Unit 1: Sterility and Wound Care

Chain of Infection

• Infectious Agent

• Reservoir

• Portal of Exit

• Mode of Transmission

• Portal of Entry

• Susceptible Host

Infectious Agent

(COI)

Disease producing, also called pathogens

Virus, parasite, fungus, bacterium

Risk factors: Virulence, pathogenicity, ability to enter host

Reservoir

(COI)

Environment/habitat where a pathogen can live and multiply

Environmental surfaces/equipment, body fluids (blood, saliva), urine/fecal material, food/water, soil, skin, respiratory tract

Portal of Exit

(COI)

How the pathogen exits or leaves reservoir

Skin to skin, skin to surface, blood, mucous membranes, oral cavity, fecal

Other potentially infectious material (OPIM): Seminal fluid, joint fluid, saliva, urine/fecal material, any body fluid contaminated with blood

Mode of Transmission

(COI)

How a pathogen moves from reservoir to susceptible host

Direct Transmission: Airborne, droplet, contact (e.g., skin), bite, needlestick or other sharps injury

Indirect Transmission: Fomites – contaminated equipment or medication (multidose vials, single dose vials), vectors, food, water

Portal of Entry

(COI)

Opening where the pathogen may enter

Body openings (e.g., mouth, eyes, urinary tract, respiratory tract), incisions, wounds

Susceptible Host

(COI)

The person at-risk: patient or healthcare worker

Factors affecting susceptibility (e.g., age, health, co-morbidities, immune system, nutrition, infective dose, medications)

Hand Hygiene

The most essential and fundamental practice to prevent infection transmission.

Alcohol-based antiseptics, handwashing with soap and water for visibly soiled hands, and surgical scrubs when required.

4 Moments of Hand Hygiene

1. Before initial patient contact

2. Before aseptic procedure

3. After body fluid exposure risk

4. After patient contact

Medical Asepsis

Clean Technique

Used for reducing the number of organisms & preventing their transfer

Hand Hygiene

PPE: Gloves, masks, gowns, and eye protection as needed.

Cleaning and Disinfection: Ensuring that surfaces, equipment, and instruments are properly cleaned and sanitized.

Proper waste disposal: Safely discarding biohazardous materials like sharps and contaminated dressings.

Surgical Asepsis

Sterile Technique

Used to eliminate all organisms from an area

Purpose of Technique: is to prevent microorganisms from entering normally sterile areas of the body. This helps protect patients from infection during procedures where the skin or body defenses are opened or bypassed.

Functions: creates and maintains a sterile field. It also prevents contamination of sterile supplies, equipment, and body sites during procedures.

Importance: This is important because even a small break in sterile technique can lead to infection. Patients with wounds, surgical sites, catheters, or central lines are more at risk because bacteria can enter the body more easily.

Common use areas: Operating room, Procedure rooms. labour and delivery, ER, and invasive bedside procedures

Bedside applications: wound care, urinary catheterization, CVAD and PICC line care, TPN setup, dressing changes, and any procedure involving sterile equipment or access to sterile body areas.

Sterile Gloves

Purpose: Prevent contamination during sterile procedures

Applications: Wound care, catheterization, CVAD/PICC care, dressing changes.

Hand Hygiene: Wash/sanitize hands before and after use.

Latex Allergy Considerations: Use latex-free gloves if patient or nurse has an allergy.

Proper Glove Sizing: Gloves should fit snugly without tearing or limiting movement

Delegation

Sterile fields cannot be prepared by unregulated care providers (UCPs).

Assisting with tasks that require the use of sterile gloves can be delegated to an unregulated care provider (UCP).

Assisting with skills that include the application and removal of sterile gloves may be delegated to a UCP.

However, most procedures that require the use of sterile gloves cannot be delegated to a UCP.

Skin

• It is the body's largest organ and serves as sensory protection, recognizing pain, touch, pressure, and temperature.

• It plays key roles in thermoregulation, metabolism, immunity, and fluid balance regulation.

• Intact ___ is the first defense against infections; breaks require evidence-based wound care to restore the barrier.

• ___ care prevents and manages breakdown, with a focus on pressure injury prevention in healthcare settings.

o Preventive measures include pressure off-loading, managing incontinence, ensuring proper nutrition, and regular repositioning.

Pressure Injuries

• These happen when prolonged pressure blocks blood flow, causing tissue damage (ischemia).

• Ischemia occurs when pressure is greater than the blood pressure in vessels.

• Common sites:

o Sacrum

o Coccyx

o Heels

o Hips (greater trochanters)

o Shoulder blades (scapulae)

o Ankles (lateral/medial malleoli)

o Sit bones (ischial tuberosities)

o Iliac crests

Braden Scale

An assessment tool for predicting pressure sore risk

Stage 1 Pressure Injury

Non-blanchable Erythema of Intact Skin

Intact skin with non-blanchable redness, which may look different on darker skin tones.

Early signs include changes in sensation, temperature, or firmness, but not purple or maroon discoloration, which suggests a deeper injury.

Stage 2 Pressure Injury

Partial-Thickness Skin Loss With Exposed Dermis

Partial-thickness skin loss with exposed dermis, which appears pink or red and moist.

The wound may include an intact or broken serum-filled blister, but deeper tissues like fat are not visible.

No granulation tissue, slough, or eschar is present.

These injuries are often caused by moisture and shear, particularly in the pelvis and heel.

Stage 3 Pressure Injury

Full Thickness Skin Loss

Full-thickness skin loss with visible fat, granulation tissue, and rolled edges (epibole) are often present.

Slough or eschar may be present.

Depth varies by location, with deeper wounds in areas with more fat.

Undermining or tunneling may occur.

Deeper structures like muscle or bone are not exposed. If slough or eschar obscures the extent of the tissue loss, it is Unstageable.

Stage 4 Pressure Injury

Full-Thickness Skin & Tissue Loss

Full-thickness skin and tissue loss with exposed fascia, muscle, tendon, ligament, cartilage, or bone.

Slough or eschar may be present.

Epibole, undermining, and tunneling often occur.

Depth varies by location. If slough or eschar hides the tissue loss, it is Unstageable.

Deep Tissue Pressure Injury

Persistent Non-blanchable Deep Red, Maroon, or Purple Discoloration

Intact or broken skin with persistent deep red, maroon, or purple discoloration, or a bloodfilled blister.

Pain and temperature changes often precede color changes, which may look different on darkly pigmented skin.

This injury is caused by intense or prolonged pressure and shear at the bone–muscle interface.

It may progress to a full-thickness injury or resolve without tissue loss.

Visible necrotic tissue or deeper structures indicates a Stage 3 or 4 injury.

Unstageable Pressure Injury

Obscured Full-Thickness Skin and Tissue Loss

Full-thickness skin and tissue loss in which the extent of tissue damage within the injury cannot be confirmed because it is obscured by slough or eschar.

If slough or eschar is removed, a Stage 3 or Stage 4 pressure injury will be revealed.

Stable eschar (i.e., dry, adherent, intact without erythema or fluctuance) on a heel or ischemic limb should not be softened or removed.

Primary Intention

Occurs when the edges of a clean surgical incision stay close together, allowing for quick healing with minimal tissue loss. Skin cells regenerate quickly and capillaries form across the wound

Secondary Intention

Happens in wounds with tissue loss or open edges, such as severe lacerations or large surgical wounds. Granulation tissue fills the wound, and scar tissue forms, which increases the risk of infection due to delayed epidermal closure. The percentage and type of tissue in the wound bed provide insight into the severity, healing progress, and effectiveness of interventions. Granulation tissue, red to pink and moist, signals healing, while black, brown, or tan tissue (slough or eschar) should be removed to avoid delayed healing

Tertiary Intention

Also called delayed primary intention, this occurs when a wound is left open for 3-5 days to reduce infection or swelling, then sutured or stapled closed.

Hemostasis Phase

Blood vessels constrict to stop bleeding, forming a clot that provides a temporary bacterial barrier. Platelets release growth factors to initiate repair

Inflammatory Phase

Vasodilation allows plasma and blood cells to enter the wound, causing edema and redness. White blood cells clean the wound, preparing it for healing.

Proliferative Phase

New epidermis and pink granulation tissue form, along with capillaries for oxygen and nutrient supply. Collagen strengthens the wound, and contraction reduces wound size.

Maturation Phase

Collagen is remodeled to provide strength. The scar forms, reaching up to 80% of the original skin's tensile strength, with the process lasting up to 2 years.

TIME

addresses barriers to wound healing and identifies key clinical assessments and treatment options

• Tissue management

• Inflammation and infection

• Moisture balance

• Edge

Serous

(Drainage)

• Clear

• Watery plasma

Sanguineous

(Drainage)

• Indicates fresh bleeding

• Bright red

Serosanguineous

(Drainage)

• Pale, red, more watery drainage than sanguineous

Purulent

(Drainage)

• Thick, yellow, green, tan, or brown drainage

Open-Drain System

Removes drainage from the wound and deposits it onto the skin surface. A sterile safety pin prevents the tubing from slipping into the wound.

Closed-Drain Systems

Use a vacuum to withdraw drainage into a collection device.

Operates only if tubing is patent and a vacuum is maintained.

Empty the device when half full, measure drainage, and reestablish the vacuum.

Jackson-Pratt Drain

Collects 100–200 mL of fluid in 24 hours.

Hemovac Drain

Suitable for larger volumes, up to 500 mL in 24 hours.

Types of Dressings

• Gauze

• Transparent film

• Hydrocolloid

• Hydrogel

• Aliginate or Hydrofibre

• Foam dressing

• Negative pressure

Skin Closure Devices

• Sutures

• Staples

• Steri-strips

• Medical Glue