Oedema

Oedema is a accumulation of liquid in the interstitial tissues (both extravascular and extracellular) and is the consequence of an increase production and or decrease removal of interstitial fluid

Homeostasis is the physiological equilibrium at microcirculation level (tissue and vascular micro circulation).

Large protein molecules, which filter through the capillary membrane, are returned to the systemic circulation by the lymphatic drainage system.

The lymphatic system is the most important drainage route for particulate matter from the interstitial space.

Decrease in the rate of removal of interstitial proteins is the most important abnormality in lymphoedema.

Chronic venous dysfunction itself reduces lymphatic function by compression of distal lymphatic drainage system, through oedema.

In summary, venous and lymphatic function are closely linked.

Because of malfunction in the drainage systems, proteins remain in the interstitial space and their oncotic pressure gradient promotes water retention that becomes clinically evident as oedema.

Oedema

1. Increase in Fluid in the interstitial tissues (Low Protein Oedemas)
   1. Increase in Hydrostatic pressure

                                          i.        Superficial, Deep Venous insufficiency either primary or secondary

                                         ii.        Right Ventricular Failure

                                        iii.        Electrolyte imbalance

2. Decrease in colloidal osmotic pressure

                                          i.        Hepatic disease

                                         ii.        Protein losing enteropathies

                                        iii.        Nephrotic syndrome

                                       iv.        Malabsorption

                                        v.        Starvation (kwashiorkor)

3. Changes in capillary wall

                                          i.        Inflammation

                                         ii.        Allergies

2. Deficiency in Lymphatic Drainage (High Protein Oedemas)

1. Primary Lymphoedema

                                          i.        Congenital Lymphoedema (agenesis or hypogenesis)

1.    Genetic and hereditary (Milroy’s)

                                         ii.        Lymphoedema praecox (hypogenesis)

1.    Begins at puberty and may be triggered of by trauma, wounds, infections or allergies

2.    Initially mainly unilateral but 50 % develop bilateral disease

                                        iii.        Lymphoedema Tarda (late onset)

1.    After age of 30

2.  Secondary Lymphoedema

                                          i.        Obstruction to the lymphatic tracts

1.    Extrinsic

a.    Tumour

b.    Fibrosis of lymphatic walls

2.    Intrinsic

a.    Infection (Lymphangitis)

b.    Parasites (Filariasis)

                                         ii.        Damage to lymphatic ducts or lymph nodes

1.    Surgery

2.    Radiotherapy

3.    Trauma

Diagnosis

Lymphoedema is a clinical diagnosis based on history examination and can be confirmed with imaging techniques

History

• Family history
• Trauma to that affected area
• Surgical operations /Radiotherapy
• Previous infections, malignancies

History of presenting illness

• When and where it first originated, better overnight
• Positive or negative response to various treatments
  • Varicose Vein surgery
  • Diuretics
  • Compression Treatment

Examination

• General Exam
  • CVS   signs of cardiac dysfunction, JVP
  • Hepatic Abdo exam LFTs
  • Renal   UA creatinine
• Musculoskeletal
  •  Exam check functional problems
• Local
  • Site
  • Extent, colour (white --- lymphatic)
  • Consistency   typically rubbery and non pitting
  • Temp (typically cool)
  • Ache is usually absent in slow onset lymphoedema
  • Signs of CVD
  • Stemmer test   positive (inability to pinch the skin of the second toe between first two fingers)

Investigations

1.    Colour Compression Ultrasound  (exclude venous pathology, show oedema and may show lymphadenopathy

2.    Radionucleotide lymphscintigraphy (non invasive)

3.    CT scan

4.    MRI

Complications

·         Uncontrolled progression lead to thickening and hyperkeratosis of the skin

·         Cellulitis/lymphangitis (Beta haemolytic streptococcus)

·         Lymphangiosarcoma

Control and Treatment

• Continuous aggressive control of oedema
• Prevention and aggressive active treatment
• If treatment is commenced fibrosis satisfactory results can be achieved

Physical Treatment

• Skin Care
  • To prevent infections
  • Treat fungal infections
• Manual lymphatic drainage 
  • Specialized physiotherapy
• Compression Therapy

• Bandages 

 When an elastic pressure bandage is applied to relaxed muscle, the pressure it exerts on underlying tissues is known as the Resting pressure

This depends on

1.    The Elasticity of the Bandage

• Low elastic (30% to 70% of their original length) continuous

                                    High working pressure and low resting pressure

• High elastic (stretch more than 140% of their length) removable
• Medium stretch (70%to 140%)

2.    The Tightness with which in is applied

3.    The Number of layers applied

a.    Spiral bandage or figure of eight

·         Elastic Stockings

·         Increase in interstitial pressure favours resorption of fluid and to a lesser extent proteins by blood and lymphatic systems.

·         Reduction in limb blood volume as a result of the decrease in size of the deep and superficial veins which leads to a faster venous flow

·         Improving valvular incompetence and venous reflux

·         Fibrinolytic and analgesic affect (release of endothelial chemical mediators)

·         Increase in lymphatic flow

·         Protects skin from damage

·         Pneumatic sequential compression

·         Drugs

·         Surgical   lymphovenous anastomosis

Prognosis

Untreated Lymphoedema progresses to severe disability and disfigurement.

Most benefit will be made by early, aggressive intervention. There is no proven role for surgery