Flow Rate Tests for Disposable Needles

Scooter's Supplies for Chronic Renal Failure (CRF)

Needle Flow Test Results

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**Time to Flow 100 Milliliters of Fluids**
Tests conducted by **Radford Hunt** (see methodology below)
Needle Brand	Diameter (Gauge)	Length (inches)	Style *	Lot 1 (mins:secs)	Lot 2 (mins:secs)	Average (mins:secs)
Terumo	18 g	1"	TW	00:55	00:51	00:53
Terumo	19 g	1"	TW	01:17	01:16	01:16
Terumo	20 g	1"	UTW	02:02	01:56	01:59
Terumo	21 g	1"	UTW	02:39	02:37	02:38
Terumo (Sur Vet Label)	21 g	1"	TW	05:59	05:53	05:56
Terumo	22 g	1"	UTW	04:05	04:13	04:09
Terumo	23 g	1"	UTW	07:16	07:03	07:09
Terumo	25 g	1"	UTW	13:21	13:20	13:20
Monoject	18 g	1"	STD	01:15	01:18	01:17
Monoject	19 g	1"	TW	01:11	01:09	01:09
Monoject	20 g	1"	STD	02:32	02:34	02:33
Monoject	22 g	1"	STD	06:21	06:08	06:15
BD	18 g	1"	STD	01:14	01:10	01:12
BD	20 g	1"	STD	02:28	02:29	02:29
Monoject	22 g	1.5"	STD	07:21	07:13	07:17
Monoject	22 g	.75"	STD	06:04	06:12	06:08
Terumo	26 g	.5"	STD	19:17	-	19:17
Terumo	27 g	.5"	STD	33:10	-	33:10

* TW = thin wall UTW = ultra thin wall STD = standard wall

Methodology:

A fixture was made that held the needle end of a 78" long Abbott Labs' 15 drops/per mL Venoset pointing straight down into a graduated cylinder marked at 100 mL.
A 1000 mL bag of Abbott's lactated ringer's solution (LRS) was fixed at a height of 57 inches above the needle end of the Venoset as measured from the bottom of the bag where the venoset pierces the seal to the opposite end where the needle is affixed. The line, being longer than the vertical distance, was made to curve once to take up the extra length but at all times remained angled down.
Each needle was tested with the beginning fluid level in the Ringers bag set at 500 mL to ensure consistency. (The Ringers bag was refilled via the injection port each time)
When the bag was refilled I would pinch the venoset as I released the crimp wheel and then I would massage the point on the venoset tubing where the wheel had flattened it. When the line was fully open, I released it and slid the graduated cylinder under the streaming needle as I started a stop watch. When 100 mL had flowed into the cylinder, I stopped the watch. I tested one of each needle (lot1) and then went back and tested a second needle of every type (lot2). The results of the two flow times were then averaged. In the table you will see the two individual times under Lot1 and Lot2 and the right hand column is the average of the two.
Note that these are free-flow times and that "in the cat" times will be longer due to back pressure and other variables
Tests were repeated using a 10 drops per mL Baxter IV set - flow times were the same.

tests performed and explanation provided by Radford Hunt