Septicemia-induced renal damage

　　一、发病原因

　　人体的防御系统一般均能将进入血液循环的致病菌迅速消灭，不致引起败血症。但在致病菌数量过多、繁殖过快、毒力强大，超过了身体的抵抗力或者在身体抵抗力减低，如年老体衰、婴儿幼童、长期消耗性疾病、营养不良、贫血等时，致病菌才容易在血中生长繁殖，产生毒素，引起败血症和脓血症。局部感染病灶处理不当，如脓肿不及时引流，伤口清创不彻底，留有异物或无效腔，亦可引起此种全身性感染。至于长期应用肾上腺皮质激素、抗癌药或其他免疫抑制剂等，能削弱正常的防御功能；广谱抗生素能改变原有的细菌共生状态，使某些非致病菌过分生长繁殖，亦同样是利于败血症发生的因素。在败血症和脓血症中，人体各组织、器官的病理改变随致病菌的种类、病程和原发感染灶的情况而异。因毒素的作用，心、肝、肾等有混浊肿胀、灶性坏死和脂肪变性；肺泡内出血和肺水肿，甚至肺泡内出现透明膜；毛细血管受损引起出血点和皮疹。致病菌本身可特别集中于某些组织，造成脑膜炎、心内膜炎、肺炎、肝脓肿、关节炎等。网状内皮系统和骨髓反应性增生，致脾肿大和周围血液中白细胞计数增多。感染严重而病程较长的病人，肺、肾、皮下组织和肌肉等可发生转移性脓肿或血管感染性栓塞。人体代谢的严重紊乱又能引起水、电解质代谢失调、酸中毒和氮质血症等。微循环受到影响，则导致感染性休克。败血症相关肾功能损害的发生也是多因素的，如内毒血症、肾低灌流量、肾毒性物质的作用等。

　　二、发病机制

　　败血症并发急性肾功能衰竭的发病机制与下列诸因素有关：

　　1、败血症常引起循环功能和呼吸功能衰竭体内缩血管物质(如某些细胞因子、血小板激活因子、内皮素及腺苷等)反应性增加，由此产生血流动力学改变及肾血流量减少是败血症并发肾功能衰竭的原因之一。除此之外，也有非血流动力学的因素，如细菌随血液迁徙至肾脏引起肾感染，在败血症性肾功能衰竭患者的肾活检发现，在肾间质和肾小管腔内有微小脓肿。

　　2、败血症并发肾功能衰竭有明显的嗜中性粒细胞激活，嗜中性粒细胞对急性肾功能衰竭的作用目前尚有争议。近有人发现，败血症时嗜中性粒细胞增多，可加重肾缺血和肾功能不全。其机制是嗜中性粒细胞整合素(integrin)与内皮细胞的细胞间黏附分子-1(ICAM-1)相互作用削弱对肾血管的保护，此外嗜中性粒细胞还可破坏内皮而减少NO合成，促进自由基生成也加重了缺血性急性肾衰竭。

　　3, Septicemia can cause rhabdomyolysis syndrome accounting for about 7.1%, of which 69% are caused by Gram-positive bacteria, most of which occur acute renal failure (68.5%). Septicemia caused by Gram-negative bacteria rarely occurs this syndrome, but the proportion of multiple organ failure (40%) is similar to that of Gram-positive bacterial septicemia (45.7%); indicating that this syndrome is only one of the factors causing renal failure.

　　4, The role of cytokines: Mariano et al. found that the level of platelet activating factor (PAF) in the blood and urine of patients with septicemia complicated by acute renal failure is elevated, which is closely related to the severity of renal failure and is related to other cytokines that cause renal damage, indicating that PAF may participate in mediating toxic shock and renal damage during sepsis. It has been found that tumor necrosis factor-α and endotoxins released by Gram-negative bacteria, a type of lipopolysaccharide (LPS) in the cell membrane, can induce apoptosis of glomerular endothelial cells.

　　1, Gram-positive bacterial septicemia often complicates acute renal failure, such as bacteria migrating to the kidney with blood causing kidney infection, interstitial nephritis, and small tubular cavity abscesses may appear.

　　2, Septicemia caused by Gram-negative bacteria often complicates infectious shock and multiple organ failure, with a proportion (40%) similar to that of Gram-positive bacterial septicemia (45.7%).

　　The main clinical manifestations are persistent high fever, chills, bacteremia, etc., and the symptoms of septicemia renal damage are similar to other infectious kidney diseases, and attention should be paid to differentiation.

　　1, Primary inflammation: The primary inflammation caused by various pathogens is related to the distribution site in the human body. The characteristics of primary inflammation are local redness, swelling, heat, pain, and dysfunction.

　　2, Symptoms of sepsis: The onset is often acute, with chills, high fever, and fever is usually remittent or intermittent, but may also be continuous fever, irregular fever, and double-peak fever. The latter is often caused by Gram-negative bacillary septicemia. Fever is accompanied by varying degrees of sepsis symptoms, such as headache, nausea, vomiting, abdominal distension, abdominal pain, malaise, muscle and joint pain, and others.

　　3, Rash: It is seen in some patients, with petechiae being the most common, mainly distributed on the trunk, extremities, conjunctiva, oral mucosa, and other places.

　　4, Joint symptoms: Large joints may appear red, swollen, hot, painful, and limited in movement, and even joint effusion and abscess may occur. This condition is often seen in the course of septicemia caused by Gram-positive cocci, meningococcus, alkaligenic bacilli, and others.

　　5, Septic shock: It occurs in 1/5 to 1/3 of septicemia patients, manifested as restlessness, rapid pulse, cold extremities, mottled skin, reduced urine output, and decreased blood pressure, and DIC may occur, which is caused by severe sepsis.

　　6、肝脾肿大：一般仅轻度肿大。

　　7、败血症性肾功能损害的症状与其他感染性肾脏疾病类似，可有尿素氮，肌酐增高和尿液异常改变。

　　1、败血症是由致病菌侵入血液循环引起的。细菌侵入血液循环的途径一般有两条，一是通过皮肤或粘膜上的创口；二是通过疖子、脓肿、扁桃体炎、中耳炎等化脓性病灶。患有营养不良、贫血、糖尿病及肝硬变的病人因抵抗力减退，更容易得败血症。致病菌进入血液以后，迅速生长繁殖，并产生大量毒素，引起许多中毒症状。

　　2、各种病原菌常循不同途径侵人机体：葡萄球菌常经由毛囊炎、疖、脓肿、脓疱病、新生儿脐炎等皮肤感染侵人机体，或由中耳炎、肺炎等病灶播散入血；革兰阴性杆菌则多由肠道、泌尿系统、胆道等途径侵人；绿脓杆菌感染多见于皮肤烧伤或免疫功能低下的病人；医源性感染，如通过留置导管、血液或腹膜透析、脏器移植等造成者则以耐药细菌为多。

　　1、血象：白细胞总数大多显著增高，中性粒细胞增多，并有核左移倾向，偶亦遇到白细胞总数不增，甚至反而减少，这可能表示预后不佳，在治疗后恢复过程中，淋巴细胞和嗜酸细胞明显增高，进行性贫血。

　　2、病原学检查：细菌培养除血培养外，从病灶部位及病变体液中有可能分离出病原菌。

　　（1）细菌培养阳性。

　　（2）细菌涂片：脓液，脑脊液，胸腔积液，腹水，瘀点等直接涂片检查，也可检出病原菌，对败血症的快速诊断有一定的参考价值。

　　3、败血症合并急性肾功能衰竭患者的血和尿中血小板激活因子(PAF)的水平升高，有明显的嗜中性粒细胞激活表现，嗜中性粒细胞明显增多，血培养阳性，肾缺血导致肾功能不全加重时，可有肾功能不全的典型实验室改变，尿检可出现蛋白尿，亦可见少许白细胞及管型，粪便稀便较多，含少许黏液。

　　4、肾活检：败血症性肾功能衰竭患者的肾活检发现在肾间质和肾小管腔内有微小脓肿。

　　5、常规行影像学，B超，心电图等检查有助于发现原发病灶。

　　一、食疗方

　　团鱼1只(约1斤去内脏洗净)，去毛去内脏白鸽1只，加调味品后一起隔水炖，食团鱼、鸽子及汤。

　　二、肾病患者的饮食须知

　　1、饮食要低盐饮食，要吃得清淡一些，忌食用酒及辛辣性食物，少食油腻及含动物蛋白多的荤腥食物(如肥肉、虾、蟹等)。

　　2. Avoid eating legumes and their products (such as tofu, sprouts, bean powder, etc.).

　　3. Patients with edema, hypertension, and heart failure should eat low-salt or salt-free diets.

　　4. Patients with renal insufficiency and uremia should pay special attention to:

　　(1) Avoid eating legumes and their products, eat less nuts (such as walnuts, chestnuts, almonds, etc.) and preserved foods (such as salted vegetables, pickled vegetables, etc.).

　　(2) The amount of high-protein food consumed daily (such as lean meat, milk, eggs, etc.) should be controlled. According to the individual condition of each patient, generally, adults should consume about 2-3 liang per day, and divide them into 3-5 meals.

　　(3) In the stage of renal failure, the kidney's water drainage capacity is limited, the intake of water should be controlled, and it is recommended to calculate according to the formula: water intake = total urine output the day before + 500-800 milliliters.

　　(4) In order to increase the excretion of creatinine and urea nitrogen, it is necessary to ensure smooth defecation. It is better to have a bowel movement twice or three times a day instead of every two or three days. Winter melon, watermelon, and gourds can diuretic, red bean soup, black bean soup, mung bean soup, drink with sugar to clear heat and diuretic. Honey, bananas, fresh pears, radishes, walnut meat, black sesame, can moisten intestines and defecate, these foods can be used in combination with medicine, and used frequently.

　　5. Patients with kidney disease should avoid spicy foods: some foods are easy to cause recurrence of kidney disease, such as: rooster, crucian carp, old pork, goose, etc., all belong to spicy foods, and patients with kidney disease should avoid eating them.

　　1. Strengthen labor protection, avoid外伤and wound infection, protect the integrity and cleanliness of the skin and mucous membranes, and avoid picking or pressing skin boils or sores with needles.

　　2. Do a good job in the disinfection and isolation work of various wards in the hospital, to prevent cross-infection of pathogenic bacteria and opportunistic pathogens within the hospital.

　　3. Rational use of antimicrobial drugs and adrenal cortical hormones, attention should be paid to prevent dysbacteriosis. When infections caused by fungi and other drug-resistant strains occur, treatment should be adjusted in a timely manner. Once sepsis or kidney damage occurs, more powerful anti-infection and symptomatic treatment should be adopted, which is an effective measure to prevent kidney damage.

　　4. When performing various technical operations such as surgery, instrument examination, venipuncture, and catheter placement, strict disinfection should be carried out and aseptic operation should be paid attention to.

　　5. Actively control and treat chronic diseases that are prone to infection, such as leukemia, diabetes, chronic liver disease, etc.