Orthopedic Tourniquet Complications Podcast

This podcast discusses complications related to tourniquet use in orthopedic surgeries. It covers the types of tourniquets used, ways to prevent complications, physiological changes associated with tourniquet use, and the importance of communication with the surgical team. It also mentions tourniquet pain and post-operative paresthesia as potential complications. Overall, it emphasizes the need for awareness and prevention of tourniquet complications in anesthesia care. All right. Hello, CRNA 854 Advanced Principal students. This is Riley, and I'm going to be making a podcast in the realm of orthopedics and anesthetic implications. This will be about complications related to tourniquet use in orthopedic surgeries. As I'm sure we've all experienced at this point in our clinical journey, tourniquets are often used in cases involving orthopedic surgeries of the extremities. Typically, they are associated with some sort of complication, although these are typically pretty benign and short-lasted. We'll discuss the different – or one of the types of tourniquets, kind of its makeup, some of the complications associated with tourniquet use, and what we can do to combat some of those complications. So before I start, or as I start, I want you to think about times that you have had tourniquets used in your cases, and a few questions to ask yourself or answer aloud are, has the surgeon considered the preoperative blood pressure in determining what tourniquet pressure he wants to use? Did the surgeon inform anesthesia or any of the OR staff that the tourniquet was coming up? And how did your patients respond? If you've used tourniquets more than once, has every patient responded in the same manner to tourniquet pain and tourniquet deflation? I guess for me personally, I haven't had a surgeon consider a preop blood pressure in determining their tourniquet inflation pressure, but I have had surgeons be gracious enough to inform the OR staff, including anesthesia, of when the tourniquet's being inflated. And then in terms of how patients respond, I've had varying responses. Some you couldn't even tell a tourniquet was on or a tourniquet was deflated. Some were much more sensitive to the tourniquet pain and the hemodynamic changes associated with the tourniquet's deflation, which we'll get into here in a bit. So tourniquets are typically used in extremity surgeries, as I mentioned, to help minimize blood loss and improve the surgical field visualization for the surgeon. The most common tourniquet used these days is the pneumatic tourniquet. They do make a non-pneumatic tourniquet, but it's not typically used. Working from the patient back to the device, a pneumatic tourniquet has numerous parts, including the inflatable cup, connective tubing, the actual pressure device, and a timer. As we consider that tourniquet going on and it's used through the procedure, we want to initially think about preventing tourniquet complications. So some ways that we can do this are ensuring that the machine is properly functioning, ensuring that we don't use that tourniquet for more than two hours. Most of those tourniquets, as I said, have a timer, and that timer is pre-set or has a pre-set alarm that will go off in 60-minute increments. So all OR staff is aware of the length of time the tourniquet has been inflated. If that tourniquet needs to be inflated for a procedure that is going to be necessary for longer than two hours, it's recommended that the tourniquet is deflated for at least 15 to 20-minute increments at that hour and a half to two-hour mark to minimize the complications. When determining what size cuff to use, we'd like to use the widest cuff possible. This assists in decreasing blood flow while also minimizing the pressure that's utilized to ensure that blood flow is decreased. Ideally, a tourniquet should be about half the limb diameter with about a three to four-inch tail wrapping around the original insertion spot. Another measure to prevent tourniquet complications is to exsanguinate the extremity prior to cuff application with an SMR bandage. We learned about this with beer blocks. And then we want to use the minimum pressure possible. Of course, anesthesia typically isn't responsible for picking the cuff pressure or inflating the tourniquet. But ideally, and as I kind of mentioned in that beginning question of the surgeon determining what pressure they're going to use, ideally that pressure should be, if it's used on the upper extremity, 70 to 90 millimeters of mercury above the systolic pressure. And then if the tourniquet is being utilized on a lower extremity, the pressure should not exceed double the systolic pressure, and again, in millimeters of mercury. So as we know, we've had it mentioned in class, we've seen it in practice, tourniquet application and inflation can directly impact our anesthesia care. So we should always be sure to document when the tourniquet is inflated. Just in case we do begin to see those hemodynamic changes, we are documenting what could be causing it. An overarching reason, I guess, that we see tourniquet complications is it leads to tissue hypoxia and acidosis. And of course, this accumulates and increases the longer the tourniquet is used. And then through that application and beginning of the inflation process, it's been documented that massive pulmonary embolisms can occur and have occurred with the inflation. So it's just something for CRNAs to be aware of and monitor for. And again, this is why communication with the surgeon is so important of when that tourniquet, or not even surgeon, maybe it's the surgical tech or the OR nurse, of when that tourniquet is being inflated. Now I'm going to discuss some of the physiological changes associated with tourniquet use. Some neurological changes, tourniquet pain can occur within 30 minutes. You will most likely see an increased heart rate and blood pressure. Sometimes this is intolerable, can be treated with minimal opioids. Other times this is going to require things such as a beta blocker or increased pain medications. And I'll touch a little bit more on that tourniquet pain here in a bit. And then post-operative nerve pain has been documented and associated with use for greater than two hours. Some of the cellular and muscle complications or physiological changes associated with tourniquet use. Cellular hypoxia past the tourniquet will occur within two minutes. You'll see cellular muscle creatinine levels decrease. Cellular acidosis will occur. And then again, after use of more than two minutes, that endothelial capillary leak can occur. With the inflation especially, and especially in bilateral use of tourniquets, which is uncommon, really shouldn't happen, you can see a slight to moderate increase in arterial and pulmonary artery pressures. Another key time of tourniquet use for the anesthesia provider is with tourniquet deflation. Tourniquet deflation results in a decrease in body temp. So of course, this is an important measure that we watch for infection prevention, making sure that patient's plenty warm, especially when that tourniquet is going down. More often than not, nearly all the time, tourniquet deflation results in metabolic waste being released into systemic circulation. This can result in a transient metabolic acidosis, hyperkalemia, increased myoglobin, and renal failure. Again, typically this is transient, a very temporary change. This may cause changes in hemodynamic readings, such as hypotension, tachycardia, increased end tidal CO2, which is indicative of that increased PaCO2. Something to be aware of, that increased PaCO2 with tourniquet deflation can result in increased cerebral blood flow. So if this happens to be a TBI patient or a patient that cannot withstand or tolerate increased ICP, we should be aware that that deflation can cause a transient increase in cerebral blood flow. And I keep saying transient, but it also is important to be aware that in patients with extreme cardiac or vascular conditions, these changes may not resolve in as quick of a manner as we see in a healthy patient. As I kind of touched on and discussed before, one of the main concerns of intraoperative tourniquet use is the development of tourniquet pain. According to Nagelhout, this pain is similar to ischemic pain and the onset of worsening pain typically occurs about 45 to 60 minutes after inflation. I guess I can speak from a personal experience note, when I have seen tourniquets used, this does seem to be that 45 to 60 minute, maybe even 75 minutes, is when I've seen the little more hyperdynamic states typically caused by that tourniquet pain. This can result in increased heart rate and blood pressure. It may require interventions such as beta blocker administration. So why does this occur? We aren't really sure, researchers aren't, but research suggests that most of the pain is due to the activation of myelinated A-delta fibers as well as C-fibers. Some of the most common ways to minimize tourniquet pain is through the use of regional anesthesia, utilizing bupivacaine and adding opioids toward all quantity and or Presidex. Some other ways that are suggested to decrease tourniquet pain include using Emlacream or Presidex or Ketamine IV. Another thing for anesthesia providers to be aware of, prolonged tourniquet use in conjunction with an improperly placed tourniquet can result in post-operative paresthesia to the affected extremity. So as we know, medicine isn't a one-size-fits-all model, and this of course doesn't exclude tourniquets, so who should we be aware of that maybe shouldn't have a tourniquet used on them? Text suggests that patients with DVTs, peripheral neuropathies, sickle cell disease, Raynaud's, or those undergoing minor surgeries, a tourniquet may not be necessary. So this is kind of a brief, but yet simplified and hopefully informative overview of tourniquet use in orthopedic surgeries. Although a lot of the effects of tourniquet use can seem benign, it's important we're aware of how we can kind of prevent these tourniquet complications. You know, we're aware of application inflation of tourniquets and the physiological changes associated. And then aware of two of the main complications associated with tourniquet use, which are tourniquet pain in the intraoperative period as well as hemodynamic changes or cellular changes with tourniquet deflation. I hope you learned something in a simple yet informative podcast.