OSTEOMYELITIS – Causes and Risk Factors, Modes of Transmission, Pathophysiology, Signs and Symptoms, Diagnostic Evaluation and Management
Osteomyelitis is an infection of a bone caused by Staphylococcus aureus. Infection with a fungus is a rare cause.
MODES OF TRANSMISSION
If some bacteria settle on a small section of bone, they can multiply and cause infection. Bacteria can get to bone:
- Via the bloodstream: this is the most cause in children. Bacteria sometimes get into the blood from an infection in another part of the body and then travel to a bone
- Following an injury: bacteria can spread to bone if you have a deep cut on the skin. In particular, if you have a broken bone which you can see through the cut skin
PATHOPHYSIOLOGY
Infection from bacteria —- the initial response to infection is inflammation, increased vascularity, and edema —- after 2 or 3 days, thrombosis of the blood vessels occurs —- ischemia with bone necrosis —- if it is not treated properly, a bone abscess forms —- new bone growth (the involucrum) forms and surrounds the sequestrum —- produces recurring abscesses —- chronic osteomyelitis
CAUSES AND RISK FACTORS
Anyone at any age can develop osteomyelitis. However, one has an increased risk if:
- Have recently fractured (broken) a bone
- Have bone prosthesis (an artificial hip, a screw in a bone following surgery, etc)
- Have recently had surgery to a bone
- Have a poor immune system. For example, AIDS, taking chemotherapy, seriously ill with another disease, etc
- Have had a previous episode of osteomyelitis
- Have reduced skin sensation. This can lead to damage and infection of the skin which can spread to the blood or to local bone. For example, some people with diabetes have reduced sensation in their feet
- Have regular kidney dialysis
SIGNS AND SYMPTOMS
- Pain and tenderness over an area of bone
- A lump may develop over a bone, which is usually very tender
- Redness of overlying skin may then develop
- Feeling generally unwell with fever (high temperature) as the infection develops
DIAGNOSTIC EVALUATION
- X-ray
- CT scan
MEDICAL TREATMENT
Antibiotics
An antibiotic is usually started as soon as possible. The initial antibiotic chosen is one that is likely to kill the bacteria which commonly cause osteomyelitis. However, the antibiotic is sometimes changed to a different one when the results of the tests confirm which bacterium is causing the infection. The symptoms may settle quite quickly after taking an antibiotic. Penicillin and cephalosporin is the drug of choices
To control pain you may be given painkillers
Surgical Management
Surgery is required if:
- An abscess develops. The pus in an abscess needs to be drained.
- The infection presses on other important structures. For example, an infection in the spine may press on the spinal cord
- The infection has become chronic (persistent) and some bone has been destroyed. Dead and infected bone may need to be removed to allow the infection to clear. Sometimes, plastic surgery is needed at the same time to cover any wound to give the best chance of cure
Rarely, amputation of a foot or leg is needed if infection persists in a leg bone
NURSING MANAGEMENT
- Acute pain related to inflammation and swelling
- Assess the level of pain
- The affected part may be immobilized with a splint to decrease pain and muscle spasm
- Elevation reduces swelling and associated discomfort
- Comfortable position is given
- Analgesic given to treat pain
- Impaired physical mobility related to pain, use of immobilization devices, and weight-bearing limitations
- Assess the normal level of activity
- The joints above and below the affected part should be gently placed through their range of motion
- The nurse encourages full participation in ADLs within the physical limitations to promote general well-being
- Analgesics are given
- Deficient knowledge related to the treatment regimen
- Assess the level of knowledge by verbalization with the patient
- Answer each question of the patient
- Clarify all doubts of the patient
