The Use of Hyaluronidase to Treat Mannitol Extravasation

To the Editor: We read with great interest the article by Edwards et al. (1), who describe a case of mannitol extravasation causing compartment syndrome in an anesthetized patient. While it is prudent to proceed with emergency fasciotomy in severe compartment syndrome, the authors make no recommendations for early extravasations that have not progressed to neurological dysfunction or compartmental pressures more than 30 mm Hg. In this group of patients, the use of hyaluronidase may dissipate the extravasated mannitol and prevent the formation of compartment syndrome. Recently, we used subcutaneous infiltration of hyaluronidase to successfully treat extravasated mannitol. A 51-year-old man underwent percutaneous ultrasonic lithotripsy under general anesthesia. A 20-gauge IV catheter was inserted in the dorsal right hand, and anesthesia was induced with propofol, fentanyl, and succinylcholine. Following uneventful induction, patient was positioned prone and covered with drapes. During an hour-long procedure, the patient received 750 mL of lactated Ringer’s solution through what appeared to be a “positional” IV catheter. Close to the end of surgery, 50 mL of 20% mannitol was administered with “some resistance” through the same IV site. At the end of surgery, we noticed significant swelling of the right hand caused by extravasation of the intravenous fluids. The pulse oximeter on the right index finger showed damped wave form and the fingertips were “dusky” with delayed capillary refill. The peripheral arterial pulses were palpable, and the hand showed no motor or sensory deficits. Since warm compresses and elevation of the right hand did not improve the capillary circulation, we proceed to try hyaluronidase. We requested and obtained from the pharmacy 150 units of hyaluronidase, mixed in 10 mL of normal saline. Using a 25-gauge needle, multiple subcutaneous injections of 0.5–1.0 mL were performed around the periphery of the extravasation. The pulse oximeter was left in place, and a plastic surgery consult was called. The hand was examined every hour. The swelling diminished after 6 h and was completely resolved by the next day. The surgical service closely followed the uneventful resolution of swelling and felt no further intervention was necessary. It must be recognized that extravasation of even small amounts of hyperosmolar fluids, if untreated, could easily swell in size from drawing in free water and rapidly escalate to compartment syndrome. Mannitol is a potent osmotic fluid, and each 50 g of mannitol causes an intracellular to extracellular shift of 1 liter of water (2). Hence, early treatment with hyaluronidase of extravasation of hyperosmolar fluids/drugs such as mannitol, parenteral nutrition solution, 10% dextrose, and 30% urea could save the patient fasciotomy. While we cannot be sure that our treatment with hyaluronidase contributed to the positive outcome in our patient, it is worth mentioning as a low-risk treatment option in early stages of hyperosmolar solutions extravasation. The technique involves subcutaneous infiltration of hyaluronidase in a pin cushion fashion at 5–10 sites along the leading edge of the extravasation. Hyaluronidase may be diluted with normal saline or 1% lidocaine to provide a concentration of 10–15 units per milliliter. The recommended total dose is 150–900 units (3). Matthew M. Kumar, MD Juraj Sprung, MD, PhD