Growth hormone is a polypeptide responsible for increasing carbohydrate and lipid metabolism and stimulating protein synthesis. Growth hormone levels are decreased in a variety of critically ill patients such as those who are thermally injured, septic, or who have experienced major trauma. Several studies investigating the use of growth hormone were conducted in trauma and burn patients and have been associated with positive outcomes such as decreased length of hospital stay and reduced mortality.
However, a recent study performed by Takala and colleagues demonstrated an increase in mortality associated with the use of growth hormone. The heterogeneous population enrolled in this large, randomized, multicenter study included cardiac and abdominal surgical patients, trauma, and respiratory failure patients. Treatment of growth hormone at a dosage of 0.10 (± 0.02) mg/kg/day was started on day 5 through 7 after hospital admission. Patients were treated for 21 days or until hospital discharge. The duration of mechanical ventilation, length of stay in intensive care, and in-hospital mortality rate were all significantly higher in the growth hormone arm vs the placebo arm of the study.
Dr. Jane Gervasio, PharmD, BCNSP, Clinical Pharmacist, Clarian Health at Methodist Hospital, Indianapolis, Indiana, indicated that the hypermetabolic and proinflammatory effects of growth hormone theoretically may explain the increase in mortality observed. This theory was published by Demling and postulates that when these patients were given growth hormone, they were not at their peak metabolic rate. Unlike the trauma and burn patient population studied previously who were at their maximal metabolic and inflammatory state of the disease process, these patients were not yet at that level. Therefore, administration of growth hormone at this time within the disease course produces an initial energy deficit due to an increase in cellular metabolism and an increase in cytokine levels. These hypermetabolic and proinflammatory effects of growth hormone are thought to have led to a lack of oxygen supply to vital tissues, resulting in multiple organ failure and death. Dr. Gervasio concludes that growth hormone, at this time, should not be given to patients with critical illness with the possible exception of thermally injured or trauma patients. Also, there are good results in children with burns in the literature, so that indication cannot be ruled out. Of note, the major significant side effects seen with the use of growth hormone are hyperglycemia and hyperinsulinemia.
Insulin-like growth factor (IGF-1) is another agent that has been studied in trauma and thermally injured patients. IGF-1 has been shown to attenuate catabolism, increase CD4/CD8 ratio, and increase nitrogen retention and muscle strength.[3,4,5] The studies that have been performed to date are small in sample size and outcomes data are lacking. With regard to safety, hypoglycemia seems to be the only concerning side effect. More data are needed in order to fully assess its role in therapy.
Medscape Pharmacists. 2001;2(2) © 2001 Medscape
Cite this: Specialized Nutrition in Critically Ill Patients - Medscape - Nov 30, 2001.