The 21st century has ushered in the era of minimally invasive surgery. The good news is smaller incisions mean fewer complications during the healing process. However, this millennium also has seen a dramatic rise in obesity in the U.S. with accompanying comorbidities and higher risks for surgical wound complications.
The prevalence of obesity has increased from 13% to 32% between the 1960s and 2004, according to researchers at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Md. Researchers also are predicting that by 2015, 41% of adults will be obese.
Whether a surgical procedure is minimally invasive or requires an open approach, obese patients, also known as bariatric patients, are at an increased risk for surgical wound complications. This is due in part to the need to manipulate large amounts of adipose tissue (fat) during procedures in order to visualize and reach organs.
More forceful retraction and longer periods of time are also often required to complete procedures. This, in addition to the comorbidities associated with obesity, adds up to greater risks for deep tissue injury, ischemia, necrosis, and infection in surgical wounds.
Building blocks of wound healing
Unfortunately, the skin and underlying tissues tend to be overlooked until there is a problem, according to Donna Driver, RN, CS, CWOCN, a medical/surgical clinical nurse specialist and a wound care nurse at Mary Washington Hospital in Fredericksburg, Va.
"The skin is an organ, but it's the last organ anyone thinks about," she says.
To be proactive in preventing skin and wound complications, nurses and other healthcare providers need to understand the factors that form the foundation of successful wound healing — nutrition, circulation, and oxygenation. A knowledge of how comorbidities associated with obesity negatively can affect these factors is key.
"Not only do you have to pay attention to the surgical wound itself, you have to look at the bariatric patient as a whole," says Driver.
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The following comorbidities associated with obesity can negatively impact the healing process.
HYPERGLYCEMIA AND DIABETES: Obese patients are at risk for elevated blood glucose levels, which can negatively impact immunity and circulation, increasing wound healing time and the risk for infection. High glucose levels can be related to preexisting Type 1 or Type 2 diabetes, and nurses need to be aware of the potential for obese patients to have undiagnosed diabetes. An acute rise in blood sugar also can occur postsurgically to both diabetic and non-diabetic patients because of the body's stress response, which results in the release of cortisol, a hormone that increases blood glucose levels.
It is not unusual for obese patients who are referred to the Wound Healing Center at Baltimore Washington Medical Center in Glen Burnie, Md., to be wrestling with diabetes, according to Priscilla Hall, RN, BSN, clinical nurse manager of the center.
"A lot of patients are diabetic, and it can be a challenge getting their sugars under control," she says.
The outpatient Wound Healing Center averages more than an 82% heal rate by providing specialized treatment of many types of non-healing wounds and their associated complications, including postoperative infections. To ensure tighter control over unregulated glucose levels and to maximize optimal healing, patients with diabetes can be referred for additional treatment to the Joslin Diabetes Center, also located within Baltimore Washington Medical Center. Staff at the Joslin Diabetes Center tailor a disease- and lifestyle-management plan for each patient that includes weight management and diabetes education.
Many hospitals also are instituting tight glycemic control protocols to ensure optimal healing for postsurgical patients with hyperglycemia from any cause. For example, the staff of Mary Washington Hospital uses a sliding scale insulin protocol to keep patients' serum glucose below 150 mg/dL in the ICU.
IMPAIRED PULMONARY FUNCTION: An impaired respiratory status is a concern for obese patients with surgical wounds. Deep inspiration is limited since the diaphragms of obese patients can't descend fully into the abdomen because of the presence of excessive adipose tissue. This also limits chest expansion and results in less effective respirations, less oxygenation, and compromised wound healing.
"Without good ventilation, you don't get good oxygenation — a big factor in wound healing," says Driver.
HYPERTENSION: Obese patients have an elevated risk of hypertension, which leads to arteriosclerosis (hardening of the arteries). This results in a decrease in circulation and, because the arterial walls are less permeable, less oxygenation and availability of other nutrients necessary to heal wounds. To ensure optimal healing, nurses need to be vigilant with blood pressure monitoring and with interventions to control blood pressure.
NUTRITIONAL DEFICITS: An adequate supply of protein is essential to the successful healing of wounds. Other important nutritional elements include carbohydrates, vitamins, and minerals.
Obese individuals might be lacking nutrients vital for wound healing, according to Driver. This might be because they have been indulging in unbalanced, high-calorie diets that are high in fat and processed carbohydrates and do not supply adequate protein, vitamins, and minerals.
To optimize wound healing, a patient's protein status should be evaluated and addressed with nutritional support as needed before surgery.
Other factors
Many other factors can complicate wound healing in obese patients, such as —
AVASCULARITY OF ADIPOSE TISSUE: Adipose tissue does not have a developed vascular system that feeds it. As a result, adipose tissue receives less oxygen, nutrients, and infection-fighting white blood cells (leukocytes) than other tissues. A lack of a developed vascular system also increases the risk for the development of infection and pressure ulcers.
"Adipose tissue is not well-vascularized and can become ischemic easily," says Driver.
HEMATOMA AND SEROMA FORMATION: Bariatric surgical patients are at risk for the buildup of blood (hematoma) or serous fluid (seroma) inside surgical wounds. Hematomas and seromas can add pressure and tension on sutured or stapled incisions which can result in wound dehiscence (separating of the edges of the wound). This buildup of pressure can compromise arterial perfusion to the wound, and the pooling of fluids can create an environment that encourages bacterial growth and infection.
The use of drains and negative pressure wound therapy devices, such as a Jackson-Pratt drain, can foster better healing of surgical wounds by draining off excess fluid, reducing pressure, and minimizing bacterial growth. There also are newer devices on the market that are proving effective in hastening the healing process.
Recent case studies showed the success of the Engenex(TM) negative pressure wound therapy device in obese patients with non-healing surgical wounds. A poster on the device was presented at the 2007 Symposium on Advanced Wound Care in Tampa, Fla. (See sidebar)
IMMOBILITY: Obese patients often have sedentary lifestyles that can impede good surgical wound healing and increase the risk for other postoperative complications, such as venous status, edema, blood clots, pneumonia, and pressure ulcers.
"If bariatric patients don't get up and aren't mobile, that can become a serious issue," says Driver, stressing post-surgical ambulation can improve pulmonary function and arterial flow, resulting in better delivery of oxygen and nutrients to healing wounds.
SKIN PROBLEMS: Keeping skin and incisions clean and dry is a challenge for postsurgical obese patients.
"These patients are prone to bouts of diaphoresis, which sets them up for the development of yeast infections," says Driver.
Fat folds of the skin, with rolls of adipose tissue, can lead to moisture buildup and are a prime breeding ground for infection. These areas are especially prone to developing infections of yeast and other microorganisms. This is especially true for obese patients whose abdominal incision is located under the abdominal pannus or "fat apron" of the lower quadrants of the abdomen. Folds of adipose tissue also create pressure and friction and can lead to skin breakdown, necrosis, and dehiscence of a surgical wound.
"Good observation of the skin and the incision is vital," says Felecia Morris, RN, BSN, staff nurse and charge nurse on med/surg floor at Baltimore Washington Medical Center.
It is also important to keep fat fold areas clean and dry. At Mary Washington Hospital, nurses even have used Bair Hugger(R) temperature control devices to circulate air and help heal fungal infections.
DEPRESSION: Another factor that indirectly can affect postsurgical wound healing is depression, according to Morris.
"I see a lot of depression in bariatric patients," she says, noting depression negatively can affect a patient's motivation to be mobile after surgery, to practice good nutrition, and to care properly for a surgical wound and keep it clean and dry.
Morris stresses the need for nurses to assess obese patients for depressive symptoms and refer to psychiatric services as appropriate.
Addressing the issues that negatively affect surgical wound healing in obese patients is a multifaceted proposition for nurses. "Keeping all these balls up in the air can be challenging," says Driver. "But nurses are very creative people and if you can maintain good blood sugars, nutrition, circulation, oxygenation, and blood pressures, and keep patients mobile and dry, you will have good outcomes."
