Background: Finding and employing intravenous access in children, especially those who are dehydrated, can be difficult. In addition, most cases of dehydration in children are caused by gastroenteritis, making oral rehydration therapy, the most commonly used treatment, less than optimal for those with vomiting. The use of subcutaneous rehydration therapy eliminates these difficulties of administration in dehydrated patients. Hyaluronidase, a spreading enzyme that breaks down the viscous component of interstitial tissue, helps in the absorption of subcutaneous fluids and drugs. Although animal-derived hyaluronidase is already used in adult patients, a newer human-derived recombinant version, rHuPH20, offers the same effectiveness with a decreased risk of allergic or anaphylactic reaction. Allen and colleagues studied the effectiveness of rHuPH20 on rehydration in children.

The Study: The authors of this single-arm, phase IV, multicenter, pilot study enrolled 52 patients, 51 of whom were given subcutaneous rHuPH20 followed by an infusion of isotonic rehydration solution. Inclusion criteria were age of two months to 10 years, weight of less than 42 kg (92.6 lb), a need for parenteral fluid administration, and the presence of one to six of the following symptoms of dehydration: general condition symptoms such as drowsiness or muscle cramps; weak radial pulse; rapid or deep respiration; sunken eyes; decreased skin elasticity; absence of tears; dry mucous membranes; little or no urine output; heart rate of more than 150 beats per minute; and a capillary refill time of more than two seconds. The primary end point was adequate rehydration, with success attributed to the use of subcutaneous rHuPH20 by the physician. Other end points included change in the number of dehydration symptoms; infusion flow rate during the first hour and total infusion time; time from the start of infusion to the first urine output; change in body weight from baseline to emergency department discharge; time from the start of infusion to emergency department discharge to home or the hospital; and parent and investigator satisfaction with therapy.

Results: Of the 51 patients treated with rHuPH20, 48 patients (94.1 percent) were deemed rehydrated by subcutaneous therapy at the end of the protocol. Forty-three patients (84.3 percent) were discharged from the emergency department, and the remaining five (9.8 percent) were admitted to the hospital. Other findings included an average time of 1.7 hours from start of infusion to first urination; a median time of 3.4 hours from emergency department admission to discharge; and a decrease in the number of symptoms of dehydration from 3.5 ± 1.2 to 0.5 ± 0.9. No patients were readmitted in the seven days following infusion. The authors saw a median change in body weight of +2.4 percent ± 5.0 percent. In 43 cases (90 percent), parents were satisfied or very satisfied with the procedure. Only three patients were not adequately hydrated through the subcutaneous route.

Conclusion: The authors conclude that the administration of subcutaneous rHuPH20 and subsequent rehydration fluid is a well-tolerated, effective method of providing fluids to children with mild to moderate dehydration.