GH and Catabolic States

It is current clinical practice to give intravenous nutrition (IVN) to critically ill postoperative septic intensive care patients to prevent loss of body protein, although it has not hitherto been possible to confirm this by direct measurement of body composition. Using a neutron activation analysis facility adapted to provide an intensive care environment and tritiated water dilution we directly measured total body water, protein and fat before and after 10 days of IVN (mean daily non-protein energy and amino acid intakes 2,750 kcal and 127 gm) in eight adult intensive care patients. All patients had recovered from the septic shock syndrome but were still ventilator dependent at the start of IVN. Six patients survived to leave hospital. As a group, the patients lost 12.5% of body protein (mean loss 1.5 +/- SE 0.3 kg; p = 0.001) despite a gain in fat (mean 2.2 +/- 0.8 kg; p = 0.026). There were, in addition, large losses of body water in most patients (mean, 6.8 +/- 2.6 kg; p = 0.036). We conclude that substantial losses of body protein occur in critically ill septic patients despite aggressive nutritional support and that further research is urgently required on the fate of infused substrates and the efficacy of alternative nutritional therapies.

After injury, infection, extensive chemotherapy, and other critical illnesses, both protein and fat are lost from the body. Although minor alterations in body composition are probably of little clinical importance, losses of body protein of 10 percent or more contribute to morbidity and debility. This catabolic response can be modified and recovery can be accelerated by a variety of approaches. First, the inflammatory response can be reduced; second, specific nutrients can be provided to support the patient's tissue requirements during catabolic illness; and third, growth factors can be used to enhance protein synthesis and tissue repair. These approaches, whether used alone or in combination, will reduce the loss of body protein, which should accelerate recovery, shorten the length of hospitalization, and reduce convalescence.

The beneficial effects of growth hormone on wound healing in severely burned children were studied. Forty patients who were 2 to 18 years old, with 40% or more total body surface area (TBSA) and 20% or more TBSA full-thickness flame or scald burns, were randomized in a double-blind study to receive placebo or 0.1 mg/kg/day recombinant human growth hormone (rHGH) until the first donor site healed or to receive 0.2 mg/kg/day rHGH or placebo from admission throughout hospitalization. Patients receiving 0.2 mg/kg/day rHGH demonstrated significantly higher serum IGF-1 levels at 4.8 +/- 1.7 U/mL compared to placebos at 1.6 +/- 0.4 U/mL (p less than 0.05) and a significant decrease in donor-site healing times compared to placebo (p less than 0.05). Length of hospital stay (LOS/%TBSA) was decreased from 0.80 +/- 0.10 days/%TBSA burned in the placebo group to 0.54 +/- 0.04 days/%TBSA burned in the 0.2 mg/kg/day treatment group (p less than 0.05). This translates, for the average 60% TBSA burned patient, to a decrease in LOS from 46 to 32 days.