The Cast Cutter and all it’s Glory
Let’s discuss, the scary but really not as cruel as you think, the cast cutter.
We have all had that patient that has come in and is due for a cast removal - when they should have followed up with their orthopedic team. If you are able to consult with that team and they give you the pass to remove the cast, then you need be handy with the cast cutter in your department. And, you may have applied a cast yourself a few days ago and the patient comes back and says “that is just too tight!” and you have to start from scratch. We know that can be a slippery slope to deal with, but if the patient has compromised neurovascular status, is saying they are too numb and tingly to bear the cast, you have to remove it, re-stabalize the injury and get a new cast on.
The Device and the Situation
So let’s talk briefly about the device itself - the cast cutter is a hand held machine that powers on and is able to get rid of casting material without stripping or damaging the skin beneath it. The machine has a serrated blade, that spins or oscillates at a very high speed without actually doing a full rotation. They have a special kind of motor called a pneumatic motor or an air motor - also known for you trivia junkies as a compressed air engine - that works by expanding compressed air. They convert the compressed air energy to do their job (cut) in a linear or rotary motion. They are found in all kinds of handheld machines such as sanders, dental drills, tire changers and even torpedoes (wooo!) and train engines etc. And for you history buffs, these things have been used since the mid 19th century in cars and the first successful application of the pneumatic motor in transportation was the Mekarski system air engine used in locomotives.
Cool history bro. In general, cast saw cutters though are handheld, portable instruments and these pneumatic powered cast saws are used in the cutting of cast with the use of dedicated plaster or fiberglass blades majorly for removing casts.
So, how does a cast cutter work? Well, you plug it in and apply it directly to what you want to cut. The oscillating blade vibrates. It does NOT spin. This is NOT a table saw. It does not cut the same way. It’s not going to cut the arm or leg into bloody pieces. The skin can resist contact without being cut while the casting material is cut. They also have special blades made out of dicronite, titanium nitride or teflon, which are great for cutting through synthetic materials.
Presently, there are several types of cast cutters which are available, which makes the discouraging task of removing casts with the use of shears a thing of the past. Most are powered electrically, but others are powered by a high-pressure air source. Both the portable and stationary systems are used, and different blades are available for cutting various casting materials. Stainless steel blades are used for plaster in Paris, but do not work well with synthetics. Special blades that produce less friction, such as dicronite, titanium nitride or Teflon, are recommended for synthetic materials.
Loud, but safe.
There are a ton of companies that make cast cutters, but Stryker and Martin make good ones. Some are louder than others, and certainly can scare the crap out of the patient, so do them a favor and explain to them how it works before you come at them with gloves, a mask and the saw! Don’t underestimate the anxiety or trauma this can cause a patient. You might know how it works - but don’t count on the average joe to know this!
In general, cast saws are super safe. Let the patient know that. As we mentioned, the blade oscillates very slightly thousands of times per minute, rather than spinning continuously. Additionally, the blade teeth are very shallow and relatively dull. This results in a device that quickly and effectively removes the cast without cutting the patient.
Time to Proceed
Keep in mind, the cast cutter does not cut through padding or stockinette.
Consider your patient: Pediatric cast saws tend to be quieter and are less menacing - so if you have a separate peds department and special cast saw for them, GO GET IT.
Consider the work area you are in: A cast saw handset only may be more portable; they can get messy and you can’t just be doing this in a triage chair. Unless you plan to explain to everyone how you want to clean it all up. Also, A loud cast saw or vacuum may interrupt others. Maybe warn someone in the room next to your patient that there will be some cutting going on first.
And, blades do wear out. So keep tabs on this device and make sure it goes through compliance checks routinely.
The Science Direct website suggests to us that sawing over bony prominences, should be avoided because skin injuries can potentially occur in these locations. “A long strip of rigid plastic is sometimes used to slip inside the cast to form a barrier between the saw blade and the patient's skin. This is especially useful when removing a cast from an especially anxious patient. If this device is not available, a wooden tongue depressor can be used to protect the skin at either end of the cast”.
When you are sawing, the blade should be FIRMLY pressed against the cast at a 90 degree angle until it can be felt to completely cut through the cast shell. LIFT if out and repeat the motion as you take off the rest of the cast. This minimizes skin burns or abrasions.
If the cast saw becomes too hot, turn it off until it sufficiently cools. Don't risk burning the patient.
The cast should be cut down both sides. BOTH SIDES. Use a cast spreader to then further widen the cut until the two cast shells can be separated and removed. Use Scissors cut off the underlying cast padding and stockinette.
This is one of those procedures that you need to pay attention to detail. Watch one, do one and teach one. Consider all our pearls and watch the video to show you more tips and tricks on exactly how to master this must know procedure. Who knew you had to put this much thought into the cast cutter!
