What is CRRT?
In 1995, at the first international CRRT academic conference held in San Diego, USA, CR
RT was officially defined as: all treatments that can continuously remove solutes and have an impact on organ function. Supports effective blood purification technology.
During World War II, Canada's Murray and Delmore successfully developed the first artificial kidney machine
and used it for clinical treatment of renal failure in 1946. Later, blood purification technology Get
rapid development. Blood purification is to guide the patient's blood outside the body and pass it through a purification device to remove certain pathogenic substances and purify the blood to treat diseases. It mainly includes hemodialysis, hemofiltration, hemodiafiltration, hemoperfusion, plasma exchange, immunoadsorption, peritoneal dialysis, etc. At present, blood purification therapy is not only used to treat patients with acute and chronic renal failure
, but has also been widely used in the rescue treatment of critically ill patients.
Continuous renal replacement therapy (CRRT) is a new blood purification technology that has achieved great development in the past ten years.
It refers to the slow and continuous removal of water and solutes. treatment modalities. As early as 1977, Karmer initially created continuous arteriovenous hemofiltration (CAVH) technology to treat acute renal failure and achieved good results. Later, according to clinical Needs have led to a variety of CRRT
modes, such as arteriovenous slow continuous ultrafiltration (SCUF), continuous venovenous hemodiafiltration (CVVHDF), continuous venovenous hemodiafiltration (CVVHDF), and continuous venovenous hemodiafiltration (CVVHDF). Hemodialysis (CVVHD), etc. CRRT technology adopts a continuous operation method (often for 24 hours); increases the blood flow in extracorporeal circulation and uses high-throughput, biocompatible It has a high-performance filter, equipped with a large amount of replacement fluid, and a precise liquid balance system. The above improvements allow CRRT to ensure that patients have stable blood flow
mechanics; it can continuously and stably control azotemia and electrolyte and water and salt metabolism; it can constantly
clear existing substances in the circulation of toxins and mid-molecule substances; providing nutritional supplements as needed and a series of other advantages
It provides the homeostasis balance required for the treatment of critically ill patients, can be applied even under hypotensive conditions, and at the same time creates good nutritional support conditions.
In the past, CRRT technology emphasized the purification effect and stabilizing the internal environment; in recent years, the international focus has been on exploring the role of CRRT technology in the treatment of sepsis, systemic inflammatory response syndrome and multi-organ dysfunction
The mechanism and efficacy of injury, as well as the replacement effect of tissue gaps.
Second question, what does CRRT do?
At this year’s National Kidney Disease Annual Meeting, Academician Li Leishi from the PLA Institute of Nephrology and Nanjing University School of Medicine mentioned that “CRRT is actually more than just a group of related
Medical measures to maintain kidney function. It can also remove various metabolites,
toxicants, drugs and various pathogenic biomolecules while regulating the balance of body fluids and electrolytes. "Therefore, it can be said that the therapeutic scope of CRRT has far exceeded the field of kidney disease, and has recently developed into artificial liver support systems and severe heart failure and severe acute respiratory diseases. Adjuvant treatment of functional failure has become one of the most important support measures in the treatment of various critical illnesses. The clinical application of CRRT has become as important as mechanical ventilation and total gastrointestinal and parenteral nutrition. Specifically, it applies to the following situations.
Acute renal failure (ARF) is accompanied by cardiac dysfunction, cerebral edema and hypercatabolic CRRT
CRRT can correct the volume load, gradually reduce the left ventricular filling pressure, and remove medium and large molecules Inflammatory mediators.
CRRT has stable hemodynamics and can protect cerebral perfusion pressure, and is the first choice for patients with severe ARF and cerebral edema.
CRRT can adequately regulate fluid balance and tolerate the required dose of parenteral nutrition.
It can excellently control metabolic abnormalities in patients with ARF complicated by hypercatabolism.
CRRT in multiple organ failure syndrome (MODS) can clear a variety of inflammatory factors, such as TNFα,
IL-1, IL-6, IL-8, etc., thereby delaying the development of Functional impairment of multiple organs caused by similar factors.
CRRT can also clear myocardial inhibitory factors, thereby preventing complement activation. Therefore, it is suitable for the treatment of MODS and
adult respiratory distress syndrome.
Systemic inflammatory response syndrome (SIRS) CRRT can well remove inflammatory mediators and is suitable for acute pancreatitis, especially severe necrotizing pancreatitis, septic shock and severe cases. Treatment of people with burn disease
.
Acute liver failure and liver transplantation Because CRRT can connect filtration, adsorption replacement, nutrition, and
extrahepatic auxiliary therapy devices in series to remove a large number of toxins related to liver disease, it can be used For fulminant liver failure, the auxiliary treatment during and after liver transplantation is the "non-biological artificial liver support system".
CRRT for congestive heart failure can quickly restore fluid balance, increase angiotensin, noradrenaline, and aldosterone levels, correct hyponatremia, and interrupt the vicious cycle. , clear
remove pulmonary edema or systemic edema and restore responsiveness to diuretics. Therefore, CRRT can treat acute heart failure with severe edema, acute pulmonary edema, liver failure or nephrotic syndrome with uncontrollable edema, etc.
The powerful filtration and removal effect of CRRT in drug and poison poisoning has been
used in clinical treatment. In addition to a variety of drug poisoning, it is also used in the poisoning and treatment of heavy metal poisons. Severe lactic acidosis, crush injury syndrome, acute hemolysis, high fever, heat stroke, etc.
Three questions: How to use CRRT?
The use of CRRT requires the establishment of a continuous blood extracorporeal circulation system at the patient's bedside; the use of
high-permeability and biocompatible filters; and high-precision liquid balance system.
There are two main types of CRRT replacement fluids currently in use. One is commercial replacement fluid, but it is not suitable for patients with damaged liver function because
it contains more lactate. , what is more commonly used clinically is self-preparation of various electrolyte liquids through intravenous infusion. For example, the improved PORT formula can obtain a final electrolyte concentration that is equivalent to human extracellular fluid. There is no conclusion yet on the amount of replacement fluid input in domestic and foreign academic circles. Acute renal failure usually requires 12 to 24 liters of replacement fluid per day, while sepsis or SIRS requires 12 to 24 liters of replacement fluid per day. A large amount of replacement fluid is used to remove inflammatory factors, up to 60 to 75 liters per day.