inotrope via syringe driver or pump?

[sister s]

We currently use a syringe driver when we infuse noradrenaline/levophed, but have had some incidents when we swap syringes with significant drops in BP, even when we have a second infusion ready to go. On some occasions nurses have said that they have left the safety clamp on the new syringe and not realized this, and the syringe driver has failed to alarm due to the low infusion rate. Then, not only do you get a low BP, when you discover the clamp is on and you un-clamp, you get a sudden purge of inotrope. We tested clamping a syringe driver that was 'infusing' at 2ml/hr, and it took the Alaris syringe driver 40 minutes before it alarmed! Then, when I un-clamped it 6 or 7 drops purged out!

My question is, if you run your inotrope through a bag and pump, rather than a syringe driver, how many of you out there have actually experienced problems with the VTBI running out or air in the line? Obviously these are factors that are avoided by using the syringe driver method, but at least with the bag and pump method you never have to stop the infusion, even momentarily while you change infusions.

[ausrnurse]

We use alaris pumps at my hospital. Whenever I give inotropes, I usually set the VTBI to lower than what is in the bag (say 60ml out of a 100ml bag), then tell the machine to "continue rate" when the VTBI is completed - so that it continues to run at the same rate even with no volume dialled up. We only run our inotropes through a pump, and we have never had any issues.

[detroitdano]

I've only used Alaris infusion pumps for pressors. As was already mentioned, I'd set the volume for less than what is actually there to avoid having the bag run dry. I also made it a habit to keep another bag of the pressor behind the infusing bag, so if it ever did run dry, another was ready to roll.

Every pump gets air in the line, that's just nature. Just hang the bag high, prime the tubing right and pray to the pump gods that it won't go off a hundred times on your shift.

[MunoRN, RN]

The problem with syringe pumps is something called "stiction". The friction that must be overcome to cause the plunger to move causes the pump to deliver medication as series of boluses rather than as an essentially continuous infusion.

"Stiction, single-use syringes and syringe pumpsSyringe pumps can deliver small volumes of drugs at low flow rates.

Single-use syringes are inexpensive and mass manufactured items, and are not meant to be highly accurate. When used in a syringe pump at low plunger speeds, the friction between the syringe plunger and the barrel causes a jerking effect and the fluid is delivered as a series of small boluses. The fit between the plunger and the barrel may vary from batch to batch and, consequently, the jerking effect may also vary. This problem is commonly known as 'stiction'. In general, the bigger the syringe and the lower the flow rate, the more pronounced the stiction."

This is more pronounced when you change a syringe because you're losing all of your pressure on the plunger, compared to just losing some of your pressure each time the plunger moves, which means it will take longer for the first mini-bolus the pump infuses.

[catamounts303]

Bottom line make them stop this and get all your pressors and sedation on infusion pumps. This must be so frustrating for you!