Administering Sub-Q Fluids

NEEDLE INSERTION: THE DESIGN OF THE NEEDLE. Hypodermic needles are engineered with a beveled face on the tip and cutting edges on the leading sides of the bevel. They're not intended to pierce at a 90 degree angle like a nail but rather to slice into the skin at a shallow angle (between 30-45 degrees) with the flat side of the bevel which contains the hole up, facing away from the skin.

Attempting to insert the needle the wrong way results in unnecessary effort at best from punching through the skin rather than cutting, leaves a larger hole, and at worst might fail to penetrate. You should be aware of the location of the flat before putting the needle on the setup, if possible by looking through the translucent sheath. (This avoids exposing the sterile needle to the atmosphere before inserting).

More about needles here: Miscellaneous_Tips

Changing needles before each treatment:

1. Grasp the line in the same place I will when inserting the needle, thumb on top, and get rid of any kinks that might cause it to twist once inserted.
2. Remove the new needle from its sterile package and locate the flat.
3. Take the old needle off of the setup (in its sheath) and immediately replace it with the new needle, also still in its sheath.
4. Adjust the bevel of the needle so that it aligns properly.
5. Inspect the line for bubbles and tap any out as described under "Flow Rate" (below).
6. Remove the sheath, squirt out just enough to see a steady stream with good pressure, replace sheath.

The needle should be fully inserted at an angle as described above. Since there's the very real possibility of back pressure gradually forcing the needle out I always keep my thumb lightly applying neutral pressure to hold the needle in.

FLOW RATE: In addition to the gauge of the needle, flow rate is affected by several things:

1. The tubing setup (venoset), which includes the drip chamber. These are rated in drops per ml, usually either 10/ml or 15/ml. 10 drops per ml are preferred (larger drops, faster flow).
2. Height of the bag. If the bag isn't at least 3 feet above the needle the flow may be slower, especially with a partially used bag having less weight to push the flow.
3. Lead of the tubing. The tubing should be arranged so that the flow is always downhill or horizontal from the bag to the needle. If the fluid has to travel uphill against the friction of the tubing the flow rate may be reduced, sometimes significantly. If there's slack in a long setup, this slack should be supported rather than allowed to sag and create an uphill slope.
4. Air in the tubing. Air bubbles aren't dangerous to the patient in subcutaneous injections, however they can completely stop the flow of fluid or slow it down until the bubble has passed. Always inspect the line for bubbles before starting. If they're found above the regulator wheel they can be made to rise back into the drip chamber by flicking the tube with your finger. If they're below the wheel they may be similarly moved to the needle end of the tube. At any rate the new needle should always be flushed briefly to ensure that it contains no concealed bubbles and that the fluid comes out as a steady stream.
5. Lie of the needle after insertion. See below for ways to adjust this.

ADJUSTMENTS: After starting the treatment always look at the drip chamber to make sure there's a steady flow. The drops should fall at a constant rate, depending on the factors above. If they don't and the line has been freed of air and flushed there might be an insertion problem which can be solved without taking out the needle.

First, try withdrawing the needle a tiny amount. It could be that the tip of the needle has lodged in something like the inner surface of the skin or muscle, and the hole may be blocked. If this had happened you probably would have felt a resistance at the end of an easy insertion.

Next, try twisting the needle around its axis (as if you were twirling it between your fingers) without changing its direction or angle. It's likely that the flat of the bevel containing the hole is resting against something that's impeding the flow, so twisting it to one side or the other will give the fluid a place to go.

Quite often, if an extreme twist is necessary to maintain the flow it may put tension on the tubing making it tend to twist back. If this happens use a free hand to gently form a loop to contain the tension, which can be laid across the kitty's back. This will save some writer's cramp from trying to fight the reverse twist through the entire treatment.