Necrotizing Fasciitis Flashcards
Q: What are necrotizing soft tissue infections (NSTIs)?
A: NSTIs are rapidly progressing infections causing extensive destruction of soft tissues, including the epidermis, dermis, subcutaneous tissues, fascia, and muscle. They can present as necrotizing forms of cellulitis, fasciitis, and myositis.
Q: What is the most aggressive form of NSTI and why?
A: Necrotizing fasciitis is the most aggressive form of NSTI because it spreads quickly within the body and has the highest mortality rate.
Q: What initial steps should you take if you suspect an NSTI in a patient?
A: Perform an ABCDE assessment to determine stability. If unstable, stabilize the airway, breathing, and circulation, obtain IV access, initiate IV fluid resuscitation, and continuously monitor vital signs.
Q: What key history elements should you ask about when suspecting NSTI?
A: Ask about severe pain, fever, chills, foul-smelling discharge, recent trauma, recent surgery, injection drug use, immunosuppression, or diabetes mellitus.
Q: What are some physical exam findings indicative of NSTI?
A: Look for signs of systemic instability such as altered mental status, tachycardia, hypotension, erythema, edema, indurated skin or soft tissue, necrotic tissue, foul-smelling discharge, and crepitus.
Q: What is crepitus and its significance in NSTI?
A: Crepitus feels like tiny pops of air or crunch under the skin and indicates the destruction of subcutaneous tissues by gas-forming organisms, highly suggestive of necrotizing fasciitis.
Q: Why is prompt treatment crucial in NSTI with sepsis or septic shock?
A: Because it is life-threatening, requiring immediate blood cultures, broad-spectrum IV antibiotics, and surgical consultation for emergent exploration and debridement.
Q: How is necrotizing fasciitis typically diagnosed?
A: Necrotizing fasciitis is definitively diagnosed intraoperatively with direct visualization of the obliterated fascia.
Q: What laboratory tests should be ordered in stable patients suspected of having NSTI?
A: Order CBC, CMP, CRP, CK, and lactate.
Q: What is the significance of necrosis and crepitus on a physical exam for NSTI?
A: The presence of either necrosis or crepitus confirms the diagnosis of necrotizing soft tissue infection.
Q: What imaging studies can be helpful in diagnosing NSTI?
A: X-rays and CT scans can be used to evaluate for gas bubbles, extent of infection, and levels of soft tissues involved.
Q: What organisms are most commonly associated with NSTI and gas formation?
A: Group A strep is the most common cause of NSTI, while clostridia are common gas-forming organisms.
Q: What is the LRINEC score and its purpose?
A: The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score helps stratify the risk of NSTIs using lab findings like CRP, WBC count, Hemoglobin, Sodium, Creatinine, and Glucose.
Q: How are imaging findings and LRINEC scores used together in diagnosing NSTI?
A: If imaging shows significant changes and/or the LRINEC score is high, it indicates a high risk of NSTI, prompting emergent surgical exploration and debridement.
Q: What should be done if a patient with suspected NSTI has a non-necrotizing soft tissue infection?
A: Continue IV antibiotics, provide supportive care, and observe with frequent reevaluations to ensure the infection is not worsening.
