Relative eosinophilia and functional adrenal insufficiency in critically ill patients

Eosinophilia in a patient with cyclical vomiting: a case report

Background

Eosinophilic gastritis is related to eosinophilic gastroenteritis, varying only in regards to the extent of disease and small bowel involvement. Common symptoms reported are similar to our patient's including: abdominal pain, epigastric pain, anorexia, bloating, weight loss, diarrhea, ankle edema, dysphagia, melaena and postprandial nausea and vomiting. Microscopic features of eosinophilic infiltration usually occur in the lamina propria or submucosa with perivascular aggregates. The disease is likely mediated by eosinophils activated by various cytokines and chemokines. Therapy centers around the use of immunosuppressive agents and dietary therapy if food allergy is a factor.

Case presentation

The patient is a 31 year old Caucasian female with a past medical history significant for ulcerative colitis. She presented with recurrent bouts of vomiting, abdominal pain and chest discomfort of 11 months duration. The bouts of vomiting had been reoccurring every 7–10 days, with each episode lasting for 1–3 days. This was associated with extreme weakness and cachexia. Gastric biopsies revealed intense eosinophilic infiltration. The patient responded to glucocorticoids and azathioprine. The differential diagnosis and molecular pathogenesis of eosinophilic gastritis as well as the molecular effects of glucocorticoids in eosinophilic disorders are discussed.

Conclusions

The patient responded to a combination of glucocorticosteroids and azathioprine with decreased eosinophilia and symptoms. It is likely that eosinophil-active cytokines such as interleukin-3 (IL-3), granulocyte macrophage colony stimulating factor (GM-CSF) and IL-5 play pivotal roles in this disease. Chemokines such as eotaxin may be involved in eosinophil recruitment. These mediators are downregulated or inhibited by the use of immunosuppressive medications.

Clinical review: corticotherapy in sepsis

The use of glucocorticoids (corticotherapy) in severe sepsis is one of the main controversial issues in critical care medicine. These agents were commonly used to treat sepsis until the end of the 1980s, when several randomized trials casted serious doubt on any benefit from high-dose glucocorticoids. Later, important progress in our understanding of the role played by the hypothalamic–pituitary–adrenal axis in the response to sepsis, and of the mechanisms of action of glucocorticoids led us to reconsider their use in septic shock. The present review summarizes the basics of the physiological response of the hypothalamic–pituitary–adrenal axis to stress, including regulation of glucocorticoid synthesis, the cellular mechanisms of action of glucocorticoids, and how they influence metabolism, cardiovascular homeostasis and the immune system. The concepts of adrenal insufficiency and peripheral glucocorticoid resistance are developed, and the main experimental and clinical data that support the use of low-dose glucocorticoids in septic shock are discussed. Finally, we propose a decision tree for diagnosis of adrenal insufficiency and institution of cortisol replacement therapy.

Endocrine evaluation of patients with critical illness

Prolonged critical illness has a high morbidity and mortality. The acute and chronic phases of critical illness are associated with distinct endocrine alterations. The acute neuroendocrine response to critical illness involves an activated anterior pituitary function. In prolonged critical illness, however, a reduced pulsatile secretion of anterior pituitary hormones and the so-called "wasting syndrome" occur. The impaired pulsatile secretion of GH, thyrotropin and gonadotropin can be re-amplified by relevant combinations of releasing factors, which also substantially increase circulating levels of IGF-1, GH-dependent IGFBPs, thyroxin, tri-iodothyronine and testosterone. Anabolism is clearly re-initiated at the time GH secretagogues, thyrotropin-releasing hormone and gonadotropin-releasing hormone are coadministered but the effect on survival remains unknown. A lethal outcome of critical illness is predicted by a high serum concentration of IGFBP-1, pointing to impaired insulin effect rather than pituitary function, and survival was recently shown to be dramatically improved by strict normalization of glycemia with exogenous insulin. In addition to the illness-induced endocrine alterations, patients may have pre-existing central or peripheral endocrine diseases, either previously diagnosed or unknown. Hence, endocrine function testing in a critically ill patient represents a major challenge and the issue of treatment remains controversial. The recent progress in knowledge of the neuroendocrine response to critical illness and its interrelation with peripheral hormonal and metabolic alterations during stress, allows for potential new therapeutic perspectives to safely reverse the wasting syndrome and improve survival.

The hypothalamic-pituitary-adrenal axis and low-dose glucocorticoids in the treatment of septic shock

Severe sepsis is the leading cause of death among patients in intensive care units. Recombinant activated protein C is the only substance known to directly improve morbidity and mortality. Adrenal insufficiency occurs frequently in patients with sepsis and is associated with poor outcome. Although high-dose glucocorticoids have not positively affected clinical outcome, small trials in which low-dose glucocorticoids were administered to patients with septic shock and relative adrenal insufficiency have shown decreased mortality. The main effect of glucocorticoids in low-doses apparently is exerted through correction of suppression of the hypothalamic-pituitary-adrenal axis. However, the therapeutic benefits of glucocorticoids may be related to their antiinflammatory properties and endogenous catecholamine-enhancing effects.

Adrenal insufficiency during septic shock

OBJECTIVE

To determine whether a baseline (random) cortisol concentration <25 microg/dL in patients with septic shock was a better discriminator of adrenal insufficiency than the standard (250 microg) and the low-dose (1 microg) corticotropin stimulation tests as assessed by the hemodynamic response to steroid replacement.

SETTING

Intensive care unit.

PATIENTS

Fifty-nine patients with septic shock. Their mean age was 57 +/- 16.7 yrs; 29 were male.

INTERVENTIONS

A baseline cortisol concentration was obtained. Patients then received an intravenous injection of 1 microg of corticotropin (low-dose test) followed 60 mins later by an injection of 249 microg of corticotropin (high-dose test). Cortisol concentrations were obtained 30 and 60 mins after low- and high-dose corticotropin. All patients were administered hydrocortisone (100 mg every 8 hrs) for the first 24 hrs while awaiting results of cortisol assessment. Patients were considered steroid responsive if the pressor agent could be discontinued within 24 hrs of the first dose of hydrocortisone.

MEASUREMENTS AND MAIN RESULTS

Forty-seven percent of patients died. Twenty-two percent of patients met the diagnostic criteria of adrenal insufficiency by the low-dose test and 8% by the high-dose test. However, 61% of patients met the criteria of adrenal insufficiency when we used a baseline cortisol concentration of <25 microg/dL. Twenty-two patients (37%) were steroid responsive; the baseline serum cortisol was 14.1 +/- 5.2 microg/dL in the steroid-responsive patients compared with 33.3 +/- 18 microg/dL in the steroid-nonresponsive patients (p <.0001). Ninety-five percent of steroid-responsive patients had a baseline cortisol concentration <25 microg/dL. Fifty-four percent of steroid responders had a diagnostic low-dose test and 22% a diagnostic high-dose test. Receiver operating characteristic curve analysis revealed that a stress cortisol concentration of 23.7 microg/dL was the most accurate diagnostic threshold for determination of the hemodynamic response to glucocorticoid therapy.

CONCLUSIONS

Adrenal insufficiency is common in patients with septic shock, the incidence depending largely on the diagnostic test and criteria used to make the diagnosis. There is clearly no absolute serum cortisol concentration that distinguishes an adequate from an insufficient adrenal response. However, we believe that a random cortisol concentration of <25 microg/dL in a highly stressed patient is a useful diagnostic threshold for the diagnosis of adrenal insufficiency.

Adrenal insufficiency in the critically ill: a new look at an old problem

Stress from many sources, including pain, fever, and hypotension, activates the hypothalamic-pituitary-adrenal (HPA) axis with the sustained secretion of corticotropin and cortisol. Increased glucocorticoid action is an essential component of the stress response, and even minor degrees of adrenal insufficiency can be fatal in the stressed host. HPA dysfunction is a common and underdiagnosed disorder in the critically ill. We review the risk factors, pathophysiology, diagnostic approach, and management of HPA dysfunction in the critically ill.

Endocrine and metabolic issues in the management of the chronically critically ill patient

The metabolic syndrome of chronic critical illness (CCI) consists of multisystem organ dysfunction resulting from the initial acute injury and chronic immune-neuroendocrine axis activation, adult kwashiorkor-like malnutrition, and prolonged immobilization with suppression of the PTH-vitamin D axis and hyper-resorptive metabolic bone disease. CCI patients can also present unique challenges in the management of diabetes mellitus, thyroid and adrenal diseases, electrolyte abnormalities and hypogonadism.

Adrenal insufficiency in critically ill patients with human immunodeficiency virus

OBJECTIVE

The adrenal gland is the endocrine organ most commonly involved in patients infected with human immunodeficiency virus (HIV). It is important to recognize patients with adrenal insufficiency, because this disorder may be fatal if untreated. The incidence of adrenal insufficiency in critically ill HIV-infected patients is unclear, partly because different criteria are used to diagnose adrenal insufficiency. To help clarify the incidence of adrenal insufficiency in HIV-infected critically ill patients, we compared the incidence based on the stress cortisol concentration, low-dose corticotropin stimulation test, and high-dose corticotropin stimulation test.

SETTING

Medical intensive care unit.

PATIENTS

Twenty-eight critically ill patients with HIV, mean age 43 +/- 9 years; 20 were male; 54% died.

INTERVENTIONS

We performed a 1-microg (low-dose adrenocorticotropic hormone; LD-ACTH) and 249 microg (high-dose; HD-ACTH) corticotropin stimulation test in HIV-infected critically ill patients not receiving corticosteroids. According to results of the stress serum cortisol concentration and LD-ACTH and HD-ACTH tests, patients were classified as having adrenal insufficiency or as normal. The results of newly revised diagnostic criteria for adrenal insufficiency (i.e., stress cortisol concentration and cortisol response to LD-ACTH <25 microg/dL) were compared with the traditional criteria (i.e., stress cortisol level and response to HD-ACTH <18 microg/dL). In addition, the associations between adrenal insufficiency and the CD4 count, human cytomegalovirus antigenemia, and other risk factors for adrenal insufficiency were determined.

MEASUREMENTS AND MAIN RESULTS

When we used a stress cortisol concentration <18 microg/dL as the sole diagnostic threshold for diagnosis of adrenal insufficiency, 50% (14 of 28) of patients had adrenal insufficiency. The incidence was 75% (21 of 28) when we used a diagnostic threshold of <25 microg/dL for the stress cortisol concentration. When we used both the stress cortisol concentration and LD-ACTH test with a diagnostic cortisol threshold concentration <18 microg/dL, 21% (six of 28) had adrenal insufficiency. The incidence was 46% (13 of 28) when we used a cortisol diagnostic threshold concentration of <25 microg/dL. When we used both the stress cortisol concentration and the HD-ACTH stimulation test with a diagnostic cortisol threshold of <18 microg/dL, 7% (two of 28) had adrenal insufficiency. The incidence of adrenal insufficiency was 21% (six of 28) with a cortisol diagnostic threshold value of <25 microg/dL. Human cytomegalovirus antigenemia was the only variable assessed that was associated with adrenal insufficiency.

CONCLUSION

There is a high incidence of adrenal insufficiency in critically ill HIV-infected patients that varies with the criteria used to diagnose adrenal insufficiency. The LD-ACTH stimulation test is more sensitive than the high-dose test for diagnosing adrenal insufficiency in this population. Because of the high incidence of inadequate adrenal function, all critically ill HIV-infected patients should undergo an evaluation for adrenal insufficiency with the stress cortisol concentration and LD-ACTH stimulation tests.

Decreased levels of dehydroepiandrosterone sulphate in severe critical illness: a sign of exhausted adrenal reserve?

INTRODUCTION

Dehydroepiandrosterone (DHEA) and its sulphate (DHEAS) are pleiotropic adrenal hormones with immunostimulating and antiglucocorticoid effects. The present study was conducted to evaluate the time course of DHEAS levels in critically ill patients and to study their association with the hypothalamic-pituitary-adrenal axis.

MATERIALS AND METHOD

This was a prospective observational clinical and laboratory study, including 30 patients with septic shock, eight patients with multiple trauma, and 40 age- and sex-matched control patients. We took serial measurements of blood concentrations of DHEAS, cortisol, tumour necrosis factor-alpha and IL-6, and of adrenocorticotrophic hormone immunoreactivity over 14 days or until discharge/death.

RESULTS

On admission, DHEAS was extremely low in septic shock (1.2 +/- 0.8 mol/l) in comparison with multiple trauma patients (2.4 +/- 0.5 micromol/l; P < 0.05) and control patients (4.2 +/- 1.8; P < 0.01). DHEAS had a significant (P < 0.01) negative correlation with age, IL-6 and Acute Physiology and Chronic Health Evaluation II scores in both patient groups. Only during the acute phase did DHEAS negatively correlate with dopamine. Nonsurvivors of septic shock (n = 11) had lower DHEAS levels (0.4 +/- 0.3 micromol/l) than did survivors (1.7 +/- 1.1 micromol/l; P < 0.01). The time course of DHEAS exhibited a persistent depletion during follow up, whereas cortisol levels were increased at all time points.

CONCLUSION

We identified extremely low DHEAS levels in septic shock and, to a lesser degree, in multiple trauma patients as compared with those of age- and sex-matched control patients. There appeared to be a dissociation between DHEAS (decreased) and cortisol (increased) levels, which changed only slightly over time. Nonsurvivors of sepsis and patients with relative adrenal insufficiency had the lowest DHEAS values, suggesting that DHEAS might be a prognostic marker and a sign of exhausted adrenal reserve in critical illness.

The hypothalamic-pituitary-adrenal response to critical illness

The maintenance of life depends on the capacity of the organism to sustain its equilibrium via allostasis'-the ability to achieve stability through change. Life-threatening disease induces acute adaptive responses specific to the stimulus and generalized responses when the disturbances are prolonged. These changes are associated with increased activity of the hypothalamic-pituitary-adrenal axis and may have survival value in preparing the body for fight or flight'. There is a shift towards an increase in glucocorticoid production and away from mineralocorticoid and androgen production, as well as an increase in the biological effects of glucocorticoids through an increased cortisol free fraction and an increased glucocorticoid receptor sensitivity. During the prolonged phase, there is a dissociation between high plasma cortisol and low adrenocorticotropin hormone levels, suggesting non-adrenocorticotropin hormone-mediated mechanisms for the regulation of the adrenal cortex. This hypercortisolism is in contrast to the very low dehydroepiandrosterone sulphate level, indicating an imbalance between the immunostimulatory and immunosuppressive adrenocortical hormones. The question is whether the total serum cortisol concentration represents sufficient glucocorticoid biological activity during the prolonged phase of critical illness.

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

Adequate adrenocortical function is essential to survive critical illness. Most critically ill patients display an elevated plasma cortisol level, reflecting activation of the pituitary-adrenal axis, which is considered to be a homeostatic adaptation. In the setting of critical illness, the failure of an appropriate neuroendocrine response can lead to the picture of vasopressor-dependent refractory hypotension. This state of relative or functional adrenal insufficiency is characterized by an inadequate production of cortisol in relation to an increased demand during periods of severe stress, particularly prolonged critical illness such as multi-organ failure. This clinical entity, however, lacks clear-cut diagnostic criteria. What are the appropriate cortisol concentrations in the critically ill? Should base-line and adrenocorticotropic hormone-stimulated cortisol concentrations be assessed? The classical adrenocorticotropic hormone stimulation test is often used, but there are problems with interpreting its results. Other diagnostic tools, such as the low-dose adrenocorticotropic hormone test and relative eosinophilia, are promising but also lack proper criteria. A prompt response to hydrocortisone treatment is a major clue to the diagnosis. Recent studies with stress doses of hydrocortisone in sepsis and septic shock have shown a marked haemodynamic improvement, but whether patients with relative adrenal dysfunction benefit most from this treatment and whether there is definitely an effect on outcome is still undecided.

Macrophage migration inhibitory factor and hypothalamo-pituitary-adrenal function during critical illness

In patients with septic shock (n = 32), multitrauma (n = 8), and hospitalized matched controls (n = 41), we serially measured serum macrophage inhibitory factor (MIF), cortisol, plasma ACTH, tumor necrosis factor-alpha, and interleukin-6 (IL-6) immunoreactivity during 14 days or until discharge/death. MIF levels were significantly elevated on day 1 in septic shock (14.3 +/- 4.5 microg/L), as opposed to trauma (3.1 +/- 1.7 microg/L) and control patients (2.5 +/- 2.1 microg/L). The time course of MIF, parallel to cortisol, but in contrast to ACTH, showed persistently elevated levels in septic patients. On admission, nonsurvivors of septic shock (n = 11) showed significantly higher MIF levels than survivors (18.4 +/- 4.8 and 10.2 +/- 4.2 microg/L, respectively). Patients with septic adult respiratory distress syndrome (ARDS; n = 8) showed higher MIF levels than those who did not develop ARDS (19.4 +/- 4.7 vs. 9.2 +/- 4.3 microg/L, respectively). Multiple logistic regression analysis demonstrated that both MIF and ARDS were independent predictors of adverse outcome. On admission, tumor necrosis factor-alpha, IL-6, procalcitonin, and lipopolysaccharide-binding protein levels were higher in patients with septic shock than in patients with multitrauma. In septic patients, regression analysis showed significant correlations between MIF and cortisol as well as between MIF and IL-6 levels and disease severity scores. No relation was found between MIF and markers of the acute phase response (procalcitonin, C- reactive protein, and lipopolysaccharide-binding protein). In multitrauma patients, MIF levels were not elevated at any time point and were not related to other variables. Our data suggest that during immune-mediated inflammation (such as septic shock) MIF is an important neuroendocrine mediator: a contraregulator of the immunosuppressive effects of glucocorticoids.

Hypothalamic-pituitary-adrenal insufficiency

Adrenal insufficiency is a common and underdiagnosed disorder that develops in critically ill patients. Most forms are acquired and will resolve with treatment of the underlying disease. Hypotension that is refractory to fluids and requires vasopressors is the most common presentation of adrenal insufficiency in the ICU. It is important to make the diagnosis of adrenal insufficiency, because current data suggest that treatment with glucocorticoids improves outcome. Diagnosis usually can be made on the basis of a stress cortisol level. Occasionally, when the level of stress is uncertain, the low-dose corticotropin stimulation test will be required for definitive diagnosis. A therapeutic trial with hydrocortisone should be started in patients with suspected adrenal insufficiency pending results of diagnostic testing.