Part one of this series focused on types of surgical wounds, their healing intention and factors that influence healing. In this article we will consider post-operative wound complications including surgical site infections (SSIs) and briefly touch on management.

By definition, a surgical site infection (SSI) is an infection that develops within 30 days after a surgical procedure or within one year if an implant was inserted and the infection appears to be related to the surgery (Gottrup, Melling & Hollander, 2005). SSIs can be superficial (occurring in the dermal and sub-cutaneous layers) or deep incisional infections involving muscle and fascia. Organ space SSIs occur in the body organs or organ spaces. Some general factors will increase a patient’s risk for SSI such as age, obesity, malnutrition, malignant disease, immunosuppression, smoking, prolonged pre-operative stay endocrine and metabolic disorders e.g. diabetes, hypoxia and anaemia. . Local factors (wound and periwound) include the presence of necrotic tissue, foreign bodies, tissue ischemia, haematoma formation and poor surgical technique (Gottrup, Melling & Hollander, 2005). The degree of microbial contamination, host susceptibility, type and virulence of organisms; and antibiotic resistance will impact risk (Gottrup, Melling & Hollander, 2005). Therefore, it is important to monitor surgical wounds closely for infection in order to prevent more serious complications. Indications that the patient has developed a SSI include classic signs of inflammation (redness, swelling, heat, erythema and increased pain); increased exudate that is cloudy, discoloured or malodorous; increase in the size of the wound or wound dehiscence (the wound breaks down at the site of the surgical incision); fever and a general feeling of being unwell or lethargic..

Other wound complications that one might encounter in the post-operative patient include surgical wound dehiscence, dead space, incisional hernias, fistula formation, contact dermatitis; and haematoma formation and bleeding. Surgical wound dehiscence and enterocutaneous fistula will be dealt with in the next article due to the complexity of these complications.

Sometimes due to the nature of the wound, wound edges beneath the skin cannot be closely approximated and separate resulting is dead space. Air and/or fluid can get trapped between the tissue layers, especially the fatty layer which has a poor blood supply. Consequently serum or blood may collect in the space providing an excellent medium for the growth of microorganisms that cause infection. Many post-operative wounds will have a drain inserted to facilitate drainage while the subcutaneous tissues heal. New or increased pain, induration on palpation and spreading erythema around the site of the surgical incision and increased temperature may indicate a collection has occurred. The patient may require systemic antibiotics or return to theatre to have the collection drained and/or a drain inserted to facilitate drainage until the wound heals.

Incisional hernias are complications occurring at the site of a previous incision that develops in the abdominal wall. Muscles at the incision site become weakened allowing internal tissues to protrude through the muscle (Millikan, 2003). The hernia protrudes under the skin and can be painful or tender to touch. SSI and surgical wound dehiscence are the most commonly reported risk factors for incisional hernia (Millikan, 2003). Other risk factors include male gender, age, obesity, abdominal distension, post-operative pulmonary complications, early re-operation, underlying disease process, suture material used in closure, choice of original incision and patient post-operative activity that may place undue stress on the deeper tissues of the abdominal wound (Millikan, 2003). Surgery may be required to repair the defect, especially if the hernia is causing problems. The use of lumbar and abdominal support belts after abdominal surgery can reduce the risk of incisional hernia as they support the abdomen post-operatively. Holding a pillow or rolled up towel against the surgical site while coughing and moving can also provide support and protect internal structures from undue stress and strain.

Haematoma formation and bleeding in and around the surgical site is common. Postoperative haematoma is basically a localised collection of blood at and/or around the surgery site. It is defined as the collection or pooling of blood under the skin, in body tissues or an organ. Haematomas form when capillaries, arteries or veins rupture, allowing blood to leak into the surrounding tissues, causing a pool of blood which eventually clots. Symptoms usually appear within the first 24 hours – bruising, pain, swelling and tightness over the area. In most cases the haematoma will be reabsorbed, however some require drainage or surgical intervention. If left untreated some haematomas get large enough to compress the tissues preventing oxygen from reaching the skin, increasing the risk of other complications such as infection, wound dehiscence and necrosis.

Contact dermatitis is a localised rash or irritation of the skin caused by contact with a foreign substance. The skin becomes red, sore or inflamed after direct contact with a substance, for example a dressing adhesive or retention tapes e.g. micropore; or latex gloves. Contact dermatitis can be irritant or allergic – always ask the patient if they have allergies before application of dressings or use of surgical gloves which contain latex. Many hospitals now have latex-free gloves for general use on the ward and latex-free surgical gloves are available.

While most surgical wounds undergo primary closure, some are left to heal by secondary intention or undergo delayed primary closure. Regardless of the method of closure, the aims of treatment are to disturb the wound as little as possible to allow healing and prevent infection, optimise patient comfort, encourage early return to full functional activity and provide education regarding the wound and self care (Davies, 2005).

Surgical incision sites that are healing by primary intention should be clean and covered with a semi-permeable, water resistant dressing e.g. ComfeelPlus or Opsite. Wounds healing by secondary intention require dressings which are appropriate to the size, depth, location and level of exudate. Surgical wound dressings are low adherent and designed to absorb blood or exudates in the immediate post-operative phase. They provide an impermeable barrier to bacteria, help to reduce the risk of infection, maintain a moist healing environment and protect the surgical incision against trauma (Davies, 2005). When dressings are applied in theatre the recommendation is to leave the dressing undisturbed unless they become stained, leak or the wound shows clinical signs of infection (Davies, 2005). Monitor the site for exudate and inflammation that extends beyond the borders of the dressing, and increased pain or tenderness around the wound site.

Remember to also monitor for sepsis, especially if the patient is aged 60 or over. Tachycardia, increased respiration rate, low blood pressure, rigors with or with-out fever, decreased urine output and new onset of confusion, disorientation, agitation or joint pain may indicate infection has become systemic. Complications of surgical wounds are costly as they increase the length of patient stay in hospital and confer pain and suffering to the patient. Always document the findings of your assessments and refer to the appropriate member of the interdisciplinary team for follow-up.

References
Davies, P. (2005). Management of post-operative wounds. Nursing Practice, 25 (12), 14-19
Gottrup, F., Melling, A., & Hollander, D. (2005). An overview of surgical site infections: aetiology, incidence and risk factors [online]. World Wide Wounds. http://www.worldwidewounds.com/2005/september/Gottrup/Surgical-Site-Infections-Overview.html
Millikan, K.W. (2003).Incisional hernia repair. Surgery Clinical North America, 83 (5):1223-1234.