Leg Ulcer Management Flashcards
What is meant by chronic venous insufficiency?
Chronic venous insufficiency can be split into three groups, many patients will have more than one of these issues.
1) Chronic venous hypertension.
2) Superficial vein incompetence.
3) Perforating vein incompetence.
Your first year student asks how a venous leg ulcer is formed. Explain the pathophysiology.
Chronic venous hypertension or vein incompetence is the starting point.
This leads to outflow obstuction caused by venous valve deterioration, calf pump impairment.
The obstruction and lack of return flow leads to a hostile biochemical microenvironment.
Left untreated, the fluid begins to move from the vascular space to the interstitial space creating oedema in the leg.
The capillary bed is stretched with the pressure and this allows fibrin to escpate into the interstitial space where it doesn’t normally go. This creates a fibrin mesh and we can see a cuff begin to form as this hardens.
The fibrin mesh traps white blood cells and growth factors, preventing healing and causing tissue death.
Any further break to the poorly perfused skin creates a wound that is unable to heal. We call this a venous leg ulcer.
What are the three types of vein found in the body?
Superficial - on the surface (low pressure)
Deep - inside the calf muscle
Perforating - connects superficial veins to the deep veins.
How does blood fight gravity to be pumped out of the legs back to the heart? And why is this relevant to all of our patients?
Veins have valves which helps to prevent backflow as the calf muscle helps to adjust the pressure between the superficial and deep veins with every contraction.
Walking works this calf muscle pump and helps to create venous return. Patients who are immobile or not mobilising are at high risk of venous insufficiency due to not activating their calf muscle pump.
Risk factors for Venous insufficiency can be split into a) venous valve incompetence and b) impaired calf muscle pump categories.
Give two examples of each category.
a) Venous valve incompetence
DVT, Trauma, Venous hypertension, heriditary, obesity, pregnancy, smoking, phlebitis.
b) Impaired Calf muscle pump
Trauma, Age, muscle wastage, bed bound, immobility, standing too long.
What are the early stage treatment options for venous insufficiency?
Lifestyle changes, leg elevation, increased activity, compression stockings.
TED stockings are used to prevent DVTs in hospital and long haul flights, how do they work?
TED stockings are deliberately tight, and as such they emphasize the effectiveness of the calf muscle pump.
By doing so they increase venous return from the legs, preventing pooling during periods of relative inactivity.
Less pooling is good for venous leg insufficiency, and reduces opportunites for blood that has become static to coagulate.
Hydrostatic pressure moves fluid from the vascular space to the interstitial space. What is the name of the process which brings it back?
Osmosis
Oedema is a normal process where fluid moves across the capillaries from the vascular space to the interstitial space.
Odema can become problematic when the fluid cannot move back.
What is happening that would prevent the fluid from returning to the vascular space?
The increased hydrostatic pressure of someone with venous insufficiency means that the process of osmosis is not strong enough to fight against this pressure.
The pressure builds until the capillary bed is stretched which further increases the flow of fluid into the interstitial space where it begins to pool.
This is oedamtus as we would see in our patients.
Rory has oedamatus in both of his legs.
What condition might this suggest Rory has?
Why does this lead to oedema in his legs?
What medication might help both the condition and his oedema?
Rory might have heart failure if the oedema has built up in both legs.
Heart failure reduces cardiac output and blood begins to get backed up in the venous system. Unable to circulate, it simply starts pooling in available space, creating hydrostatic pressure in the legs which causes fluid to leak into the tissue. Additionally, patients with heart failure are quite breathless on exertion, so their normal calf pump isn’t used as often.
Diuretics will help to emphasise the excretion of urine and offload the excess fluid. This will reduce the oedema and reduce the workload of the heart, easing the symptoms of heart failure.
When the capillaries are stretched beyond their limit, the gaps become big enough for red blood cells to move into the interstitial space. They have no where to go and quickly die, leaving the pigmentation of Hb to stain the surrounding skin.
What is this phenomenon known as?
Haemosiderin staining.
What is the phsyiology behind the pain of a venous leg ulcer, even where the skin has not yet broken?
The build up of oedema stops the skin from being perfused.
This hypoxia leads to a change in the metabolic pathway, a by-product of which is lactate and CO2.
This triggers the nociceptors of the surrounding nerves and the signal is transmitted to the brain where it is perceived as pain.
Paula reports moderate pain in her leg which is known to have a venous leg ulcer.
Apart from analgesia, what other strategies would you recommend to help relieve the pain?
Elevate the legs to improve venous blood flow.
Rest to reduce oxygen demand of the leg muscles.
Cold packs to induce vasoconstriction which will reduce swelling to area.
Kieran attends an appointment with the general practice nurse to discuss a wound that he has had for a few weeks.
He reports that the pain is much worse when he moves around and that the only relief he gets is when he elevates it on the sofa.
What might Kieran have, and what assessments would you carry out to identify any significant risks and aid your diagnosis?
Possibly a venous leg ulcer as the wound hasn’t healed in over 2 weeks and the pain is better when the leg is elevated.
Risks
DVT -
Arterial insufficiency - assessed with Ankle-Brachial Pressure Index (ABPI)
Sepsis - Check for signs of infection (heat, redness, swelling, pain). Swabs of wound if necessary, as well as bloods to identify infection.
Peripheral Arterial disease affects arteries outside of the heart.
True or false?
True.
If vessels inside the heart are affected this is coronary artery disease.
