Septic (Infectious) Arthritis - Musculoskeletal Infections

SEPTIC (INFECTIOUS) ARTHRITIS

Joints can become infected through spread of infection from other parts of the body (hematogenous spread) or directly through trauma or surgical instrumentation. Previous trauma to joints, joint replacement, coexisting arthritis, and diminished host resis-tance contribute to the development of an infected joint. S. aureus causes most adult joint infections, followed by streptococci and gram-negative organisms. Prompt recognition and treatment of an infected joint are important because accumulating pus results in chondrolysis (destruction of hyaline cartilage).

Clinical Manifestations

The patient with acute septic arthritis usually presents with a warm, painful, swollen joint with decreased range of motion. Sys-temic chills, fever, and leukocytosis are present. Risk factors in-clude advanced age, diabetes mellitus, rheumatoid arthritis, and preexisting joint disease or joint replacement.

Gerontologic Considerations

Elderly patients and patients taking corticosteroids or immuno-suppressive medications may not exhibit typical clinical manifes-tations of infection. Therefore, they require ongoing assessment to detect infection as early as possible in the infectious process.

Assessment and Diagnostic Findings

An assessment for the source and cause of infection is performed. Diagnostic studies include aspiration, examination, and culture of the synovial fluid. Computed tomography and MRI may dis-close damage to the joint lining. Radioisotope scanning may be useful in localizing the infectious process.

Management

Prompt treatment is essential and may save a joint prosthesis for patients who have one. Broad-spectrum IV antibiotics are started promptly and then changed to organism-specific antibiotics after culture results are available. The IV antibiotics are continued until symptoms disappear. The synovial fluid is monitored for sterility and decrease in WBCs.

In addition to prescribing antibiotics, the physician may aspi-rate the joint with a needle to remove excessive joint fluid, exu-date, and debris. This promotes comfort and decreases joint destruction caused by the action of proteolytic enzymes in the pu-rulent fluid. Occasionally, arthrotomy or arthroscopy is used to drain the joint and remove dead tissue.

The inflamed joint is supported and immobilized in a func-tional position by a splint that increases the patient’s comfort. Analgesics, such as codeine, may be prescribed to control pain. After the infection has responded to antibiotic therapy, NSAIDs may be prescribed to limit joint damage. The patient’s nutrition and fluid status is monitored. Progressive range-of-motion exer-cises are prescribed after the infection subsides.

If septic joints are treated promptly, recovery of normal function is expected. The patient is assessed periodically for re-currence. If the articular cartilage was damaged during the in-flammatory reaction, joint fibrosis and diminished function may result.

The nurse describes the septic arthritis process to the patient and teaches the patient how to relieve pain using pharmacologic and nonpharmacologic interventions. The nurse also explains the importance of supporting the affected joint, adhering to the pre-scribed antibiotic regimen, and observing weight-bearing and activity restrictions. Additionally, the nurse demonstrates and en-courages the patient to practice safe use of ambulatory aids and assistive devices.

The nurse teaches the patient strategies to promote healing through aseptic dressing changes and proper wound care. The pa-tient is then encouraged to perform range-of-motion exercises after the infection subsides.