Edema Management Flashcards
(38 cards)
What is edema?
- A condition characterized by an excess of watery fluid collecting in the cavities or tissues of the body
- A natural response following an acute injury as it is part of the inflammatory phase of wound healing
What can edema cause?
- Swelling
- Pain
- Loss of motion and function
- Compression on nerves and blood vessels and tendons may result in stiffness. If edema is chronic it can result in fibrosis
- Increased scarring of the skin if there was a laceration injury/open wound
What is fibrosis?
- The thickening of connective tissue, usually a result of injury. It is different than scar tissue. It is physical, mechanical change of the soft tissues that affect all tissues including: blood vessels, lymphatics, muscles, ligaments, tendon, and skin
What are causes of edema?
- Trauma
- Infection
- Venous insufficiency
- Cancer
- Lymphatic dysfunction
- Arterial occlusion: cool pale, in this case in the LE
- Venous obstruction: blush with decrease in temperature. The extremity needs to be elevated
- Metabolic imbalance: salt intake, hypothyroidism, diabetes
- Poor circulation/immobility
- Pressure in an area or BP or too much compression in an area
What is the physiology of edema?
- Body fluid regulation between interstitial fluid (IF) and blood plasma
- Arterial system brings oxygen and nutrients to the cells
- Venous system removes waste and carbon dioxide (CO2)
- Lymphatic system removes waste in the form of plasma proteins from interstitial fluid. It takes out the big molecules of trash in forms of plasma proteins
What is the role of histamine?
- It is part of an immune response to foreign pathogens
- Found in nearby connective tissues
- There is vasodilation and a fall in BP
- Increases the permeability of capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues - it essentially opens the gates
- Increased vascular permeability causes fluid to escape from capillaries into the tissues, which leads to the classic symptoms of an allergic reaction: a runny nose and watery eyes
- High amounts of histamine can increase edema
- Foods can increase histamine
What are the key points of edema physiology?
- There is a constant fluid exchange between tissue and plasma across the capillary membrane
- Fluid enters and exits through gates along the capillary wall
- The molecules that make up this fluid vary in size
- For this reason fluid in the tissue can vary in consistency from thick to thin
- Protein molecules are large and have difficulty getting through the capillary gate
What two forces determine whether water stays as part of the blood in a blood vessel or if water leaves to become part of the interstitial fluid?
- Hydrostatic pressure
- Osmotic pressure
What is capillary hydrostatic pressure?
- The force that is exerted by a fluid against the capillary wall
- Helps in the movement of fluid between capillaries and the interstitial fluid. It is created by the pumping action of the heart
- The capillary wall is semipermeable and fluid will leak out at a rate depending on the pressure of flow
- When pressure inside is higher than outside, the BP forces fluid out of the capillaries
- ## The highest capillary hydrostatic pressure is observed at the arteriolar end of the capillary and the lowest pressure is observed at the venous end
What is osmotic pressure?
- The minimum pressure applied to a solution to prevent the inward flow of water across a semipermeable membrane
- Also defined as the measure of the tendency of a solution to take in water by osmosis
Is blood slightly more hypertonic or hypotonic compared to interstitial fluid?
- Hypertonic and tends to keep water inside the blood vessel
Do osmotic pressure and hydrostatic pressure work together or against one another?
- They work against one another
- Blood pressure is forcing water out and osmotic pressure forces are trying to keep blood in
- The two forces do not cancel one another out. Hydrostatic pressure wins because it is slightly stronger than osmotic pressure
What is the capillary hydrostatic pressure at the arterial end and the venous end?
- Arterial end: 35 mm Hg
- Venous end: 15 mm Hg
How is the capillary filtration rate calculated?
- Capillary hydrostatic pressure minus osmotic pressure
- The rate depends on which end of the capillary and the BP
What happens if capillary hydrostatic pressure is greater than osmotic pressure?
- Fluid leaves the capillary
What happens if capillary hydrostatic pressure is less than osmotic pressure?
- Fluid enters the capillary
Why is physiology important to therapy?
- Because therapists use pressure to push fluid into the capillaries
What should a therapist remember when using pressure garments and performing various edema massage?
- Therapists must know the amount of pressure to provide
- For the purpose of reducing edema, garments should apply between 25 and 35 mm Hg of pressure but no more than 35 mm Hg in the UE and 30 to 40 mm Hg in the LE. Otherwise, the system will shut down and swelling will increase
- Compression garments for burns should be less (17-24 mm Hg)
- Damage to the lymphatic system occurs at 70 mm Hg
What are the different types of edema?
- Normal acute edema
- Pitted edema
- Brawny edema
- Lymphadema
What is normal acute edema?
- Response to injury
- Expected as part of the inflammatory stage of wound healing
- Necessary to clean up the area of trauma
What is the viscosity of normal acute edema?
- Thin and can be mobilized
- Responds to elevation
- Responds to retrograde massage
- Responds to compression garments
What is the viscosity of pitted edema?
- Thick and harder to mobilize
- Pitted edema can be displaced with pressure but leaves an indentation
- Pitted can advance to brawny
- Can be caused by diabetes
What is the viscosity of brawny edema?
- Firm to touch, fluid does not move freely, hard
- There are more plasma proteins in pitted and brawny edema which makes the viscosity thicker
What is lymphedema?
- A result of a compromised lymphatic system
- Can be either congenital/genetic or the result of cancer treatments or cancer in general
- Can also result from excision of lymph nodes, parasite infection, or hypothyroidism
- People with lymphedema are more susceptible to infections because the system is already under stress