Brazil.

PATIENTS

Fifty-seven children with septic shock. Children with HIV infection, those with a history of adrenal insufficiency, and those submitted to any steroid therapy or etomidate within the week before diagnosis of septic shock were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A short corticotropin test (250 microg) was performed, and cortisol levels were measured at baseline and 30 and 60 mins posttest. Adrenal insufficiency was defined by a response < or =9 microg/dL. Absolute adrenal insufficiency was further defined by a baseline cortisol <20 microg/dL and relative adrenal insufficiency by a baseline cortisol >20 microg/dL. Absolute adrenal insufficiency was observed in 18% of children, all of whom had catecholamine-resistant shock. Relative adrenal insufficiency was observed in 26% of children, of whom 80% had catecholamine-resistant and 20% had dopamine/dobutamine-responsive shock. All children with fluid-responsive shock had a cortisol response >9 microg/dL. Children with adrenal insufficiency had an increased risk of catecholamine-resistant shock (relative risk, 1.88; 95% confidence interval, 1.26-2.79). However, mortality was independently predicted by chronic illness or multiple organ failure (p < .05), not adrenal insufficiency.

CONCLUSIONS

Absolute and relative adrenal insufficiency is common in children with catecholamine-resistant shock and absent in children with fluid-responsive shock. Studies are warranted to determine whether corticosteroid therapy has a survival benefit in children with relative adrenal insufficiency and catecholamine-resistant septic shock.

Risk factors of relative adrenocortical deficiency in intensive care patients needing mechanical ventilation

OBJECTIVE

To study the factors associated with relative adrenocortical deficiency in mechanically ventilated, critically ill patients.

DESIGN AND SETTING

Prospective observational study in a multidisciplinary ICU of a university-affiliated teaching hospital.

PATIENTS

Sixty-two consecutive, acutely ill patients needing mechanical ventilation for more than 24 h.

MEASUREMENTS AND RESULTS

A high-dose short corticotropin test 24 h after endotracheal intubation. Relative adrenocortical deficiency ("nonresponder" group of patients) was defined by a rise in cortisol less than 90 microg/l after stimulation. Twenty-seven patients were classified as nonresponders and 35 as responders. On univariate analysis nonresponders were more often men, had lower mean arterial pressure, required vasoactive agents more often, had lower creatinine clearance, higher SAPS II, higher organ dysfunction scores, and received etomidate as a single bolus for endotracheal intubation more often than responders. On multivariate analysis, only etomidate administration was related to relative adrenocortical deficiency (OR 12.21; 95% CI 2.99-49.74) while female gender was protective (OR 0.13; 95% CI 0.03-0.57).

CONCLUSIONS

A single bolus infusion of etomidate could be a major risk factor for the development of relative adrenocortical deficiency in ICU patients for at least 24 h after administration. Female gender is an independent protective factor.

Interaction Between Dexamethasone Treatment and the Corticotropin Stimulation Test in Septic Shock

OBJECTIVE:

To review dexamethasone interaction with corticotropin stimulation testing, particularly as it applies to treating septic shock.

DATA SOURCES:

Pertinent literature was identified through MEDLINE (1966–February 2004) using combinations of the key words dexamethasone, adrenocorticotropic hormone stimulation, and pretreat. Only articles written in the English language and evaluating human subjects were considered. Reference lists of identified articles were reviewed for additional citations.

DATA SYNTHESIS:

Accurate interpretation of the corticotropin stimulation test is important to identify patients with septic shock who may benefit from corticosteroid supplementation. In healthy volunteers, short-term dexamethasone administration prior to the corticotropin stimulation test may depress the baseline cortisol level, but does not inhibit the response to the corticotropin challenge. This may result in a slight increase in the difference between baseline and post-stimulation values.

CONCLUSIONS:

In 2 small trials in healthy adults, short-term, low-dose dexamethasone pretreatment decreased baseline cortisol levels, but values following corticotropin stimulation were unaffected. Accordingly, caution in interpreting corticotropin stimulation test results is warranted. However, the application of the findings from these studies to patients with septic shock is difficult, given the important differences in physiology between normal and septic patients. As of December 29, 2004, a dexamethasone dose >2 mg or prolonged dexamethasone therapy (>2 days, totaling 4 mg) preceding corticotropin stimulation has not been studied in any population.

A Patient with Concurrent Primary Hyperaldosteronism and Adrenal Insufficiency

A 73-year-old man with history of longstanding primary hyperaldosteronism developed adrenal insufficiency after he ruptured an abdominal aortic aneurysm and had a prolonged hypotensive episode. The patient presented as a diagnostic dilemma with recurrent hypotensive episodes and hypokalemia. A cosyntropin (Cortrosyn) stimulation test demonstrated a blunted cortisol response while at the same time having a suppressed plasma renin activity level and an elevated plasma aldosterone value. Diagnosis of Addison disease and concurrent primary hyperaldosteronism resulted in the patient's being treated with an unusual combination of prednisone and spironolactone followed by marked improvement in his symptoms.