Case Presentation

Gerald R is referred to your outpatient wound clinic because of a nonhealing lower extremity ulcer. He is 63 years old, 6 ft (1.8 m) tall, and weighs 210 lb (95 kg). He tells you that he has had the ulcer for almost a year, and it is getting bigger despite multiple rounds of antibiotics and topical creams prescribed by his primary care physician. His doctor thinks it is not healing because he is a diabetic, and Mr R has been referred to your clinic to see if there is anything else that can be done.

History and Physical Examination

History of Present Illness

Ulcer History

Not sure exactly how the ulcer started-"I must have gotten an insect bite or a little scratch"; he has been treated with triple antibiotic ointment, silver sulfadiazine cream, mupirocin ointment, and oral antibiotics. It has continued to get larger and is now draining large volumes of serous exudate.

Pain Pattern

Reports aching pain late in day (7 on a scale of 1 to 10) relieved by rest and elevation.

Past Medical History

Cholecystectomy; bilateral inguinal hernia repairs; cardiac catheterization, and angioplasty involving 3 vessels 3 years ago; type 2 diabetes / 22 years managed with oral hypoglycemics; stopped smoking 3 years ago (42 pack year history); and motor vehicle accident 2 years ago resulting in fractured femur right leg.

Social History

Stopped smoking 3 years ago (42 pack year history); occasional alcohol use (2-4 drinks/week); married; works as a software engineer; and usually watches sports on TV when not at work.

Current Medications

Simvastatin (Zocor) 40 mg/day; acetylsalicylic acid (aspirin) 80 mg/day; glipizide (Glucotrol) 10 mg daily; metformin hydrochloride (Glucophage) XR 750 mg daily (in evening); and ibuprofen 400 mg prn pain.

Vascular Assessment

Dorsalis pedis and posterior tibialis pulses diminished but easily palpable; venous filling time 20 seconds; capillary refill 3 seconds; ankle brachial index 0.68; nails thickened and discolored; skin normal texture; no hair growth mid-calf to toes; 2+ edema right lower extremity (ankles to knees); and no edema left lower extremity.

Sensorimotor Assessment

Response to 5.07 monofilament, 5/9 on right and 4/9 on left; no vibratory sense right or left; hammertoes 4/5 toes bilaterally; callus first metatarsal heads bilaterally; and dry cracked skin on feet bilaterally.

Physical Findings/Wound Characteristics

Location 1 cm superior to lateral malleolus right leg; dimensions 7 cmx6 cmx0.1 cm; ulcer bed 80% red nongranulating and 20% covered with thin layer adherent yellow slough; wound edges open; and surrounding tissue macerated and pruritic.

Questions

1. Which of the following best explains the etiology of this ulcer?

a. Arterial ulcer complicated by venous insufficiency

b. Venous ulcer complicated by arterial insufficiency

c. Arterial ulcer complicated by neuropathy

d. Neuropathic ulcer that is nonhealing due to arterial insufficiency

2. Which of the following is an ESSENTIAL element of an effective management plan?

a. Hyperbaric oxygen therapy

b. Referral to neurologist and endocrinologist

c. Static compression wrap delivering 30 to 42 mm Hg pressure at ankle

d. Modified compression therapy (23 mm Hg at ankle)

Answers

1. b: Venous ulcer complicated by arterial insufficiency.

Discussion/Explanation

Critical indicators for determining the etiology of a leg ulcer are location, appearance of wound bed, volume of exudate, and pain pattern. While this patient clearly has arterial insufficiency and neuropathy, these are comorbid conditions and not the cause of his ulcer. The ulcer is located around the malleolus; it is shallow and 80% red tissue, with a large amount of exudate. In addition, the patient reports aching pain late in the day that is relieved by elevation. Finally, the vascular assessment supports venous insufficiency as primary etiology, in that pulses are palpable, the ABI is 0.68, venous filling time is 20 seconds, and there is 2+ edema in the right lower extremity.1,2

In contrast to venous leg ulcers, arterial ulcers typically occur distally (toes and forefoot) in the tissues farthest from the heart. (Arterial insufficiency may also result in a nonhealing wound that began with trauma.) Arterial ulcers usually present with a pale or necrotic wound bed and minimal exudate. Pain is worsened by activity or elevation and relieved by rest and dependency. The ABI would typically be <0.5 or >1.3, and capillary refill and venous filling time would be prolonged. While this patient does have arterial insufficiency as evidenced by diminished pulses and ABI of 0.68, his arterial disease is not yet severe enough to cause tissue necrosis. Rather, healing is expected in a patient with palpable pulses, a viable wound bed, and an ABI of 0.68.3

Neuropathic ulcers typically occur on the plantar surface of the foot or on surfaces that are in contact with footwear and exposed to repetitive friction. If there is no associated arterial insufficiency, the wound bed is typically red and exudative. Pain is typically described as "burning or stinging" and usually relieved by activity. This patient has evidence of sensory neuropathy, motor neuropathy, and autonomic neuropathy and requires a referral for appropriate footwear as well as intensive education regarding appropriate foot care; however, the ulcer is clearly not neuropathic in origin.1

2. d: Modified compression therapy (23 mm Hg at the ankle).

Discussion/Explanation

Since the ulcer is venous in origin, effective management must include measures to improve venous return, and the standard of care is compression therapy. Standard static compression wraps are contraindicated for individuals with an ABI of <0.8; the standard of care for individuals with an ABI of >0.5 and <0.8 is modified compression (ie, devices providing 23-30 mm Hg compression at the ankle).3

References