NCLEX Review Guide: Methicillin-Resistant Staphylococcus aureus (MRSA)

Understanding MRSA

• MRSA is a gram-positive bacterium resistant to methicillin and other beta-lactam antibiotics due to genetic mutations. It spreads through direct contact with infected wounds, contaminated hands, or shared personal items.
• Two main types exist: Community-Associated MRSA (CA-MRSA) affects healthy individuals in community settings, while Healthcare-Associated MRSA (HA-MRSA) occurs in healthcare facilities among immunocompromised patients.
• MRSA colonization can occur without symptoms, particularly in the nares, axilla, and groin areas. Colonized individuals can transmit the organism even without active infection.

Signs and Symptoms

• Skin infections present as red, swollen, painful lesions that may appear as boils, abscesses, or cellulitis with purulent drainage. The surrounding tissue often shows warmth and induration.
• Systemic symptoms include fever, chills, malaise, and lymphadenopathy when infection spreads beyond the initial site. Monitor for signs of sepsis including altered mental status and hypotension.
• Pneumonia manifestations include productive cough with purulent sputum, chest pain, dyspnea, and bilateral infiltrates on chest X-ray.

Contact Precautions

1. Place patient in private room or cohort with another MRSA-positive patient
2. Don personal protective equipment (PPE) before entering room: gown and gloves minimum
3. Perform hand hygiene with alcohol-based sanitizer or soap and water before and after patient contact
4. Use dedicated equipment (stethoscope, blood pressure cuff) or disinfect between patients
5. Remove PPE in proper sequence: gloves first, then gown, followed by hand hygiene

• Wound care requires sterile technique with proper disposal of contaminated dressings in biohazard containers. Change dressings as ordered and document drainage characteristics, amount, and wound appearance.
• Educate patient and family about proper hand hygiene, wound care at home, and importance of completing entire antibiotic course even if symptoms improve.

Antibiotic Therapy

• Vancomycin remains the gold standard for serious MRSA infections, administered intravenously with monitoring of peak and trough levels to prevent nephrotoxicity and ototoxicity. Target trough levels of 15-20 mg/L for severe infections.
• Alternative antibiotics include linezolid (Zyvox) for skin and soft tissue infections, available in oral and IV forms, and daptomycin (Cubicin) for bloodstream infections and endocarditis.
• Topical agents like mupirocin (Bactroban) effectively treat localized skin infections and nasal decolonization in carriers.