Variations in adrenocortical responsiveness during severe bacterial infections. Unrecognized adrenocortical insufficiency in severe bacterial infections

Solumedrol Treatment for Severe Sepsis in Humans with a Blunted Adrenocorticotropic Hormone-Cortisol Response: A Prospective Randomized Double-Blind Placebo-Controlled Pilot Clinical Trial

PURPOSE

To test the benefits of Solumedrol treatment in sepsis patients with a blunted adrenocorticotropic hormone (ACTH)-cortisol response (delta <13 µg/dL) with regard to the number of days on ventilator, days on intravenous blood pressure support, length of time in an intensive care unit (ICU), 14-day mortality, and 28-day mortality. The trial was prospective, randomized, and double-blind. As part of a larger sepsis trial, 54 patients with sepsis had an intravenous ACTH stimulation test using 250 µg of ACTH, and serum cortisol was measured at times 0, 30, and 60 min. Eleven patients failed to increase their cortisol concentration above 19.9 µg/dL and were excluded from the clinical trial as they were considered to have adrenal insufficiency. The remaining 43 patients had a baseline cortisol of 32 ± 1 µg/dL increased to 38 ± 3 µg/dL at 30 min and 40 ± 3 at 60 min. All cortisol responses were <12.9 µg/dL between time 0 and time 60, which is defined as a blunted cortisol response to intravenous ACTH administration. Twenty-one were randomized to receive 20 mg of intravenous Solumedrol and 22 were randomized to receive a matching placebo every 8 h for 7-days. There was no significant difference between the two randomized groups. Data analysis was carried out bya two-tailed test and P < .05 as significant.

RESULTS

Results: The mean age was 51 ± 2 (mean ± SEM) with 61% female. Groups were well matched with regard to APACHE III score in Solumedrol versus placebo (59 ± 6 vs 59 ± 6), white blood cell count (18.8 ± 2.2 vs 18.6 ± 2.6), and incidence of bacteremia (29 vs 39%). The 28-day mortality rate was reduced in the Solumedrol treated arm (43 ± 11 vs 73 ± 10%; P < .05). There was no change in days in ICU, days on blood pressure agents, or days on ventilator. Seven days of high-dose intravenous Solumedrol treatment (20 mg every 8 h) in patients with a blunted cortisol response to ACTH was associated with an improved 28-day survival. This small study suggests that an inability to increase endogenous cortisol production in patients with sepsis who are then provided steroid treatment could improve survival.

Critical illness-related corticosteroid insufficiency in dogs with systemic inflammatory response syndrome: A pilot study in 21 dogs

Critical illness-related corticosteroid insufficiency (CIRCI) refers to a lack of adequate corticosteroid activity, which occurs in up to 48% of dogs with sepsis. However, data regarding the occurrence of CIRCI in critically-ill dogs are still scarce. This study aimed to assess: (1) the relationship between CIRCI and clinicopathological inflammatory markers, hypotension and mortality; and (2) the impact of low-dose hydrocortisone treatment on survival. Twenty-one dogs diagnosed with systemic inflammatory response syndrome (SIRS) were enrolled in a prospective case-control study. All dogs were initially evaluated for adrenal function with an ACTH stimulation test and dogs with Δcortisol ≤ 3 μg/dL were diagnosed with CIRCI. Mean arterial pressure (MAP), white blood cell (WBC), band neutrophils (bNs), c-reactive protein (CRP), and 28-day mortality rate were assessed. Fourteen dogs were treated with low-dose hydrocortisone. The relationships between CIRCI and MAP, WBC, bN, CRP, basal cortisol and mortality were investigated, as was the association between mortality and hydrocortisone treatment. Ten of 21 (48%) dogs were diagnosed with CIRCI. Increased bNs were associated with the presence of CIRCI (P = 0.0075). CRP was higher in dogs with CIRCI (P = 0.02). Fourteen of 21 (66%) dogs died during the study (6/14 had CIRCI). Basal hypercortisolemia (>5 μg/dL) was associated with increased risk of mortality (P = 0.025). Based on our diagnostic criteria, CIRCI occurs frequently in dogs with SIRS and was associated with increased bNs and increased CRP. In this study, CIRCI and low-dose hydrocortisone treatment were not significantly associated with mortality, but basal hypercortisolemia was associated with increased mortality.

Unexpectedly Low Natriuretic Peptide Levels in Patients With Heart Failure

OBJECTIVES

The purpose of this study was to determine the frequency of unexpectedly low natriuretic peptide (NP) levels in a clinical population.

BACKGROUND

Higher NP concentrations are typically observed as a compensatory response to elevated cardiac wall stress. Under these conditions, low NP levels may be indicative of a "NP deficiency."

METHODS

We identified 3 clinical scenarios in which high B-type natriuretic peptide (BNP) levels would be expected: 1) hospitalization for heart failure (HF); 2) abnormal cardiac structure or function; or 3) abnormal hemodynamics. In Vanderbilt's electronic health record, 47,970 adult patients had BNP measurements. A total of 13,613 patients had at least 1 of the 3 conditions (hospitalized HF, n = 9,153; abnormal cardiac structure/function, n = 7,041; abnormal hemodynamics, n = 363). We quantified the frequency of low BNP levels. We performed whole exome sequencing of the NPPB gene in a subset of 9 patients.

RESULTS

Very low BNP levels (<50 pg/ml) were observed in 4.9%, 14.0%, and 16.3% of patients with hospitalized HF, abnormal cardiac structure/function, or abnormal hemodynamics, respectively. A small proportion (0.1% to 1.1%) in each group had BNP levels below detection limits. Higher body mass index was the strongest predictor of unexpectedly low BNP. Exome sequencing did not reveal coding variation predicted to alter detection of BNP by clinical assays.

CONCLUSIONS

A subset of patients with confirmed HF or cardiac dysfunction have unexpectedly low BNP levels. Obesity is the strongest correlate of unexpectedly low BNP levels. Our findings support the possible existence of NP deficiency, which may render some individuals more susceptible to volume or pressure overload.

Investigation of serum cortisol concentration as a potential prognostic marker in hospitalized dogs: a prospective observational study in a primary care animal hospital

BACKGROUND

Dogs with various medical diseases are usually treated at hospitals; however, the prognostic markers in dogs remain unknown. The aim of this study was to investigate the ability of serum cortisol concentration (SCC) to predict the prognosis of dogs with medical diseases. At 0 and 24 h after hospitalization, the neutrophil count, lymphocyte count, blood glucose concentration, and SCC were measured. Survival for 30 days from the time of hospitalization was investigated, and the dogs were divided into a survivor group and a non-survivor group.

RESULTS

The neutrophil count at 24 h, SCC at 24 h, increase in SCC from 0 to 24 h (Inc-SCC), and the rate of increase in SCC from 0 to 24 h (R-Inc-SCC) were significantly higher in the non-survivor group than in the survivor group. The area under the receiver operating characteristic (ROC) curve values for the neutrophil count at 24 h, SCC at 24 h, Inc-SCC, and R-Inc-SCC were 0.695, 0.72, 0.63, and 0.66, respectively. Using the highest area under the ROC curve value, the sensitivity and specificity of SCC at a cutoff level of 6.6 μg/dL for predicting mortality were 89.5 and 61.9%, respectively. Moreover, the Kaplan-Meier curves confirmed the significant prognostic influence of SCC at 24 h.

CONCLUSIONS

SCC as a marker of stress is a useful biomarker for predicting the prognosis of dogs with medical diseases requiring hospital treatment.

Evaluation of Random Plasma Cortisol and the Low Dose Corticotropin Test as Indicators of Adrenal Secretory Capacity in Critically Ill Patients: A Prospective Study

It is unclear whether a random plasma cortisol measurement and the corticotropin (ACTH) test adequately reflect glucocorticoid secretory capacity in critical illness. This study aimed to determine whether these tests provide information representative of the 24 hour period.

Plasma cortisol was measured hourly for 24 hours in 21 critically ill septic patients followed by a corticotropin test with 1 μg dose administered intravenously. Serum and urine were analysed for ACTH and free cortisol respectively. Marked hourly variability in plasma cortisol was evident (coefficient of variation 8–30%) with no demonstrable circadian rhythm. The individual mean plasma cortisol concentrations ranged from 286±59 nmol/l to 796± 83 nmol/l. The 24 hour mean plasma cortisol was strongly correlated with both random plasma cortisol (r2 0.9, P<0.0001) and the cortisol response to corticotropin (r2 0.72, P<0.001). Only nine percent of patients increased their plasma cortisol by 250 nmol/l after corticotropin (euadrenal response). However, 35% of non-responders had spontaneous hourly rises >250 nmol/l thus highlighting the limitations of a single point corticotropin test. Urinary free cortisol was elevated (865±937 nmol) in both corticotropin responders and non-responders suggesting elevated plasma free cortisol. No significant relationship was demonstrable between plasma cortisol and ACTH.

We conclude that although random cortisol measurements and the low dose corticotropin tests reliably reflect the 24 hour mean cortisol in critical illness, they do not take into account the pulsatile nature of cortisol secretion. Consequently, there is the potential for erroneous conclusions about adrenal function based on a single measurement. We suggest that caution be exercised when drawing conclusions on the adequacy of adrenal function based on a single random plasma cortisol or the corticotropin test.

Elevated Baseline Cortisol Levels Are Predictive of Bad Outcomes in Critically Ill Children

OBJECTIVE

The definition of an adequate adrenal response in critically ill children continues to be controversial. We aimed to evaluate the cortisol levels at baseline and after adrenocorticotropin (ACTH) stimulation and determine their association to clinical outcome of critically ill children.

METHODS

All children who underwent an ACTH test in the pediatric intensive care unit (PICU) in a tertiary medical center between 2006 and 2013 were included in the study. Data on age, sex, diagnosis, vasoactive-inotropic score, length of pediatric intensive care unit stay, and mortality were obtained. Laboratory variables included hematologic and chemistry data, arterial lactate, and total plasma cortisol levels at baseline and after ACTH stimulation.

RESULTS

Ninety-nine patients (61 males; median [range] age, 2 [0-204] months) were enrolled. The mortality rate of children with a baseline cortisol level of 600 nmol/L or greater was 36% (12/33 patients) versus 18% (12/66 patients) for children with a baseline cortisol level of less than 600 nmol/L (odds ratio, 2.6 [95% confidence interval, 1-6.6]; P = 0.05). There was a positive correlation between baseline cortisol and lactate levels (r = 0.40, P < 0.0001), vasoactive-inotropic scores (r = 0.24, P = 0.02), and mortality (P = 0.05). There was no correlation between peak cortisol measured at the ACTH test or the delta increment of cortisol from baseline and mortality.

CONCLUSIONS

A high baseline cortisol level in critically ill children was associated with more severe illness, higher lactate level, and a higher mortality rate. Routine baseline cortisol assessment is recommended to identify patients at high mortality risk.

Controversies in Corticosteroid use for Sepsis

BACKGROUND

Severe sepsis and septic shock are potentially deadly conditions managed in the emergency department (ED). Management centers on source control, fluid resuscitation, broad-spectrum antimicrobials, and vasopressors as needed. The use of corticosteroids is controversial.

OBJECTIVE

To evaluate the evidence behind corticosteroid therapy in patients with septic shock.

DISCUSSION

Septic shock is associated with severe mortality and morbidity. Cytokine release produces a systemic inflammatory state. Vasopressor-resistant septic shock warrants consideration of the disease state and other pathologies such as adrenal insufficiency. Many studies and meta-analyses have been conducted evaluating corticosteroid therapy for this population. High-dose corticosteroid therapy is associated with increased harm, but physiologic-dose corticosteroids may decrease the need for vasopressors. Mortality benefit is controversial, with much of the literature demonstrating no effect. The risk of superinfection is not suggested by the majority of studies. The Surviving Sepsis Campaign advises consideration of corticosteroids in patients with vasopressor and fluid-resistant septic shock. Patients with vasopressor-resistant septic shock with no contraindications to corticosteroids may benefit from hydrocortisone 100 mg intravenously (i.v.) every 8 h or 50 mg i.v. every 6 h. Fludrocortisone is not recommended at this time.

CONCLUSIONS

Septic shock is associated with higher mortality, specifically for patients with vasopressor and fluid-refractory shock. The use of physiologic-dose steroids can reduce vasopressor requirements and improve time of shock resolution. Current literature suggests corticosteroids do not improve mortality, but further studies are required.

Adrenal Insufficiency in the Intensive Care Setting

In the intensive care setting, the question of adrenal insufficiency arises most frequently in patients whose endogenous adrenal function may be suppressed by pre ceding glucocorticoid therapy or in patients with the acquired immunodeficiency syndrome. Less often the question arises in patients whose adrenal tissue may have been destroyed by autoimmune disease, tuber culosis, meningococcal or other infection, hemorrhage, or replacement by malignancy, or in patients whose adrenal function has been suppressed by certain drugs. Measurements of plasma adrenocorticotrophic hor mone (ACTH), cortisol, aldosterone, and renin levels and the response of cortisol and aldosterone to exoge nously administered ACTH form the basis for clinically evaluating the adequacy of a patient's adrenal function. The naturally occurring glucocorticoid, hydrocortisone, remains the cornerstone of adrenal replacement therapy along with appropriate fluid and electrolyte administra tion. In rare instances the addition of a mineralocor ticoid is necessary. A brief review of the use of mega- dose glucocorticoids in the treatment of sepsis, shock, and the adult respiratory distress syndrome is included.

The utility of the corticotropin test to diagnose adrenal insufficiency in critical illness: an update

OBJECTIVE

One of the most common dynamic testing procedures for assessment of adrenocortical function is the standard corticotropin or the cosyntropin test. The aim of this review was to examine the evidence base underlying the corticotropin test in the management of the critically ill patient.

DATA SYNTHESIS

The principle behind the corticotropin test is the demonstration of an inappropriately low cortisol production in response to exogenous ACTH, a situation analogous to physiological stress. The corticotropin test was originally described in nonstressed subjects, and its applicability and interpretation in the setting of critical illness continues to generate controversy. Attempting to determine the prevalence of an abnormal corticotropin test in critical illness is complicated by the use of different end-points and different populations. Moreover, the test result is also influenced by the assay used for measurement of plasma cortisol. Trials assessing the relationship between corticotropin response and severity of stress and organ dysfunction have produced divergent results, which may reflect differences in the methodology and the association being measured. Moreover, controversy exists with respect to the methodology and the interpretation with respect to the following variables: dose of corticotropin, end-points for assessment of total or free cortisol, effect of plasma cortisol variability, adrenal blood flow and its equivalence with other tests of adrenocortical function.

CONCLUSIONS

The corticotropin test is used widely in the evaluation of adrenocortical function in the endocrine clinics. Its role in the critically ill patient is less well established. Several confounding variables exist and to have a 'one-size-fits-all' approach with a single end-point in the face of several methodological and pathophysiological confounders may be flawed and may result in the institution of inappropriate therapy. The current evidence does not support the use of the corticotrophin test in critical illness to assess adrenocortical function and guiding steroid therapy in critical illness.

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.

Increased Total Serum Random Cortisol Levels Predict Mortality in Critically Ill Trauma Patients

Dysfunction in the hypothalamopituitary adrenal axis is thought to exist; however, there continues to be controversy about what level of serum cortisol corresponds to adrenal insufficiency. Few studies have focused on the significance of serum random cortisol in the critically ill trauma patient. Trauma patients with total serum random cortisol levels drawn in the intensive care unit within the first seven days of hospitalization were retrospectively reviewed. The primary outcome measured was in-hospital mortality. Two hundred forty-two patients were analyzed. Non-survivors had significantly higher mean cortisol levels than survivors (28.7 ± 15.80 mg/dL vs 22.9 ± 12.35 mg/dL, P = 0.01). Patients with cortisol 30 mg/dL or greater were more likely to die with odds ratio of 2.7 (95% confidence interval [CI], 1.5 to 5). The odds ratio increased to 4.0 and 3.8 (95% CI, 1.4 to 11.4 and 1.3 to 10.9) when cortisol was drawn on hospital Day 2 and Days 3 through 7, respectively. Among nonsurvivors, patients with an injury severity score less than 25 had significantly higher cortisol levels than patients with an Injury Severity Score 25 or higher (35.3 ± 19.21 mg/dL vs 25.7 ± 13.21 mg/dL, P = 0.009). Patients with massive transfusion, traumatic brain injury, spinal cord injury, or solid organ injury did not have significantly different cortisol levels. The covariate-adjusted area under the receiver operating characteristic curve indicated that cortisol level has a 77 per cent accuracy in differentiating survivors from nonsurvivors. Higher cortisol levels were predictive of mortality in critically ill trauma patients. Whether serum cortisol level is a marker that can be modified remains an area of interest for future study.

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.

Adrenal insufficiency in cardiothoracic patients: an evaluation of the corticotrophin stimulation test and other diagnostic methods

PURPOSE

The purposes of the study were to determine the incidence of adrenal insufficiency (AI) using several published techniques, compare the response rates using a low-dose (LD) corticotropin (ACTH) stimulation test vs a standard dose (SD), and identify the technique that is most closely related to vasopressor use.

MATERIALS AND METHODS

Consecutive adult patients who were undergoing open heart surgery for CAD or valvular disease were prospectively enrolled. Exclusion criteria included history of steroid use, operative steroid, or etomidate administration. Postoperatively, each patient underwent ACTH stimulation with 1 μg (LD) and 249 μg (SD), 60 minutes apart. Agreement among the tests was evaluated, and vasopressor use was compared between groups.

RESULTS

There were 40 patients evaluated. The incidence of AI based on operative change, postoperative values, and LD-ACTH and SD-ACTH tests was 53%, 38%, 60%, and 38%, respectively. Agreement between the LD- and SD-ACTH tests was 73% (κ = 0.476, P = .001). There was a significant difference in the need for (93% vs 52%, P = .013) and duration (18.9 [0-180.6] vs 0.6 [0-73.2] hours, P = .003) of vasopressor therapy in patients with and without AI but only using the SD-ACTH definition.

CONCLUSION

The incidence of AI will vary greatly based on technique used for diagnosis. The SD-ACTH stimulation test should be used to determine AI in open heart patients postoperatively because of the close association with vasopressor usage.

Association of hyperglycemia, glucocorticoids, and insulin use with morbidity and mortality in the pediatric intensive care unit

BACKGROUND

Studies of pediatric intensive care unit (PICU) patients have shown a significant association of morbidity and mortality with hyperglycemia. We retrospectively evaluated the degree of hyperglycemia as well as its correlation with glucocorticoid and insulin use and assessed its association with hospital length of stay (LOS) and mortality. This study preceded the initiation of a standard glycemic control protocol.

METHODS

We examined medical records at Kosair Children's Hospital for all PICU admissions from 2008 of patients without diabetes mellitus. Critical illness hyperglycemia (CIH) was defined by having three or more peak glucose values greater than thresholds of 110, 140, 180, and 200 mg/dl. These patients were evaluated for glucocorticoid, insulin use, and outcome measures.

RESULTS

We evaluated the eligible 1173 admissions, where 10.5% of these patients reached the highest threshold (200 mg/dl) of CIH. Glucocorticoids were used in 43% of these patients, with dexamethasone being the most common (58%). There was a significant correlation between glucocorticoids and higher peak glucose values, where 81% of the patients who were above the 200 mg/dl cutoff level were treated with glucocorticoids. Only 36.8% in that group were also treated with insulin. Patients at the 200 mg/dl cutoff had the highest median PICU and total hospital length of stays (4 and 10 days, respectfully). Mortality was associated with increasing glucose levels, reaching 18.7% among patients above the 200 mg/dl cutoff.

CONCLUSION

Hyperglycemia was prevalent in the PICU and was associated with increased morbidity, as characterized by increased LOS and increased mortality. Glucocorticoid use was prevalent among patients exhibiting hyperglycemia. Insulin use was uncommon.

Adrenocortical (dys)function in septic shock - a sick euadrenal state

A central feature of the endocrine pathophysiology of septic shock is thought to be the existence of adrenal dysfunction. Based on changes in glucocorticoid secretion and responsiveness, protein binding, and activity. These changes have been described by the terms "Relative Adrenal Insufficiency" (RAI), or "Critical Illness Related Corticosteroid Insufficiency" (CIRCI), and form part of the rationale for trials of glucocorticoid treatment in septic shock. Diagnostic criteria for these conditions have been based on plasma cortisol profiles and have proven notoriously difficult to establish. The uncertainty in this area arises from the inability of current tests to clearly identify who is truly glucocorticoid "deficient" at a cellular level, and hence who requires supplemental glucocorticoid administration. Emerging data suggest that there may be abnormalities in the tissue activity of glucocorticoids in patients with severe sepsis and plasma profiles may not be reliable indicators of tissue glucocorticoid activity, We put forward an alternative point of view, that is the spectrum of adrenocortical dysfunction in sepsis - plasma and tissue, can be grouped under the umbrella of a "sick euadrenal syndrome" rather than an adrenocortical insufficiency.

Assessment of adrenocortical reserve in stable patients with cirrhosis

BACKGROUND & AIMS

Adrenal insufficiency (AI) is reported in critically ill patients with cirrhosis and is associated with increased mortality. It is unclear if AI is an underlying condition or triggered by critical events (e.g. sepsis). We investigated AI in cirrhosis without infection or hemodynamic instability.

METHODS

A total of 101 consecutive patients with cirrhosis were studied. AI was defined by a total serum cortisol (TC) <18 μg/dl at 20 or 30 min after injection of 1 μg of tetracosactrin. Transcortin, calculated free cortisol (cFC), and free cortisol index (FCI) were assessed in a subgroup of 41 patients, with FCI>12 representing normal adrenal function.

RESULTS

AI was present in 38 patients (38%). Child score (median, 10 vs 7, p<0.0001), MELD score (median, 17 vs 12, p<0.0001), ascites (68% vs 37%, p<0.01), basal TC (median,7.6 vs 14.9 μg/dl, p<0.001), albumin (28 ± 0.8 vs 33 ± 0.7 g/L, p<0.0001), INR (median, 1.6 vs 1.2, p<0.0001), total bilirubin (median, 51 vs 31 μmol/L, p<0.05), total cholesterol (median, 120 vs 142, p<0.05), and LDL (median, 76 vs 81, p<0.05) were significantly different between those with and without AI. ROC curves showed a basal TC ≤ 12.8 μg/dl to be a cut-off value closely associated with AI. The cFC was significantly related to TC for baseline values (R=0.94, p<0.0001), peak values (R=0.90, p<0.0001), and delta values (R=0.95, p<0.0001), in patients with and without AI. However, no patient had a FCI<12.

CONCLUSIONS

AI defined by an abnormal response to 1 μg tetracosactrin is frequent in stable patients with cirrhosis, in the absence of infections or hemodynamic instability and is related to the severity of liver disease. However, evaluation of the true incidence of AI should comprise direct assays of free cortisol. Clinical consequences of AI need to be explored.

Relative adrenal insufficiency in the intensive care population; background and critical appraisal of the evidence

Dysfunction of the hypothalamo-pituitary adrenal axis has become a central feature in descriptions of the pathophysiology of sepsis. However; despite hundreds of published articles including literature reviews and consensus statements, controversy still exists regarding the fundamental nature of the disorder and its relevance to clinical management. Often referred to as 'relative adrenal insufficiency', a recent consensus conference has proposed the alternate term 'critical illness related corticosteroid insufficiency' and suggested diagnostic criteria of a delta serum cortisol of less than 9 microg/l after adrenocorticotrophic hormone administration or a random total cortisol of under 10 microg/l. This review attempts to establish a critical reappraisal of the evidence for the existence of relative adrenal insufficiency/critical illness related corticosteroid insufficiency in patients with sepsis and examines the background, controversies and possibilities for future research into the condition.

Prevalence of occult adrenal insufficiency and the prognostic value of a short corticotropin stimulation test in patients with septic shock

Background:

Corticosteroid insufficiency in acute illness can be difficult to discern clinically. Occult adrenal insufficiency (i.e., Δmax ≤9 μg/dL) after corticotropin may be associated with a high mortality rate.

Objective:

To assess the prevalence of occult adrenal insufficiency and the prognostic value of short corticotropin stimulation test in patients with septic shock.

Materials and Methods:

A total of 30 consecutive patients admitted in the adult intensive care unit of the Sheri Kashmir Institute of Medical Sciences who met the clinical criteria for septic shock were prospectively enrolled in the study. A low dose (1 μg) short corticotropin stimulation test was performed; blood samples were taken before the injection (T0) and 30 (T30) and 60 (T60) minutes afterward.

Results:

The prevalence of occult adrenal insufficiency was 57%. The 28-day mortality rate was 60% and the median time to death was 12 days. The following seven variables remained independently associated with death: organ system failure scores, simplified acute physiology score II score, mean arterial pressure, low platelet count, PaO₂:FIO₂, random baseline cortisol (T0) >34 μg/dL, and maximum variation after test (Δmax) of ≤9 μg/dL. Three different mortality patterns were observed: (I) low (T0 ≤34 μg/dL and Δmax >9 μg/dL; a 28-day mortality rate of 33%),(II) intermediate (T0 >34 μg/dL and Δmax >9 μg/dL or T0 ≤34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 71%), and (III) high (T0 >34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 82%).

Conclusion:

A short corticotropin test using low-dose corticotropin (1 μg) has a good prognostic value. High basal cortisol and a low increase in cortisol on corticotropin stimulation test are predictors of a poor outcome in patients with septic shock.

Cosyntropin as a diagnostic agent in the screening of patients for adrenocortical insufficiency

Adrenocortical insufficiency occurs when there is inadequate release of cortisol from the adrenal cortex. Disturbances of the hypothalamic-pituitary-adrenal axis are common following trauma, surgical stress, and critical illness. While this is often a protective mechanism, these responses may become "uncoupled" or maladaptive resulting in an exacerbation of organ failure and higher mortality rates. In these clinical settings, the patient presents with a persistent systemic inflammation state, a hyperdynamic cardiovascular response, and vasopressor dependent shock. As such, the occurrence of adrenal insufficiency in the setting of critical illness is most appropriately termed critical illness-related corticosteroid insufficiency. In these settings, recent data suggests that these patients may benefit from a short course of low-dose steroid replacement therapy. Cosyntropin, a synthetic derivative of adrenocorticotropic hormone, is being used with increased frequency in the evaluation and diagnosis of adrenocortical insufficiency in this patient population. A random cortisol level is checked before a 250-μg injection of cosyntropin and then 30-60 minutes later. The cortisol levels and response to cosyntropin may be interpreted to identify an insufficient adrenal response. Of note, the setting of critical illness can greatly affect the cosyntropin test sensitivity on identifying adrenal insufficiency. Changes in the stress response during critical illness combined with the resuscitation and management of these patients greatly disturbs serum protein levels, especially those of albumin and transcortin. Common intensive care unit (ICU) diagnoses such as sepsis and malnutrition can increase baseline levels and blunt the cortisol response to cosyntropin stimulation, respectively. As well, numerous pharmacological agents routinely used in the ICU have been shown to interfere with cortisol levels and cosyntropin responsiveness. While steroids have a place in the ICU, specific dosing and length of administration remain inconsistent.

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.

Adrenal insufficiency in prolonged critical illness

INTRODUCTION

Adrenal insufficiency is common in critically ill patients and affects their prognosis, but little is known about how adrenal function changes during prolonged critical illness. This study was conducted to investigate dynamic changes in cortisol levels in patients with critical illness who do not improve after treatment.

METHODS

This observational cohort study was performed in the intensive care units of a university hospital. We studied acutely ill patients with initial cortisol level above 34 microg/dl, but who did not improve after treatment and in whom follow-up cortisol levels were determined during critical illness. All clinical information and outcomes were recorded.

RESULTS

Fifty-seven patients were included. Ten patients had follow-up cortisol levels above 34 microg/dl, 32 patients had levels between 34 and 15 microg/dl, and 15 patients had levels under 15 microg/dl. Outcomes did not differ significantly among the three groups with different follow-up cortisol levels. In Cox regression analysis, those patients who survived to hospital discharge with second cortisol levels under 15 microg/dl had a longer hospital length of stay (odds ratio = 14.8, 95% confidence interval = 2.4 to 90.0; P = 0.004).

CONCLUSION

The majority of acutely ill patients who remained in a critical condition had decreased serum cortisol levels. Depressed cortisol levels at follow up may lead to worse clinical outcomes. We propose that repeated adrenal function testing be conducted in patients with prolonged critical illness.

Adrenal insufficiency in critical illness

One of the more controversial areas in critical care in recent decades relates to the issue of adrenal insufficiency and its treatment in critically ill patients. There is no consensus on which patients to test for adrenal insufficiency, which tests to use and how to interpret them, whether to use corticosteroids, and, if so, who to treat and with what dose. This review illustrates the complexity and diversity of pathophysiological changes in glucocorticoid secretion, metabolism, and action and how these are affected by various types of illness. It will review adrenal function testing and give guidance on corticosteroid replacement regimens based on current published literature. There remain inherent difficulties in interpreting the effects of glucocorticoid replacement during critical illness because of the diversity of effects of glucocorticoids on various tissues. Investigation and treatment will depend on whether the likely cause of corticosteroid insufficiency is adrenal or central in origin.

Altered fluid, electrolyte and mineral status in tropical disease, with an emphasis on malaria and leptospirosis

Fluid, electrolyte and mineral perturbations are prevalent features of tropical disease. Hemodynamic alterations, fever, nitrogen wasting, and changes in membrane transport and acid-base balance contribute to these perturbations. Models of malaria and leptospirosis have been used to show that common hemodynamic changes in tropical disease include decreased systemic vascular resistance, increased cardiac output and increased renal vascular resistance. Blood volume is initially increased, but it decreases as disease progresses. Response to fluid loading is decreased. Diabetes insipidus is occasionally observed in malaria. Hyponatremia occurs frequently in tropical diseases, as a result of increased levels of antidiuretic hormone (vasopressin), entry of sodium into cells, sodium loss and resetting of osmoreceptors. Natriuresis and kaliuresis are observed in patients with leptospirosis. Large amounts of sodium and potassium are lost in stool as a result of diarrhea. Hypernatremia is uncommon, whereas hypokalemia caused by hyperventilation is often observed (more frequently in patients with leptospirosis and kaliuresis). During severe tropical infective episodes, hyperkalemia results from intravascular hemolysis or rhabdomyolysis, and occasionally from decreased activity of Na+,K+-ATPase. Hypocalcemia, hypomagnesemia and hypophosphatemia are common features of both malaria and leptospirosis. Loss of magnesium in the urine is uniquely associated with leptospiral nephropathy. Hypozincemia and hypocupremia can also develop during tropical infection, and might interfere with a patient's immune response. These electrolyte and mineral perturbations are transient and quickly resolve when the disease is controlled.

Systemic illness

Systemic illnesses are associated with alterations in the hypothalamic-pituitary-peripheral hormone axes, which represent part of the adaptive response to stressful events and may be influenced by type and severity of illness and/or pharmacological therapy. The pituitary gland responds to an acute stressful event with two secretory patterns: adrenocorticotropin (ACTH), prolactin (PRL) and growth hormone (GH) levels increase, while luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyrotropin (TSH) levels may either decrease or remain unchanged, associated with a decreased activity of their target organ. In protracted critical illness, there is a uniformly reduced pulsatile secretion of ACTH, TSH, LH, PRL and GH, causing a reduction in serum levels of the respective target-hormones. These adaptations are initially protective; however, if inadequate or excessive they may be dangerous and may contribute to the high morbidity and mortality risk of these patients. There is no consensus regarding the type of approach, as well as the criteria to use to define pituitary axis function in critically ill patients. We here provide a critical approach to pituitary axis evaluation during systemic illness.

Serum cortisol and thyroxine concentrations as predictors of death in critically ill puppies with parvoviral diarrhea

OBJECTIVE

To evaluate the role of adrenal and thyroid hormones in the prediction of death in a population of critically ill puppies with parvoviral diarrhea by measuring serial daily serum concentrations of cortisol and thyroxine.

DESIGN

Prospective case-control study.

ANIMALS

57 critically ill puppies with parvoviral diarrhea admitted to the hospital and 17 clinically normal control puppies.

PROCEDURES

Basal serum cortisol and thyroxine concentrations were measured for each dog with parvoviral diarrhea at admission (prior to treatment) and daily until death, euthanasia, or discharge.

RESULTS

Median time between admission and death was 48 hours (ie, on day 3). Median serum cortisol concentration on day 1 (admission) in all dogs with parvoviral diarrhea (248 nmol/L) was significantly higher than in control dogs (77 nmol/L). No significant difference was found in the day 1 median serum cortisol concentration of 11 dogs that died (302 nmol/L) and 46 dogs that survived (238 nmol/L). A significantly higher median serum cortisol concentration was, however, found in nonsurvivor group dogs, compared with survivor group dogs, on days 2 and 3. Median serum thyroxine concentration on day 1 in dogs with parvoviral diarrhea was significantly lower than in control dogs (8.12 nmol/L vs 35 nmol/L, respectively). Median serum thyroxine concentration of nonsurvivor group dogs (4.4 nmol/L) was significantly lower than that of survivor group dogs (9.2 nmol/L) at admission and became even lower on days 2 and 3.

CONCLUSIONS AND CLINICAL RELEVANCE

High serum cortisol and low serum thyroxine concentrations at 24 and 48 hours after admission were associated with death in dogs with parvoviral diarrhea.

Free and Total Cortisol Levels as Predictors of Severity and Outcome in Community-acquired Pneumonia

RATIONALE

High cortisol levels are of prognostic value in sepsis. The predictive value of cortisol in pneumonia is unknown. Routinely available assays measure serum total cortisol (TC) and not free cortisol (FC). Whether FC concentrations better reflect outcome is uncertain.

OBJECTIVES

To investigate the predictive value of TC and FC in community-acquired pneumonia (CAP).

METHODS

Preplanned subanalysis of a prospective intervention study in 278 patients presenting to the emergency department with CAP.

MEASUREMENTS AND MAIN RESULTS

TC, FC, procalcitonin, C-reactive protein, leukocytes, clinical variables, and the pneumonia severity index (PSI) were measured. The major outcome measures were PSI and survival. TC and FC, but not C-reactive protein or leukocytes, increased with increasing severity of CAP according to the PSI (P < 0.001). TC and FC levels on presentation in patients who died during follow-up were significantly higher as compared with levels in survivors. In a receiver operating characteristic analysis to predict survival, the area under the receiver operating characteristic curve (AUC) was 0.76 (95% confidence interval, 0.70-0.81) for TC and 0.69 (0.63-0.74) for FC. This was similar to the AUC of the PSI (0.76 [0.70-0.81]), and better as compared with C-reactive protein, procalcitonin, or leukocytes. In univariate analysis, only TC, FC, and the PSI were predictors of death. In multivariate analysis, the predictive potential of TC equaled the prognostic power of PSI points.

CONCLUSIONS

Cortisol levels are predictors of severity and outcome in CAP to a similar extent to the PSI, and are better than routinely measured laboratory parameters. In CAP, the prognostic accuracy of FC is not superior to TC. Clinical trial registered with www.controlled-trials.com (ISRCTN04176397).

Mechanisms and clinical consequences of critical illness associated adrenal insufficiency

PURPOSE OF REVIEW

Adrenal insufficiency is being diagnosed with increasing frequency in critically ill patients. There exists, however, much controversy in the literature as to the nature of this entity, including its pathophysiology, epidemiology, diagnosis and treatment. The review summarizes our current understanding of the causes and consequences of adrenal insufficiency in critically ill patients.

RELEVANT FINDINGS

Activation of the hypothalamic-pituitary-adrenal axis with the production of cortisol is a fundamental component of the stress response and is essential for survival of the host. Dysfunction of the hypothalamic-pituitary-adrenal axis with decreased glucocorticoid activity is being increasingly recognized in critically ill patients, particularly those with sepsis. This condition is best referred to as 'critical illness-related corticosteroid insufficiency'. Critical illness-related corticosteroid insufficiency may occur due to dysfunction at any point in the hypothalamic-pituitary-adrenal axis including tissue glucocorticoid resistance. Critical illness-related corticosteroid insufficiency leads to an exaggerated proinflammatory response with increased tissue injury and organ dysfunction.

SUMMARY

Critical illness-related corticosteroid insufficiency is common in critically ill patients, particularly those with sepsis. Supplemental corticosteroids may restore the balance between the pro-and anti-inflammatory mediators in patients with severe sepsis, septic shock and acute respiratory distress syndrome, and thereby improve the outcome of patients with these conditions.

Endocrine predictors of mortality in canine babesiosis caused by Babesia canis rossi

This prospective, cross-sectional, observational study was designed to determine the association between the hormones of the pituitary-adrenal and pituitary-thyroid axes and outcome in dogs with naturally occurring Babesia canis rossi babesiosis. Ninety-five dogs with canine babesiosis were studied and blood samples were obtained from the jugular vein in each dog prior to treatment at admission to hospital. Serum cortisol, adrenocorticotrophic hormone (ACTH), thyroxine, free thyroxine and thyrotropin (TSH) concentrations were measured. Diagnosis was confirmed by polymerase chain reaction and reverse line blot and dogs infected with Babesia canis vogeli or Ehrlichia canis were excluded. Three outcomes were defined: hospitalization with subsequent death (n=7); hospitalization followed by recovery (n=56); and treatment as an outpatient (n=32). Serum cortisol and ACTH concentrations were significantly higher in the dogs that died, compared to hospitalized dogs that survived and compared to dogs treated as outpatients. Serum T4 and free T4 concentrations were significantly lower in the dogs that died, compared to the hospitalized dogs that survived and compared to dogs treated as outpatients. Serum TSH concentrations were not significantly different between any of the groups. Mortality was significantly associated with high cortisol and high ACTH concentrations and with low T4 and fT4 concentrations in dogs suffering from B. canis rossi babesiosis.

A prospective study on adrenal cortex responses and outcome prediction in acute critical illness: results from a large cohort of 203 mixed ICU patients

OBJECTIVE

To assess whether adrenal cortex hormones predict ICU mortality in acute, mixed, critically ill patients.

DESIGN AND SETTING

Prospective study in consecutive intensive care patients in the general ICU of a teaching hospital.

PATIENTS

203 severely ill patients with multiple trauma (n = 93), medical (n = 57), or surgical (n = 53) critical states.

MEASUREMENTS AND RESULTS

Within 24 h of admission in the ICU a morning blood sample was obtained to measure baseline cortisol, corticotropin (ACTH), and dehydropiandrosterone sulfate (DHEAS). Subsequently a low-dose (1 microg) ACTH test was performed to determine stimulated cortisol. The incremental rise in cortisol was defined as stimulated minus baseline cortisol. Overall, 149 patients survived and 54 died. Nonsurvivors were older and in a more severe critical state, as reflected by higher SOFA and APACHE II scores. Nonsurvivors had a lower incremental rise in cortisol (5.0 vs. 8.3 microg/dl and lower DHEAS (1065 vs. 1642 ng/ml) than survivors. The two groups had similar baseline and stimulated cortisol. Multivariate logistic regression analysis revealed that age (odds ratio 1.02), SOFA score (1.36), and the incremental rise in cortisol (0.88) were independent predictors for poor outcome.

CONCLUSIONS

In general ICU patients a blunted cortisol response to ACTH within 24 h of admission is an independent predictor for poor outcome. In contrast, baseline cortisol or adrenal androgens are not of prognostic significance.

Adrenal dysfunction in critical illness: a clinical entity that requires treatment?

Corticosteroids are of key importance in controlling the immune system and in the maintenance of cardiovascular function. Thus, an adequate function of the adrenal cortex is essential for survival in critical illness. There is growing evidence that adrenocortical function can become impaired during critical illness, because of deleterious effects of cytokines, leading to a state of relative adrenal dysfunction. Under these circumstances, administration of corticosteroids is necessary for recovery of the patient. How such a state of adrenal dysfunction should be detected is still not clear, however, making it difficult to decide when to administer corticosteroids and to which patients.

Evidence of altered cortisol metabolism in critically ill patients: a prospective study

CONTEXT

Changes in cortisol metabolism due to altered activity of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) have been implicated in the pathogenesis of hypertension, obesity and the metabolic syndrome. No published data exist on the activity of this enzyme in critical illness.

OBJECTIVE

To investigate cortisol metabolism in critically ill patients utilising plasma cortisol: cortisone ratio as an index of 11beta-HSD activity.

SETTING

Tertiary level intensive care unit.

PATIENTS

Three cohorts of critically ill patients: sepsis (n = 13); multitrauma (n = 20); and burns (n = 19).

MAIN OUTCOME MEASURES

Serial plasma cortisol: cortisone ratios.

MEASUREMENTS AND MAIN RESULTS

Plasma total cortisol cortisone ratios were determined serially after admission to the intensive care unit. As compared with controls, the plasma cortisol:cortisone ratio was significantly elevated in the sepsis and trauma cohorts on day 1 (22 +/- 9, p = 0.01, and 23 +/- 19, p = 0.0003, respectively) and remained elevated over the study period. Such a relationship was not demonstrable in burns. The ratio was significantly correlated with APACHE II (r = 0.77, p = 0.0008) and Simplified Acute Physiology Score (r = 0.7, p = 0.003) only on day 7 and only in the burns cohort. There were no significant correlations observed between total plasma cortisol or cortisone and sickness severity in the sepsis and trauma cohorts.

CONCLUSIONS

In critically ill patients, there is evidence of altered cortisol metabolism due to an increase in 11beta-HSD activity as demonstrated by an elevation of plasma cortisol: cortisone ratios. Further studies with larger sample sizes specifically designed to examine altered tissue 11beta-HSD activity and its clinical significance and correlation with outcome are warranted.

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.

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.

Hypothalamic pituitary adrenal function during critical illness: limitations of current assessment methods

CONTEXT

Activation of the hypothalamic-pituitary-adrenal (HPA) axis represents one of several important responses to stressful events and critical illnesses. Despite a large volume of published data, several controversies continue to be debated, such as the definition of normal adrenal response, the concept of relative adrenal insufficiency, and the use of glucocorticoids in the setting of critical illness.

OBJECTIVES

The primary objective was to review some of the modulating factors and limitations of currently used methods of assessing HPA function during critical illness and provide alternative approaches in that setting.

DESIGN

This was a critical review of relevant data from the literature with inclusion of previously published as well as unpublished observations by the author. Data on HPA function during three different forms of critical illnesses were reviewed: experimental endotoxemia in healthy volunteers, the response to major surgical procedures in patients with normal HPA, and the spontaneous acute to subacute critical illnesses observed in patients treated in intensive care units.

SETTING

The study was conducted at an academic medical center.

PATIENTS/PARTICIPANTS

Participants were critically ill subjects.

INTERVENTION

There was no intervention.

MAIN OUTCOME MEASURE

The main measure was to provide data on the superiority of measuring serum free cortisol during critical illness as contrasted to those of total cortisol measurements.

RESULTS

Serum free cortisol measurement is the most reliable method to assess adrenal function in critically ill, hypoproteinemic patients. A random serum free cortisol is expected to be 1.8 microg/dl or more in most critically ill patients, irrespective of their serum binding proteins. Because the free cortisol assay is not currently available for routine clinical use, alternative approaches to estimate serum free cortisol can be used. These include calculated free cortisol (Coolens' method) and determining the free cortisol index (ratio of serum cortisol to transcortin concentrations). Preliminary data suggest that salivary cortisol measurements might be another alternative approach to estimating the free cortisol in the circulation. When serum binding proteins (albumin, transcortin) are near normal, measurements of total serum cortisol continue to provide reliable assessment of adrenal function in critically ill patients, in whom a random serum total cortisol would be expected to be 15 microg/dl or more in most patients. In hypoproteinemic critically ill subjects, a random serum total cortisol level is expected to be 9.5 microg/dl or more in most patients. Data on Cosyntropin-stimulated serum total and free cortisol levels should be interpreted with the understanding that the responses in critically ill subjects are higher than those of healthy ambulatory volunteers. The Cosyntropin-induced increment in serum total cortisol should not be used as a criterion for defining adrenal function, especially in critically ill patients.

CONCLUSIONS

The routine use of glucocorticoids during critical illness is not justified except in patients in whom adrenal insufficiency was properly diagnosed or others who are hypotensive, septic, and unresponsive to standard therapy. When glucocorticoids are used, hydrocortisone should be the drug of choice and should be given at the lowest dose and for the shortest duration possible. The hydrocortisone dose (50 mg every 6 h) that is mistakenly labeled as low-dose hydrocortisone leads to excessive elevation in serum cortisol to values severalfold greater than those achieved in patients with documented normal adrenal function. The latter data should call into question the current practice of using such doses of hydrocortisone even in the adrenally insufficient subjects.

Adrenal Insufficiency in Hemorrhagic Shock

Adrenal insufficiency during sepsis is well documented. The association between hemorrhagic shock and adrenal insufficiency is unclear and may be related to ischemia, necrosis, or resuscitation. This study was designed to determine the incidence of relative adrenal insufficiency in hemorrhagic shock. A retrospective review of a prospectively gathered database for patients admitted to the trauma intensive care unit with hemorrhagic shock was undertaken. A random serum cortisol of <25 mcg/dL defined relative adrenal insufficiency. All of the cortisol levels were drawn within the first 24 hours of admission. Data analyzed included demographics, length of stay, injury mechanism, infections, and mortality. Fifteen patients presented with hemorrhagic shock, with 14 of 15 meeting the criteria for relative adrenal insufficiency. The average serum cortisol level was 15.8 (9–26.8). The average APACHE II score was 18.3 (4–33), and the average Injury Severity Score was 22.5 (8–41). The mechanism was blunt trauma in 10 patients and penetrating trauma in 5. The average intensive care unit and hospital length of stay were 13.2 and 27.4 days, respectively. There were five urinary tract infections, four blood stream infections, and two wound infections. Two of the 15 patients died. Relative adrenal insufficiency appears to be common in hemorrhagic shock. Future research is warranted to elucidate the pathophysiology, as well as to prospectively determine which patients may benefit from steroid replacement.

Effects of hemorrhagic shock on adrenal response in a rat model

INTRODUCTION

There is a documented association between critically ill patients who are in refractory shock and adrenal insufficiency. The underlying pathophysiology may be related to ischemia, necrosis, reperfusion, or resuscitative dilution. We hypothesize this blunted adrenal response is due to ischemia and necrosis of the adrenal parenchyma.

METHODS

Thirty Sprague-Dawley rats were intravascularly catheterized and hemorrhagic shock induced to a mean arterial pressure of 65 mm Hg. After 4 hours of hypotension, fluid resuscitation was initiated with a crystalloid solution (Lactated Ringers). A control group underwent catheterization without hemorrhage. Serum corticosterone levels were measured and adrenal glands harvested for histologic evaluation of hemorrhagic necrosis.

RESULTS

Baseline corticosterone was 30.8 ng/mL in control animals and 35.3 ng/mL in hemorrhagic animals (P = 0.10). One hour after hemorrhage, corticosterone was maximally stimulated at 406.2 ng/mL and in control animals was 35.0 ng/mL (P = 0.0001). In experimental animals after 4 hours of hypovolemia, corticosterone dropped to 308.9 ng/mL (P = 0.0001). At 6 hours, corticosterone levels dropped to 149.0 ng/mL in experimental animals (P = 0.0001). Adrenal microscopy showed 1.5+ hemorrhagic necrosis in experimental animals compared with 0.0+ in controls (P = 0.004).

CONCLUSION

Our model suggests that ischemia and necrosis of the adrenal glands may be responsible for the adrenal insufficiency seen in patients with hemorrhagic shock. Further research may enable clinicians to discern earlier which patients will benefit from adrenal corticoid replacement.

Response of rat fasciculata-reticularis cells in primary culture to bacterial lipopolysaccharide

The aim of this study was to determine the direct effect of a wide range of concentrations of lipopolysaccharide (LPS) of Escherichia coli O111:B4 on fasciculata-reticularis cells in primary cultures. In short-term cultures of fasciculata-reticularis cells, the presence of low (1-10 microg/ml) doses of LPS in the medium produced a decrease in ACTH-induced corticosterone secretion, in a dose-dependent manner and independent of the culture medium. The corticosterone production stimulated by db-cAMP was slightly decreased by the presence of LPS in culture medium, while the pregnenolone induced corticosterone biosynthesis was not modified. LPS modified the binding of [125I]-Tyr23-ACTH to the fasciculata-reticularis cell membrane and the signal transduction pathway, as LPS reduced ACTH-induced cAMP production. In long-term cultures, the presence of LPS in the medium produces a decrease in the specific binding of [125I]-Tyr23-ACTH, while the presence of ACTH in the culture medium produced an increase in its specific binding. The use of high doses of LPS (100-250 microg/ml) has helped to clarify some aspects of the LPS action. These doses of LPS severely inhibited ACTH-induced corticosterone production, and clearly reduced the corticosterone production stimulated by db-cAMP and the binding of ACTH to its receptors. In long-term cultures, LPS decreased the number of ACTH receptors, an effect that was reversed by subsequent exposure to ACTH. These results indicate that LPS exerts a direct action on fasciculata-reticularis cells and a model of the mechanism of LPS action is proposed.