This week a patient sent a note that her mom was to undergo surgery and the anesthesia crew was planning on using the local anesthetic bupivacaine. She knew from reading the blog that this wasn’t a good idea, so let’s explore just how nasty this drug is to joints and why doctors are still using it.
A local anesthetic is a medication that is injected to make an area numb. These drugs commonly include lidocaine, bupivacaine, ropivacaine, and mepivacaine. They work by altering the body’s ability to transport the chemicals that start the nerve response, with the clear winner for the duration of action being bupivacaine (aka Marcaine). As a result, bupivacaine is very popular in anesthesiology, where the longer a part is numb, the better.
About a decade-plus ago, a pump was invented to keep shoulder joints numb after surgery, which helped with post-op pain. It infused bupivacaine continuously and was hailed as a modern wonder until the patients began to show up post-op with shoulders that had no cartilage. Turns out that bupivacaine is highly toxic to cartilage cells. As a result of the additional research performed, the American Academy of Orthopedic Surgeons put out a warning in 2012, warning surgeons not to use bupivacaine in joints.
Just How Bad Is Bupivacaine?
In 2007, our lab research group did its first study to see how the common local anesthetics we used might impact stem cells. At that point, bupivacaine was a real standout. It was toxic to stem cells at almost homeopathic dilutions (i.e., a dilution of 100 or more from the amount that’s used clinically). In 2014, we followed that up with publishing a research paper that also showed the same thing. However, our research isn’t alone in its findings that bupivacaine is a really bad boy. In addition, there’s also a surprising new entrant on the list of local anesthetics not to inject into joints.
As recent as March, a research paper was published that reviewed the results of 12 studies on the effects of local anesthetics on cartilage in joints. Bupivacaine and lidocaine were found to be more chondrotoxic (cartilage killing) than mepivacaine and ropivacaine. The amount of dead cartilage cells was directly related to the dose used of the local anesthetic, and joints with arthritic cartilage were more vulnerable than normal ones. The authors concluded that the only commonly used anesthetic that can be used in concentrations that still numb the joint and won’t have an effect on cartilage cells is ropivacaine (0.1–0.2%). The paper warned that “The use of lidocaine should be avoided.” This is new info, as while we knew lidocaine had some issues, it’s still being commonly used.
Who Still Hasn’t Gotten the Memo?
As we can see from my patient’s story, there are still physicians who haven’t gotten the memo about the cartilage toxicity of local anesthetics (other than ropivacaine). From what I see, the doctors still using dangerous drugs like bupivacaine and lidocaine to numb joints are usually surgical anesthesiologists and interventional pain-management doctors performing spine injections. They both like bupivacaine for its long-acting effects and also routinely use high-dose lidocaine because it can give a dense type of numbing block. One of the likely problems is that the safe anesthetic, ropivacaine, is little known in these fields because it’s commonly used in labor and delivery and its about 10 times more expensive per unit volume. For example, a bottle of lidocaine will run a clinic a few dollars; whereas, the same bottle of ropivacaine will run $30–40.
So Is It Malpractice to Inject Bupivacaine or Lidocaine into an Arthritic Joint?
While 10 years ago the literature on the toxicity of local anesthetics in joints was just getting going, and 5 years ago it was evolving, we have enough data in 2017 to state that injecting either bupivacaine or lidocaine into an arthritic joint is medically contraindicated. This is a fancy way of saying that it shouldn’t be done. Is that malpractice? That’s more of a legal definition defined by the courts, but suffice it to say that we have enough data to give a smart attorney ample ammunition to make a case.
What Can You Do if You’re a Patient?
If you’re a patient, always ask which local anesthetic is being injected into your joint. This is true whether it’s a knee, shoulder, ankle, or spine joint, like a facet. Make sure that it’s ropivacaine and not bupivacaine nor lidocaine! The brand name for ropivacaine is Naropin, and the brand name for bupivacaine is Marcaine. Here’s a pneumonic I made up that can help you remember:
R and N are right as RaiN; all others won’t help my pain!
In this pneumonic, R is for ropivacaine and N is for Naropin. So if you ask about the anesthetic that will be used and the name starts with an L, like lidocaine, or a B or an M, like bupivacaine or Marcaine, then that’s not the right stuff!
The upshot? In 2017 we still have doctors who haven’t gotten the memo that common local anesthetics can destroy the remaining cartilage inside arthritic joints. If you’re a physician reading this, it’s time to change anesthetics—there are no more excuses. If you’re a patient, remember my pneumonic and if a doctor tries to use a toxic anesthetic, run and find a new doctor!