Infusion Strategies (Who is already doing this?)
One of the most time consuming and frustrating aspects of a critical care interfacility transport is switching over all their infusions to your transport pump. We try to make this process go as smooth as possible, but the truth is, this is one area the majority of clinicians could improve on. I have seen crews take the hospital (non transport approved) pumps and get themselves in deep with alarms that they are unfamiliar with. I have seen providers get frustrated with a stubborn alarm and attempt to hang a pump necessary infusion to gravity. So what is the "best practice" when it comes to getting this task done in an efficient and timely manner... I don't know. However, I have been working on several ideas that seem to make a whole lot of sense in my head. Here is my plan.
To understand the most efficient way to set an infusion assembly up, we must understand "infusion theory". Usually if a medication is running below a certain ml/hr it will be tied into a "drive line". This is usually an isotonic solution (0.9% saline) that serves as a constant flow through the infusion set. I almost think of a drive line like bias flow through a vent circuit. This will (A) maintain patency of the line, and (B) Boost medications through that are running at a rate lower than the dead space in the infusion line allows. For example.. Vasopressin usually is running at 0.04 units/minute. This correlates to 2.4 units per hour. The typical concentration for Vasopressin is 1:1. This would mean your infusion is running at 2.4 ml/hr, which without a drive line would never reach the patient! So when you decide to disconnect your saline drip to make room for more infusions, you could very easily be preventing important medications from making their way to the patient.
My solution is a three way stopcock manifold. You will attach one stopcock for each infusion that is compatible to run into one site. At the end of the stopcock manifold you will attach a drive line at a calculated ml/hr (usually like 75 ml/hr) depending on equipment and line distance to patient. Typically an extension set has a priming volume of 1.2 ml's. You will add an additional 0.5 ml for each stopcock that is added. In the illustration below you would have a priming volume of 2.2ml's. For this reason small bore tubing is commonly used in the PICU setting. It also is important to look at the concentration of the medication being administered. Midazolam is commonly mixed in a 1mg/ml concentration. If a provider flushed this line with a 5cc's of 0.9% saline, they are actually giving a 5 mg bolus of Midazolam! When high concentration mixes are used it would be important to duplicate the facilities drive line rate.
Some ICU’s will use their highest rate infusion as a carrier line.The infusion will have a domino effect and will hit the blood stream with every piston drive of the pump. This is another time when copying the facilities drive line rate would be beneficial.
The distal end of the stop cock will attach to the patients IV extension set. The extension set does not HAVE to be used. The manifold can be attached to an extension from a central line. The incoming compatible infusions will be then be labeled at the pump end and at the stopcock connection. This is illustrated below.
It is important that each medication that is connected to the circuit be run through the IV pump. This will prevent backflow from a higher flow/higher positioned infusions.
It may be a smart idea to leave one additional stop cock at the patient end of the circuit to deliver bolus medications through as needed (i.e.: Analgesics).
Again, it important with any infusion transfer to know Y site compatibility. This strategy just avoids multiple infusions joining in at drastically different distances from the patient. It also cuts down on the confusion of which lines connect to which port in the spaghetti mess that can ensue.
You are on your way to a critical care transport and prepare the following items enroot.
1. Set up and text vent circuit with ETC02 adapter already attached.
2. Spike a bag of 0.9% saline and assemble your drive line.
3. Assemble a 3-4 stopcock board and attach it to your drive line.
4. Throw a ton of alcohol/sterile prep's in your pocket for attaching lines on scene.
When you arrive at the bedside you follow the outline laid out in Sam's last blog on CC Scene Logistics. You fill up the drip chamber on the drips you are switching over so that the facility pump can pull from the chamber while you re-spike the bag with your pump tubing. You follow this strategy until you have each infusion connected to your stopcock manifold primed and ready. The facilities infusions to the patient have not been interrupted yet. You now attach your stopcock manifold to the patients IV extension set and hit "Start". Infusions that weren't compatible with your board are set up last on another site.
They do make commercial manifolds that may be more efficient than the way I explained above. However this may take some time to convince your service to buy, and three way stopcocks are usually readily available at most services.
I am really interested to know your feedback and best practices on this topic. I have asked several providers what they are doing and received some excellent suggestions. My friend Kyle Driesse had some excellent advice that he gave back in Podcast 4 "Organization Tips & Tricks".
I look forward to your comments!