NUR246 TOPIC 3 LECTURE

Topic Three Lecture: Immunology - Infection & Fever

Infection and Infectious Disease

• Definition of Infection: An infection occurs when a pathogen invades the body, multiplies, and produces disease.

• Signs and Symptoms: Result from pathogen activity which triggers inflammation and various immune responses.

• Categories of Infection:

  • Localized: Infection confined to a specific area.

  • Disseminated: Infection spreading to other areas.

  • Systemic: Widespread infection affecting the entire body.
    (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Types of Pathogens

1. Bacteria: One-celled organisms that cause disease through:

   • Entering the body and multiplying within human cells.

   • Secreting toxins that damage cells.

2. Viruses: Infectious particles made of a small amount of genetic material that hijack host cells to replicate.

3. Fungi: Organisms similar to plants (without chlorophyll) that can cause 'mycotic' infections.

4. Protozoa: Single-celled, animal-like microorganisms.

5. Prions: Infectious agents composed of abnormally shaped proteins.
   (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Chain of Infection

• Components of the Chain:

  1. Susceptible host

  2. Causative agent

  3. Portal of entry

  4. Means of transmission

  5. Reservoir

  6. Portal of exit
     (Figure 13.1: The chain of infection; Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Causative Agents and Reservoirs

• Causative Agents: Include bacteria, viruses, fungi, and parasites whose ability to cause disease is termed pathogenicity. Not all pathogens are pathogenic as some can exist without causing disease.

• Reservoirs: Environments that support microorganisms to live outside the host until they can colonize within the host.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Susceptible Hosts

• In healthcare settings, both direct-care staff and patients are considered the most susceptible to infections. Risk of exposure is influenced by:

  • Type of procedures performed by caregivers.

  • Presence and type of infective organisms.

  • Patient susceptibility.

• Vaccination: Stimulates the immune system to develop adaptive immunity targeting specific antigens.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Portal of Entry and Transmission

• Portal of Entry: Route through which microorganisms enter a host, critical for multiplication. Main portals include:

  • Skin

  • Trauma sites

  • Mucous membrane of respiratory tract

  • Gastrointestinal tract (GIT)

  • Genitourinary tract

• Transmission Mechanisms:

  • Contact (direct and indirect)

  • Inhalation

  • Inoculation

  • Ingestion

  • Transplacental
    (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Immune Responses

• Innate/Non-specific Immunity:

  • Skin and mucous membranes provide barriers when intact.

  • Skin contains keratin, making it an inhospitable environment for bacteria.

  • The epidermis is tough, and dermal sebaceous and sweat glands inhibit many microorganisms.

• Inflammatory Response: A specific immune response effectively targets the microorganism via the generation of antibodies and cell-mediated responses involving phagocytes, macrophages, neutrophils, and natural killer cells.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Inflammatory Response Phases

The inflammatory response can be segmented into four phases:

1. Vascular response

2. Cellular response

3. Formation of exudate

4. Healing

Healthcare-associated Infections (HAIs)

• Examples of Diseases Warranting Transmission-Based Precautions:

  • Acute incontinent diarrhea with an infectious cause

  • Meningitis

  • Generalized petechial/ecchymotic rash with fever, history of travel to high-risk areas

  • Respiratory infections, particularly in infants or young children

  • Abscesses or draining wounds that cannot be covered
    (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Infections in Older Adults

• Older adults experience 2-3 times the rate of healthcare-associated infections due to age-related changes such as:

  • Impaired immune function

  • Physical disabilities

  • Diabetes

• Common infections include pneumonia, urinary tract infections, skin infections, and tuberculosis (TB).
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Antimicrobial-Resistant Organisms

• The timely and appropriate administration of antibiotics is crucial because microorganisms are highly adaptive and many have developed resistance to first-line antibiotics such as penicillin.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Infection Prevention and Control: 5 Moments for Hand Hygiene

1. Before touching a patient

2. Before performing a septic procedure

3. After touching a patient

4. After body fluid exposure

5. After touching patient surroundings
   (Reference: WHO Guidelines on Hand Hygiene in Health Care, Geneva, Switzerland: WHO; 2009.)
   (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Fever During Inflammation

• The activation of monocyte-macrophages releases cytokines (IL-1, IL-6, TNF) that reach the hypothalamic temperature-regulating center, causing:

  • Increased synthesis and secretion of Prostaglandin E2 (PGE2) in the anterior hypothalamus.

  • Raising the thermostatic set-point.

• The autonomic nervous system is stimulated leading to:

  • Heat Conservation:

    • Cutaneous vasoconstriction

    • Decreased sweating

  • Heat Generation:

    • Increased muscle contraction

    • Shivering reflex
      (Figure 10.3 Production of fever; Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Types of Inflammation

1. Acute: Healing occurs within 2-3 weeks, usually leaving no residual damage; neutrophils are predominant.

2. Sub-acute: Similar to acute but lasts longer (e.g., infective endocarditis).

3. Chronic: Lasts for months or years, with lymphocytes and macrophages predominant (e.g., rheumatoid arthritis, osteomyelitis), may be exacerbated by immune response alterations.
   (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Nursing Management of Inflammation

• Prevention of infection and trauma, particularly in perioperative situations.

• Increased nutrition and hydration are important, as fever during inflammatory responses raises metabolic rates.

• Early recognition of symptoms of inflammation is critical for effective assessment and management.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Acute Interventions

• Observations: Monitor vital signs for elevated temperature, pulse, and respiration.

• Manage fever by determining its underlying cause, especially temperatures exceeding 40°C.

• Assess for potential risks of symptoms that could be masked due to immunosuppression or treatment.

• Caution in assessing older adults as they may show a slower temperature response to inflammation.

• Administer medication therapy to control temperature and pain as needed.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Medication Therapy for Inflammation Management and Healing

• Antipyretics:

  • Salicylates (aspirin): Inhibit synthesis of prostaglandins (PGs) and lower temperature by acting on the hypothalamic heat-regulating center.

  • Paracetamol: Similar action as above.

  • NSAIDs (e.g., ibuprofen): Inhibit synthesis of PGs.

• Anti-inflammatory Agents:

  • Corticosteroids (e.g., prednisone): Interfere with tissue granulation and induce immunosuppressive effects; inhibit PG synthesis.

  • Vitamins:

    • Vitamin A: Promotes epithelialization.

    • Vitamin C: Assists in collagen and new capillary synthesis.

    • Vitamin D: Aids calcium absorption.
      (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Other Management Strategies

RICE (Rest, Ice, Compression, Elevation) for Soft-Tissue Injuries

• Rest: Allows for healing and repair; prevents disturbance to wound edges.

• Cold Therapy: Promotes vasoconstriction, reducing swelling and pain.

• Heat Therapy: Can be applied 24-48 hours post-injury to enhance circulation and healing.

• Compression: Reduces edema and mobilizes metabolism.

• Elevation: Alleviates edema and pain caused by engorging blood at the injury site.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Bioburden of the Wound

• Definition: Refers to the presence of bacteria (or microorganisms) in chronic wounds. This can lead to an increased bioburden from poor host immune response.

Stages of Bioburden

1. Contamination: Presence of bacterial flora or environmental bacteria.

2. Colonization: Microorganisms adhere, replicate but are non-pathogenic and do not require treatment.

3. Critical Colonization: Replicating bacteria inhibit wound healing but without classic signs of infection; topical antimicrobials are indicated.

4. Infection: Microorganisms invade tissue leading to local or systemic responses, requiring culture to guide antibiotic choice.
   (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Cellulitis

• Definition: A spreading infection of the dermis and subcutaneous tissues.

• Common Pathogens: Usually caused by Group A Streptococci and Staphylococcus aureus, commonly affecting lower limbs (typically one leg).

• Risk Factors: Common in elderly and individuals with leg ulcers, lymphoedema, or venous disease.

• Symptoms: Area appears red, hot, swollen, and painful with demarcation between affected and normal skin; often accompanied by fever, malaise, and vomiting.

• Treatment: Flucloxacillin is commonly used.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

How to Take a Wound Swab (Revision)

Levine Technique

1. Ideally, obtain the specimen before starting ant microbial therapy as it may affect microorganism growth.

2. Assemble all necessary equipment.

3. Perform hand hygiene, don gloves, and irrigate the wound with 0.9% saline.

4. Moisten the swab with 0.9% saline.

5. Select a clean, viable tissue area (1 cm square) and rotate the swab on it.

6. Insert the swab into a sterile container.

How to Complete a Pathology Request Form

1. Patient label

2. Date and time

3. M, C & S = Microscopy, Culture, Sensitivities

4. Clinical Notes

5. Signature

Intravenous Antibiotics via PICC

• Indicated for patients requiring intermittent or long-term antibiotic therapy.

• A Peripherally Inserted Central Catheter (PICC) is utilised for this purpose.

• Central Venous Access Device: Various methods are available for administration, with the Baxter infusor being common in community settings.

PICC Lines

• Definition: A long catheter inserted in the antecubital fossa, primarily through the basilic vein.

• Measurements: Typical length is 50-60 cm.

• Insertion: Commonly performed by a nurse trained in PICC insertion.

• Benefits: Facilitates IVABs and chemotherapy management at home.

PICC Dressing Guidelines

• Change all dressings that are not intact, dry, and clean.

• Primary dressing changes occur every 24-48 hours.

• Frequency of change depends on dressing material used.

• Transparent occlusive dressings should be changed every 7 days.

• Biopatch or chlorhexidine impregnated antimicrobial sponge is applied at the insertion site.

• Document changes at each dressing in the patient’s medical record.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Flushing Guidelines

• Use positive pressure caps/valves to reduce blood reflux into the catheter.

• Employ a rapid pulsating or intermittent action when flushing.

• A 10ml syringe should be used to mitigate the risk of catheter rupture.

• Utilize luer lock syringes exclusively to prevent disconnections.

• Never fully empty the flushing syringe to prevent blood reflux, reducing blockade risk.
  (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

Complications to Monitor

1. Assess insertion site daily for:

   • Inflammation, redness, tenderness, and potential discharge.

2. Check for signs of infection, indicated by fever (38 degrees or higher) and rigors post-flushing.

3. Monitor for PICC line migration, overexertion, excessive coughing, bleeding at site, occlusion of the line, and difficulties flushing the line.
   (Brown, Edwards, Buckley & Aitken: Lewis’s Medical–Surgical Nursing © Elsevier Australia, 2020)

HOSPITAL IN THE HOME NURSE

Roles of a HiTH/HaTH Nurse

• Administering intravenous antibiotics and other medications in the home setting, often via devices like PICC lines.

• Performing advanced wound care, including wound swabbing using techniques like the Levine technique, and managing bioburden stages.

• Monitoring and managing symptoms of infection and inflammation, such as fever, and applying interventions like RICE for soft-tissue injuries.

• Educating patients and their families on infection prevention, medication adherence, and wound care.

• Assessing and monitoring patients for complications, including those related to PICC lines (e.g., migration, occlusion, infection) and general infection (e.g., cellulitis).

Required Skills/Qualifications

• Clinical Expertise: Strong clinical assessment skills to monitor patient conditions remotely and identify early signs of deterioration or complications (e.g., changes in vital signs, signs of infection like fever $\ge 38^{\circ}C$).

• IV Therapy Competency: Proficient in the insertion, maintenance, and troubleshooting of central venous access devices, including PICC lines, and adhering to strict flushing and dressing guidelines.

• Wound Care Knowledge: Expertise in wound assessment, dressing changes (e.g., PICC dressing changes), and understanding of wound healing processes and infection stages (contamination, colonization, critical colonization, infection).

• Infection Control: Adherence to infection prevention and control principles, including diligent hand hygiene and proper use of personal protective equipment.

• Patient Education: Ability to educate patients and caregivers on medication administration, wound care, and recognizing warning signs.

• Autonomy and Critical Thinking: Capacity to work independently, make critical decisions, and manage unexpected situations in a home environment.

Potential Challenges

• Monitoring and Assessment: Difficulty in real-time observation and immediate intervention compared to an acute hospital setting, especially with vulnerable populations like older adults who may present with atypical symptoms.

• Home Environment: Ensuring a sterile environment for procedures like PICC dressing changes and IV administration, and maintaining equipment.

• Logistics: Managing scheduling, travel, and access to necessary supplies and medications.

• Patient Adherence: Ensuring patients and families understand and comply with complex treatment plans, including medication schedules and wound care protocols.

• Complication Management: Managing potential complications such as PICC line infection or occlusion without immediate access to hospital resources.

• Social and Environmental Factors: Addressing potential issues in the home that could impact patient care, such as lack of proper hygiene facilities, social isolation, or nutritional deficits.