01.08 Nursing Care and Pathophysiology for Osteomyelitis

Hi guys. Today we're going to learn all about osteomyelitis. We’ll review what osteomyelitis is, how it occurs, how it’s diagnosed, and we’ll also go over the assessment findings and nursing considerations when you are caring for these patients.

Osteomyelitis really is just a bone infection. This happens when a pathogen gets into the bone tissue and causes infection - like bacteria, viruses, and fungi. There are a few different types of osteomyelitis. Exogenous is when the pathogen enters from outside the body like in a compound fracture. The bone pierces the skin and the pathogen has a direct entry point into the body. There is also endogenous or hematogenous, which is when the pathogen is carried from infection somewhere else in the body via the bloodstream like bacteremia. Contiguous is when the infection is caused from skin infection of the surrounding tissue, like in cellulitis. Acute osteomyelitis is exactly as it sounds - a new episode - so this could be a penetrating trauma that leads to direct inoculation with the pathogen - person steps on a dirty nail - boom - pathogen enters the body. Chronic osteomyelitis is commonly seen in diabetics. These are also patients with recurrent infections or if osteomyelitis is misdiagnosed, if there’s inadequate treatment, or if the patient is noncompliant with antibiotic therapy.

Now that we get the basics - osteomyelitis = bone infection, let’s take a look at EXACTLY what is going on in the body and how that infection happens. First, a pathogen starts the inflammatory response which leads to increased vascularity. All of that extra fluid leads to edema formation. Increased edema = blood vessel thrombosis. The vessels can’t handle the extra fluid. When the blood vessel bursts, exudate is released into body tissue which leads to decreased blood flow to the bone because the vessels aren’t working properly, which then leads to ischemia of bone tissue. Low blood flow leads to bone necrosis - the affected bone dies. Then, the necrotic bone separates from other bone tissue, which is called sequestrum. Sequestrum prevents bone healing and causes infection which is commonly seen as a bone abscess. The cycle repeats. New infection → further inflammation → vessel thrombosis → necrosis.So, ultimately the goal of treatment is going to be to break this cycle and prevent it from recurring.

Testing usually starts with an x-ray of the affected body part and a CBC. The x-ray will show if there are any abnormalities like in this picture. As you can see the red arrow is pointing to osteomyelitis of the first toe. The CBC will show us if the patient has some sort of infectious process - elevated WBC. If osteomyelitis is suspected or if the x-ray is unclear usually a MRI or bone scan are ordered for clearer imaging. Some cases require more testing. If a patient is diagnosed with osteomyelitis, is started on broad spectrum antibiotics, and is not responding well to treatment then a needle aspiration or bone biopsy is typically the next step to determine what the infectious pathogen is so we can treat it more directly. Patients with osteomyelitis can get pretty gnarly infections and can turn septic. In this case, blood cultures would be ordered to see if there is any bacteria in the blood.

The assessment findings can be different for acute and chronic osteomyelitis. With acute osteomyelitis you’ll see a fever - usually over 101 degrees fahrenheit, edema - from the increased vascularity, as well as pain. Pain in both acute and chronic osteomyelitis is described as constant, localized to the affected area, a pulsing sensation, and worse with movement. Acute osteomyelitis also presents with erythema, warmth to the area upon palpation, and elevated WBC as it is an ACUTE infection. Chronic osteomyelitis presents a little differently. These patients still have the same pain, but they may also have ulceration and drainage from the affected area. Since it’s a chronic issue, the WBC could be normal or just slightly elevated.

Let’s look at treatment options. These patients need to be started on antibiotics ASAP. They’ll be on these for several weeks to several months. If long term antibiotics are anticipated, a PICC line is usually placed so they can go home and still get their IV antibiotics. Antibiotics are given at specific times to maintain therapeutic levels and sometimes several types of antibiotics are needed depending on the infection. Pain control is a priority and NSAIDS are usually the medication of choice. Of course, some cases will require stronger pain medication if their pain is uncontrolled with NSAID administration. With ulcerations seen in chronic osteomyelitis, there could be wound care such as dressing changes or antibiotic irrigations. These will both be doctors orders if indicated. Hyperbaric oxygen therapy, sometimes called HBO therapy is an excellent treatment modality and is used on my floor frequently for osteomyelitis treatment. It increases tissue perfusion in chronic osteomyelitis by exposing the affected area to high oxygen concentration. This diffuses into the tissues which helps with healing. This is a patient in a HBO chamber getting a treatment. Since bone can’t heal properly when necrotic tissue is present, sometimes a sequestrectomy is needed to get rid of the sequestrum (necrotic bone tissue that separates from other bone). A sequestrectomy debrides the dead tissue and allows for revascularization. If the procedure leaves a large bone defect or sizable cavity, sometimes a bone graft, microvascular bone transfer, or a muscle flap are indicated. Amputation is the next step if non surgical and surgical management fails. With an amputation you’ll monitor signs of bleeding, vital signs, frequent pain assessments, and will monitor for phantom limb pain.

You’ll be doing frequent neurovascular checks on these patients and will be monitoring for things like pain, sensation, movement, temperature, distal pulses, color, capillary refill, and edema. Let’s say you are doing your first neuro check on your patient and you discover that the affected leg has +1 pedal pulse and the good leg has a +2 pedal pulse. There’s a few things to consider with this assessment finding. 1- has the patient always had a +1 pedal pulse in the affected leg? If so, it is usually okay as long as it is not changing. 2- Let’s say the patient had a +2 pedal pulse in the affected leg for the previous shift but now has a +1 pedal pulse. This is a concerning finding and would be something that you should notify the provider about because it’s an acute change and different from their baseline. This consideration also applies to other things like sensation, temperature, and color of the extremity. The patient could have abnormal findings like numbness and tingling in the affected leg, but if it is not a new finding and is not getting worse you don’t have to call the provider to report this. New, acute neurovascular changes should always be reported to the provider as circulation or perfusion are usually impaired. If the patient has edema you can use elevation to increase venous return. It’s important that you also monitor the patient’s vital signs and monitor for signs of worsening infection. Like I mentioned before, these patients can get septic and can be very sick.

Some of the education topics you want to review include antibiotic therapy, reporting changes in sensation, and infection education. Depending on the severity of infection patients could be discharged with home health/antibiotic therapy at home. Educate about PICC line care if applicable. Patients may be switched to PO antibiotics after a certain amount of time. Patients should stick to the prescribed regimen and should not skip doses or stop treatment until it is finished. Patients should report changes in sensation and pain as these could indicate worsening infection. Infection education is so important. Make sure to educate not only about the antibiotic therapy but recurrence of osteomyelitis and signs and symptoms of worsening condition.

The priority nursing concepts for patients with osteomyelitis include comfort, infection control, and mobility. Their comfort is altered due to the bone infection and the pain that results. Infection control is huge. We want to control the infection and prevent it from getting worse or spreading. Mobility is a priority nursing concept as the bone is affected and can cause alterations in mobility.

Key points to remember include infection control, pain control, and patient education. With infection control antibiotics should be started ASAP, the regimen should be followed and completed, and you should monitor for worsening infection and for sepsis. Pain control is a priority. Usually these patients are started on NSAIDS and medication strength is escalated as needed. Patient education is key. Educate about antibiotic therapy, reporting changes in sensation, and infection education.

Alright guys, that’s it for our lesson on osteomyelitis. Make sure to check out the other resources attached to this lesson. Now, go out and be your best self today. And, as always, Happy Nursing!