Presentation on theme: "Which area of sterile protective clothing is not considered sterile even before coming in contact with a nonsterile object? a. front of gown above waist."— Presentation transcript:
Which area of sterile protective clothing is not considered sterile even before coming in contact with a nonsterile object? a. front of gown above waist level b. front of gown below waist level c. sleeves d. gloves
Arterial, Venous (and Lymphatic) Systems Their Significance in Chronic Lower Extremity Wounds
Pain occurring when an extremity is elevated indicates: A.Arterial disease B.Venous disease C.Lymphatic disease
When describing the benefits of your exercise program to your patient (to educate and also to improve compliance), you tell her that regeneration of the affected part of her circulatory system is possible. Which part of the circulatory system would have been impaired for this to be true?
A.Arterial system B.Venous system C.Lymphatic system
The arterial system contains what percentage of total body blood volume? A.30% B.50% C.90%
The venous system is: A.Low volume, low pressure B.High volume, low pressure C.Low volume, high pressure D.High volume, high pressure
“...it is best to think of a wound not as a disease, but rather as a manifestation of disease.” Joe McCulloch
In order to manage wounds effectively, it is essential to appreciate the underlying cause.
Part I A Brief Review of Structure and Function of Vascular Structures
Overview of 3 Circulatory Systems Arterial Venous Lymphatic
Common Vessel Wall Layers or Coats (Tunics) Tunica intima - endothelial cells and basement membrane; uniformly smooth in all structures; (inner) Tunica media - smooth muscle and elastic tissue (middle) Tunica adventitia – collagen fibers plus blood vessels & nerves (outer)
Variations in Vessel Walls The common theme of the three layers varies widely, depending on type, size, and location of the artery, vein, or lymph vessel.
Arterial System Conveys oxygenated blood to tissues Responds to sympathetic and humoral stimuli that maintain blood pressure Shunts blood from nonworking to working organs Contains 30% of blood volume
Artery Characteristics Aorta to arteriole Media: thick layers of muscular and elastic tissue Diameter responds to left ventricular pressure Lie on flexor side of major joints
Arterial Pressure -normal systolic pressure< 140 mm Hg -arterial capillary pressure 25 mm Hg -high pressure/low volume system
Arteries of the Anterior Leg
Arteries of the Posterior Leg
Venous System Removes interstitial fluid from tissues Returns deoxygenated blood to right atrium Contains 70% of blood volume
Vein Characteristics Large, medium, and small Superficial, deep, and perforating veins Valves in medium and large veins formed by folds in intima Two large, major veins usually accompany each major artery on flexor side of joints
Venous Pressure - wide variation (10-90 mm Hg) - low pressure/high volume - blood conveyed back to heart by: muscle pump respiratory “pump” (vacuum?) valves
? Questions ? What 3 “factors” return venous blood to the heart? Bonus: What is one more factor not included in this program? What forms venous valves?
Superficial Veins, Posterior Leg
Superficial Veins, Anterior Leg
Lymphatic System removes interstitial fluid and large cells that cannot pass into capillary or venule has immunologic and phagocytic functions controls tone of precapillary arterioles
Characteristics of Lymphatics Very thin walls Many semilunar, paired valves in larger vessels No major direct link to artery or vein except the thoracic and right lymphatic ducts
Pressures in Lymphatics Very low pressure Lymph moved centrally by valves*, negative pressure in chest, muscle pump (like veins) *Lymphangion: lymph vessel segments with valves at either end—a “lymph pump”
Capillary Bed -capillaries allow diffusion of O 2 and nutrients to tissues, AND -CO 2 and other waste products diffuse out of tissues, WHILE - Open-ended lymphatics move comparatively small amounts of fluid from the capillary bed, but handle large cells
Review: Equilibrium at the Capillary Bed Adequate Arterial Supply Functional Venous Return Structures Patent Lymphatic Structures Normal Interstitial “Space”
Part II Vascular Diseases Producing Wounds in the Lower Extremity
Classifications of Wounds in Lower Extremity Arterial Venous Mixed
Basis for Wounds of Arterial Origin Arteriosclerosis – “hardening of arteries” -calcification of arteries of all sizes - loss of elasticity of arterial walls Atherosclerosis – fibrous “plaque” - thickening of inner coat (intima) - fatty degeneration of middle layer (media)
Events Producing Wounds of Arterial Origin Diminished arterial flow Thrombus or microembolus formation Blockage - most often at bifurcations Tissue hypoxia and cell death
Arterial Diseases associated with Wound Development Arteriosclerosis obliterans Other Examples - Diabetes - Vasculitis (RA) -Sickle Cell Disease Thromboangiitis obliterans*
Arteriosclerosis obliterans Disease of large and medium sized arteries Associated with: –High blood pressure –Hyperlipidemia –Arterial occlusion particularly at bifurcations
Necrosis of Toe in Arteriosclerosis obliterans
Heel Ulcer in Arteriosclerosis Obliterans
Other Examples: Arterial Diabetes – hyperglycemia—”sticky blood” adds to development of atherosclerosis Vasculitis – inflammation blocks blood flow Sickle Cell Disease – clumps of misshapen red cells occlude small arteries
Thromboangiitis obliterans Also called Buerger’s Disease Affects adults under age 40 *Veins also involved Unlike arteriosclerosis obliterans, may affect hands Primary cause: cigarette smoking!
Thromboangiitis obliterans - early
Thromboangiitis obliterans - late
Noninvasive Tests of Arterial Sufficiency Doppler ultrasound Skin temperature Arterial perfusion –Pulses # –Capillary refill test # –Venous filling time # –Rubor of dependency #
Rubor of Dependency in Arteriosclerosis obliterans
Etiology of Venous Stasis Wounds Old theory: venous congestion (1917) insufficient oxygenation of tissues WRONG !!! Tissues have been shown to be adequately oxygenated.
Etiology of Venous Stasis Wounds, continued Arteriovenous fistula theory (1947) Fibrin cuff theory (1982) Leukocyte activation (1988) ALL mostly discredited as causes of ulcers...
Question ??? True or False Your patient was once told that the reason she developed ulcers at the ankles was that the swelling in her legs prevented adequate oxygen from reaching the tissues. How would you respond?
Present Theory of Etiology of Venous Stasis Wounds High pressure causes extravasation of macromolecules (e.g. fibrinogen) and red blood cells into dermal interstitium. Degradation of these molecules and cells attracts leukocytes, macrophages, mast cells (inflammation). Inflammation leads to tissue injury (breakdown) and wound development.
Venous Stasis Ulcer
Importance of the “Calf Pump” Normal Edema Present
Appearance of Limb in Venous Insufficiency (Early) Stasis dermatitis Erythema weeping blebs or vesicles edema
Stasis Dermatitis - Early
Appearance of Limb in Venous Insufficiency (Late) Induration of subcutaneous tissue Brawny (brownish) discoloration: “Hemosiderin” iron-containing pigment Edema Ulceration usually around medial malleolus
Stasis Dermatitis (Late)
Questions... 1.Your venous stasis wound patient asks specifically: a.why she developed varicose veins b. why her lower calf is discolored. You would explain that...
Noninvasive Tests of Venous Sufficiency Doppler ultrasound Plethysmography Percussion test # Brodie-Trendelenburg test # Venous filling time #
Venous Filling Time
Tests for Deep Venous Thrombosis (DVT) - cuff test # - test for Homan’s sign #
Combined Pathologies Arterial and venous disease may coexist Venous disease can contribute to lymphatic dysfunction, and vice-versa
How is Lymphedema different from Edema? Edema: tissue fluid accumulated in the interstitial spaces secondary to many causes Lymphedema: protein rich fluid that accumulates in the tissue secondary to lymphatic blockage
Lymphedema itself not usually associated with wounds A complete discussion of lymphedema will be addressed in the oncology section of this course.
Combined Pathologies Thorough examination Teamwork Patient education General rule: treat most threatening aspect first (usually arterial insufficiency)