Infection and Immune Response Concepts

Culture and Sensitivity

• Definition: Culture refers to the identification of bacteria causing an infection, while sensitivity indicates which antibiotics are effective against those bacteria.

• Importance: Understanding culture and sensitivity is crucial in treating infections effectively, especially in determining the right antibiotic to administer.

Bacterial Resistance:

• Bacteria can develop mechanisms that make antibiotics less effective, leading to treatment challenges.

Symptoms of Trauma:

• Common symptoms include:

• Road rash

• Bruising

• Swelling

• Symptoms of chronic conditions manifest differently than acute injuries, typically less rapidly progressing.

White Blood Cells (WBC) Differentiation:

• Segs (Segmented Neutrophils): Mature white blood cells that respond to infection.

• Bands (Band Neutrophils): Immature white blood cells released when the demand for immune response exceeds production capability.

• Left Shift: A condition where the count of immature bands exceeds that of mature segs due to high stress or infection, indicating an acute response to trauma.

Inflammatory Response:

• Inflection leads to mediators being released that act on the infection, prompting a cycle of immune response.

Asepsis:

• Definition: Asepsis is the prevention of disease-causing contamination, integral in healthcare settings.

• Key concepts include surgical and medical asepsis.

Hospital-Acquired Infections (HAIs):

• Typically result from invasive procedures (e.g., catheters, IV lines, ventilators) which can introduce pathogens.

• CAUTI: Catheter-Associated Urinary Tract Infection; occurs from prolonged catheterization.

• Ventilator-associated pneumonia is another HAI due to improper sterile techniques around respiratory tubes.

Immunity Types:

• Natural Immunity: Long-lasting immunity developed by the body's own immune response.

• Passive Immunity: Temporary immunity provided by external antibodies (e.g., vaccines).

Antibiotic Treatment Protocol:

• Immediate antibiotic administration is necessary upon suspicion of infection, while awaiting culture results.

• Adjustments can be made once culture and sensitivity results indicate resistance to the initially administered antibiotic.

Standard Precautions:

• Includes handwashing, wearing gloves for contact with bodily fluids, and maintaining a sterile field.

• Equipment used for patients must not be shared to prevent cross-contamination.

Infection Assessment:

• Evaluate patient history for signs of infection; common symptoms include fatigue, fever, and changes in mental status, especially in elderly patients.

• Trends in WBC counts are important to evaluate patient improvement, rather than relying solely on single lab results.

Use of PPE:

• Correct removal and disposal of PPE is critical to prevent contamination.

• Use a step-wise approach for removing PPE, maintaining hand hygiene throughout the process.

Chapter References:

• Refer to Chapter 26 for detailed information on isolation precautions, PPE, and sterile field practices as they apply to patient care, particularly for conditions like C. Diff.

C. Diff Observations:

• Highly transmissible and is known for its distinct odor during outbreaks. Educate families and visitors about isolation practices and the importance of hygiene.