ObjectiveTo compare the extravasation rates and insertion complications under gravity and 300 mm Hg (40 kPa) pressure infusion of threaded (SurFast Registered Trademark and Sussmane-Raszynski intraosseous needles, Cook Critical Care, Bloomington, IN); and nonthreaded needles (16-gauge disposable intraosseous needle with 45 degrees trocar Cook Critical Care, Bloomington, IN; Jamshidi bone marrow needle; Baxter Health Care Corp, Valencia, CA).DesignA prospective, randomized study.SettingAn animal laboratory at a university center.SubjectsFive healthy mix breed piglets, weighing 15 to 15.5 kg.InterventionsPiglets were anesthetized and ventilated. Tibial, femoral, and humeral osseous sites were exposed by dissection of overlying tissue. All bleeding points were cauterized and oozing was prevented by sealing with cyanoacrylate. Intraosseous access devices then were inserted one at a time in random order and rated for difficulty of insertion. Normal saline solution was infused under gravity or 300 mm Hg (40 kPa) pressure. Extravasation rates then were calculated from the increase in weight of a gauze sponge wrapped tightly at the base of the needle during infusion.Measurements and Main ResultsNo significant (p more than .05) differences in extravasation rates were noted among the different types of needles, either under gravity or pressure infusions. The Sussmane-Raszynski needle was significantly more difficult to insert than the others (rated difficult to insert and control in 16 of 34 attempts). Inadvertent penetration of both cortices occurred with nonthreaded needles only (three of 66 attempts). The Sur-Fast Registered Trademark needle provided greatest penetration control and was most resistant to accidental dislodgement.ConclusionsUnder ideal conditions, needle type does not influence extravasation rates. However, difficulty with insertion and penetration of both cortices occur commonly and may lead to extravasation during stressful emergency situations or when performed by unskilled personnel.(Crit Care Med 1995; 23:2023-2028)