COMPARISON OF SUBCUTANEOUS AND INTRAVENOUS ADMINISTRATION OF A SOLUTION OF AMINO-ACIDS IN OLDER PATIENTS

OBJECTIVE: To compare the plasma amino acid (AA) concentrations obtain ed by the infusion of an AA solution (660 mOsm/L, pH 7) using the subc utaneous (SC) with that using the intravenous (TV) route in older pati ents. DESIGN: A prospective, randomized, cross-over study. SETTING: A hospital geriatric ward. PARTICIPANTS: Six patients with a mean age of 84 years. MEASUREMENTS: The infusion of the AA solution (IV or SC) la sted 6 hours. Blood was sampled at 0, 2, 4, 6, 8, 10, 14, 18, and 24 h ours from the start of the infusion to determine plasma AA level by th e phenyl-isothiocyanate method. RESULTS: Compared with baseline values , plasma AA concentrations increased to a significantly higher level f rom the second to the tenth hour and from the second to the fourteenth hour during IV and SC infusions, respectively. Plasma AA levels did n ot differ between the two routes. SC infusion was well tolerated. CONC LUSION: Assuming that nutritional sufficiency is the desired result of plasma AA. infusion, we conclude the SC route is well tolerated and o ffers the possibility of nitrogen supplementation for older patients o ver short periods of time, when oral protein intake is transiently ins ufficient or impossible, as a way to limit, but not to treat, protein- energy malnutrition.