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

Neuroendocrine changes in patients with spontaneous supratentorial intracerebral hemorrhage

BACKGROUND

Neuroendocrine changes have been reported after ischemic stroke, subarachnoid hemorrhage, and brain trauma. As there are no corresponding data in patients with intracerebral hemorrhage (ICH) we analyzed various neuroendocrine parameters to investigate possible alterations in hormone profiles of patients with ICH.

METHODS

Twenty patients with ICH were prospectively enrolled in the study. Patients were a priori parted into two groups: Ten non-ventilated patients treated on the stroke-unit (hemorrhage volumes <20 ml, "small ICH"), and 10 ventilated patients treated on the neurocritical care unit (hematoma volumes >20 ml with possible additional ventricular involvement ("large ICH"). Neuroendocrine parameters were compared between both groups referring to reference values. The following parameters were obtained over a period of 9 days in 20 patients with spontaneous supratentorial ICH: thyrotropin, free thiiodothyronine and thyroxine, human growth hormone, insulin-like growth factor 1, luteinizing hormone, follicle-stimulating hormone, testosterone, prolactin, adrenocorticotropic hormone, and cortisol.

RESULTS

Small ICH patients were in a median 71 (54-88) years old and had a mean ICH volume of 9.5 ± 6.5 ml, whereas large ICH patients were 65 (47-80) years old and showed a mean volume of 56 ± 30.2 ml. None of the patients revealed pathological alterations for thyrotropin, free thiiodothyronine, thyroxine, human growth hormone, insulin-like growth factor 1, and testosterone. There was only a mild decrease of adrenocorticotropic hormone and cortisol on day 3 in large ICH patients. Small ICH patients showed pathologically elevated levels of luteinizing and follicle-stimulating hormone throughout the observation period. Large ICH patients showed a marked increase of prolactin that developed during the course.

CONCLUSIONS

Overall, neuroendocrine changes in ICH patients are not as profound as reported for ischemic stroke or subarachnoid hemorrhage. The clinical significance of increased LH and FSH levels in small ICH is unclear, whereas elevation of prolactin in large ICH was anticipated. Future randomized controlled trials should also focus on neuroendocrine parameters to clarify the impact of possible hormonal alterations on functional outcome.

Neuroendocrine changes in patients with acute space occupying ischaemic stroke

OBJECTIVE

To evaluate neuroendocrine changes in critical care patients with acute space occupying hemispheric stroke.

METHODS

22 patients with acute space occupying hemispheric stroke were studied (mean age 57.7 years; five women, 17 men). Plasma levels of prolactin, thyrotropin (TSH), total thyroxine (T4), free thyroxine (FT4), and total triiodothyronine (T3) were measured on admission and thereafter on days 3, 5, 7, and 9. Cortisol and ACTH levels were analysed at 8.00, 16.00, and 24.00 hours each day. A TRH stimulation test with measurements of TSH and prolactin was done on day 3.

RESULTS

Nine patients underwent decompressive craniectomy and nine were treated with moderate hypothermia. All patients received vasopressor drugs because of arterial hypotension. Plasma ACTH and cortisol values were abnormally low despite systemic hypotension and acute systemic illness, and remained low throughout the observation period. The diurnal rhythm of cortisol was not preserved. Prolactin levels increased during the observation period, and were well above normal on day 9. Thyroid function was slightly suppressed until day 7. TRH stimulation of plasma TSH and prolactin was low.

CONCLUSIONS

Patients with an acute space occupying cerebral infarct show profound neuroendocrine changes. The central regulation of adrenal and thyroid function and prolactin release is impaired, which may compromise the clinical course of affected patients and have implications for therapeutic management.

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.