Edema

The edema ( from Ancient Greek οἴδημα, oídēma, " swelling " ) or the " dropsy " is a swelling of the tissue due to an accumulation of fluid from the vascular system.

Is a balance between on the one hand, and filtration, as well as lymph absorption shifted towards the other hand, the filtration is increased as the liquid in the tissue. The result is an accumulation of water in the interstitium: edema.

Formation

Edema are usually the result of an underlying condition, ie in the strict sense, a symptom, for example, in a cardiac or renal disease or cirrhosis. Venous drainage disorders can lead to localized edema, a leg vein thrombosis, for example, can lead to a swelling of the affected leg. If the fluid is not discharged in the tissue sufficiently aware of the lymphatics, it is called this lymphedema. Furthermore, it comes to edema, when the concentration of blood proteins ( albumins ) decreases ( hypoalbuminemia ). This happens for example when famine edema (insufficient protein intake ) and in nephrotic syndrome, which is characterized by high protein loss through the kidneys. The liquid emerging here is low in protein and transudate is called.

By inflammatory or allergic processes may lead to an increased permeability of the capillaries. The case into the tissue escaping liquid is rich in protein and exudate is called.

Even drugs (eg cortisone, antidepressants or calcium antagonists) may contribute to Ödementstehung. Edema can also be caused hormonally.

Another cause is a long-lasting impact of exclusive sitting or standing ( orthostatic edema), especially if this reduced movement ( Inaktivitätsödem ) and the tissue water can not be taken away by the muscle pump. This is mainly in older age is a common phenomenon: for example, one side in the paralyzed leg after stroke, but also often in a wheelchair due to lack of regular movement of the legs.

In rare cases, infection can cause edema B19 parvovirus.

Pathophysiology

Two basic steps are prerequisite to the formation of edema:

• A change in the fluid mechanics of blood in the capillaries, which favors the passage of liquid from the vessel into the surrounding tissue ( interstitium ).
• The retention ( decreased excretion ) of sodium and water by the kidneys. Apart from local edema edema is only visible if at least 2.5 are converted to 3 l liquid into the tissue. Since the plasma volume is usually around 3.5 l, edema would lead to hypovolemia shock when the lost fluid would not be replaced.

The loss of fluid into the tissue results in a decreased filling of the arterial system which, however, contains only about 15% of total blood volume. The total blood volume may therefore be increased in edema certainly if it only the venous blood volume is affected. Also, a decreased cardiac output, such as in heart failure, or a dilation of blood vessels ( vasodilation ), such as in cirrhosis of the liver or during pregnancy can lead to decreased filling of the arterial vascular system. This is of arterial stretch receptors in renal, aortic arch and carotid artery ( carotid artery ) registered. The result is activation of the renin -angiotensin -aldosterone system in the kidney, stimulation of the sympathetic nervous system and the release of vasopressin in the hypothalamus. Ultimately, this leads to increased reabsorption in the renal tubules of water and sodium.

In the case of heart failure, although it comes in overfilling of the venous system, which is registered by stretch receptors in the left atrium, resulting in the release of atrial natriuretic peptide and thus actually to increased sodium and water excretion. The activation of the arterial stretch receptors predominate but so that, in effect, sodium and water are stored.

Diagnosis

Anamnesis (case history )

The compilation of the medical history (anamnesis) is asked to pre-existing conditions (eg, coronary heart disease, hypertension, alcohol abuse ), and drugs that can lead to heart, kidney or liver disease.

The localization of water retention are more information: When shortness of breath may be a pulmonary edema in case of failure of the left ventricle before. Water retention in the abdomen ( ascites) indicate a liver disease. Swelling of the legs can be caused by failure of the right ventricle, chronic renal failure, venous disease or lymphatic drainage.

Also important is the temporal course: In women, it can come as part of the menstrual cycle to periodic water retention. However, this should not be treated with diuretics, as the symptoms were rather worse by the treatment.

Physical examination

When pulmonary edema can be heard moist rales when listening with a stethoscope ( auscultation ). For reliable diagnosis, lung x-ray recording is required, as other pulmonary diseases such as pulmonary embolism may cause similar symptoms. Swelling of the body may indicate fluid retention in the abdominal cavity ( ascites) in liver cirrhosis, nephrotic syndrome, or right heart failure. When tapping is a muffled knocking sound heard, may interfere with a fluid wave are triggered when tapping the abdominal wall. The diagnosis can be confirmed by an ultrasound scan. Water retention in the abdominal wall and flanks ( anasarca ) may occur in severe heart failure or advanced renal failure. The push- swelling of the legs indicate venous drainage disorders, heart failure or kidney disease, a unilateral swelling of the leg speaks for venous disease. Non crushable swelling of the legs can be found, however, in lymphatic drainage and myxedema due to an underactive thyroid. Swelling of the eyelids may indicate protein loss through the kidneys.

Laboratory diagnostics

An increase of creatinine in serum indicates a kidney disease. If the protein excretion in the urine than 2.5 g per day, is most likely in front of a nephrotic syndrome.

Therapy

Is treated, depending on the cause. Cardiac, renal and hepatic edema are flushed with diuretics. Mostly, oral administration is sufficient only for Resorptionsproblemen or in an emergency ( pulmonary edema) with intravenous infusion is preferred. In this case, a reduction in weight should not be more than 1-1.5 kg. In the absence of excretion in renal failure the fluid balance must be controlled by dialysis. Lymphedema can be treated with physical therapy and a lymphatic drainage or vacuum therapy, edema due to protein deficiency by substitution. Allergic processes are treated symptomatically with antihistamines and cortisone.

Special forms of edema

• Angioedema
• Blutstauungsödem
• Dorsonuchales edema
• Hereditary Angioedema (HAE )
• Cerebral edema
• Altitude cerebral edema ( HACE ), high altitude pulmonary edema ( HAPE )
• Famine edema or Eiweißmangelödem
• Hydrops fetalis
• Hygroma colli
• Imbibition
• Bone edema
• Nuchal translucency
• Nasopharynxödem
• Laryngeal edema
• Pulmonary edema
• Lymphedema
• Myxedema
• Macular edema
• Penile edema
• Perifocal edema
• Reinke 's edema
• Angioneurotic edema
• Schwangerschaftsödem
• Lipoedema
• Lipolymphödem