Standard, Appropriate, and Advanced Care and Medical-Legal Considerations: Part One -- Diabetic Foot Ulcerations

Gerit Mulder, DPM, MS, David Armstrong, DPM, Susie Seaman, MSN, NP, CETN

Disclosures

Wounds. 2003;15(4) 

In This Article

Patient Assessment

A thorough history and physical examination is the first step necessary to determine the patient and ulcer status, establish a baseline for treatment, develop a treatment plan, determine a patient's risk status, and provide a prognosis for wound closure. Historical information should include diabetes control, current and past complications and treatments, and comorbidities. Physical examination should include information on vascular, neurological, and musculoskeletal status.

A simple neurological examination performed with a 5.07 monofilament provides immediate information on the degree of patient neuropathy. Semmes-Weinstein monofilaments are inexpensive devices recommended for neurosensory testing.[14] The 5.07 monofilament is considered the single most practical measurement of ulcer risk assessment.[14]

Clinical recommendations for treatment of people with diabetes suggest that all patients should be assessed annually with the Semmes-Weinstein monofilament.[15,16] Vibratory perception threshold (VPT) is tested with a biothesiometer or with a 128-Hz tuning fork.[12,16,17] Inability to perceive vibration from the tuning fork correlates with loss of protective sensation. Armstrong, et al.,[17] found that insensitivity to Semmes-Weinstein 5.07 monofilament at four or more sites combined with a VPT using a biothesiometer at 25V had a sensitivity of 100 percent and specificity of 76.5 percent in screening for risk of diabetic foot ulceration in diabetic patients.

The greater the degree of neuropathy, the greater is the risk of developing a diabetic foot. Neuropathic patients have reduced awareness of trauma, infection, and complications, which may occur on the foot ulcer. Sensory, motor, and autonomic neuropathy represents the greatest risk for ulcer development in diabetic patients.[18]

Motor neuropathy affects the function of the intrinsic and extrinsic musculature of the foot.[19,20] Claw toes, hammer toes, and shifting of the weight from the toes to the metatarsal heads may lead to increased pressure over boney prominences, excessive and abnormal pressures, and subsequent ulceration.[20] Patients must be educated on the risks of ulcer formation and how to decrease the risk of ulcer development through offloading devices.

Autonomic neuropathy is reflected by decreased sweating, loss of skin temperature regulation, and autosympathectomy. Anhydrosis results in xerotic skin and predisposes skin to fissures, cracks, and callus formation.[10]

Once neuropathy has been established, related education becomes a component of appropriate care. The patient must be made aware of the increased need for lower-extremity pressure reduction, offloading, and routine examinations. Neurosensory testing is an essential component of appropriate care yet is not standard care in the majority of treatment settings. Neuropathy will not be detected unless the clinician performs the necessary tests. Detecting and interpreting the results of neurosensory testing will help establish the guidelines for appropriate treatment.

The vascular examination, particularly the noninvasive vascular exam, establishes the degree of vascular and tissue perfusion. Patients with severe arterial disease will have difficulty with wound closure and are at high risk for amputation secondary to inadequate oxygenation and perfusion of tissue. Peripheral arterial disease may contribute to complications and death.[21] Atherosclerotic disease in a diabetic patient is the same as in the nondiabetic patient; however, the vessels between the knee and ankle are involved, with sparing of the pedal vessels in the majority of cases. There is no evidence of microvascular occlusion in the diabetic patient, although there is good evidence of microvascular dysfunction, which can affect local flow. Although distal bypass may no longer still be the standard of care in the diabetic patient, it is certainly appropriate.[22] While most ulcers are of neuropathic or mixed etiology, ischemic ulcers occur in approximately 10 percent of diabetic patients.[8]

Vascular testing of new and high-risk patients may not be viewed as part of standard care, yet it is appropriate care, as results will guide the type and degree of medical intervention. Manual pulse examination is part of a standard examination; however, it does not adequately determine the patient's vascular status. Doppler-derived lower-extremity arterial pressures or Doppler or pulse volume waveforms assist with determining foot pulses while eliminating the risk of feeling one's own pulse while palpating the foot. Ankle-brachial index (ABI) measurements are useful but may provide falsely elevated rates due to noncompressible arteries, which result from medial arterial calcification.[20] While transcutaneous oxygen (TcpO2) measurement is a useful tool for measuring local tissue oxygenation, the extensive equipment necessary for these measurements may not be available to most clinicians. Duplex imaging, laser Doppler, and skin perfusion measurements all help determine levels of flow and oxygenation of affected tissue. Toe pressures can also be considered a standard noninvasive measure to determine adequate perfusion into the digits.

Patients with severe vessel occlusion may not be candidates for sharp/surgical wound debridement and, when not surgical candidates for revascularization, may be at a high risk for limb loss. Debriding nonviable tissue in a patient without the potential to heal may result in a larger wound. Through appropriate testing and determination of vascular status, treatment expectations and wound closure potential may be established and treatment prognosis and potential clearly explained to the patient. A patient that understands his or her own medical status and risks, including risks associated with morbidity and mortality, is less likely to take legal action in the face of a complication secondary to treatment.

The musculoskeletal exam and associated radiographs may identify deformities resulting in focal points of increased pressure. Repetitive trauma to these sites, as well as sustained pressure, shear, and friction, may contribute to ulcer development. Appropriate intervention may include palliative care, surgery, or prophylactic measures.

Appropriate care entails addressing the above issues to reduce the incidence of ulcer development and to assist with wound closure. Patient education and compliance become integral parts of addressing musculoskeletal deformities through offloading devices and conservative care. Severe deformities, prescribed treatment, and noncompliance must be carefully and legibly documented in the patient's records.

A comprehensive assessment of the patient and the ulcer assists with the determination of risk factors. The number and types of risk factors are correlated with the risk of ulceration. Lavery, et al., defined risk on the basis of loss versus no protective sensation, presence of deformity, and history of amputation.[23] Simeone and Veves have also been published on these risks for diabetic ulceration.[24] Additional factors, including age, obesity, duration of diabetes, and glycosylated hemoglobin (HbA1c), are associated with an increased incidence of ulcers.[25] High-risk patients without ulceration should be examined every three months,[26] while those with open wounds not requiring hospitalization should be seen at least once a week. Even people with diabetes at low risk for ulceration and amputation should have their feet examined on an annual basis, while moderate risk patients may be seen twice a year. The latter examination schedule would be considered appropriate care.

Appropriate care extends beyond a brief wound examination to include all the above factors as well as patient education about foot care and individual risk for limb loss. The patient's knowledge of his or her medical status, his or her ability to care for the wound, and his or her compliance will directly affect treatment results. Elderly and disabled individuals may require home or special care. Documentation of the patient's compliance and level of understanding is important from a treatment and medical-legal perspective. Standard care does not include these assessments, while appropriate care encompasses all aspects of the global assessment.

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