Wound Assessment: Part 2 Assessing the Wound for Infection Dot Weir, RN, CWON, CWS

Objectives Discuss the spectrum of bioburden in open wounds. Describe the evolution of a biofilm Name the steps in obtaining a meaningful wound culture

The Skin as Protection Provides mechanical barrier to the invasion of bacteria and other pathogens into the deeper tissues Skin oils, lipids and sweat help prevent invasion of bacteria into tissue The skin surface is a relatively acidic environment (pH 4-6.6), not supportive of bacterial growth Skin cells shed into the environment keeping the bacteria at a tolerable level Stotts NA. Bioburden Infection, In: Baranoski S, Ayello EA. Wound Care Essentials, Practice Principles, 4th edition, 2016 Lippincott Williams & Wilkins, Philadelphia

Defining Bioburden Degree of microbial contamination or microbial load; the number of microorganisms contaminating an object1 Assumed to be quantified relative to the object In wound management and wound healing, often a statement to the presence of bacteria on a wound as well as a qualitative descriptor of the bacterial status of the wound As a result, it has also become a term used to document and consequently rationalize and support the use of various treatment alternatives - Specifically dressings and devices known to impact surface wound bacteria, such as antiseptics, antimicrobial dressings, and modalities such as ultrasound 1. Stedman’s Medical Dictionary

Describing Bacteria Bacteria are described in a number of ways Shape Gram Stain Need, or lack of need, for oxygen Mode of growth

Shape Great variation but 3 basic shapes Coccus: round Spirillum or spirochete: spiral shaped cylinder Coccus: round or ball shaped Rod or bacillus: cylindrical

Gram-positive cells have thick walls which will uptake crystal violet Gram Stain Staining technique for the early identification of bacteria Gram-positive cells have thick walls which will uptake crystal violet Gram-negative cells have thinner walls, do not hold violet dye, and retain counter-stained red color

O2 vs. O2 Aerobic vs. Anaerobic Do they require oxygen to survive? © Dot Weir - Used with permission

Microbial States in Wounds Contamination Presence of non-replicating organizations in the wound; no host immune response Colonization Presence of replicating organizations in the wound; no host immune response Critical Colonization/ Locally Infected Replicating organizations competing for resources, begin to see changes in the wound; biofilm forming; host tissue reaction Infection Presence of replicating organizations in the wound with a host immune response © Dot Weir - Used with permission © Dot Weir - Used with permission

What Does This Look Like? Sterile Infected Contaminated Colonized Critically Colonized

Critical Colonization Presence of bacteria on the wound Healing process compromised No standard signs of infection May delay healing via bacterial competition with tissue cells for oxygen and nutrients, production of bacterial toxins and inflammatory mediators Also referred to as “locally infected” (vs. spreading infection)

Potential Signs of Critical Colonization Granulation tissue Color Friability Absent or abnormal Odor – subtle or dramatic change Failure to heal Increased/high exudate levels in the presence of granulation tissue Wounds attempt to “flush out” foreign particles or chemicals

Bacterial Growth Planktonic: free floating, individual cells that work independently Wound cultures are testing for planktonic growth Most topical antimicrobial agents target planktonic growth Antibiotics are developed to target specific sites to kill them Easily transferred from one surface to another Skin to wound Contamination from outside source

Biofilms Complex communities of bacteria (and other organisms) that adhere to solid surfaces (e.g. catheters) Embedded in an extracellular polymeric substance Have ability to survive in hostile environments Contain different structures including channels in which circulation of nutrients can occur Possess unique ability to communicate Reduced metabolic activity leading to reduced metabolic needs Systemic and most topical antibacterial/ antimicrobial agents cannot impact or kill

Predisposing Conditions that Contribute to Infections… Damage of stratum corneum allowing for bacterial penetration High concentration of bacteria Immunocompromised host Type of bacteria Disruption of blood supply to the area A favorable environment for bacteria Moisture oxygen/lack of oxygen necrotic debris Serosanguinous ©

Infection: Definition Invasion by and multiplication of pathogenic microorganisms in a bodily part or tissue, which may produce subsequent tissue injury and progress to overt disease through a variety of cellular or toxic mechanisms. Serosanguinous http://medical-dictionary.thefreedictionary.com/infection Accessed 3/17/13 ©

Infection: Clinical Picture Swelling Induration Erythema Warmth Pain Odor

Assessment of Bacterial Burden © Dot Weir - Used with permission

Diagnosis Diagnosing infection is a clinical skill and not a microbiologic technique Culturing doesn’t tell you whether you have an infection or not; it identifies the organism and appropriate antibiotic The culture is important but also need to focus on the host (the patient) and the wound environment

Method of Wound Culture Biopsy Aspiration Swab © Dot Weir - Used with permission © Dot Weir - Used with permission © Dot Weir - Used with permission

Quantitative Tissue Biopsy © Dot Weir - Used with permission Historically the “gold standard” or at least best practice Painful (may need anesthetic) Skill intensive Used more in research than clinical practice >105 colony forming units (CFU) per gram of tissue considered to be infected © Dot © Dot Weir - Used with permission

Aspiration Goal: obtain fluid for specimen below the surface of the wound Skin is prepped (alcohol) Needle inserted, fluid aspirated Apply to swab

Improve Swab Technique Thoroughly rinse wound surface with non-preserved saline/cleaner Don’t swab through dressing residue, old exudate, necrotic tissue, blood Choose area that is free of non-viable tissue if possible Don’t bother with dry surfaces Place in carrier, transport ASAP

Methods of Swab Culture Z Stroke Levine’s Technique Goal is to get sampling of organisms on or in surface tissues of the wound Necrotic tissue harbors large numbers of bacteria so should be avoided © Dot Weir - Used with permission © Dot Weir - Used with permission

Methods of Swab Culture Z Stroke Less optimal Likely to pick up organism from necrotic tissue if present, skin edges © Dot Weir - Used with permission © Dot Weir - Used with permission © Dot Weir - Used with permission

Levine’s Technique 1 cm area Surface swab of a one cm2 area of healthy tissue in the wound Press into wound to obtain fluid

Levine’s Technique

Location, Location, Location… © Dot Weir - Used with permission © Dot Weir - Used with permission Aim for clean area of the wound Avoid touching necrotic tissue

Culture Reporting Need to have the most information available to make sound decisions for treatment Know the hospital/labs method of reporting cultures Gram Staining: automatically done or need to order separately? Qualitative Semi-quantitative Quantitative © Dot Weir - Used with permission © Dot Weir - Used with permission

Culture Reporting Gram Staining Provides early information as to the bacterial species likely to be present on the wound (not 100%) Also may indicate host response Presence of white blood cells © Dot Weir - Used with permission © Dot Weir - Used with permission

Culture Reporting Qualitative Cultures: Presence of bacteria and antibiotic activities only © Dot Weir - Used with permission © Dot Weir - Used with permission

Culture Reporting 1+ 2+ 4+ 3+ Semi-quantitative cultures: Dish divided into 4 quadrants, serially streaked, and the number of quadrants with growth is reported 1+ 2+ 4+ 3+ © Dot Weir - Used with permission © Dot Weir - Used with permission

Culture Reporting Quantitative cultures: provides actual colony forming units per gram of tissue of the bacteria identified in the wound. Usually needs tissue biopsy to determine. © Dot Weir - Used with permission © Dot Weir - Used with permission

Key Nursing Concepts Assessment Caring Communication Ethics Evidence-based practice Infection Infection Control Pain Patient Education Prevention Self Care Deficit Safety Tissue Integrity

Key Nursing Diagnoses Potential for Alteration in Skin Integrity Tissue Integrity Impaired Skin Integrity Impaired Tissue Integrity Oral Mucous Membranes, Altered Knowledge Deficit r/t Self Care Deficit r/t

Key Nursing Practice Issues Registered Nurses (RN) assess wounds; Licensed Practice Nurses monitor wounds per state nurse practice acts Accurate wound assessment and documentation is foundation for evaluating attainment of progress towards goal of care Early recognition of a change in the bacterial load on an open wound is critical to prevent deeper infection When culturing needed, attention to detail and getting a meaningful, usable culture is essential

Websites for Further Information on Wounds - Association for the Advancement of Wound Care www.aawc1.org - Canadian Association for Wound Care www.cawc.net - National Pressure Ulcer Advisory Panel www.npuap.org - World Union of Wound Healing Societies www.wuwhs.org - Wound Ostomy Continence Nurses Society www.wocn.org

www.WhyWoundCare.com