Kidney damage

Introduction to kidney damage The kidney is deeply hidden in the kidney socket and is well protected by the surrounding structure. The normal kidney has an activity of 1 to 2 cm, and the incidence of injury is slightly less than that of other organs. With the rapid development of industrial technology, modern transportation and modern high-tech warfare The emergence of new and medium-sized weapons has caused more injuries, combined injuries have increased significantly, and the damage is more serious and complicated. Among them, closed injury is more common, while in 1/3 of closed renal injury, other visceral injuries occur, and more than half of them have fractures. basic knowledge The proportion of illness: 0.03% Susceptible people: no special people Mode of infection: non-infectious Complications: hydronephrosis, kidney stones

Cause of kidney injury

Direct and indirect violence (60%):

The kidney area is directly hit, and the wounded fall on a hard object or squeezed between two foreign violence. When a person falls from a height, his feet or hips touch the ground and hurt the kidneys due to severe vibration.

Spontaneous rupture (5%):

The kidney can also spontaneously rupture without significant external violence. This type of "spontaneous" renal rupture is often caused by kidney lesions such as hydronephrosis, tumors, stones and chronic inflammation.

Puncture injury (15%):

Often a penetrating injury can damage the whole kidney or one of them, usually accompanied by abdominal or other visceral injuries in the chest.

(two) pathogenesis

1. Mechanism of closed renal injury

(1) Direct violent strike: The focus of trauma is very important. If the abdomen is directly hit, the incidence of kidney injury is 10.0% to 20.1%, and the waist is hit by about 60%. The cause of injury is mainly impact, followed by fall. Traffic accidents, etc., foreign traffic accidents, accounting for more than 50%, the highest of 80%, in addition to being injured by others or ball in sports, sudden body rotation or strong muscle contraction can also occur kidney damage, Such lesions are more common in microscopic hematuria, the so-called exercise hematuria, which is more common in the right kidney. Fancz et al. used a computer to simulate a two-dimensional model of the kidney to study the conduction and pressure distribution of energy in the kidney when the kidney was hit. They found that the maximum pressure point appeared at the edge of the renal parenchyma, and the pressure at the pressure point was also affected by the hydrostatic pressure in the renal pelvis and the presence of renal cysts in the renal parenchyma. When the hydrostatic pressure in the renal pelvis is high or the kidney is present in the kidney parenchyma. In the case of cysts, the pressure at the maximum pressure point on the edge of the renal parenchyma is also increased under the same external force, which is clinically seen in the kidney when the abdominal injury is more common in the kidney. Surface water and the obstruction of the kidney and renal cysts consistent with renal kidney damage occurs more easily.

(2) Deceleration injury: more common when falling from the height of the heel or hips and when the body suddenly decelerates in a traffic accident, the kidney continues to descend due to inertia, or violently hit the ribs or lumbar vertebrae to cause damage to the kidney parenchyma or kidney pedicle. Due to the sharp displacement of the kidney, the renal pedicle is pulled up or down violently, the adventitia and muscle layer are stretched, but the inelastic inner membrane undergoes different degrees of contusion or fracture, resulting in subendocardial hemorrhage. Stenosis or thrombosis, a more severe injury can cause vascular muscle and epicardial rupture leading to tearing or rupture of blood vessels.

(3) Impact injury: Kidney damage caused by impact injury is less common and relatively light, but the combined heart, lung, liver, spleen, intestine and pancreas are common and heavier, and the main damage of the kidney is For subcapsular or parenchymal plaque hemorrhage, occasionally there is a small tear or infarction, the damage is mainly caused by the impact of shock wave overpressure and dynamic pressure, negative pressure may also have a certain effect, it The doctrines that cause kidney damage include:

1 Fragmentation effect, also known as spalling effect: When the pressure wave is transmitted from the denser tissue to the looser tissue, it will cause reflection at the interface between the two, resulting in the damage of the denser tissue due to the sudden increase of local pressure.

2Inertia effect: In the tissue with different density, the speed of pressure wave transmission is different. The loose tissue transmits faster and the dense tissue transmits slowly, so the two are easy to cause separation damage.

3 In recent years, the most important progress in the research of shock wave injury mechanism is to try to explain the mechanism of primary impact injury by biomechanics. The physical process of the body's response to shock wave is proposed by American Stuhmiller et al. including three stages: A. Surface surface shock wave The rapid response of the load, the magnitude of the shock wave acting on the surface force is called the impact load, and the surface of the shock wave source is the most stressed. The geometry of the structure allows the shock wave to be diffracted or focused, in a partially open structure. The impact load is much larger than that in the free field; B. After the impact load acts on the body, the tissue and organs will be deformed, and stress will be generated in the tissue; C. Tissue stress and damage, certain stress can cause tissue bleeding or rupture.

(4) crush injury: more common in traffic accidents, the cause of injury is complex, directly hit or squeezed in the abdomen, causing a sharp increase in intra-abdominal pressure to cause kidney damage.

2. Mechanism of open kidney injury

(1) Modern firearm injuries: When a low-speed projectile penetrates into a tissue, its force advances along the axis of the ballistics. During its advancement, it directly breaks, tears and penetrates the tissue on the ballistics, forming a so-called bruise. Road or primary wound, the high-speed projectile penetrates into the tissue not only has a forward force, but also forms a primary wound, but also generates a lot of energy and speed, and spreads around, forcing the tissue of the primary wound to quickly compress around. And shifting, thereby forming an elliptical cavity that is several times or even tens of times larger than the diameter of the original wound or projectile, ie, an instantaneous cavity, and a rapid change in pressure within the cavity can cause the wound around, or even away from, The tissue of the wound is displaced and oscillated, forming a so-called "explosive effect", which causes the tissue to be injured. The kinetic energy of the projectile increases with the square of the velocity, while the release of energy increases with the cube of the velocity. When the velocity exceeds a certain limit. The degree of increase is greater. Each time the projectile releases 1 J of energy in the tissue, a cavity of 80.1×102 cm 3 can be formed. At the same time, the light weight and high-speed bullets are likely to rebound after entering the human body. Change the direction of advancement, resulting in multiple organ damage. There have been reports of high-speed bullets hitting the buttocks and sharply changing direction, passing through the chest and abdominal cavity, causing multiple injuries to the chest and abdominal organs. The current mechanism of firearm injury is The following doctrines:

1 direct damage: there are two kinds of forces when the projectile penetrates into the tissue: one is the forward momentum, which advances along the elastic axis, directly destroys the tissue, causing penetrating injury or non-penetrating injury (blind tube injury) and forming a permanent injury; The second is the side impact force, which is perpendicular to the wound and spreads around the wound, forming a transient cavity effect, causing damage to the surrounding soft tissue.

2 Water particle motion theory: As early as 1848, French scholar Hugier believed that the "explosion effect" of the warhead on the body tissue is due to the diffusion of water particles, that is, the projectile transmits kinetic energy to the liquid particles of the surrounding tissue, accelerating it and becoming a successor. The projectiles quickly leave the wound and spread to the surrounding to create an "explosive effect", causing extensive damage to the tissue surrounding the wound.

3 pulsed instantaneous cavity effect: a high-speed flying projectile has a large amount of energy when it penetrates into the tissue, compresses the tissue around the wound in the form of pressure waves, and rapidly displaces it to form a primary wound or projectile. A cavity that is several times larger or even several times larger in diameter, its expansion is caused by the pressure difference between the ambient pressure and the internal pressure of the tissue, and then the surrounding medium prevents the cavity from continuing to expand and is made hollow under the action of tissue elasticity. The cavity shrinks, and the process of contraction and expansion occurs 7 to 8 times in tens of milliseconds, causing the tissue around the wound to be pulled, torn and oscillated, resulting in extensive uneven damage.

4 Pressure wave action: When the projectile penetrates into the body at a very high speed, part of the energy is transmitted to the tissues and organs in the form of pressure waves, which propagate in the tissue at a speed of about 1500 m/s, when the pressure waves pass different impedances (wave speed) When the interface with the medium is the interface of the medium, reflection and refraction superposition will occur. The solid organs are high in density and brittle. When the strength of the pressure wave exceeds the tensile strength of the tissue, the tissue fiber band is broken, resulting in Different degrees of rupture.

5 far-reaching effect: refers to the damage of the remote organ without direct anatomical connection with the primary wound, which is mainly related to the strong disturbance of the body fluid caused by the strong pressure wave acting on the circulation line (blood vessel), and the visual inspection is mostly the organ. The flaky hemorrhage is different from the secondary scattered miliary hemorrhage caused by post-traumatic neurohumoral factors.

Due to the special action effect of the projectile on the tissue, the tissue damage caused by it has special pathological characteristics, that is, A. Primary wound area: the primary wound area is a persistent existence due to the direct damage of the projectile. The cavity, which is filled with foreign matter such as broken, inactivated tissue, clots, dirt, clothing fragments, etc., due to the influence of projectiles and tissue characteristics, the diameter of each part of the primary wound is inconsistent, visible under the light microscope The inner surface of the area is uneven, the normal structure of the tissue completely disappears, and a large number of red blood cells and neutrophils are densely packed in the necrotic tissue or on the surface thereof. B. Contusion area: the area is close to the primary wound, which is the energy of the projectile. Squeeze of lateral conduction and transient cavity effect, tissue inactivation zone formed by pulling action, C. Oscillation zone: shock zone outside the contusion zone, the main pathological change is blood circulation disorder and its consequences, There is no significant change in the short time after injury. After several hours or even a few days, blood circulation disorders such as congestion, congestion, hemorrhage, thrombosis, exudation and edema may occur. Thrombosis may lead. Tissue necrosis, edema can compress the surrounding tissue, causing local hypoxia and necrosis. The more hemorrhage of tissues and organs with more water content, the wider the shock zone formed. There is no obvious boundary between the above three pathological divisions, especially The pathological changes in the contusion zone and the turbulent zone are often uneven and staggered. This phenomenon is more obvious in the case of high-speed, high-energy projectile damage.

(2) Stab wound: The open injury of the kidney caused by sharp weapon can be seen in normal wartime, which can cause direct damage to the organ tissue that the sharp weapon penetrates into the injured road. Because the kidney is deeper, there are more adjacent organs. The upper part of the back is in contact with the diaphragm, and the diaphragm is adjacent to the 11th and 12th ribs. The lower part and the psoas muscle are adjacent to the lumbar muscle. The tops of both kidneys are covered with adrenal glands. The fronts of the two kidneys are different. Adjacent to the right lobe of the liver, the lower part is adjacent to the colonic hepatic curvature, the medial side is adjacent to the descending part of the duodenum, the anterior upper part of the left kidney is adjacent to the fundus and spleen, the middle part has the tail of the pancreas, and the lower part is connected with the jejunum and colon. The spleen is connected, so when it is penetrated from different parts of the body and causes kidney damage, it often combines different tissues and organ damage. Among them, the combined injury of colon, liver and spleen is the most common. Noel et al reported a group of 187 cases of thorns. 122 (65%) of the patients with kidney injury caused by injury had other organ damage, including 42 cases (22%) with liver injury, 37 cases (18.5%) with blood-thoracic injury, and 20 cases (10% with spleen injury). ) 19 cases (9.5%) with colon injury and 17 cases (8.5%) with small bowel injury. There were 14 cases (7%) with injury, 13 cases (6.5%) with gastric injury, 12 cases (6%) with cardiovascular injury, 10 cases (5 %) with diaphragmatic injury, and 9 cases (4.5%) with mesenteric injury. There were 7 cases (3.5%) with pancreatic injury, 5 cases (2.5%) with renal pelvis injury, 3 cases (1.5%) with ureteral injury and 1 case (0.5%) with adrenal injury.

3. Iatrogenic damage can be seen in:

(1) Perform surgery and endoscopic sinoscopy on the kidney and its adjacent tissues, such as pelvis or sinus nephrolithotomy, or percutaneous nephrolithotomy.

(2) Kidney injury caused by extracorporeal shock wave lithotripsy, early renal injury is mainly glomerular and renal interstitial hemorrhage, renal tubular necrosis, decreased glomerular filtration rate and perirenal hematoma, etc. Unclear, it may be caused by the cavitation effect caused by high-energy shock waves generated by ESWL. There are also many reports at home and abroad that kidney stones are complicated by subcapsular hematoma, renal laceration, and perirenal hematoma when ESWL is treated. Sexual surgery treats these complications and even nephrectomy.

Kidney damage prevention

Prevention requires early detection and early treatment.

Regular preventive measures for kidney damage: diet should use high-quality low-protein, high-vitamin, low-salt, low-potassium foods. A high-quality protein diet means that about 50%-60% of them must be proteins rich in essential amino acids (ie, high bio-quality protein). ), such as eggs, fish, lean meat and milk, should eat less foods rich in vegetable protein, such as peanuts and their products, because they contain more non-essential amino acids, in order to limit the intake of plant protein.

Kidney injury complications Complications, hydronephrosis, kidney stones

Most of the complications of severe injury are caused by blood or urine extravasation and secondary infections. Mainly have perirenal abscess, urinary fistula, pyelonephritis and pus kidney, ureteral stricture, hydronephrosis, pseudourinary cyst, stones, loss of renal function, arteriovenous fistula, hypertension and hematoma calcification. Some cases have persistent morphological changes such as renal pelvis, renal pelvis deformation, partial renal parenchymal atrophy, etc., but without any symptoms.

Symptoms of kidney injury Common symptoms Trauma, extravasation, glomeruli, "three highs", hypertensive hematuria

Substantial injury and blood, urinary extravasation, and timely detection of combined injury, renal injury with typical peritoneal irritation or mobile dullness, should be alert to the possibility of intra-abdominal organ injury, abdominal puncture has a certain diagnostic value.

1. Hematuria may occur in severe hematuria, and mild hematuria may occur in microscopic hematuria. If the ureter, rupture of the renal pelvis or rupture of the renal pedicle, there may be no hematuria.

2. Shock severe kidney injury, especially with other organ damage, manifests as traumatic shock and hemorrhagic shock, and even life-threatening.

3. Pain and abdominal mass pain caused by local soft tissue injury or fracture, can also be caused by increased renal capsule tension; sometimes due to ureteral clot obstruction caused by renal colic, when renal perihematomal and urinary extravasation are formed, local Swelling occurs and a mass is formed.

4. High fever due to blood, urine extravasation caused by perirenal infection.

5. When the wound is bleeding or the penetrating injury affects the kidney, the wound can flow a lot of blood. The amount of bleeding is related to the degree of kidney damage and whether there are other organs or blood vessels.

Kidney damage examination

The diagnosis of kidney injury is generally based on the history of trauma, clinical symptoms and signs, combined with urine tests and angiographic examination. Most cases can be diagnosed according to the injured part and hematuria. If there is a combined injury of abdominal organs, care should be taken not to ignore Kidney damage.

In the diagnosis of kidney injury, it is necessary not only to determine whether there is any damage, but also to understand the degree of injury, the condition of the contralateral kidney and the development trend of the injured kidney. If the diagnosis is difficult, a special examination of the urinary system is considered.

1. CT is of great value in the diagnosis and follow-up of renal injury. It should be the first choice when the patient's general condition permits. It can not only accurately understand the extent, extent and blood and urine extravasation of renal parenchymal injury. In the case of the situation, it is also possible to determine whether there is damage to other abdominal organs.

2. B-ultrasound can initially understand the extent of renal injury and the perihematomal hematoma and extravasation.

3. X-ray examination According to the situation of leakage of contrast agent during excretory urography, the extent and extent of renal injury can be understood, and the renal function of both sides can be understood. When the excretory urography is not developed, it is suspected. Renal angiography, renal angiography, but should be implemented when the condition is stable, renal angiography can be found with contrast agent spillover and renal vascular obstruction, after renal angiography confirmed, can also be selective The renal artery branches are embolized to control bleeding.

4. Radioisotope scanning is also helpful for the diagnosis and follow-up examination of renal injury. The scanning method is simple and safe, and can be used according to the situation.

Patients with lumbar and abdominal injuries and suspected kidney injury should immediately undergo a routine urine examination to understand the bleeding, catheterization if necessary, and urine retention for colorimetric observation, but the amount of hematuria is sometimes not proportional to the degree of injury.

Diagnostic identification of renal injury

diagnosis

The diagnosis of renal injury can be determined based on medical history, symptoms and signs, urine tests, and X-ray urography. In most cases, the diagnosis of kidney damage can be confirmed by the above steps or only from clinical phenomena and hematuria. Kidney damage is often accompanied by severe injuries such as craniocerebral, chest and abdomen internal organs and fractures. Because of the serious symptoms of these injuries, people often overlook the performance of kidney damage. However, as long as you are alert to the possibility of kidney damage, in the timely processing of these injuries, rescue shock, detailed inquiries about the nature of the injury, the nature of the violence, the direction of the penetrating wound, careful examination of signs and urine routine examination, most patients can be diagnosed. When the condition deteriorates rapidly, it indicates that the injury is serious and needs to be actively rescued. In order to choose conservative or surgical treatment, it is often necessary to use some auxiliary examinations to understand the true condition of the injured kidney.

Differential diagnosis

1. Abdominal organ damage is mainly liver and spleen injury, sometimes coincides with kidney injury, manifested as hemorrhage, shock and other critical symptoms, obvious peritoneal irritation, abdominal puncture can draw hemorrhagic fluid, urine test without red blood cells; Ultrasound examination showed no abnormalities in the kidney; IVU showed renal pelvis, normal renal pelvis morphology, and no contrast agent spillover.

2. Renal infarction manifests as sudden low back pain, hematuria, and elevated blood pressure; IVU shows slow or no development of the kidney, retrograde pyelography can reveal signs of subrenal hematoma, and patients with renal infarction often have a history of cardiovascular disease or renal arteriosclerosis. Serum lactate dehydrogenase, glutamate oxaloacetate transaminase and alkaline phosphatase are elevated.

3. Spontaneous renal rupture suddenly has low back pain and hematuria symptoms. Physical examination shows obvious tenderness and muscle tension in the waist and abdomen. It can touch cystic mass with unclear margin. IVU examination shows renal pelvis, renal pelvis deformation and contrast agent spillover. B-ultrasound examination The kidney collection system is disordered, and there is a liquid dark area around the kidney. Generally, there is no obvious history of trauma. In the past, there were many kidney tumors, kidney tuberculosis, and hydronephrosis.

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