Endocrine Abstracts

Critical illness due to sepsis, trauma, surgery, organ failure or burns is associated with dramatic effects on most hormonal axes. Complex changes occur at the hypothalamic, pituitary, circulatory and tissue levels of hormone action. In the early stages of critical illness these changes appear to be adaptive but this may not be the case in prolonged illness. Common problems faced by endocrinologists are the recognition of pre-existing endocrine disorders in critically ill patients and the identification of endocrine conditions induced by specific illnesses or their treatment. Additionally, a variety of endocrine treatments have been proposed to counteract common problems likely to develop during critical illness such as sepsis and protein catabolism. An awareness of the expected changes in the adrenal, thyroid and somatotroph axes can help identify abnormal responses and guide replacement therapy. Circulating hormone levels, however, may not accurately reflect hormone action at a tissue level and thus biochemical tests must be interpreted in the clinical context.

Endocrine replacement/manipulation in critical illness is controversial. A few landmark studies have evaluated the impact of endocrine intervention on mortality. Intensive insulin therapy in hyperglycaemic patients has been shown to reduce mortality whereas growth hormone treatment was detrimental. High dose glucocorticoid treatment in unselected patients may be harmful but low dose hydrocortisone replacement may be of value in selected patients with septic shock. Future studies will hopefully further clarify the impact of endocrine replacement on morbidity and mortality in specific clinical situations.