Enlarging pediatric i.v. catheters.

The Streamline (Menlo Care, Menlo Park, CA) intravenous catheter is constructed of an elastomeric hydrogel (Aquavene) that softens and increases in diameter when exposed to aqueous solutions. The flow rates of 22-gauge x 1'', 24-gauge x 0.7'', and 26-gauge x 0.625" catheters were ascertained during 90 minutes of hydration in 37 degrees C normal saline. Ten tests of each size catheter were performed every 15 minutes starting at 0 minutes and continued throughout the 90-minute period of hydration. Each test consisted of measuring the time for 10 ml of saline to flow through the catheter. All three gauges had a significant increase in flow and reached a maximum at the 75 minute test. Maximum increase in flow rates were 43, 39, and 32% for the 22-, 24-, and 26-gauge catheters, respectively. None of the catheters exceeded the initial flow rate of the next larger gauge catheter.