Malignant pleural fluid, ascites occurrence principle and symptom manifestation The human thoracic cavity, abdominal cavity and pericardial cavity are collectively known as the plasma cavity. In a normal human being in a physiological state, these cavities contain a small amount of fluid inside. When the lungs do respiratory movements and the gastrointestinal tract does digestive peristalsis, this fluid acts as a friction-reliever between the lungs, the gastrointestinal tract and their sidewall plasma membranes, helping the movement of the body’s organs. These fluids are as indispensable as the lubricant in a car engine. In normal times, no fluid is usually collected in these cavities; however, in pathological states, the balance of fluid production and absorption in the plasma membrane cavities is disrupted, generating excessive fluid accumulation in these cavities, i.e., pleural fluid or ascites. Severe and large amounts of fluid accumulation can compress internal organs and cause many uncomfortable symptoms such as difficulty in breathing, heart pressure, and abdominal distension in humans. Malignant pleural fluid is common in advanced lung cancer, with an incidence of up to 60%, often increasing in a progressive manner. The cause is mainly due to the invasion and obstruction of capillaries and lymphatic vessels by metastatic nodules in the pleura, so the pleural fluid contains a large amount of protein and blood-forming components, and hemorrhagic pleural fluid accounts for about 75%. Patients with malignant pleural fluid mostly prefer to lie on the affected side, and in severe cases, they mostly take a semi-recumbent position and cannot lie flat, the affected side of the thorax is full, the respiratory movement is weakened, and in severe cases, respiratory distress and hypoxia can occur, such as shortness of breath when moving, open-mouth breathing, and cyanosis of the face and lips. Malignant ascites is common in gynecological tumors, gastrointestinal tumors and hepatocellular carcinoma, and is also dominated by hemorrhagic ascites. In the case of ascites caused by malignant tumors, abdominal distention is the earliest and most basic symptom. Most of them have vague abdominal pain with progressive aggravation; often accompanied by low fever, weakness and generalized hyperemesis. The patient’s abdomen is bulging, and the abdominal wall is taut and shiny, which may appear as a bulge or frog-like change. Palpation of the abdomen may often palpate a mass with unclear borders, poor mobility, unsmooth surface and pressure pain. General principles of management of malignant pleural fluid and ascites When a patient goes to the doctor and is found to have pleural fluid or ascites, the doctor will first arrange an ultrasound examination, which can identify whether the ascites is free or separated and exclude ovarian cysts, abdominal abscesses and hematomas; the ultrasound can also guide the localization of thoracic or abdominal puncture. Subsequently, most of the time, a portion of the pleural or ascites fluid needs to be extracted. First, in the presence of a large amount of fluid, the symptoms of compression are relieved by aspiration of some of the pleural or ascites fluid; second, the nature of this pleural or ascites fluid should be analyzed by laboratory tests. A number of tests such as physical and chemical characteristics, microbiology, immunology, and cytology of the pleural or ascites fluid can assist the physician in diagnosing the primary disease causing the pleural or ascites fluid. Diseases such as tuberculosis, lung abscess, bronchopulmonary cancer, metastatic tumors, lymphoma, heart failure, cirrhotic portal hypertension, nephrotic syndrome, etc. can be diagnosed or assisted by laboratory analysis of pleural or ascites. The examination of thoracoabdominal fluid includes: routine examination of thoracoabdominal fluid, chemical examination, bacteriological examination, exfoliative cell examination and joint detection of tumor markers, which is an important basis for determining benign and malignant tumors and distinguishing primary and secondary tumors. At present, the tumor marker CEA (carcinoembryonic antigen) has been widely used in the detection of pleural or ascitic fluid, CEA is a large molecule, which is easily degraded in blood, and CEA is higher in malignant pleural and ascitic fluid than in blood. However, the diagnostic accuracy, sensitivity and specificity of single index are not satisfactory, CEA and AFP, CA19-9, CA125, CA242 combined test have higher diagnostic value and can improve the sensitivity of diagnosis. 2, symptomatic treatment: for the moderate amount of malignant thoracoabdominal fluid, the main thing is to supplement albumin, improve the colloid osmotic pressure in the blood, reduce exudation, and pay attention to replenishing electrolytes while using high-dose diuretics to accelerate drainage. When malignant thoraco-abdominal fluid increases to a large amount and patients have obvious pressure symptoms, at this time, puncture can be performed appropriately to release fluid, which can reduce patients’ pressure symptoms on the one hand, and at the same time, thoracic or abdominal cavity can be administered after drainage of thoraco-abdominal fluid to play a therapeutic role. Patients with malignant thoracoabdominal fluid can generally be injected with chemotherapeutic drugs: cisplatin or 5-fluorouracil, etc. After the injection, the patient is instructed to continuously change position (about 20 minutes to change position once), so as to facilitate the mixing of drugs in the cavity. Although direct extraction of large amount of thoracoabdominal fluid can quickly relieve the symptoms of compression, however, thoracoabdominal fluid contains more nutrients and protein is also leaked out. Long-term simple extraction of thoracoabdominal fluid can easily cause hypoproteinemia and water and electrolyte disorders, so that thoracoabdominal fluid leaks out more and faster. After the drainage of malignant pleural fluid is complete, it is also possible to inject intrapleural cavity: mushroom polysaccharide, thymopentin, interleukin-2, high polysaccharide and other biological response regulators, which can activate the cellular immune function of the body to produce artificial active immunity in the pleural cavity, prompt the immune cells and fibrin exudation, make the dirty and wall layer pleural adhesion, achieve the purpose of closing the pleural cavity, and also reduce the pleural fluid leakage. The treatment of malignant ascites is tricky, and intestinal adhesions often occur easily if some drugs are improperly applied in the peritoneal cavity. If abdominal distension is obvious, moderate extraction of ascites can be considered, but repeated extraction of ascites can result in loss of large amounts of protein and blood components and can easily lead to peritonitis. Intraperitoneal injection of chemotherapeutic agents may be effective for sensitive tumors, but often the ascites is not controlled for long and can be used for patients in good general condition. Malignant pleural fluid, ascites life conditioning Bed rest, increased protein: patients drainage of pleural fluid, ascites during more bed rest. Bed rest increases hepatic blood flow, while renal blood flow also increases, aldosterone secretion decreases, so that the glomerular filtration rate increases and urine volume increases. After ascites extraction, the abdomen can be wrapped with a lap band to increase intra-abdominal pressure to reduce intra-abdominal exudation, but it should not be wrapped too tightly so as not to cause discomfort to the patient. The thoraco-abdominal water contains a large amount of nutrients, and a large amount of extraction of thoraco-abdominal water can cause a large amount of protein and nutrients to be lost. At this time, a high-protein diet should be given, which can increase the plasma protein content and protect the liver, such as various fish, milk, eggs, lean meat and other animal proteins and soybean products like vegetable proteins, fresh fruits and vegetables, etc. However, it should be noted that, 1. If the liver function of patients with advanced liver cancer is significantly reduced or the aura of liver coma appears, in order to reduce the burden of liver and the concentration of ammonia in blood, so as to avoid further deterioration of the disease, the protein intake should be strictly limited. Then protein intake should be strictly limited, not more than 20 grams per day. 2. Control the intake of water and sodium: control the daily water intake to about 1500 ml and control the amount of intravenous fluids to maintain the balance of outgoing and incoming fluids. Control sodium intake, because water retention depends on sodium retention. Reduce sodium intake can make the urine volume increase, ascites has receded. 3, diet conditioning: reasonable rich nutrition and calories for the recovery of the body is positive, to ensure that the daily calories in 2000Kcal or more, to supplement carbohydrates, to eat less and more meals, especially in the emergence of ascites, pay more attention to reduce the amount of food each time, so as not to increase the feeling of fullness and discomfort. Those with hepatic portal hypertension combined with esophageal varices should be given liquid diet, such as vegetable puree, meat froth, rotten rice, etc. In case of upper gastrointestinal bleeding, fasting should be given.