Subcutaneous rehydration: updating a traditional technique

Subcutaneous (SC) rehydration therapy (SCRT), originally referred to as "hypodermoclysis," shows promise as an alternative to intravenous (IV) fluid administration for treatment of dehydration. A simple, safe, and effective technique, SCRT is indicated for treatment of mild-to-moderate dehydration. Augmentation of SCRT with administration of a recombinant human formulation of the hyaluronidase enzyme at the infusion site gives rise to SC fluid administration rates up to 5-fold faster than those achieved without the enzyme, making the technique more clinically practical. Unlike older, animal-derived forms of hyaluronidase, recombinant human hyaluronidase has a lower chance of allergic reactions with repeated dosing. Clinical trials have demonstrated that recombinant human hyaluronidase effectively and safely facilitates fluid delivery in adults and children and is well accepted by parents and clinicians. In the emergency department setting, SCRT may be an appropriate alternative to IV fluid administration in certain situations because it is less invasive and generally less painful, while still permitting administration of appropriate volumes of rehydration fluids. Subcutaneous rehydration therapy appears to be particularly useful in patients who present with mild-to-moderate dehydration and have had failed attempts at oral rehydration. The SC route also provides benefits in patients with small, collapsed, or difficult-to-visualize veins or in those who may be agitated or distressed by IV catheterization. Continued research will further clarify the role of recombinant human hyaluronidase-facilitated SCRT in the rehydration treatment algorithm.