Tourniquet syndrome is a life-threatening complication that can occur after reperfusion of a body part that has previously been ligated for an extended period of time. It can include shock, cardiac arrhythmias, and irreversible renal damage.
What is tourniquet syndrome?
Tourniquet syndrome is also called reperfusion trauma. It occurs when a part of the body that has had inferior blood flow or no blood flow at all for several hours is reconnected to the systemic circulation. The tolerance time during which ischemia (reduced blood flow) can persist without subsequently causing tourniquet syndrome averages about 6 hours. However, the exact tolerance time varies greatly from individual to individual. Tourniquet syndrome gets its name from tourniquet ligation, a surgical device formerly used to tie off large vascular trunks.
Causes
Tourniquet syndrome seems paradoxical at first: The layperson intuitively thinks that the restored blood flow to a previously undersupplied part of the body is not threatening but saving. The problem is that prolonged ischemia in the ligated limb throws the metabolism out of balance. Reperfusion causes pathologic metabolites to be flushed into the rest of the organism, where they can cause damage. In particular, hyperacidity (acidosis) occurs in the area affected by oxygen deficiency due to increased formation of lactate. Increased oxygen radicals are formed, which can cause cell damage. After a certain time, rhabdomyolysis sets in, i.e. a dissolution of striated muscle tissue. Dying cells release potassium and myoglobin, among other substances. The released particles in the extracellular space cause edema, which in turn causes additional damage to the surrounding tissues due to increased pressure. Potassium is primarily responsible for the danger to life in tourniquet syndrome: if it is distributed throughout the organism after reperfusion and causes systemic hyperkalemia, cardiac arrhythmias and even cardiac arrest are imminent.
Typical symptoms and signs
- Necrosis, ischemia
- Hyperkalemia
- Hyperacidity (acidosis)
- Cardiac arrhythmia
- Kidney failure
- Circulatory arrest (cardiovascular failure)
Diagnosis and course
That a Tourniquet syndrome is imminent can already be recognized by the still ligated limb: Progressive tissue damage is noticeable by swelling, redness, and hyperthermia. After reperfusion, there is almost always generalized edema and resulting volume-deficiency shock with the typical signs of shock such as pallor, drop in blood pressure, and increased heart rate. The shock index is positive. Pain and sensory and motor deficits occur at the previously ligated extremity. The diagnosis of Tourniquet syndrome is supported by laboratory findings: the patient’s blood shows severe metabolic acidosis and elevated potassium levels. The released myoglobin can also cause renal damage, including acute renal failure. A dark brown coloration of the urine and myoglobinuria indicate a threat to the kidney.
Complications
Tourniquet syndrome is already a serious complication that can lead to death if left untreated. Typical sequelae of the syndrome include necrosis and ischemia. There is a risk that the ligated body part will die completely and require amputation. Such necrosis is usually also associated with serious cardiovascular problems and circulatory disorders. In addition, kidney failure and, in the worst case, circulatory arrest may occur. Furthermore, acidosis may occur, a hyperacidity of the blood associated with low blood pressure, headache, shortness of breath and hyperventilation. Reperfusion may be followed by the development of edema, usually associated with volume-deficiency shock and severe shock symptoms such as hypotension and tachycardia. Tourniquet syndrome is also always associated with pain and sensory and motor deficits. Treatment of the syndrome also carries risks. Dialysis carries the risk of further cardiovascular problems. Infections or injuries at the site of the puncture also cannot be ruled out. In most cases, the patient is prescribed relatively strong painkillers, which can lead to side effects.Allergic patients may experience allergic reactions up to and including anaphylactic shock. Interactions with other medications can also not be ruled out.
When should you go to the doctor?
Tourniquet syndrome is a medical emergency. The affected person must be treated immediately by a physician. Symptoms of necrosis or hyperkalemia suggest reperfusion trauma and require evaluation. The syndrome may occur because of previous illness or in association with an accident or fall. If it is suspected that an extremity is not receiving adequate blood supply, either blood flow must be restored or a physician must be consulted. Symptoms such as swelling or redness indicate reperfusion. Later, generalized edema and typical signs of shock such as pallor, drop in blood pressure, or increased heart rate are added. A dark brown coloration of the urine indicates impending renal damage due to released myoglobins. The above symptoms are clear warning signs that need to be clarified immediately. The right person to contact is the family doctor or, in the case of acute symptoms, the emergency medical services. The patient must be treated in a hospital and, depending on the cause, see other specialists such as the orthopedist or cardiologist.
Treatment and therapy
Treatment of Tourniquet syndrome initially focuses on controlling life-threatening hypovolemic shock and cardiac arrhythmias. Metabolic acidosis can be counteracted by hyperventilation; it may also be buffered by bicarbonates. Massive volume administration and possibly hemofiltration may be necessary to preserve the kidney. The success of treatment depends crucially on how early reperfusion of the affected part of the body takes place. If ischemia continues for too long and tissue damage is too severe, only amputation can prevent the patient’s death. If the patient is treated within the first 4 hours after ischemia, the amputation rate is only four percent. After at least 12 hours of ischemia, amputation is necessary in 30 to 50 percent of cases. Modern intensive care measures have significantly increased the chances of surviving a Tourniquet syndrome, but the threatening nature of this clinical picture should not be underestimated. In tourniquet syndrome after lower extremity ischemia, the lethality is still reported in the literature to be as high as 20 percent.
Prevention
The best prevention of tourniquet syndrome is to never tie off a body part longer than absolutely necessary. If ligation cannot be avoided because of an otherwise imminent loss of blood, it is helpful to cool the affected limb down before reperfusion-this reduces certain enzyme activities and allows fewer harmful metabolites to be produced. In cases of prolonged ischemia, amputation is the only way to save the remaining organism from tourniquet syndrome.
Here’s what you can do yourself
Self-treatments provide cure or relief in certain cases. Time-honored recipes that have been passed down through generations save you from having to consult a doctor. However, this form of therapy is not suitable for life-threatening conditions such as Tourniquet syndrome. In this condition, acute medical treatment is inevitable. Intensive medical monitoring regularly follows. If the limb cannot be saved, it usually has to be amputated. Patients then continue to live with functional limitations. Affected persons can only take minor preventive measures to rule out the cause of Tourniquet syndrome. They must ensure that a body part is never tied off for longer than necessary. Tourniquet syndrome is particularly dangerous in young children. This is because they cannot articulate sufficiently, which means that parents cannot pinpoint the actual cause of the pain. Even hair caught in the socks can cause the loss of a toe. Tourniquet syndrome sometimes brings suspicion of abuse. This is because strangulation can result from a criminal act. Affected individuals should therefore extensively explore the causes of tourniquet syndrome and contact their local police department if they suspect it.