Arterial Wound Basics

There are several types of wounds, other than surgical or pressure related wounds, that are common in the clinical setting. These include (but are not limited to) arterial, venous, and diabetic ulcers. The following will briefly discuss ideas related to the specific cause, diagnostics, appearance, and treatment of an arterial wound etiology.

Arterial ulcers are caused by decreased blood flow to the lower extremity. Diagnostics to confirm this diagnosis include arteriograms,color duplex angiography, magnetic resonance arteriogram, arterial doppler, and transcutaneous oxygen monitoring. Treatment typically is achieved by improving the circulation with a bypass graft or angioplasty. Typically these wounds are very painful, so a silicone dressing like Mepitel or wound veil is a good choice for the primary dressing (if the wound is not infected). If the arterial wound consists of dry gangrene then betadine can be painted or Iodosorb ointment (Smith and Nephew) placed over the gangrenous tissue ( to keep the gangrenous tissue dry). There is a high risk for amputation in patients who are unable to be revascularized or if the gangrene converts to wet or gas gangrene.

Venous Wound Basics

There are several more common types of wounds, other than surgical or pressure related wounds, that are common in the clinical setting. These include (but are not limited to) arterial, venous, and diabetic ulcers. The following will briefly discuss ideas related to the specific cause, diagnostics, appearance, and treatment of a venous wound etiology.

Venous ulcers form by a complex cascade of physiological events in the venous circulation related to venous hypertension. Diagnostics used to confirm venous hypertension include pneumoplethysmography (maximum venous outflow), venous photoplethysmography, and bi-directional color doppler.  Treatment for venous ulcers includes compression wrap bandages, intermittent pneumatic compression, and apligraf.   High compression bandaging is considered the gold standard of treatment of venous leg wounds, yet the majority of published clinical data indicate that only 65% of ulcers are likely to be healed within 24 weeks of appropriate compression therapy, with 20% of ulcers remaining unhealed after more than 50 weeks (1).

(1) Skene AI, Smith JM, Dore CJ, Charlett A, Lewis JD. Venous leg ulcers: a prognostic index to predict time to healing. BMJ 1992; 305(6862): 1119-21.

Common Terms include:

FIBRINOUS– Accumulation of fluids and fibrin (a stringy insoluble protein).

HEMOSIDERIN STAINING – Hemoglobin deposited in tissues. Appears as brownish patches. Symptomatic of venous disease.

LIPODERMATOSCLEROSIS – an induration and erythematous hyperpigmentationof the leg.

MALLEOLUS – A common location of venous wounds located at either of the two rounded protuberances on the side of the ankle, the inner formed by a projection of the tibia and outer projection of the fibula.

PERIPHERAL VASCULAR DISEASE (PVD) – Alterations in the arteries and veins of the extremities; those conditions which interfere with adequate flow of blood to or from the extremities. Peripheral vascular disease broadly describes the underlying pathology of venous stasis ulcers and arterial ulcers.

VARICOSITIES – swollen, twisted veins.

VAVULAR INCOMPETENCE – Refers to damaged valves in the perforator veins of the legs; results in poor venous return to the heart. Valvular incompetence is the underlying pathology of venous stasis ulcers.

VENOUS HYPERTENSION
Patients with varicose veins or nonfunctional venous valves after deep vein thrombosis develop ambulatory venous hypertension, that is, distal venous pressure remains elevated despite ambulation. This constant venous hypertension seems to cause white cell and fibrin buildup, which impairs capillary blood flow or traps growth factors. Macromolecules pass into the dermis and eventually cause the hemosiderin deposition and brawny induration in the distal leg (gaiter area) characteristic of chronic venous insufficiency.

VENOUS INSUFFICIENCY – Stagnation of the normal flow of blood from the lower extremities to the heart due to valvular incompetence; also called venous hypertension.

VENOUS STASIS – Stagnation of the normal flow of blood from the lower extremities to the heart due to valvular incompetence; also called venous hypertension.

Diabetic Wound Basics

There are several more common types of wounds, other than surgical or pressure related wounds, that are common in the clinical setting. These include (but are not limited to) arterial, venous, and diabetic ulcers. The following will briefly discuss ideas related to the specific cause, diagnostics, appearance, and treatment of the diabetic foot wound etiology.

Diabetic wounds are related to microvascular and neuropathic changes in the diabetic patient. Diagnosis of the diabetic ulcer includes a compatible history of diabetes, monofilament test (to assess for loss of sensation), and noninvasive vascular assessments including a transcutaneous oxygen monitoring (TCOM) study. Treatment options for diabetic ulcers include off loading, growth factors (Regranex), debridement, and skin substitutes (Apligraf and Dermagraft).

Approximately 15% of Diabetic Foot Ulcers result in lower extremity amputation (2).    Though 40% to 50% of all diabetes-related amputations are preventable (1) .   Foot-care programs for diabetics (including teaching self foot assessments)  have been shown to reduce the rate of ulcers and amputations by 45% to 85% (1).

1. Garcia – Diaz, J., Pankey, G., & Gentry, Layne., 2006. The contemporary Diagnosis and Management of Diabetic Foot Infections. Health Care Co., Newtown, Pennsylvania. pg.16

2. Snyder, R., Kirsner, R., Warriner, R., Lavery, L., Hanft, J. and Sheehan, P., April 2010. Consensus recommendations on advancing the standard of care for treating neuropathic foot ulcers in patients with diabetes. Supplement to April 2010 OWM, S4.

Diabetic Wound Related  Terms:

Diabetic (Neuropathic) Ulcer – Sensory neuropathy involving the feet may lead to unrecognized episodes of trauma caused by ill-fitting shoes or walking barefoot. This is compounded by motor neuropathy causing intrinsic muscle weakness and spaying of the foot on weight bearing. The result is a convex foot with a rocker-bottom appearance. Multiple fractures go unnoticed, until bone and joint deformities become marked. This is termed a Charcot foot (ie, neuropathic osteoarthropathy) and is observed most commonly in people with diabetes mellitus, affecting approximately 2% of persons with diabetes.

Diabetes: The long-term effects of diabetes impair wound healing by diminishing sensation and arterial inflow. In addition, even acute loss of diabetic control can affect wound healing by causing diminished cardiac output, poor peripheral perfusion, and impaired polymorphonuclear leukocyte phagocytosis.

DIABETIC ULCER – An ulcer that develops due to diabetic risk factors. Diabetes affects circulation as well as the nerve endings in the feet. As a result, many diabetics suffer reduced circulation and loss of sensation in their feet. The loss of sensation is dangerous, because diabetics are unable to feel rubbing, pinching or other pain that could cause a wound to develop on the foot. Lack of circulation to the feet makes it very difficult for a wound to heal. Risk factors for developing a diabetic foot ulcer include loss of sensation or peripheral neuropathy, structural foot deformity, infection, and decreased circulation.

Charcot Foot (Arthropathy) –Acute- Foot deformity with sudden onset of swelling,
increased local skin temperature, erythema, rapid joint changes, looseness of ligaments,
dislocation and fractures without apparent cause.

Charcot Foot (Arthropathy -Chronic -progressive degeneration of the stress-bearing
portion of a joint, with hypertrophic changes at the periphery. It is manifested by rapid
joint changes, looseness of ligaments, dislocation and fractures.

HgbA1c – Glycated hemoglobin, also known as glycohemoglobin, glycosylated hemoglobin, HbA1c or HbA1, refers to a series of stable hemoglobin components formed by the combination of glucose and hemoglobin. Individuals with higher levels of blood glucose will have higher levels of glycated hemoglobin. Because the hemoglobin
components are stable, the level provides an average indication of the overall blood glucose levels over the prior two to three month period. The most commonly used version of the glycated hemoglobin test is the HbA1c.

Hyperkeratotic – Hypertrophy of the horny layer of skin and often appears as a callus ring around a diabetic wound.

Monofilament Test or Semmes Weinstein Monofilament Test  – Is a sensory exam of the foot to detect sensory neuropathy – a 10 gram monofilament
which is pressed to several sights on the feet for 1.5 seconds on each sight and the patient is asked to say “yes” when the monofilament is felt.

Orthotics – a full contact semi rigid, soft insert designed to redistribute pressure, reduce impact, shear and stabilize involved joints. A suitable prescription should include a
complete diagnosis, reflecting the risk category of the patient. Orthotics must be casted and fitted appropriately by an experienced professionally trained clinician.

Osteomyelitis – Inflammation of bone and marrow, usually caused by infection.

Biofilm and Wound Care

A Biofilm is a surface-associated community that is composed of various types of microbes, which encases itself in a 3-dimensional matrix of extracellular polymeric substances (EPS) (e.g. polysaccharides, nucleic acids and proteins) and demonstrates increased resistance to cellular and chemical attack.

Microorganisms may exist in at least two distinct phenotypes – planktonic (free floating) and sessile (attached). A biofilm refers to a group or community of planktonic bacteria that may be incased in part of the extracellular matrix. The fragments have the ability to attach to another suitable surface and reform a biofilm community in the new area.

AAWC, (2008). Advancing your practice: Understanding wound infection and the role of biofilms. UKCT-A0021

Consider biofilm if the wound signs and symptoms includes:

Thick tenacious slough non-responsive (in the form of fast returning slough) to sharps debridement

Bright pink hypergranular tissue that bleeds easily

Wound bed has a slimy appearance

A biofilm may explain the delayed healing seen in some chronic wounds

Tx:

Serial Debridement

Alternate Silver (Acticoat) with Iodine based (Iodosorb)

Dakin’s solution 0.025 BID (for uncomplicated wounds)

Antibiotics

For more information connect to the center for biofilm engineering at Montana State University www.erc.montana.edu/

Twitter and Wound Clinics a Unique Combination

Take a look at my article in Today’s Wound Clinic on how Twitter can help your Wound Clinic communicate more effectively. http://www.todayswoundclinic.com/twitter