Technology introduction
The so-called artificial liver technology is a new medical technology that uses blood purification technology to temporarily replace liver functions, so that liver cells can be restored and regenerated, and ultimately save the lives of patients. As early as 1986, Li Lanjuan, academician of the Chinese Academy of Engineering and director of the State Key Laboratory of Infectious Disease Diagnosis and Treatment of the First Affiliated Hospital of Zhejiang University School of Medicine, and her scientific research team began technical research in this field. His research results have not only won many national scientific and technological progress awards and major national scientific research projects, but also have been recognized and highly praised by the international community. This brand-new technology has been recognized by the international medical community, "opening up a new approach to the treatment of severe hepatitis and liver failure."
Technical features
Different from traditional treatment methods, the artificial liver support system can temporarily replace the damaged liver to'exercise' various functions, including: clearing the liver Jaundice and toxins supplement the coagulation factors and proteins synthesized by the liver itself.
Clinical statistics from the First Affiliated Hospital of Zhejiang University show that after the use of artificial liver technology, the cure rate of acute and subacute severe hepatitis in this hospital has increased significantly from 21.1% to 88.1%, and the cure of chronic severe hepatitis has improved. The rate increased significantly from 56.6% to 84.6%. Through the treatment, the patient's liver function was significantly improved, the plasma endotoxin and viral load were significantly reduced, and the disturbance of consciousness disappeared or improved significantly.
Asian people are susceptible to liver disease, with chronic hepatitis B patients accounting for more than 2/3 of the world. Statistics show that there are more than 90 million people with hepatitis B infection and more than 30 million patients with chronic hepatitis B in China. Among them, the mortality rate of severe hepatitis patients is as high as 80%. Many patients died of liver failure due to lack of effective treatment methods or unable to wait for a suitable donor.
Artificial liver technology has become an effective method for the rescue of critically ill patients in major hospitals across the country. Artificial liver technology can significantly reduce the fatality rate of patients with acute and subacute severe hepatitis. For those chronic severe hepatitis patients who do not have the ability to regenerate stem cells, artificial liver technology can also delay and effectively control the disease, gaining time for waiting for donors.
Method of operation
The domestic application of artificial liver technology is a complete set including plasma exchange, hemodialysis, hemofiltration, blood/plasma perfusion, molecular adsorption circulatory system, continuous blood purification The treatment and other methods are combined with the technology and treatment methods for the treatment of severe hepatitis. Clinicians choose to use the above techniques alone or in combination according to the patient's condition.
After admission, patients with severe hepatitis receive routine examinations and comprehensive medical treatment. The treatment group was given artificial liver support system treatment at the same time, and the methods of plasma exchange, hemoperfusion, hemofiltration, hemodialysis, and plasma adsorption were used alone or in combination according to the condition. If accompanied by hepatic encephalopathy, choose plasma exchange plus plasma perfusion; when accompanied by renal failure, choose plasma exchange plus hemodialysis or hemofiltration; when accompanied by hyperbilirubinemia, choose plasma-specific bilirubin Adsorption; when accompanied by water and electrolyte disorders, use plasma exchange plus hemofiltration or hemodialysis; sometimes at the same time, more than 3 methods are used in combination. The frequency and frequency of treatment should be determined according to the condition. The first and second weeks are 2-5 times a week, and then 1-2 times a week, with an average of about 3-5 times. The amount of plasma exchange is 3000-4600ml (50-70ml/kg). ), the blood flow rate is generally 60-150ml/min, the plasma separation rate is 15%-30% of the blood flow rate, the amount of plasma and substitutes added, albumin 20 -40g , the replenishment rate of the plasma exchange solution should be equal to The plasma separation speed is balanced. Routine application of dexamethasone or 10% calcium gluconate, heparin before treatment, the dosage should be determined according to the specific conditions of the patient. During the treatment, the thromboplastin time (ACT) was monitored repeatedly, and the amount of heparin and the amount of protamine at the end of the treatment were adjusted according to the ACT value. During the treatment, monitor the ECG and blood pressure, and closely observe the changes of the condition and the changes of transmembrane pressure and arteriovenous pressure.
The specific methods used are as follows:
Hemodialysis
Therapeutic principle: using the characteristics of certain medium and small molecular substances that can pass through semipermeable membranes, with the help of membranes The concentration gradient on both sides and the pressure gradient on both sides of the membrane remove toxins and small molecules from the blood to the body.
Standard dialysis: The membrane has a small pore size, which can only remove small molecular substances with a relative molecular mass below 500,000-300,000, such as urea nitrogen, creatinine, and blood ammonia.
High-throughput dialysis: dialysis using polypropylene eye membrane (PAN). The membrane has a large pore size and can pass through substances with a molecular weight of less than 15,000 000, including free bilirubin, free fatty acids, and aromatic amino acids.
Features: ①Mainly to remove small molecular substances. For example, the application of high flux membrane can remove part of the middle molecular substances. ②It can correct the common water and electrolyte disturbances and the imbalance of acid-base balance in liver failure. ③Affected by the pore size of the membrane, various toxins bound to the protein are difficult to remove. ④Suitable for various severe hepatitis with hepatorenal syndrome, hepatic encephalopathy, water and electrolyte disorders, acid-base balance disorders, etc.
Hemofiltration
Therapeutic principle: Use a membrane with a larger pore size, relying on the pressure difference between the liquids on both sides of the membrane as the transmembrane pressure, and convection the toxins in the blood. Removal by the removal of water is closer to the filtration function of the human kidney glomerulus, and it is more effective in the removal of middle molecular substances. The removal of middle-molecular substances does not depend on the concentration difference between the two sides of the membrane for dispersion removal, but by the pressure gradient along with the removal of water. Then the more water is removed, the more middle-molecular substances are removed. In the treatment, due to the loss of a large amount of water (up to 20L or more each time), a large amount of replacement fluid needs to be supplemented at the same time to maintain the body's fluid balance and electrolyte balance. This process is equivalent to the reabsorption function of the renal tubules.
Features: ①Mainly remove middle molecules and some macromolecular substances. ②It can correct the common water and electrolyte disturbances and the imbalance of acid-base balance in liver failure. ③Suitable for various severe hepatitis with hepatorenal syndrome, hepatic encephalopathy, water and electrolyte disorders, acid-base balance disorders, etc.
Plasma exchange
The principle of treatment: the patient’s blood is taken out of the body, the patient’s plasma is separated and discarded from the whole blood through a membrane plasma separation method, and then an equal amount of Replacement fluids such as fresh frozen plasma or human albumin can remove various metabolic toxins and pathogenic factors in the patient's body to achieve the purpose of treatment. Since the plasma exchange method can not only remove the metabolic toxins of small and medium molecules in the body, but also remove macromolecular substances such as proteins and immune complexes, the removal rate of harmful substances is far better than that of hemodialysis, hemofiltration, and hemoperfusion. At the same time, it supplements essential substances such as albumin and blood coagulation factors that are lacking in the body, which better replaces certain functions of the liver.
Features: ①It can remove small, medium and large molecules, especially for toxins bound to proteins. ②It has a certain effect on the correction of electrolyte disorders and acid-base balance disorders that are common in liver failure, but it is far less than hemodialysis and hemofiltration. There is no improvement in the situation of excessive water load. ③Using this method requires a large amount of plasma, which can supplement the human body with a large amount of protein, coagulation factors and other essential substances. However, if a large amount of blood products such as plasma is inputted many times, it may be infected with various new viral diseases. ④Suitable for all kinds of severe hepatitis patients. ⑤The replacement is mainly fresh frozen plasma (FFP), and some substitutes such as low molecular dextran, hydroxyethyl starch, etc. can be added.
Hemoperfusion
Therapeutic principle: The blood is directly sent to the hemoperfusion device and fully contacted with adsorbents such as activated carbon or resin, and the special pore structure of the adsorbent is used to reduce the toxicity in the blood. The substance is adsorbed and removed.
Features: ①Compared with conventional hemodialysis, activated carbon or adsorption resin has a higher clearance rate of middle molecular substances and protein-bound substances, and inhibits leukocyte inhibitory factors in the blood of patients with liver failure. Cytotoxic substances from hepatocyte growth, as well as bilirubin, aromatic amino acids, phenols, short-chain fatty acids, etc., can be effectively adsorbed. ②In the course of clinical treatment, hypotension and thrombocytopenia are prone to occur, which may be due to the adsorption and damage of white blood cells and platelets in the blood, and the release of amines that act on blood vessels, resulting in a drop in blood pressure. ③It has no corrective effect on the imbalance of water, electrolyte and acid-base. ④Suitable for various severe hepatitis complicated with hepatic encephalopathy, endotoxemia and acute poisoning. However, patients with significant reduction of platelets are not suitable for application, because it can lead to further reduction of platelets and increase the risk of bleeding.
Plasma perfusion
Therapeutic principle: Plasma perfusion is the application of plasma membrane separation technology to directly separate plasma from the blood and send it to the hemoperfusion device to separate the plasma This toxin is absorbed and then returned to the body.
Features: ①It can effectively remove the molecular toxins in the blood. ②No damage to formed elements such as platelets and red blood cells. ③It has no corrective effect on the imbalance of water, electrolyte and acid-base.
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Specific bilirubin adsorption
Therapeutic principle: The essence of specific bilirubin adsorption treatment is also plasma perfusion, mainly the applied perfusion device It has specific adsorption effect on bilirubin, has a small amount of adsorption effect on bile acid but has no effect or little adsorption effect on other metabolic toxins.
Features: Specific adsorption of bilirubin and a small amount of bile acid.
Molecular adsorption cycle
Therapeutic principle: MARS artificial liver uses existing dialysis technology to simulate the detoxification process of the liver, through MARS membrane (simulating liver cell membrane) and albumin dialysis (simulating liver Detoxification process) Selectively and effectively remove metabolic toxins from the body. MARS treatment includes 3 circulations: blood circulation, albumin circulation, and dialysis circulation.
The process of removing toxins in MARS system: One side of MARS membrane (MARS FLUX dialyzer) is in contact with blood containing toxins, and the other side is 20% albumin dialysate. The protein-bound toxins and water-soluble toxins in the blood are transported through the MARS membrane and transferred to the albumin dialysate circulation circuit; the protein in the dialysis binds toxins in the form of ligand-bound transport proteins; the toxins pass through the activated carbon adsorption column and anion exchange The adsorption column is removed, and the albumin dialysate can be regenerated and recycled; at the same time, water-soluble small molecules such as urea, uric acid, and creatinine are removed through the dialysis circuit.
Features: ① Effectively remove protein-bound toxins and water-soluble toxins. ② Correct the balance of water, electrolyte and acid-base.
Continuous blood purification therapy
Therapeutic principle: Continuous blood purification therapy is a more accurate way of continuous renal replacement therapy (CRRT) It is understood that the essence is continuous blood purification for 24 hours or more to treat kidney, liver, heart, lung and other multiple organ failures to replace part of the damaged organ functions.
Features: Because of its simulating kidney function, it slowly and continuously removes water, medium and small molecules to metabolize toxins, which is more in line with the physiological state, and can continuously maintain the body's environmental water, electrolyte, and acid-base balance And the stability of hemodynamics, eliminate inflammatory mediators and improve nutritional support. The operation is simple and can be carried out at the bedside.
The treatment modes are: CVVHD, CVVHF, CVVHDF, HVHF, CAVHD, CAVHF, CAVHDF, modified day CRRT, etc.
Indications: Various severe hepatitis is accompanied by multiple organ failure such as hepatorenal syndrome and hepatic encephalopathy, as well as water and electrolyte disorders, acid-base balance disorders, etc.
Heparinization method
According to the principle of individualization, heparin usually has three application programs: conventional application program, limited application program, and local heparin application program (in vitro heparinization). Patients who need artificial liver treatment often have poor coagulation function, and generally use limited application programs. Local heparinization is often used in patients with a high risk of bleeding.
Conventional heparinization
This method not only prevents blood coagulation in the extracorporeal blood circuit, but also prevents the coagulation process in the patient's body. It is relatively simple, but it may cause bleeding. Recent studies have confirmed that compared with unfractionated heparin, low-molecular-weight heparin has the same effect and significantly reduces adverse reactions, so it can be considered as a priority. There are two methods of using heparin in artificial liver treatment: continuous infusion and intermittent infusion.
①After the first dose of heparin is given by continuous infusion, the heparin is dissolved in normal saline, and the heparin is continuously and slowly injected into the blood circuit through a micropump.
②Intermittent infusion of heparin method This method is to give the first amount of heparin at the beginning of the artificial liver, and then give a small dose of heparin in the middle of the process.
Limited heparinization
Specific method: ①Determine the basal clotting time or ACT. ②The first dose of heparin given: 750U, not even the first dose. ③Start artificial treatment and maintain the heparin infusion rate at 600 U/h. ④ ACT was measured every 30 minutes, and the maintenance speed of heparin was adjusted accordingly. ⑤Continue heparin infusion until the end of treatment.
Extracorporeal heparinization
Extracorporeal heparinization is the local heparinization of the extracorporeal blood circuit, so that the blood remains heparinized in the extracorporeal circuit. The method is to use a heparin pump to continuously inject heparin at the arterial end of the vascular access (the pipeline through which blood flows from the patient's body), and continuously inject protamine at the venous end of the vascular access (the pipeline through which the blood is returned to the patient's body). The heparin returned to the patient is inactivated.
①Do not give the first heparin dose at the beginning of treatment. ② Continuously inject heparin with a heparin pump at the arterial end of the vascular access. Maintain the clotting time (CT) in the separator at about 30 minutes. ③ Continuously inject protamine with a syringe pump at the intravenous end, and the amount of protamine is based on the ratio of heparin to protamine obtained in the neutralization titration test. Generally, the amount of heparin per hour is 2-30mg, and the ratio of heparin to protamine is 1:1. During treatment, it is necessary to repeatedly measure the CT of the arterial and venous ends of the vascular circuit, and adjust the heparin dose. ④ After the treatment, routinely inject 10-15 mg of protamine, and repeat the injection after 4 hours if necessary. The rebound phenomenon of heparin (after the completion of extracorporeal heparinization treatment, after the anticoagulation effect disappears and the clotting time has returned to normal, the anticoagulation effect appears again, causing bleeding after treatment), which requires close attention. Generally, heparin rebound usually occurs 3-4h after treatment, and the longest can be up to 18h. Therefore, at the end of artificial liver treatment, if the coagulation time of the patient is longer than normal, a small dose of protamine should be added.
Physical and chemical properties of protamine
Protamine is a low molecular weight protein. Originally extracted from fish, there are many strong bases that can be combined with heparin containing acidic groups to inactivate heparin. Each 5ml of protamine contains 50mg of protamine. The neutralization reaction between heparin and protamine is a simple electrochemical reaction, that is, the positively charged protamine neutralizes the negatively charged heparin.
The adverse reactions of protamine are as follows: ①Bleeding tendency. Large doses of protamine also have anticoagulant effects and can cause bleeding. Therefore, the dosage of protamine over 100mg should be avoided in a short time. ② Protamine allergic reaction Under normal circumstances, protamine is not antigenic. But sometimes it can also cause bradycardia, dyspnea, low blood pressure, and facial flushing, suggesting the occurrence of allergic reactions. In most patients, the allergic reaction is mild and can be closely observed without treatment, and can relieve itself in a short time. If it cannot relieve itself, it should be dealt with in time.
Artificial treatment without heparin
For patients with a high risk of bleeding, the coagulation time has exceeded 30 minutes before treatment, and conventional anticoagulation methods are used for artificial liver treatment , Can aggravate bleeding tendency. For these patients, heparin-free therapy can be used.
The treatment of artificial liver without heparin includes ① heparin flushing, flushing the extracorporeal blood circuit with saline containing 3000U heparin per liter. In order to prevent the heparin-containing solution from entering the patient's body, the extracorporeal blood circuit can be flushed with the patient's blood or heparin-free saline. ②Improve the blood flow speed to prevent blood stagnation in the extracorporeal blood circuit. If the patient can tolerate it, the blood flow speed can reach 120-130ml/min.
Limited heparinization, extracorporeal heparinization, and heparin-free artificial liver treatments are more troublesome in actual operation, prone to extracorporeal circulation coagulation, and require more proficient clinical operation experience. Be cautious in actual selection.
Nursing methods
1. Nursing before artificial liver treatment
①The purpose of psychological nursing is to alleviate the psychological tension and anxiety of the patient, and try to rescue the patient from the psychological crisis.
②Observe the condition A. Ask a detailed medical history before treatment, understand the patient’s course time, liver and kidney functions, especially total bilirubin, prothrombin time, blood type, history of bleeding, platelet count, Whether there are early manifestations of hepatic coma, etc., be aware of it to facilitate observation during treatment. If you have a history of allergies to plasma, preoperative anti-allergic treatment can reduce the risk of intraoperative allergies. To avoid interruption of treatment due to allergies, once patients with hyperallergic physique can choose bilirubin adsorption treatment. B. Monitor body temperature, pulse, respiration, blood pressure, and heart rate. Artificial liver treatment can be performed only after correction of low blood pressure, fast heart rate, and high body temperature. C. Do a good job in hygiene education: Instruct patients to drink as little water as possible before treatment and prepare a high-quality breakfast to avoid hypoglycemia and hypotension. Before surgery, you should gradually exercise on the bed to relieve your bowels and urinate to prevent you from getting used to the bed during and after the treatment. Getting out of bed too often can cause the intubation to fall off and shift or affect the healing of the wound after extubation. In order to relieve the psychological burden, it should be explained that this treatment is an internal medicine method and not an operation.
2. Artificial liver treatment technology nursing
①Operation method and disinfection and isolation A. Before entering the treatment room, medical staff must wear hats, masks, change working shoes, wear isolation gowns, and wear disinfection gloves during operation. During the process of medical staff contacting the patient, flushing the pipeline and puncturing the blood vessel, there is also the potential risk of self-infection and infecting others. Before the operation, the hands can be soaked with 0.05% iodophor disinfectant for 5-10 minutes.
B. Separator flushing. Plasma exchange separator and blood circuit disinfection: extracorporeal circulation pipelines and separators need to be installed aseptically. Flush the pipelines with 1000ml of normal saline at 38°C, and then use 500ml of physiological saline. 20mg of saline and heparin to flush the pipeline. The flushing of the blood perfusion pipeline: the installation and flushing process varies according to the type of the perfusion device, please refer to the instruction manual. When flushing, the arterial end faces down vertically. The activated carbon infusion device requires 500ml of 5% glucose saline to combine the charcoal with glucose to reduce the drop in blood glucose level during infusion. Other infusion devices require saline flushing. The flushing of the bilirubin adsorption tube: basically similar to the plasma exchange device, because the bilirubin adsorber needs to be added, first use 2000ml of 38℃ normal saline when flushing, and then use 500ml of normal saline plus 20mg of heparin to flush the tube . Fully remove the microbubbles in the separator or perfusion device. After the treatment, the treatment instrument is scrubbed with 0.5% peracetic acid solution, and the loop and separator are treated with dirt or strictly disinfected with 20% glutaraldehyde before being discarded. Repeated application is not allowed to avoid cross-infection. C. Room temperature adjustment During treatment, patients are often susceptible to chills and chills due to the replenishment of a large amount of plasma and fluid. Therefore, it is necessary to keep the room temperature constant. Keep the room temperature at about 26-28°C in summer and 28-30°C in winter. Plasma and liquid should be preheated in water temperature of 37-38℃, and the temperature of the treatment device should be adjusted to about 38-39℃.
②Observation and treatment of complications during treatment
The following points must be paid attention to during operation:
A. Properly preserve and thaw plasma, protein products, and freeze The plasma should be shaken and melted in a 37°C water bath. The water temperature should not be too high, otherwise it will cause protein coagulation. The prepared plasma should be used within 6 hours, and 4 hours in hot weather.
B. Strictly implement three checks and seven pairs, the same blood type should be the principle, and the time on the plasma label should be checked and the packaging is not damaged.
C. Deal with allergic reactions in time. For mild cases such as skin itching, 4 mg of astemizole can be taken orally. For severe cases, such as blood pressure drop, nausea, vomiting, and chills, plasma infusion should be stopped immediately and the infusion should be changed temporarily. Albumin and oxygen inhalation, dexamethasone 5 mg intravenous bolus or 12.5 mg phena root injection intramuscularly, stop treatment for patients who are ineffective after treatment.
3. Monitoring and nursing of patients after artificial liver treatment
After artificial liver treatment, patients still need to be strictly observed and cared for.
①Monitoring of changes in blood biochemistry during artificial liver treatment will reduce plasma protein, and sometimes electrolytes can be changed. For example, blood sugar changes in diabetic patients are greater. Regularly monitor blood biochemistry and prothrombin time, and find out in time. Given the corresponding treatment, patients can avoid unnecessary complications. Monitoring blood biochemical changes also helps to observe the effects and changes in the condition.
②Monitor body temperature, prevent infection, measure body temperature, pulse, blood pressure every day; oral care: rinse mouth with 0.02% metronidazole solution, 4-6 times a day, keep the mouth clean and moist; skin care: every Wipe the bath with warm water every day to keep the skin and mucous membranes clean and dry; it is best to set up a single room, keep the air in the sick room fresh, the temperature and humidity are appropriate, reduce the number of accompanying persons, and irradiate with quartz ultraviolet light for 1 hour every day. Use 0.5% peracetic acid solution to wipe the tabletop and floor. Strictly follow the principle of sterility during the operation. Observe the bleeding of the wound, the dryness of the dressing, and whether the wound is contaminated after urination and defecation.
③Nursing care of vascular access A. Vascular access is the second lifeline for patients undergoing artificial liver treatment and a guarantee for smooth artificial liver treatment. How to care for the patient's vascular access and reduce catheter-related bacteremia is an important part of treatment and care.
The preventive effect of antibiotic sealing tube: The antibiotic sealing method can effectively prevent or cooperate with the treatment of catheter-related bacteremia. After each artificial liver treatment, the tube is sealed with sensitive antibiotics to keep the antibiotic solution In the lumen of the catheter. Maintain until the next artificial liver treatment. The turbidity appears after mixing gentamicin and heparin, but it does not affect the curative effect.
B. Prevent the catheter from coming out, causing it to be fixed with the skin with sutures. Sometimes it is easy to cause the suture to detach from the skin if it is stretched or left for a long time. The action should be light when the tube is connected. For comatose patients, the indwelling catheter should be bandaged to prevent the catheter from being pulled out when the patient is irritable.
C. Reduce the contamination of the catheter lumen, indwell the double-lumen catheter to avoid other uses (infusion, blood sampling, etc.) to reduce the number of openings of the spiral heparin cap.
Prevention and treatment of complications
1. Bleeding
Many patients who need artificial liver treatment have blood coagulation dysfunction, and then anticoagulation with drugs, some patients may have bleeding complications.
①Bleeding at the intubation site is clinically manifested as bleeding, subcutaneous hemorrhage or hematoma at the intubation site. In severe cases, it can be life-threatening. The reasons include accidental injury to the artery or deep vein during intubation, rupture of the indwelling catheter or failure of the switch, loosening or shedding of the junction between the indwelling catheter and the skin, etc.
②The clinical manifestations of gastrointestinal bleeding include hematemesis, bloody stools, melena, and severe cases may quickly appear irritability, fatigue, nausea, thirst, pale skin, clammy, fast pulse, decreased blood pressure, cyanosis, Symptoms such as oliguria. Emergency gastroscopy revealed diffuse bleeding of the gastric mucosa. Therefore, preventive antacids should be used routinely before surgery. Patients with obvious bleeding tendency or positive fecal occult blood should use heparin as little as possible during surgery or use extracorporeal heparinization. Once massive gastrointestinal bleeding occurs, the amount of bleeding should be estimated correctly, and treatments such as volume expansion, antacids, and hemostasis should be given in time.
③Skin and mucosal bleeding can be clinically manifested as epistaxis, skin petechiae, and ecchymosis.
④Intracranial hemorrhage is the most serious hemorrhagic complication, and the amount of hemorrhage is often large, and patients are prone to brain herniation and death.
2. Coagulation
If the amount of anticoagulant drugs in patients receiving artificial liver treatment is insufficient, blood coagulation is prone to occur, which manifests as coagulation in the perfusion device and coagulation in the indwelling tube.
①The clinical manifestation of perfusion coagulation is a sharp increase in transmembrane pressure (TMP), followed by a gradual increase in arterial pressure, leading to clinically high TMP, causing mechanical damage to blood cells, resulting in artificial After liver treatment, blood cells decreased significantly, especially platelets, or the artificial liver treatment could not be continued because the TMP exceeded the warning value.
②Indwelling tube coagulation can cause indwelling tube coagulation due to insufficient heparin concentration or insufficient dosage. Clinically, the blood flow is not smooth during artificial liver treatment. Therefore, when indwelling and sealing the tube, the amount of heparin should be appropriately larger, and a sufficient dose should be given according to the length of the indwelling tube.
3. Hypotension
Prevention and treatment: ①Patients with hypoalbuminemia receive plasma, albumin or other colloidal solutions before or during the artificial liver treatment to maintain the patient's plasma osmotic pressure. ②Patients with severe anemia should be supplemented with blood before artificial liver treatment. ③ Those who are allergic to drugs or plasma will be given anti-allergic treatment in advance. ④Correct acid-base balance, water and electrolyte disorders. ⑤Treat arrhythmia. ⑥ Patients undergoing artificial liver treatment should closely observe the changes in blood pressure and heart rate during the operation. ⑦ Once the blood pressure is low or the clinical symptoms are obvious (pale, sweating), if it is caused by non-cardiogenic causes, immediately inject normal saline to replenish blood volume, but the amount of rehydration should not be too much, and control as appropriate. After rehydration treatment If the blood pressure still does not rise, blood pressure drugs should be used immediately. If there is arrhythmia, treat it as arrhythmia. ⑧Hemoperfusion syndrome, anti-platelet aggregation drugs such as persentine and aspirin can be taken in advance to prevent the adhesion of platelets and activated carbon. Prostaglandin, as an auxiliary anticoagulant of heparin, is suitable for patients with hepatic encephalopathy undergoing hemoperfusion therapy. It can reduce the occurrence of complications such as hypotension and thrombocytopenia during perfusion, or switch to plasma perfusion to reduce its incidence.
4. Secondary infection
①Patients with temporary intubation (subclavian or internal jugular vein, femoral vein) for infection related to the artificial liver treatment circuit develop fever. If no obvious infection is found, Blood culture should be done, the indwelling tube should be pulled out in time, and the head of the catheter should be cut off for culture. If the infected catheter is not removed in time, it may cause serious bacterial infection complications (such as sepsis, etc.). Before the blood culture results are reported, it can be treated with antibiotics such as compound penicillin, first and second low cephalosporins, aminoglycosides, fluoroquinones, and vancomycin. However, the choice of antibiotics is not absolute, and depends on the drug sensitivity of common bacteria in the area where the patient is located. Staphylococcal bacteremia in patients can cause endocarditis; therefore, patients with staphylococcal bacteremia should not only remove the indwelling tube, but should also be treated with sensitive antibiotics for at least 4 weeks.
②Artificial liver treatment of patients with blood-borne infections. Artificial liver treatment includes hemodialysis, hemofiltration, blood (plasma) perfusion, plasma exchange and bioartificial liver, etc., especially plasma exchange, which requires a large amount of Allogeneic plasma is prone to blood-borne infections. Due to my country's emphasis on hepatitis B virus testing and the maturity of testing technology, and the vast majority of patients undergoing artificial liver treatment are hepatitis B virus infections, the risk of blood-borne infection is more focused on hepatitis C virus infection and HIV infection.
5. Allergic reactions
①Plasma substitutes Plasma substitutes are increasingly used in the treatment of artificial liver. In addition to supplementing blood volume, they are also used as a substitute for self-transfusion and blood dilution. During use, the human body may have various reactions, some of which are allergic reactions, and most of them are allergic-like reactions (also known as allergic reactions), that is, have nothing to do with antigen-antibody reactions, and IgE antibodies and others cannot be detected in the blood. Immunologically active substances, and the clinical manifestations are urticaria, dyspnea, cardiovascular symptoms, gastrointestinal symptoms and other similar allergic reactions. Commonly used clinical plasma substitutes include dextran, gelatin solution and hydroxyethyl starch (HES), among which gelatin solution also includes blood generation and blood stability. Patients with symptoms such as hypotension, shock, and bronchospasm should take active and effective treatment measures immediately. Quickly open the intravenous access to infuse a large amount of fluid, restore blood volume, and correct arterial hypoxia. If there is airway obstruction, you should immediately inject epinephrine 5μg/kg. For more intractable bronchospasm, aminophylline should be given. In severe hypotension, dopamine, epinephrine or norepinephrine can be given. Some other drugs that are effective in the treatment of allergic reactions include cortisone, isoproterenol, atropine and so on. Patients with cardiac and/or respiratory arrest must undergo cardiopulmonary resuscitation immediately.
②Allergic reactions to protamine (see above)
③Allergic reactions to fresh frozen plasma mostly occur in the late stage of blood transfusion or at the end of the blood transfusion, usually showing urticaria, eye Facial vascular nerve edema often subsides after a few hours.
6. Common alarm principles and treatment during treatment
①When power failure alarm treatment, if there is a sudden power failure, manually rotate the blood pump to maintain the blood flow 100-130ml/min, restore the power supply as soon as possible, and the power supply will not be available within half an hour. Treatment should be terminated.
②The bubble alarm should check whether there are bubbles in the venous line above the defoamer or whether the blood level of the defoamer is too low, and deal with the above situations accordingly.
③The reasons for the increase in venous pressure include poor blood return, insufficient heparin, and compressed, angled, twisted, and blocked pipelines. The cause of the drop in venous pressure is the loss of the tube and the drop in blood pressure. All are handled according to judgment.
④In the arterial pressure observation, the increase in arterial pressure is mostly caused by poor blood flow in the arterial duct. Reduce the blood pump flow or adjust the puncture position and direction or check whether the plasma separator is blocked and unnecessary forceps are clamped on the circuit.
⑤ A large amount of colder plasma is exchanged into the patient's body by temperature regulation, which can produce chills and chills. Prevention method: heat the outside of the plasma bag to 37°C, and warm the tubing to 38-39°C during treatment.
⑥ Observation of transmembrane pressure The increase in transmembrane pressure is mostly caused by insufficient heparin dose or too fast blood flow. Treatment method: increase the amount of heparin, slow down the blood flow rate, and rinse with normal saline to adjust.
Treat H7N9
In April 2013, Fang Qiang, the chief physician of the ICU ward of the First Affiliated Hospital of Zhejiang University School of Medicine, stated that Zhejiang Yi "Blood purification technology" was grafted to the treatment of "H7N9 avian influenza". This technology has been put into use on 6 H7N9 avian influenza patients. Among them, the lung inflammation of the first patient using this technology has improved significantly.
Principle
The reason why the "artificial liver" technology is applied to the H7N9 avian influenza virus, the important principle of human infection with H7N9 avian influenza virus causing severe pneumonia and acute respiratory failure is "inflammation "Storm" means that the patient's inflammation develops rapidly, and there is a viral substance in the patient's blood, which accelerates the spread of inflammation. Therefore, trying to use a way to excrete the poisonous substances in the blood from the body, so as to observe the patient's inflammation.
Effect
The hospital has already used "artificial liver technology" for treatment of 6 patients with H7N9 avian influenza. Among them, the lungs of the first patients who used this technology have improved significantly , The transparency of the lungs increases, and the oxygen and condition begin to improve. In addition, the five critically ill patients using this technology are still alive.
Note
Not all H7N9 avian influenza patients can use this technology. It is limited to some high-risk and dying patients. Apply this technology to H7N9 avian influenza More in-depth research and exploration is needed for the treatment of the disease, but overall, the signs are good.