Osteomyelitis Flashcards
What is osteomyelitis?
Osteomyelitis is a severe infection of the:
- Bone
- Bone marrow
- Surrounding soft tissue
Describe Indirect Entry.
Blood carries infection from another area of the body to the bones (also called hematogenous)
Describe Direct Entry.
An open wound (e.g., penetrating wounds, fractures, surgery) allows microorganisms to enter directly into the bone.
Pathophysiology of osteomyelitis.
- After entering the blood, microorganisms proliferate
- This proliferation increases pressure in the bones (bones have non-expanding nature)
- This increasing pressure leads to ischemia and eventually necrosis
Describe the process of osteomyelitis.
- Initial infection occurs in the bone
- Sequestrum (dead bone) forms around the infection
- Involucrum (new bone) forms around sequestrum
- Antibiotics and WBCs can’t get past the new bone to the original site of infection
Define sequestrum.
- Sequestrum is dead bone that forms around the initial infection.
- May become a reservoir for microorganisms that spread to other sites (brain, lungs)
- If the sequestrum does not resolve or is not debrided surgically, a sinus tract may develop (internally or externally)
Define involucrum.
The part of the periosteum that continues to have a blood supply forms new bone called involucrum.
What is acute osteomyelitis?
- Initial infection
- Infection of less than 1 month
Acute osteomyelitis local manifestations?
- Bone pain that worsens with activity and unrelieved by rest
- Restricted movement of the affected part
- Swelling
- Tenderness and warmth at the infection site
- Later signs include drainage from cutaneous sinus tracts or the fracture site
What is chronic osteomyelitis?
- Bone infection that lasts longer than 1 month
- Infection that did not respond to initial antibiotic treatment.
Chronic osteomyelitis manifestations?
- Local signs of infection become more common
- Constant bone pain
- Swelling and warmth at the infection site
- Over time, granulation tissue turns to scar tissue
- The avascular scar tissue is an ideal site for continued microorganism growth because it cannot be penetrated by antibiotics
What changes would you see in the CRP and ESR?
Inflammation and infection causes increased ESR and CRP.
What diagnostic test would be able to make the definitive diagnosis?
Bone or soft tissue biopsy will identify the causative agent
What is the disadvantage of the HCP depending on an x-ray in diagnosing osteomyelitis?
Signs usually do not appear on x-rays until 2 to 4 weeks after the initial clinical symptoms
First-line treatment for acute osteomyelitis?
Aggressive, prolonged IV antibiotic therapy if bone ischemia has not yet occurred.
Patient education for IV antibiotic therapy?
- IV antibiotic therapy starts in the hospital (acute setting) and then continues at home for 4 to 6 weeks.
- Some people will require intravenous antibiotic therapy for 3 to 6 months.
- Patients may be discharged to home care or a skilled nursing facility so the antibiotics can be given through a central venous access device (CVAD)
Gentamicin (IV antibiotic) side effects?
- Nephrotoxic (kidneys) and ototoxic (hearing)
- Pay attention to:
- Kidney function tests
- Urine appearance/amount
- “I’m not hearing as well as I used to.”
What is hyperbaric O2 therapy?
Treatment that involves breathing pure oxygen in a pressurized chamber
How does a hyperbaric chamber help treat osteomyelitis?
- Delivers 100% O2 to the patient
- Stimulates new bone growth
- Heals the infected tissue
What question do you need to ask patients before hyperbaric O2 therapy?
- Are you claustrophobic?
- Do you get anxious when you are in enclosed spaces?
Osteomyelitis nursing interventions?
- Some immobilization of the affected limb (e.g., splint, traction) is usually needed to decrease pain and reduce the risk of further injury.
- Dressings are used to absorb drainage from wounds and debride dead tissue from the wound bed.
- Good body alignment and frequent position changes promote comfort and prevent complications related to immobility.
