LACK OF EFFECTS OF RECOMBINANT GROWTH-HORMONE ON MUSCLE FUNCTION IN PATIENTS REQUIRING PROLONGED MECHANICAL VENTILATION - A PROSPECTIVE, RANDOMIZED, CONTROLLED-STUDY

Objective: To evaluate the benefit of recombinant human growth hormone administration on muscle strength and duration of weaning in critical ly ill patients undergoing prolonged mechanical ventilation. Design: P rospective, randomized, controlled, single blind study. Setting: Inten sive care unit. Patients: Twenty patients requiring greater than or eq ual to 7 days of mechanical ventilation for acute respiratory failure. Intervention: Random assignment to receive either 0.43 IU (-0.14 mg) recombinant growth hormone/kg body weight/day (treated group), or sali ne (nontreated group) for 12 days. Measurements and Main Results: Nutr itional support was guided by indirect calorimetry, Cumulative nitroge n balance was positive throughout the study period in the treated grou p (44.9 +/- 17.3 [SEM] g/12 days) vs. the nontreated group (-65.8 +/- 11.8 g/12 days) (p < .0001), Despite similar initial plasma concentrat ions, recombinant growth hormone supplementation resulted in marked in creases in growth hormone, insulin like growth factor-1, and insulin c oncentrations (p < .05, .02, and .0001, respectively, vs. nontreated g roup), Body impedance determined net fat-free mass increased in the tr eated group (0.8 +/- 0.6 kg) vs. the nontreated group (-1.1 +/- 0.5 kg ) (p < .03). Initial peripheral muscle function, assessed by computer controlled electrical stimulation of the adductor pollicis, was simila rly lower in treated and nontreated groups than sex and age-matched no rmal controls, and decreased further during the study period, Arterial blood gases, cumulative total mechanical ventilation time, and number of hrs/day of mechanical ventilation during weaning were similar in b oth patient groups, Only three of the ten patients in each group were weaned from mechanical ventilation by day 12. Conclusions: Daily admin istration of recombinant growth hormone in mechanically ventilated pat ients with acute respiratory failure promotes a marked nitrogen retent ion, However, this action is accompanied neither by an improvement in muscle strength nor by a shorter duration of ventilatory suppport.