Pressure ulcers. An obvious risk because of weight is the development of pressure ulcers. If the bariatric patient becomes immobilized for a length of time, the risk for deep tissue injury and pressure ulceration rises. The risk is present particularly over bony prominences such as the sacrum and heels.4,23,32,33
What may not be as evident is the development of atypical pressure ulcers located deep within skin folds that create pressure on each other.12,25 Although the area below a large pannus (which in some patients can weigh hundreds of pounds) is an obvious place to assess, atypical pressure ulcers can occur anywhere on the body, including the neck, upper back, upper medial thigh, flanks, and posterior legs/ankles. Relief of pressure is the ultimate intervention. Poorly sized beds can exacerbate poor positioning and promote cursory skin fold assessment.15 This can mean moving all lines, catheters, tubes, and fat deposition areas (eg, pannus) every 2 hours. Addressing other contributing factors such as friction, shear, moisture, and poor nutrition is also important. Notably, no pressure ulcer risk assessment scales have been validated for the obese.15
Irritant dermatitis. Perigenital irritant dermatitis due to urinary and/or fecal incontinence is another common problem. Good general and perigenital hygiene is essential to skin health. Despite the best of intentions, bariatric patients may not be able to toilet effectively. Large skins folds or large hip tissue (sometimes called saddle bags) may impede access for self-care. A Grade 3 to Grade 5 pannus (in a five-grade system in which a higher number indicates how far down the pannus apron sags)covering the mid thigh to the knee and beyond compounds the challenge. Once skin irritation has occurred, a need exists for cleansing and ongoing protection. If the environment is not set up for bariatric clientele, the patient may be unable to cleanse and dry the urethral and rectal orifices and be in danger of falling.
Skin infections. Skin infections in the morbidly obese occur on a spectrum of simple benign conditions to life-threatening necrotizing infections. Notably, both diabetes mellitus and obesity are risk factors for necrotizing soft tissue infections.34 Research suggests that obesity is playing a major role in hospitalization rates. Swiney35 noted that the proportion of obese patients hospitalized for skin and soft tissue infections increased from 47.56% in 2003 to 50.42% in 2007.
Obesity increases risk for skin infections by several mechanisms. Excessive skin folds trap humidity and moisture, inducing maceration and related microbial overgrowth. Lymphatic flow also is hindered, decreasing oxygenation of surrounding tissues. With possible venous insufficiency, perfusion to tissues may be further impaired. Increased tension on wound edges from obesity may predispose to poor wound healing or actual dehiscence of a closed wound. Skin pH is higher in obese individuals, increasing risk for candida, which thrive in alkaline environments.35 Skin infections can be relatively benign (candidal intertrigo) or more serious (cellulitis). Necrotizing fasciitis is a disorder with severe consequences if inadequately treated.
Cellulitis. Cellulitis is inflammation of interstitial tissues, usually due to infectious processes. Because of all the physiologic challenges created by visceral adiposity, cellulitis of the lower extremities is most common. The risk is ratcheted up when the obese person is also diabetic. Therapy for cellulitis involves good skin cleansing, possible topical antimicrobial therapy using advanced dressings for open wounds, and systemic antibiotic therapy. Severe lymphedema and venous congestion can impede perfusion of antibiotics to affected tissues.4
Necrotizing fasciitis. Necrotizing soft tissue infections such as necrotizing fasciitis are a threat to the obese population, especially the morbidly obese. Although morbid obesity is not specifically an identified risk factor, diabetes mellitus is a particularly well-documented risk factor. Because diabetes and morbid obesity are common comorbidities, the risk relationship is evident.34
Known as “flesh-eating bacteria,” the organisms causing the disorder (Group A streptococci or Staphylococcus aureus) for type II infection (the most virulent) can be present in both the community and on the patient’s skin. Diabetes is a critical factor in necrotizing infection. These infections occur most commonly in the lower extremities but also in the head/neck and perineum regions.34 If a morbidly obese person develops the infection, care can be challenging given the impact of larger body habitus on requisite extensive surgical debridement and antibiotic therapy.34
Characteristic features of type II necrotizing fasciitis include pain out of proportion to the findings, erythematic (without sharp margins) swelling, and a warm shiny appearance. The affected area changes color rapidly from erythematic to red-purple or blue-gray. Notably, the development of anesthesia or the gradual loss of sensation in the affected area may precede the appearance of skin necrosis. Fever, tachycardia, change in mentation, and other signs of toxicity occur. Rapid recognition and therapy are imperative. Surgical exploration with debridement is the only definitive therapy. Broad-spectrum, empiric antibiotic treatment and management of septic shock (if present) are required.34
Fournier’s gangrene is necrotizing fasciitis that affects the perineum. Because morbidly obese patients may have difficulty with perineal cleansing, a risk for the condition is present. Critically ill, morbidly obese patients are at risk due to the immune compromise associated with critical illness. Treatment is similar in that systemic antibiotics, serial surgical debridement, and hemodynamic support therapy are necessary. Because of the large tissue defects associated with necrotizing skin infections such as Fournier’s gangrene, skin grafts usually are required. However, graft failure is common in obese, especially morbidly obese, individuals. Consequently, wound care for large open areas healing by secondary intention is possible.4
Intertrigo. Intertrigo is an infectious or noninfectious inflammatory condition of two opposed skin surfaces. The maceration of the skin due to excess moisture and friction can occur within deep skin folds or commonly under a large abdominal pannus. These intertrigal fissures can be several inches in length and painful due to their depth.36 Risk factors for intertrigo and especially its most common form, candidal (fungal) intertrigo, include obesity, hyperhidrosis (excessive sweating), tight clothing, diabetes mellitus, incontinence, and medications (eg, glucocorticoids, antibiotics).36
Intertrigo presents as erythematous, macerated plaques and erosions with possible scaling. Candidal intertrigo has red satellite papulo-pustules that are the seeding of the infection into adjacent tissue. Most intertrigo and candidal infections are diagnosed clinically because of classic appearance, classic locations (eg, perineal area, deep skin folds), and complaints of itchiness (pruritus). Two major interventions include treating with topical antifungal (eg, mycostatin powder) and use of drying agents (eg, aluminum acetate [Domeboro’s solution, Bayer Healthcare, Leverkusen, Germany]), fans, and special materials with drying and antimicrobial properties (Interdry, Coloplast, Minneapolis, MN). A hairdryer set on cool also may help dry the patient’s skin folds.37 If a patient fails topical therapy, oral antifungal agents (eg, fluconazole) may be needed for a short term of therapy.36
Erythasma. Another condition affecting skin folds and the perineal area is erythrasma. A superficial infection of the skin caused by Corynebacterium minutissimum, erythrasma presents as macerated reddened scaly plaques in intertriginous areas, commonly in the groin, axilla, and foot. If the infection is long-term, the involved areas have a brown discoloration, visible fine scale, and wrinkling. The areas may be itchy or asymptomatic. Risk factors include obesity, excessive sweating, and type 2 diabetes. The condition is more common in tropical or hot, humid climates. Because the infection is bacterial, antifungals do not work. For localized disease, topical therapy with clindamycin or benzoyl peroxide is therapeutic. For more widespread infection, systemic clarithromycin or erythromycin is helpful. For prevention, bariatric patients need to avoid moist, uncleansed skin folds and any kind of occlusive diapers or garments that trap moisture.38
Acanthosis nigricans. Acanthosis nigricans is another disorder for which bariatric patients are high risk.6 The benign condition is characterized by velvety, hyperpigmented plaques on the skin and intertriginous areas such as the back of the neck and the axillae. In the US, acanthosis nigricans is seen more in persons of African, Hispanic, and Native American origin. Obesity is the most common reason for development of acanthosis nigricans. Disorders associated with insulin resistance also are seen with the condition (eg, type 2 diabetes, metabolic syndrome).
Abdominal elephantiasis. A highly unusual condition, abdominal elephantiasis can occur in the large abdominal pannus. Due to prolonged lymphedema and associated fibrous tissue proliferation, the affected pannus becomes characterized by chronic, thickened, edematous skin and associated skin and subcutaneous tissue inflammation.28 Morbidly obese patients develop this massive localized edema and associated skin changes secondary to increased tissue tension. It is theorized the massive panniculus causes increased interstitial and intravascular pressure, predisposing patients to low-grade cellulitis and lymphangitis.28 Differential diagnosis of abdominal wall cellulitis versus elephantiasis may depend on accompanying systemic signs and symptoms and laboratory testing (eg, blood count, blood cultures). Possible treatment involves antibiotic therapy, meticulous skin care, use of drying agents, and use of 5% salicylic acid products if hyperkeratosis requires removal.
Venous insufficiency and lymphedema. Bariatric patients are at great risk for the development of venous insufficiency, venous ulcers, and lymphedema. Venous insufficiency is a disorder where blood supply to the lower extremities is adequate to good but the return path is impaired. Venous blood pools in the extremities with the generation of edema (fluid in the interstitial tissues) and eventual hemosiderin staining (leeching out of the hemoglobin component of the red blood cells to permanently discolor the tissue). Early in the process, the ankles of both legs may look “dirty.” Selected risk factors for the disorder include deep vein thrombosis, multiple pregnancies, venous injury, and obesity, to name only a few. Years to decades of obesity can severely damage the venous system and circulatory changes ensue.14,24 A more serious sequela of venous insufficiency is venous ulceration. A wound will occur most commonly above the inner malleolus and can exude substantial amounts of fluid due to the associated edema.
Therapy for venous ulceration is compression combined with an absorptive dressing. The obese or severely obese patient presents a real dilemma for care. The leg itself may be difficult to wrap due to fat depositions. Further, self-care may be impossible if a patient cannot reach around a large pannus. The excessive weight placed on the extremities with ambulation further exacerbates the venous hypertension situation. Leg elevation may be impossible, because it may impair ability to breathe. Lymphedema is a serious disorder of the lymphatic system seen most frequently in older women. Recent reports suggest lymphedema is present to a substantial degree in the morbidly obese population (up to 75%).14,24 In this group, lymphedema is usually secondary in nature (not congenital) due to damage of the lymphatic pathways related to excessive weight. Notably, in the morbidly obese, edema can occur in the extremities, hands, face, and abdomen (in the pannus).
Clinical presentation of lymphedema in the obese relates to duration of the disorder. Skin inflammation, related to the lymphedema, generates functional impairment, pain, and chronic cellulitis. Usually Stemmer’s sign (an inability to pinch a fold of skin at the base of the toes) is present in lymphedema. Skin can be dry, hyperkeratotic, and chronically affected by fibromas, lymphangiomas, and papillomas.14
Lipedema. Lipedema is a pathological accumulation of fat in both lower extremities. It can affect persons of normal weight or the obese. Several features differentiate lipedema from lymphedema. In lipedema, the feet are spared of edema (the swelling stops at the ankle), and in lipedema both legs are affected symmetrically. It is possible that with time an individual can develop both conditions known at “lipolymphedema.” 14
Management of the skin issues associated with these disorders can include containment or absorption of wound fluid (lymphorrhea) and decreasing skin bacteria. If wounds are present, they require quality wound bed preparation and protection. However, lymphedema requires special approaches including complete decongestive therapy or manual lymph drainage. When combined with special bandages that are wrapped distal to proximal gradiently (that is, the higher pressure more distally), the swelling can be significantly improved. For morbidly obese patients, semi-rigid devices like the Circaid boot (Circaid Medical Products, Inc, San Diego, CA) may be more appropriate.
Management of wounds due either to venous insufficiency or lymphedema must address treatment of the underlying disorder. Management of lymphedema consists of four basic cornerstones: compression, exercise, skin care, and lymphatic drainage. With the exception of lymphatic drainage, all are important for venous insufficiency.30 Topical interventions include controlling bioburden (cleansing, antimicrobial dressings), debridement of slough and detritus, and drainage management.
Skin care and prevention involve good cleansing of the extremities, good drying processes, and moisturizers. Razors should be used carefully and avoided if possible to avoid nicking and trauma. For hyperkeratotic skin, lactic acid products (eg, Lachydrin, Bristol Myers Squibb Co, New York, NY) can be helpful in removing old tissue and nurturing new skin health.14 Vigilance for skin infections and inflammation is critical to avoid future complications.
Diabetic foot ulceration. Because obesity is a major risk factor for chronic hyperglycemia, obesity and type 2 diabetes are closely related. One disorder that affects about 15% of persons with diabetes is DFUs.4 For obese or severely obese clients, DFUs can become life-threatening because self-care and self-awareness may be substantively impaired by excess weight.
DFUs most often occur on the sole of the foot, commonly at the base of the metatarsals. Quality care requires debridement of the callus around the wound opening, management of bioburden, and protection against osteomyelitis; in addition to surgical debridement and antibiotics, therapy is dependent on offloading of the ulcer.4,21,24 This goal can be daunting in a morbidly obese patient. Special larger-size offloading devices for the extremity or the enforcement of non-weightbearing (eg, bed rest, wheelchair) may assist with better outcomes.
SSIs. SSIs are a grim risk for obese patients. Even patients who have opted for life-changing bariatric surgery are still at risk for wound infection.
Morbidly obese and obese patients typify many of the risk factors for SSIs. Type 2 diabetes, difficulty breathing due to visceral adiposity, poor nutritional baseline status (protein deficiency), the presence of large subcutaneous spaces with poor blood supply,40 and other metabolo-endocrine dysfunctions (eg, hypothyroidism) can contribute to substantially higher risk. In addition, perioperative subcutaneous wound and tissue oxygen tension is substantially reduced in morbidly obese patients. Tissue hypoxia is pronounced during surgery and may contribute to wound infection risk in obese individuals.26 Wound edges must be assessed for stress on the surgical incision, including pain and obvious dehiscence. An appropriately sized abdominal binder may be needed to support the abdominal wall.15
Wound healing processes may be impaired by the obesity process itself, even when patients are post bariatric surgery and have lost substantial weight. D’Ettorre et al41 examined the effect of gastric bypass on wound healing parameters compared to preoperative samples, analyzing the biochemical parameter content of scar skin samples in seven postbariatric surgery patients (six women, one man) 36 months after the surgery. The authors found significantly decreased (P <0.001) biochemical healing parameters (protein, elastin) in scar skin tissue postoperatively and suggest high mechanical stress of tissues before bypass probably influences wound healing afterwards.
Warmth, redness, pain, and drainage at the incision may indicate wound infection. If a drain is being used, the amount, color, odor, and consistency of wound fluid should be monitored and documented. Fever, malaise, and other signs of systemic toxicity should be shared with the surgeon.9
Prevention of SSIs in obese and morbidly obese persons is the best “therapy.” Preoperative administration of antibiotics such as cefazolin (Ancef, GlaxoSmithKline, Research Triangle Park, NC) or, if allergic to beta-lactam agents, use of clindamycin plus ciprofloxacin may decrease the risk.16 In addition, prevention of intraoperative hypothermia, good blood glucose control, and quality perioperative skin preparation can lower SSI risk. Research by Kabon et al26 suggests postoperative supplemental oxygen administration (10 L/min) also may lower SSI risk because it improved subcutaneous tissue oxygen tension in morbidly obese surgical patients. The researchers randomly assigned 42 laparoscopic bariatric surgery patients to either 80% oxygen (10 L/minute) via a Hi-Ox (Ceretec, Garden Grove, CA) mask or 30% oxygen via nasal cannula (2 L/minute) following surgery to the next morning. The authors measured subcutaneous tissue oxygen tension and found a significantly higher level in the Hi-Ox group (58 mm Hg versus 43 mm Hg, P = 0.002). Theoretically, a primary defense against surgical pathogens is oxidative killing by neutrophils that depends on tissue oxygen tension.
If a wound infection occurs in a bariatric patient, aggressive intervention is usually necessary. Antibiotics will be used based on culture and/or empirical choices, but dosing antibiotics in morbidly obese patients can be challenging due to uneven pharmacokinetics (marked changes in distribution, binding, and elimination of medications).4,15 Dosing of hydrophilic medications (eg, vancomycin) is based on actual body weight; lipophilic (fat-soluble) medications (eg, opioids) are dosed based on ideal body weight.15,18 However, evidence-based guidelines to determine dosing strategies for acutely and critically ill bariatric patients with BMI >40 are lacking.18
Bariatric patients are at risk for general postoperative complications such as hemorrhage, deep vein thrombosis, arrhythmias, and pneumonia. A challenge for quality assessment relates to the excess weight. Signs of cardiac failure such as jugular venous distention, peripheral edema, and hepatomegaly may be masked by body habitus. Perceptive assessment is crucial for optimal care.15 Advanced therapies including negative pressure wound therapy or special dressings (eg, silver-impregnated, alginates) may be needed. Dressings also should be selected with pain control in mind.4
Bariatric-specific surgery. Various review articles support that bariatric patients can resolve their morbid obesity comorbidities most effectively by undergoing some form of gastric bypass (malabsorptive) or gastric restrictive procedures.3,5,7,42-44 Therefore, many bariatric patients may opt for this surgery. Bariatric patients also may require emergency surgeries such as C-sections or appendectomies. Whatever the reason, bariatric patients are faced with a higher risk of SSI than normal weight individuals. Rates of wound infection are specifically higher in open gastric bypass (10% to 15%) than laparoscopic (3% to 4%) surgery.16