2 English references Necrotizing fasciitis
Conclusion Necrotizing fasciitis is skin injury or skin and fascia infection after operation, which leads to subcutaneous vascular thrombosis and skin and fascia necrosis.
Necrotizing fasciitis is a widespread and rapid soft tissue infection, characterized by subcutaneous tissue and fascia necrosis, often accompanied by systemic toxic shock. As early as 187 1, American surgeon Josepoh Jones called this disease "hospital gangrene". 1909 Feden described this disease and called it "acute infectious gangrene"; McCafferty and others later called this disease "suppurative fasciitis"; 1924, Meleney named the disease "hemolytic streptococcus gangrene"; 1952 Wilson suggested that the progressive gangrene of superficial and deep veins of subcutaneous tissue be collectively referred to as acute necrotizing fasciitis.
Necrotizing fasciitis is a rare serious soft tissue infection. Different from streptococcus necrosis, it is a mixed infection of many bacteria, mainly aerobic bacteria, such as streptococcus pyogenes and Staphylococcus aureus. Necrotizing fasciitis infection only damages subcutaneous tissue and fascia, and does not involve muscle tissue at the infected site, which is its important feature.
In the past, anaerobic bacteria were often not found because of the backward culture technology of anaerobic bacteria, but in recent years, it has been confirmed that anaerobic bacteria such as Bacteroides, Streptococcus digestion and cocci are often one of the pathogenic bacteria of necrotizing fasciitis, but they are rarely infected by simple anaerobic bacteria. Necrotizing fasciitis can be divided into two types according to the condition: one is that pathogenic bacteria spread through trauma or primary focus, which suddenly aggravates the condition and causes rapid necrosis of soft tissue. Another disease develops slowly, mainly cellulitis. There are many ulcers on the skin, and the pus is thin and smelly, like washing dishes. The skin around the ulcer is widely invisible, with distorted pronunciation and local numbness or pain. These features are not common cellulitis. Patients often have obvious toxemia, chills, high fever and low blood pressure. Hypocalcemia occurs when the subcutaneous tissue is necrotic in a large area. Bacteriological examination is of great significance to diagnosis, especially the smear examination of wound pus.
The key to the treatment of necrotizing fasciitis is early and thorough expansion surgery, which can fully cut the latent skin edge and remove necrotic tissue, including necrotic subcutaneous adipose tissue or superficial fascia, but usually the skin can be preserved. Open the wound, rinse it with 3% hydrogen peroxide or 1∶5000 potassium permanganate solution, loosely wrap it with gauze, or insert several polyethylene catheters for postoperative lavage. Baxter suggested washing with normal saline containing neomycin 100mg/L and polymyxin B 100mg/L, while others suggested washing with carbenicillin or 0.5% metronidazole solution. The dressing change after operation accelerated the shedding of necrotic tissue, and it was found that necrotic tissue needed to expand again. Bacterial culture should be repeated during dressing change to find secondary bacteria at an early stage, such as Pseudomonas aeruginosa, Serratia marcescens or Candida.
Necrotizing fasciitis has severe symptoms of systemic poisoning and many dangerous complications, such as disseminated intravascular coagulation, toxic shock and multiple organ failure, which are the main causes of death.
To prevent necrotizing fasciitis, it is necessary to improve immunity and actively treat primary systemic diseases and local skin injuries. Long-term use of glucocorticoid and immunosuppressant should pay attention to strengthening systemic nutrition and preventing trauma. When the skin is injured, remove pollutants in time and disinfect the wound; If you feel unwell, you should actively seek the help of a doctor.
4 disease name necrotizing fasciitis
5 English name necrotizing fasciitis
6 Necrotizing fasciitis, another name for suppurative fasciitis; Acute infectious gangrene; Gangrene of hemolytic streptococcus; Gangrene hospitalization; Progressive gangrene of superficial and deep veins of subcutaneous tissue
7 classification-dermatology > spherical dermatosis
7. 1 ICDNo。 L02.8
8 classification 2 general surgery > surgical infection > purulent infection of skin and soft tissue
8. 1 ICD number M72.5
9 Etiology of necrotizing fasciitis In the past, it was thought that necrotizing fasciitis was only hemolytic streptococcus gangrene caused by hemolytic streptococcus, but recently it was found that a variety of highly toxic bacteria were cultured in the focus, including B- hemolytic streptococcus, staphylococcus, Enterobacter and anaerobic bacteria.
Necrotizing fasciitis is often a mixed infection of many bacteria, including Gram-positive hemolytic streptococcus, Staphylococcus aureus, Gram-negative bacteria and anaerobic bacteria. With the development of anaerobic culture technology, it is proved that anaerobic bacteria are an important pathogen, and necrotizing fasciitis is often the result of the synergistic effect of aerobic bacteria and anaerobic bacteria.
Necrotizing fasciitis is often accompanied by immune function damage of whole body and local tissues, such as minor skin injuries such as abrasion, contusion, insect bite, cavity organ surgery, drainage of perianal abscess, tooth extraction, laparoscopic surgery, and even after injection (mostly after injection of drugs). People who use corticosteroids and immunosuppressants for a long time are prone to this disease. Some patients with necrotizing fasciitis are complicated with diabetes, atherosclerotic cardiovascular disease, obesity, malnutrition, nephropathy, shock, metastatic tumor, multiple myeloma and other diseases.
10 Pathogenesis A variety of bacteria invade subcutaneous tissue and fascia. Aerobic bacteria first consume oxygen in infected tissues and reduce the redox potential difference (Eh) of tissues. At the same time, enzymes produced by bacteria decompose H2O2 in tissues, thus creating an oxygen-deficient environment, which is conducive to the breeding and reproduction of anaerobic bacteria.
Bacterial infection spreads rapidly and widely along fascia tissue, causing extensive inflammation, congestion and edema of infected tissue, followed by inflammatory embolism of skin and subcutaneous vascular network, tissue malnutrition, leading to ischemic tunnel necrosis of skin, and even annular necrosis. Microscopic examination showed that there was obvious inflammation in the blood vessel wall, neutrophil infiltration in the deep dermis and fascia, fibrous embolism in the blood vessels in the affected fascia, and cellulose necrosis in the arteriovenous wall. Gram staining can find pathogenic bacteria in damaged fascia and dermis without muscle injury.
Clinical manifestations of necrotizing fasciitis 1 1 necrotizing fasciitis mainly occurs after skin trauma or surgery, such as skin abrasion, surgical incision, bedsore, perianal fistula or diabetic foot ulcer. Different pathogen infections will have different clinical manifestations. It can be manifested as acute necrosis process or chronic intractable latent disease. And it is more common in patients with diabetes, cardiovascular disease and kidney disease.
Necrotizing fasciitis can involve all parts of the body, and the incidence site is mostly in limbs, especially lower limbs. Followed by abdominal wall, perineum, back, buttocks and neck. The local symptoms of the patient are still mild, and the whole body presents severe poisoning symptoms, which is the characteristic of necrotizing fasciitis.
1 1. 1 The local symptoms are acute, and the early local signs are often hidden, which can spread to the whole limb within 24 hours.
(1) Flaky redness and pain: In the early stage, the skin was red and swollen, with purple flakes, unclear boundaries and pain. At this time, the subcutaneous tissue has been necrotic, and there are few lymphangitis and lymphadenitis, because the lymphatic pathway has been quickly destroyed. The infection will spread to the whole limb within 24 hours.
Individual cases may have a slow onset and be in a latent state in the early stage. The affected skin is red or white, with edema, obvious tenderness, unclear focus boundary and diffuse cellulitis.
(2) Pain relief, numbness of the affected part: Due to the invasion of inflammatory substances and bacteria, severe pain occurred at the early infected site. When the sensory nerve in the lesion is destroyed, severe pain can be replaced by numbness or paralysis, which is one of the characteristics of this disease.
(3) bloody blisters: due to the destruction of nutrient vessels and vascular embolism, the skin gradually turns purple-black, and blisters or bullae containing bloody liquid appear.
(4) Odd bloody exudates: subcutaneous fat and fascia edema, thick, turbid, black, and finally liquefied and necrotic. The exudate is bloody slurry with peculiar smell. Necrosis spreads widely and sometimes produces subcutaneous gas, which can be found by inspection (figure 1).
1 1.2 Symptoms of systemic poisoning At the initial stage of the disease, the symptoms of local infection are still mild, that is, the patient has severe symptoms of systemic poisoning such as chills, high fever, anorexia, dehydration, disturbance of consciousness, hypotension, anemia and jaundice. If not treated in time, disseminated intravascular coagulation and toxic shock may occur.
1 1.3 hemolytic streptococcus gangrene is a serious acute suppurative disease caused by hemolytic streptococcus, and some people think it is gangrenous erysipelas. Shortly after trauma or abrasion, painful swelling with clear boundaries occurs explosively, and soon local redness, swelling, pain, bullae or blood blisters appear, with burning sensation, some of them merge into pieces, and blisters are easy to break. After rupture, the necrotic epidermis was peeled off, revealing bright red abscess surface, and some of them were deeply necrotic to form gangrene and ulcer. It is more common in limbs, but it can also have metastatic lesions in other parts of the body, often accompanied by systemic symptoms such as high fever and failure. If not treated in time, you may die of sepsis or shock.
1 1.4 Clostridium anaerobic cellulitis is a kind of serious skin tissue necrosis caused by Clostridium, which has extensive gas formation and often occurs in unclean or incomplete wound debridement, especially in anus, abdominal wall, buttocks, lower limbs and other easily contaminated parts. Its clinical manifestations are similar to necrotizing fasciitis, with sudden redness, swelling and pain on the skin. It quickly developed into a black plaque with a black center and gradually turned into gangrene, accompanied by fever and chills. However, there are also some phenomena of hypoxic gangrene, whose secretions are black and smelly, often containing fat drops, and there are obvious distortions around the lesions. X-ray examination showed that there were a lot of gas and mixed anaerobic bacteria in the soft tissue.
1 1.5 Non-clostridial anaerobic cellulitis The symptoms of non-clostridial anaerobic cellulitis are similar to those of clostridial anaerobic cellulitis, which are basically necrotizing fasciitis, but mainly mixed anaerobic bacteria infection.
1 1.6 Fournier gangrene Fournier gangrene is a serious gangrene that occurs in men, scrotum, perineum and abdominal wall. It may be caused by Enterobacter, Gram-positive bacteria or anaerobic bacteria infection. It is more common in patients with diabetes, local trauma, incarcerated phimosis, urinary fistula or genital surgery. Its skin necrosis is caused by perianal fasciitis, which affects the blood supply of the skin. The clinical manifestations are acute onset, sudden redness and swelling of local skin, and most of them develop into central dark erythema and ulcer. Ulcer edge peristalsis, serous exudation on the surface, intense tenderness and frequent fever. A large number of gram-positive bacteria, enterobacteria and anaerobic bacteria can be detected in the lesion.
1 1.7 cooperative necrotizing cellulitis cooperative necrotizing cellulitis is a variation of necrotizing fasciitis, which is characterized by systemic poisoning and bacteremia. It mostly occurs in patients with diabetes, obesity, old age and heart and kidney diseases, and the lesions often occur around the lower limbs and anus, which often leads to death.
Complications of necrotizing fasciitis 1. Anemia.
2. Diffuse intravascular coagulation.
3. Toxic shock.
4. Multiple organ failure.
13 Laboratory examination 13. 1 Blood routine (1) Red blood cell count and hemoglobin determination: 60% ~ 90% of patients have a slight to moderate decrease in red blood cells and hemoglobin due to the inhibition of bone marrow hematopoietic function by toxins such as bacterial hemolytic toxins.
(2) White blood cell count: Leukemia-like reaction, white blood cells increased, mostly between (20 ~ 30) × 109/L, and the nucleus moved to the left with toxic particles.
13.2 serum electrolytes can cause hypocalcemia.
13.3 urine test (1) urine volume and urine specific gravity: oliguria or anuria occurs when the fluid supply is sufficient, and the urine specific gravity is balanced, which is helpful to judge the early damage of renal function.
(2) Qualitative analysis of urine protein: Positive urine protein indicates that glomeruli and renal tubules are damaged.
13.4 blood bacteriology examination (1) smear microscopy: take the secretion and blister fluid at the edge of the lesion for smear examination.
(2) Bacterial culture: The secretion and blister fluid were cultured with aerobic bacteria and anaerobic bacteria respectively, and no clostridium helpful for the diagnosis of this disease was found.
13.5 There are antibodies induced by streptococcus in the blood (hyaluronidase released by streptococcus and deoxyribonuclease B can induce high titer antibodies), which is helpful for diagnosis.
13.6 serum electrolytes may have hypocalcemia.
13.7 The increase of serum bilirubin indicates hemolysis of red blood cells.
14 auxiliary examination 14. 1 imaging examination (1)X-ray film: there is gas in the subcutaneous tissue.
(2)CT: showing small bubbles in the tissue.
14.2 biopsy is also helpful for the diagnosis of necrotizing fasciitis.
Diagnosis of necrotizing fasciitis 15 The main feature of necrotizing fasciitis is that local signs are not commensurate with the severity of systemic symptoms.
Fisher put forward six diagnostic criteria, which have certain reference value:
1. The superficial fascia under the skin is extensively necrotic, with extensive underground passages and spreading to surrounding tissues.
2. Moderate to severe symptoms of systemic poisoning, accompanied by mental changes.
3. No muscle involved.
4. Clostridium was not found in the wound and blood culture.
5. There is no obvious vascular obstruction.
6. Debridement and pathological examination: extensive leukocyte infiltration, focal necrosis of fascia and adjacent tissues and microvascular embolism were found.
Bacteriological examination is of great significance to the diagnosis of necrotizing fasciitis. It is best to take culture from the edge of progressive lesion and blister fluid for smear examination, and conduct aerobic and anaerobic culture respectively. It is helpful to determine whether there are antibodies induced by streptococcus in blood (hyaluronidase and deoxyribonuclease B released by streptococcus can produce high titer antibodies).
16 differential diagnosis 16. 1 erysipelas is a local flaky erythema with no edema, clear boundary and frequent lymph nodes and lymphangitis. There is fever, but the general symptoms are relatively mild, and there is no characteristic manifestation of necrotizing fasciitis.
16.2 necrotic streptococcus necrotic streptococcus is infected by β hemolytic streptococcus. Mainly skin necrosis, not involving fascia. At the early stage, the local skin was red and swollen, then turned dark red, and blisters appeared, containing bloody serous fluid and bacteria. After skin necrosis, dry scab, similar to burn scab.
16.3 synergistic bacterial necrosis is mainly skin necrosis, and fascia is rarely involved. Pathogens include non-hemolytic streptococcus, Staphylococcus aureus, obligate anaerobic bacteria, Proteus and Enterobacter. The patient's symptoms of systemic poisoning are mild, but the wound pain is severe. The center of the inflammatory area is purplish red induration with redness around it. After necrosis in the central area, ulcers are formed, and the skin is peristalsis, and small ulcers are scattered around.
16.4 Clostridium myonecrosis Clostridium myonecrosis is an obligate anaerobic infection, which often occurs under the conditions of war injury, trauma and wound pollution. Early local skin is bright, tense and twisted, and the lesion may involve deep muscles. Gram-positive bacilli can be detected by secretion smear. Muscle is filthy and necrotic, myoglobinuria can appear, and X-ray film can find free gas between muscles.
16.5 Clostridium perfringens myonecrosis is rare because it is caused by anaerobic streptococcus or various anaerobic bacteria. The inducement is similar to gas gangrene, but the condition is mild, the wound has serous pus and the gas in the inflammatory tissue is limited.
Treatment of necrotizing fasciitis 17 necrotizing fasciitis is a critical surgical emergency and develops rapidly. Once diagnosed, extensive incision and drainage should be performed immediately. It is reported in the literature that the sooner or later incision and drainage is directly related to the mortality rate. Necrotizing fasciitis spreads along the fascia, sometimes the fascia is necrotic, but the skin is normal, so incision and debridement should not be based on the affected skin, but should be based on incision to the normal fascia. If the affected area is too large, more incisions should be made. Rinse the incision repeatedly with hydrogen peroxide to eliminate the growth environment of anaerobic bacteria. As soon as possible, apply large doses of antibiotics to the whole body, and first give large doses of penicillin injection or cephalosporins. Patients with severe systemic symptoms can be treated with glucocorticoid at the same time. Strengthen supportive therapy and symptomatic treatment.
The treatment principles of necrotizing fasciitis are: early diagnosis, early debridement, application of a large number of effective antibiotics and systemic support.
17. 1 antibiotic necrotizing fasciitis is a mixed infection of various bacteria (various aerobic and anaerobic bacteria). The symptoms of systemic poisoning appear early and the condition is serious, so antibiotics should be used in combination. Metronidazole is highly effective against Bacteroides fragilis, and clindamycin can control Bacteroides fragilis. Aminoglycosides (gentamicin, tobramycin, amikacin, etc. ) can control Enterobacter; Ampicillin is sensitive to enterococcus and anaerobic peptic streptococcus. Cefotaxime, ceftriaxone and other cephalosporins have broad-spectrum antibacterial properties, which are effective against both aerobic and anaerobic bacteria.
17.2 necrotizing fasciitis debridement and drainage of vascular thrombosis around the diseased tissue has a wide range, and drugs are often difficult to reach. Therefore, when active high-dose antibiotics 1 ~ 3 days have no obvious effect, surgery should be performed immediately.
Thorough debridement and adequate drainage are the key to successful treatment. Necrotic fascia and subcutaneous tissue should be completely removed until they can't be separated with fingers. Common methods:
(1) Cut off healthy skin at the infected site for later use: remove necrotic tissue and clean the wound; Free skin grafting was performed to cover the wound. This method can prevent a large amount of serum from oozing from the wound and help maintain the balance of body fluids and electrolytes after operation.
(2) Make multiple vertical incisions on healthy skin: remove necrotic fascia and adipose tissue, and rinse the wound with 3% hydrogen peroxide, metronidazole solution or 0.5% ~ 1.5% potassium permanganate solution to create an environment that is not conducive to the growth of anaerobic bacteria; Then wet compress with gauze soaked with antibiotic liquid medicine (metronidazole, gentamicin, etc.). ), and change the dressing every 4 ~ 6 hours 1 time. When changing dressing, it is necessary to explore whether the skin, subcutaneous tissue and deep fascia are separated to determine whether it is necessary to further expand the drainage.
(3) Selective skin grafting: When the skin defect is large and difficult to heal itself, skin grafting should be carried out at an appropriate time after the inflammation subsides.
Attention should be paid to the protection of healthy fascia during operation, which is easy to cause infection and spread after injury. Local wet application of metronidazole can delay skin growth, so it is not suitable for long-term application.
17.3 support treatment to actively correct water and electrolyte disorders. Anemia and hypoproteinemia can be infused with new blood, albumin or plasma; Nasal feeding or intravenous high nutrition and elemental diet can be used to ensure adequate calorie intake.
17.4 hyperbaric oxygen therapy in recent years, the mixed infection of anaerobic bacteria in surgical infections has increased day by day, and hyperbaric oxygen is effective for obligate anaerobic bacteria. Some people used hyperbaric oxygen to treat this disease and achieved good results. For example, in the comparative treatment of 29 patients, Riseman showed that 17 patients received hyperbaric oxygen therapy (2.5ATM, 90min, with an average of 7.4 treatments), and the average debridement was 1.2 times, with a mortality rate of 23%; 12 patients who did not receive hyperbaric oxygen therapy, the average number of debridement operations was 3.3, and the mortality rate was 66%. After statistical test, there was significant difference between the two groups. Knity treated 1 1 patients with hyperbaric oxygen, of which 8 cases were better than the previous cases. It should be noted that although hyperbaric oxygen therapy can reduce the mortality of patients with necrotizing fasciitis and reduce the need for additional debridement, it can never replace surgical debridement and antibiotic therapy.
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17.5 observation of complications during the treatment of necrotizing fasciitis, the patient's blood pressure, pulse and urine volume should be closely observed, and hematocrit, electrolyte, coagulation mechanism and blood gas analysis should be done to treat heart and renal failure in time and prevent disseminated intravascular coagulation and shock.
18 Prognosis Necrotizing fasciitis has severe symptoms of systemic poisoning, and many and dangerous complications, such as disseminated intravascular coagulation, toxic shock and multiple organ failure, are the main causes of death.
Prevention of necrotizing fasciitis 19 should improve the body's immunity and actively treat primary systemic diseases and local skin injuries. Long-term use of glucocorticoid and immunosuppressant should pay attention to strengthening systemic nutrition and preventing trauma. When the skin is injured, remove pollutants in time and disinfect the wound; If you feel unwell, you should actively seek the help of a doctor.
Related drugs: oxygen, ribonucleic acid, metronidazole, clindamycin, gentamicin, tobramycin, penicillin, cefotaxime, potassium permanganate.
2 1 Related examination of red blood cell count, hemoglobin, white blood cell count, urine specific gravity, hyaluronic acid and hematocrit.
Acupoint life gate for treating necrotizing fasciitis