Endocrine Function in the Critically III

Hormones mediate much of the body's response to critical illness. As a consequence of this homeostatic function, circulating hormonal levels are often abnormal in critically ill patients. In this chapter the hormonal and metabolic response to acute illness is reviewed. The distinction between the ‘euthyroid-sick syndrome' and hypothyroidism is detailed. Similarly, the response of the adrenal glands to critical illness and illness-induced changes in calcium, phosphorus and magnesium metabolism are reviewed.