Comparison of subcutaneous and intravenous rehydration in geriatric patients: a randomized trial

To compare the acceptance, feasibility, and adverse effects of subcutaneous (SC) and intravenous (IV) rehydration in dehydrated geriatric patients and clinical changes exhibited by the patients.

A prospective, randomized, open clinical trial.

Hospital geriatric wards during a period of 20 months.

Ninety-six patients with a mean age +/- standard deviation of 85.3 +/- 6.7 with signs of mild to moderate dehydration needing parenteral fluids.

Geriatric patients were randomly allocated to receive SC or IV infusions of half-normal saline-glucose solutions as long as clinically necessary.

A standardized patient record form was used to document the observed adverse effects. Using a Likert-like scale based on the German school marks system with scores ranging from 1 = very good to 6 = very bad, patients were asked to score their discomfort; nurses and doctors scored the feasibility of the intervention. Changes in laboratory and clinical findings (including patients' orientation and activities of daily living using the Barthel Index) and adverse effects were recorded.

Forty-eight patients were randomized into each group. Median duration of fluid administration was 6 days (SC and IV, P =.33). Median volume was 750 mL/day (SC) and 1,000 mL/day (IV, P =.002). In 13 patients, the therapy had to be changed from SC to IV (SC/IV subgroup): 11 times because of the exigency of an IV drug application and twice because of poor resorption. In 17 patients, there was a change from IV to SC (IV/SC subgroup), mainly because of impossibility of further peripheral IV punctures (8 times) and permanent removal of the IV cannula (5 times). The patients of the IV/SC subgroup scored their discomfort significantly worse (median 5.5 vs all other groups median 2, P =.017). This corresponded with the scoring of feasibility by the nurses (IV/SC: median 4.25 vs all other groups median 2, P =.009) and by the doctors (IV/SC: median 4 vs all other groups: median 2, P =.001). Both methods of rehydration caused only few systemic adverse reactions; acute cardiac failure occurred twice in the SC group versus four times in the IV group (P =.68) and hyponatremia once in the SC group versus twice in the IV group (P = 1.0). Some patients experienced local side effects (SC, n = 29 vs IV, n = 24; P =.41), mainly to a mild extent (SC, n = 25 vs IV, n = 24; P = 1.0). Major local side effects (large edema, phlebitis, cellulitis, erythema and strong pain) occurred in nine SC and eight IV (P = 1.0) patients. The clinical and laboratory changes during therapy were similar in both trial arms.

Rehydration by hypodermoclysis is equally well accepted by geriatric patients as the IV therapy and offers a similarly easy feasibility. Additionally, in confused patients and in those in whom IV punctures are difficult to achieve, it represents the far superior method. Both techniques are comparably safe and effective.