Post-ischemic syndrome

The post-ischemic syndrome is a complex of symptoms that arise as a result of long-term circulatory disorders. Depending on the location and size of the affected area, post-ischemia syndrome can be life-threatening.

What is Post-Ischemic Syndrome?

Ischemia is an abnormally reduced or even abolished blood flow to a tissue. In the case of relative ischemia, a blood flow can still be detected; in the case of absolute ischemia, there is no longer any arterial blood flow. Tissues with a high need for oxygen, such as the brain, usually only tolerate short-term shortages of insufficient supplies.

Even a short interruption of blood flow of a few minutes can lead to serious and irreversible damage. The symptoms of post-ischemia syndrome, however, are not caused directly by the lack of or absent blood flow, but rather arise from the restored blood flow after the cause of the ischemia has been eliminated.

This process is also known as reperfusion injury. Since at first glance it seems quite contradicting that a resuming blood flow causes more damage than the lack of blood flow, one speaks at post-ischemia syndrome also from one Reperfusion paradox.

causes

A post-ischemia syndrome can develop after a shutter speed of five hours. The causes of ischemia are very diverse. Vascular occlusions through blood clots (thrombosis) or through deposits on the vessel walls (arteriosclerosis) are conceivable. A disease that is characterized by progressive occlusion of the vessels in the arms and legs is peripheral arterial occlusive disease, or PAD for short.

In most cases, PAD is based on arteriosclerosis. Smokers are particularly at risk of developing PAD. Rheumatic diseases such as endangiitis obliterans or collagenoses can also lead to an obstruction of blood vessels and thus result in ischemia. The same applies to diseases of the blood that are associated with an increased number of cells. The changed viscosity of the blood leads to vessel occlusions more quickly.

Examples of such hematological diseases are polycythemia vera or essential thrombocythemia. Of course, ischemia can also result from external blockages, for example from ligating or constricting an extremity. The compartment syndrome can develop primarily through blunt trauma, i.e. trauma that does not cause open wounds. The tissue pressure rises due to the trauma, so that the arterial blood flow is interrupted.

Other typical causes of post-ischemia syndrome are Leriche syndrome and paraphimoses. In paraphimosis, a narrowed foreskin clamps the glans of the penis and cannot be pulled back again.

Diseases with this symptom

• thrombosis
• Polycythemia vera
• Compartment syndrome

• arteriosclerosis
• Thrombangiitis obliterans
• Leriche Syndrome

• Peripheral arterial disease
• Collagenosis
• Paraphimosis

Diagnosis & course

During ischemia, more and more potentially toxic substances such as myoglobin, lactate and potassium are formed and accumulated in the affected areas of the body. If the tissue is supplied with blood again after ischemic, these substances are flushed out of the tissue and distributed in the body. The potassium causes hyperkalemia, which means that the serum potassium level is above 5.2 mmol / l.

In addition to symptoms such as muscle weakness and abnormal sensations in the extremities, hyperkalemia can also cause severe cardiac arrhythmias. These can lead to ventricular fibrillation and asystole, i.e. cardiovascular arrest. The increased attack of myoglobin can result in a crushed kidney with the complication of absolute kidney failure. The high lactate levels in the blood also cause metabolic acidosis. The pH of the blood drops below 7.36. This situation is life threatening.

Because of the ischemia, the vessel walls in the affected area are particularly permeable. One speaks of an increased vascular permeability. If blood now flows through these vessels again, liquid emerges from the vessels and flows into the tissue. This creates edema. Depending on the size of the ischemic area, the loss of fluid into the tissue can cause hypovolemic shock. In the first stage, this only manifests itself through damp, cool and pale skin.

In the second stage, the systolic blood pressure falls, the pulse rises. Patients complain of thirst. Hardly or no more urine is produced and excreted. In the third stage, blood pressure drops below 60 mmHg. The pulse is barely palpable. Disturbances in consciousness occur and ultimately death.

In addition, the edema compresses the blood-supplied vessels again, so that ischemia can occur again. This is the beginning of a vicious circle.

Complications

Post-ischemic syndrome (tourniquet syndrome) usually results from an atherosclerotic process. A vessel is closed and the subsequent tissue of the vascular occlusion is no longer adequately supplied with blood, resulting in ischemia. This ischemia can be endured for a long time without complications, but after a certain time, usually five to six hours, the tissue dies and necrosis develops.

The cells die and various substances such as lactate, potassium and myoglobin are released. Too much potassium in the blood (hyperkalaemia) can cause dangerous arrhythmias, such as ventricular fibrillation, which, if left untreated, can quickly lead to cardiac death. In addition, the release of the substances can cause a so-called crush kidney, which can lead to kidney failure (renal insufficiency).

In addition, a metabolic acidosis develops, which can also lead to cardiac arrhythmias and can lead to unconsciousness. The ischemia makes the vessels more permeable. If the area is released again, there may be increased leakage and painful edema, which can become inflamed.

In addition, so much fluid can escape that there is a lack of volume in the circulatory system and a reduced blood pressure in the sense of shock can result. In addition, the edema can compress vessels that supply various muscle groups. This leads to an insufficient supply of the muscles and to the compartment syndrome, which can lead to the death of the muscles.

When should you go to the doctor?

A doctor should be consulted immediately if post-ischemic syndrome is suspected. If left untreated, circulatory disorders develop into life-threatening symptoms that can lead to further complications. A visit to the doctor is recommended at the latest when there is kidney pain or a stinging in the heart area. In general, pain in the internal organs and warm extremities indicate a circulatory disorder which, if left untreated, can develop into post-ischemic syndrome.

Patients who already suffer from a heart or kidney disease should speak to their doctor as soon as possible if they suspect a circulatory disorder. Typical symptoms of impaired blood circulation include visual disturbances, confusion, disorientation and pain when walking. In addition, there are tightnesses in the chest, which predominantly occur during physical exertion, and temporary numbness in the arms and legs. If one or more of these symptoms occur, a visit to the doctor is recommended. Usually the blood circulation can be regulated again by simple measures and a post-ischemia syndrome can be averted.

Doctors & therapists in your area

Treatment & Therapy

Post-ischemia syndrome is a life-threatening condition that requires intensive medical care. The potassium level is checked at regular intervals, and blood gas analyzes are carried out to check the pH value. Fluid is substituted to prevent hypovolemic shock. The formation of edema and the burden on the kidneys from myoglobin are prevented with diuretics.

If there is metabolic acidosis, therapy is carried out with sodium bicarbonate buffering. Diuretics are also given to treat hyperkalemia. In addition, so-called cation exchangers are administered. Insulin, glucose, sympathomimetics and sodium bicarbonate are used to ensure that the potassium is transferred from the blood to the cells.

Of course, with post-ischemia syndrome, the cause should always be completely eliminated. In the case of strangulations it is sufficient to remove them. In the case of paraphimosis, the foreskin must be repositioned or removed if necessary. Embolisms are treated with lysis therapy. Amputation may be required in severe post-ischemic syndrome.

Outlook & forecast

Post-ischemia syndrome is a life-threatening condition that needs medical treatment as soon as possible. A lot of blood tests are done to check the pH level. If post-ischemic syndrome is discovered quickly based on the symptoms, the chances of recovery are very good.

Fluid is substituted to avoid hypovolemic shock. If the post-ischemic syndrome is too advanced, an amputation is required. Under no circumstances should the affected patient wait. Waiting too long will make the blockages even bigger. The blood flow can then no longer take place properly and the patient has to reckon with even more complications. Heart attacks are not infrequently the result of waiting too long in post-ischemic syndrome.

prevention

Post-ischemia syndrome can only be prevented to a limited extent. If there are indications of an underperformance of any kind, a doctor should be consulted as soon as possible. This is the only way to prevent long-term ischemia and, as a result, the post-ischemia syndrome.

You can do that yourself

An emergency doctor must always be consulted with post-ischemic syndrome. As already mentioned, it is a life-threatening condition after a long-term circulatory disorder. Without emergency medical treatment, the affected part of the body initially dies.

The organism is in great danger due to the distribution of toxic metabolic products throughout the body. For these reasons, self-medication is not possible. Attempts at self-help are urgently to be refrained from with this illness, because any delay in professional medical treatment is counterproductive. The necrosis of the tissue releases lactate, myoglobin and potassium. These substances accumulate in the blood and lead to cardiac arrhythmias, kidney failure and acidification of the organism. Your values ​​must be constantly monitored and balanced by intensive care medicine. That can only be done in the intensive care unit of a hospital.

After successful treatment of the vascular occlusion, the underlying disease must be treated. Depending on the disease, self-medication can sometimes take place here, but this must be discussed with the doctor. For example, long-term drug treatment with blood-thinning agents may be necessary to prevent the formation of thrombi. Constant medical checks are also important. The patient can also prevent vascular occlusion through a balanced diet, plenty of exercise and refraining from smoking and alcohol.