Crush syndrome

Introduction to crush syndrome Squeeze syndrome refers to the fact that a person is buried or squeezed by heavy objects such as stones, especially when the muscles are full of limbs for more than one hour (such as the thigh), and then cause a series of pathological changes in the body. Oliguria or even no urine, characterized by renal failure. Renal failure is a serious condition, and if the treatment is not timely, the consequences are mostly serious. After trauma, the toxic intermediate metabolites destroyed by blood and tissue proteins are absorbed into the blood and cause acute tubular necrosis after trauma and acute renal failure caused by it. This is a common cause of late death in patients with extensive soft tissue contusion. Squeeze syndrome is an acute orthopedic disease of orthopedics and should be rescued in time to achieve early diagnosis, early injury and reduction of the injured limb and prevention of renal failure. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: non-infectious Complications: renal failure

Cause of crush syndrome

Cause:

Accidents and natural disasters (55%):

Squeeze syndrome occurs mostly in the case of collapse of houses, accidents such as project collapses, traffic accidents, etc., and can occur in batches during severe natural disasters such as wartime or strong earthquakes.

Position factor (15%):

In addition, occasionally in patients with coma and surgery, the limbs are prolonged by the self-pressure of the fixed position. The position of the patient during surgery should be easy to operate, and the patient can tolerate the principle.

Pathophysiology of crush syndrome:

Muscles are subjected to heavy bruises, bleeding and swelling, necrosis of muscle tissue, and release of a large number of metabolites, myoglobin, potassium ions, creatine, creatinine, muscle ischemia and hypoxia, acidosis, etc. It escapes from the inside of the cell, so that the blood potassium concentration rises rapidly. After the crush injury of the limb, the hypovolemic shock causes the peripheral blood vessels to contract. The kidney shows ischemia, renal blood flow and glomerular filtration decrease, and the kidney. The small tube mainly relies on the glomerular bulging artery to supply blood, the glomerular artery contraction, can aggravate the degree of renal tubular ischemia, and even necrosis. The serotonin and renin increase during shock can aggravate the damage of the renal tubule and release a large amount of muscle tissue after necrosis. Myoglobin needs renal tubular filtration, in acidosis, acidic urine can be deposited in the renal tubules, forming myoglobin casts, aggravating the degree of kidney damage, and eventually to acute renal failure.

Squeeze syndrome prevention

Because the mortality rate of this disease is relatively high, prevention is the key. The general preventive measures are:

1 After injury, lactated Ringer's solution and colloidal fluid: as soon as possible after injury, if the colloidal fluid can be used plasma or dextran, you can enter the colloidal fluid 80~100ml per 1% of the compressed area, each pressure for 1 hour, per kilogram of body weight Rehydration 3~4ml, plus the required amount of 1500ml for 24 hours, is the amount of rehydration on the first day after injury, and then adjusted according to the situation, but if the crush syndrome occurs, the rehydration can not be done according to the above, and the infusion volume should be controlled.

2 alkalized urine: due to crush syndrome often acidosis, so early application of alkaline drugs to alkalinize urine, prevent acidosis, prevent myoglobin and acidic urine deposition in the renal tubules, Oral sodium bicarbonate solution or intravenous 5% sodium bicarbonate, given daily about 25 ~ 30.

3 Diuretic: When the blood pressure is stable, diuresis can be performed, so that before the renal parenchyma is damaged, more alkaline urine passes through the renal tubules, increasing the excretion of harmful substances such as myoglobin, and can be quickly intravenously input with 20% mannitol. Its high osmotic pressure can increase renal blood flow, increase glomerular filtration rate, maintain renal tubular filling, reduce renal interstitial edema, prevent sedimentation in renal tubules, thereby protecting renal function, so early application.

4 relieve renal vasospasm: after crush injury, blood concentration of renin, histamine and other vasoconstrictors increased, causing renal vasoconstriction, early use of mannitol can also add vasodilators to relieve renal vasospasm, increase kidney Blood flow.

5 cut the fascia to release the exudate under reduced pressure, improve the circulation: the incision should be in the most severe part of the muscle swelling, and it is not necessary to probe the deep part beyond the swollen area. For the muscles that have been necrotic, once the myoglobinuria or other early stages appear Renal failure signs, decisive amputation.

Compression syndrome Complications, renal failure

The disease often causes acidosis, leading to acute kidney failure and life-threatening.

Squeeze syndrome symptoms Common symptoms Nitrogenemia Hyperkalemia Body swelling Squeeze chest tightness Heart palpitations Skin indentation Nausea bloating blood venous

Clinical manifestation

(1) Local symptoms: blood damage, blood stasis, blood stasis, blood stasis, meridian occlusion, local pain, limb swelling, skin indentation, hardening, subcutaneous blood stasis, skin tension increased, in When there is blisters around the compressed skin, it is worth noting that if the distal end of the limb does not weaken, the muscle tissue still has the risk of ischemic necrosis. Pay attention to the muscle and nerve function of the limb and actively move. It can cause pain when pulled with passive force, which is helpful for judging the affected muscle compartment of the fascia.

(2) systemic symptoms: due to internal injuries, blood, meridians, viscera, patients with head dizziness, loss of appetite, facelessness, chest tightness, abdominal distension, constipation and other symptoms, accumulation of heat can be expressed fever, face red, urine yellow, Red tongue, yellow greasy moss, pulse frequency, etc., severe palpitations, shortness of breath, and even pale, limbs cold, sweat out of oil and other symptoms (shock), the main characteristics of the crush syndrome are described as follows:

1 Shock: Some casualties may not have shock in the early stage, or the shock period is short and not found. Some wounded people have strong nerve stimulation due to crush injury, extensive tissue destruction, and a large amount of blood loss, which can quickly produce shock and increase.

2 myoglobinuria: This is an important condition for the diagnosis of crush syndrome. After the injured person releases the pressure, brown urine or self-reported hematuria occurs within 24 hours. Mucin and myoglobinuria should be considered in the blood. And the concentration in the urine reaches a peak 3 to 12 hours after the decompression of the injured limb, and then gradually decreases, and can be cleared after 1 to 2 days.

3 Hyperkalemia: Because of muscle necrosis, a large amount of intracellular potassium enters the circulation, combined with difficulty in excreting potassium in renal failure, blood potassium can rise 2mmol/L per day during oliguria, and even rises to a fatal level within 24 hours. Hyperkalemia is accompanied by high blood phosphorus, high blood magnesium and low blood calcium, which can aggravate the effect of blood potassium on myocardial inhibition and toxicity.

4 Acidosis and azotemia: After muscle ischemic necrosis, a large amount of acidic substances such as phosphate and sulfate are released, which lowers the pH value of body fluid, causes metabolic acidosis, and has a strong catabolism after severe trauma, and a large amount of intermediate metabolism. The product accumulates in the body, and the non-protein nitrogen rises rapidly. Clinically, there may be unconsciousness, deep breathing, and irritability. Nausea and other acidosis, uremia and other performance, should be recorded daily, often measured urine specific gravity, if the urine specific gravity is below 1.018, is the main indicator of diagnosis.

Clinical grading

The crush syndrome can be divided into three levels according to the severity of the injury, the volume of muscle involvement and the corresponding test results.

(1) Level 1: Positive for myoglobinuria test, CPK is greater than 10,000 units (normal value is 130 units), and those without systemic reactions such as acute renal failure may not undergo fasciotomy if they are injured early. A systemic reaction occurs.

(2) Level 2: Myoglobinuria test is positive, CPK is more than 20,000 units, serum creatinine and urea nitrogen are increased without oliguria, but there is obvious plasma infiltration into tissues, effective blood volume loss, and hypotension.

(3) Level 3: Positive myoglobinuria test, CPK increased significantly, oliguria or closed urine, shock, metabolic acidosis and hyperkalemia.

Squeeze syndrome examination

Laboratory inspection

(1) Urine examination: early urine volume is small, the specific gravity is above 1.020, urine sodium is less than 60mmol/L, and urea is more than 0.333mmol/L. In the period of oliguria or anuria, the urine volume is small or urine is closed, the urine specific gravity is low, fixed at about 1.010, urinary myoglobin is positive, urine contains protein, red blood cells or tube type, urine sodium is more than 60mmol/L, urea Less than 0.1665mmol / L, the ratio of urea nitrogen in the urine to blood urea nitrogen is less than 10:1, the ratio of urine creatinine to serum creatinine is less than 20:1, the urine specific gravity is still low in the most urine and recovery period, urine routine can be Gradually returned to normal.

(2) Hemoglobin, red blood cell count, hematocrit: to estimate the degree of blood loss, loss of plasma components, anemia or water retention during oliguria.

(3) platelets, clotting time: can indicate the body's coagulation, abnormal fiber-melting mechanism.

(4) Aspartate aminotransferase (GOT), creatine phosphatase (CPK): The enzyme released by muscle ischemic necrosis can be used to understand the degree of muscle necrosis and its growth and decline.

(5) blood potassium, blood magnesium, blood myoglobin determination: to understand the severity of the disease.

Diagnosis and identification of crush syndrome

diagnosis

The diagnosis of crush syndrome is mainly based on medical history, clinical manifestations (local symptoms and systemic symptoms), and laboratory tests. TCM syndrome differentiation is divided into four types: sputum resistance under the coke, water wet retention, qi and yin deficiency, and qi and blood deficiency. Clinical can be divided into three levels.

The short-term death after crush injury is often caused by traumatic hemorrhagic shock or hyperkalemia. In a few days, the deaths are often caused by crush injury and renal failure or multiple organ failure. Therefore, in the forensic autopsy work, if the cause of death is highly suspected, the crush syndrome must be taken from the kidney, and pathological examination should be performed to confirm the misdiagnosis.

Differential diagnosis

No need to distinguish from other diseases.

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