We have all heard the saying: a dry cell is a dead cell… we know that a moist wound bed is most conducive to healing. If a wound is too dry, we add moisture… and if a wound is too wet, we try to absorb the drainage. There must be a balance of moist and dry to promote an optimal healing environment. Much like a dry cell is a dead cell, a wound that is too moist often has delayed wound healing.
We have heard it called many things… wound drainage, exudate, weeping, pus… the fluid that comes out of the wound. We often describe wound drainage by listing the characteristics, the amount, and whether there is a presence of odor (after cleansing the wound). So, what does the wound drainage tell us?
Common Types of Wound Drainage
- Serosanguineous: Serosanguineous exudate is usually a combination of red or bloody and serous (clear) drainage, and it is common in many wounds. Serosanguineous drainage is often a normal part of the wound healing process.
- Sanguineous: Sanguineous exudate is bloody. This may be seen with a fresh cut or laceration, in surgical wounds, or in a patient who is anticoagulated. Sanguineous wound drainage is not abnormal, but if bleeding persists, the cause should be determined and the condition remedied. Sanguineous drainage typically manifest as fresh blood, such as with a new laceration, surgical wound, or injury.
- Serous: Serous exudate is clear drainage and is typically seen in venous leg ulcers, weepy legs, or wounds with a lymphatic origin. Serous wound drainage is clear and can sometimes be copious, depending on the wound etiology (think venous stasis ulcers in a patient who is in the dependent position most of the day). Serous— clear, watery, thin—drainage is often seen in the inflammatory stage of the healing process.
- Purulent: Purulent exudate is usually yellow, tan, or green, thick drainage. An odor can be present with this type of wound drainage, which could indicate a local wound infection. It often requires further follow-up on cause, treatment (local vs. systemic), and a multidisciplinary approach to be resolved.
- Liquefied slough: Liquefied slough is different from purulent wound drainage, but it can have similar characteristics. When an autolytic or enzymatic debriding agent is used on a wound with necrotic tissue, it can cause this tissue to lift and liquefy. The liquefied slough or necrotic tissue from the wound can manifest as thick, yellow drainage that is easily wiped away. There is typically not an odor after cleansing, and the drainage lessens as the amount of necrotic tissue in the wound lessens.
- Blue-green: Bright blue or green wound drainage often indicates an infection. Pseudomonas infection may be present with this type of exudate. Wound culture and follow-up with an infectious disease specialist should be considered anytime there is concern for a wound infection because of the possibility of complications, delayed healing, and/or progression to systemic infection.
- Thick brown, tan, or yellow drainage from a surgical wound, new opening in a surgical wound, or effluent that is mixed with food particles: This drainage can sometimes indicate an enterocutaneous fistula (an abnormal opening from the intestine to the skin, sometimes seen with abdominal surgical wounds). Drainage from a fistula can be abrupt and require a wound manager or pouch and further follow-up with the surgical team.
Wound Drainage and the Plan of Care
Understanding wound drainage and what it means for each individual wound is particularly important when developing a treatment plan and identifying key players in treating the wound. Treating the whole patient and not just the hole in the patient is an especially important concept, which I am sure we have heard before. Being able to identify the type of wound drainage accurately and hopefully understand the cause is important. Too much drainage can lead to hypergranulation tissue, which also impedes the healing process. A wound that is too dry will stall, as mentioned earlier—a dry cell is a dead cell. There need to be a moisture balance, absence of infection, and an appropriate topical treatment in place, along with management of the patient’s health as a whole (including nutrition, mobility, psychological state, etc.), for healing to occur. Additionally, if wound drainage is not correctly identified and managed, it may also delay the healing process. To best manage the wound topically, accurate identification and management of drainage are imperative. Understanding wound etiology can also help with understanding drainage types. Certain wounds are more prone to certain types of drainage.
Understanding the cause of the wound and aiming to fix that problem are key aspects of wound healing. Drainage and tissue types are also important parts of a comprehensive wound assessment and treatment plan. If you are not sure, consult with your wound specialist and the interdisciplinary team to formulate an evidence-based, comprehensive plan of care.
Doughty DB, McNichol LL, eds. WOCN Society Core Curriculum: Wound Management. Philadelphia, PA: Wolters Kluwer; 2016.
About the Author
Holly is a board-certified gerontological nurse and advanced practice wound, ostomy, and continence nurse coordinator at The Department of Veterans Affairs Medical Center in Cleveland, Ohio. She has a passion for education, teaching, and our veterans. Holly has been practicing in WOC nursing for approximately six years. She has much experience with the long-term care population and chronic wounds as well as pressure injuries, diabetic ulcers, venous and arterial wounds, surgical wounds, radiation dermatitis, and wounds requiring advanced wound therapy for healing. Holly enjoys teaching new nurses about wound care and, most importantly, pressure injury prevention. She enjoys working with each patient to come up with an individualized plan of care based on their needs and overall medical situation. She values the importance of taking an interprofessional approach with wound care and prevention overall, and involves each member of the health care team as much as possible. She also values the significance of the support of leadership within her facility and the overall impact of great teamwork for positive outcomes.
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.