Purpose of review
Protein catabolism is common among critically ill patients, contributing to organ dysfunction, muscle weakness, prolonged mechanical ventilation and length of stay in the ICU, with adverse impact on patient prognosis and resource utilization. Neither adequate enteral nutrition nor parenteral nutrition stems this catabolism. Recombinant growth hormone supplementation in surgical trauma and burn injury patients has demonstrated nitrogen retention, increased insulin-like growth factor-1 levels, decreased length of stay and improved survival. As a result, growth hormone became widely used in the ICU, until two large randomized trials in 1999 noted increased mortality associated with infection and organ dysfunction.
Small clinical trials have revisited growth hormone supplementation in prolonged critical illness, demonstrating nitrogen conservation and increased serum levels of insulin-like growth factor-1 and insulin-like growth factor-1 binding protein in patients receiving adequate nutrition support. These trials suggest growth hormone supplementation may be safe and more efficacious in a subclass of chronic critically ill patients.
Prior to proposing new prospective randomized clinical trials, case reports describing anecdotal experience with growth hormone in selected chronically critically ill patients may provide insight into redefining the ICU population most likely to benefit from growth hormone supplementation. Current guidelines continue to recommend against the use of growth hormone in critical illness.