Supplement deficiency, damage surplus, no monitoring, careful nutrition

Source: parenteral and enteral nutrition modern clinical nutrition support and treatment has experienced half a century of development, from understanding and imitating physiology, to exploring and correcting pathology, from heat support conforming to physiology, to metabolic treatment intervening pathology; Parenteral nutrition has become one of the public platforms for clinical multidisciplinary treatment, especially for the treatment of severe patients Since 2016, several academic organizations in the European and American critical and clinical nutrition circles have successively or jointly or separately updated several clinical nutrition guidelines or consensus on critical patients What they have in common is that they all emphasize that parenteral nutrition is not recommended for severe patients in the early critical period, but only enteral nutrition with different caloric content suitable for patients' utilization ability The changes are exactly in line with the author's long-term appeal I'm glad that I would also like to elaborate my own views on nutrition therapy and metabolic regulation of severe patients First, the patients with acute severe diseases will try their best to mobilize the body's own strength to resist the invasion and damage of pathogens In fact, the patient's body is in a strong state of metabolic stress at this time For a long time, it was thought that catabolism increased and anabolism decreased in the stress of disease and trauma But with the emergence of radioimmunoassay and other means, we know that in the early stage of intense stress, the body is in an unbalanced state of hypermetabolism, both catabolism and anabolism are increasing, but the marker of anabolism is no longer the white protein and muscle protein in physiological state, instead of various acute phase proteins, such as various (inflammatory) cytokines Including tumor necrosis factor (TNF) - α, interleukin (IL) - 6, IL-10, C-reactive protein, procalcitonin, fibrinogen, etc in order to avoid complete failure of organ function, some organ cells and mitochondria are indeed dormant, but other cells and mitochondria are still working desperately Most of the raw materials for the synthesis of the above acute phase proteins come from the patients themselves, that is, the amino acids provided by the decomposition of their own muscles and visceral proteins On the one hand, the continuous decomposition of visceral and muscle proteins will lead to organ structural damage; on the other hand, a large number of acute phase proteins will be produced continuously, which will maintain and intensify the inflammatory response of the body; Finally, this vicious circle leads to organ dysfunction and even life-threatening Muscle and visceral proteins have different amino acid structure components with various cytokines With the help of different transaminases, many tissues and cells of the body must try to transform the amino acids produced by the decomposition of muscle and visceral proteins into the amino acids needed for the formation of various cytokines, thus increasing the metabolic burden of the body's tissues and organs; however, the amino acids that are not needed or difficult to be converted and utilized are finally discharged from the body through the kidney Therefore, the above-mentioned metabolic process of acute stress is actually the process of aggravating the burden of catabolism and anabolism of all organs and tissues of the body It is also the pathophysiological basis for people's appetite to decline at the beginning of a serious disease, so as to protect themselves by reducing the burden of organ metabolic stress by reducing food intake Based on the progress of the above knowledge, in the past 20 years, the so-called "metabolic conditioning, nutrition therapy" concept has gradually been accepted by the majority of people That is to say, the supply of amino acids (as well as lipids) necessary for some inflammatory reactions is deliberately increased or limited by supplement of nutrient substrates, that is, the so-called "supplement deficiency, damage surplus", to regulate the metabolic stress response of the body, not only to reduce the decomposition of visceral and muscle proteins, but also to reduce the excessive inflammatory response of the body, and ultimately to achieve the purpose of metabolic therapy to protect organ functions Second, the concept of "metabolic regulation" was introduced carefully without monitoring, which gradually replaced the previous concept of nutritional support which aimed to achieve the specified calorie Therefore, in recent years, many studies have been carried out on the so-called "restricted (low calorie) feeding" at home and abroad, and the conclusions vary greatly from the initial stage to the consensus on the early critical stage of severe patients after the recent stratified study and analysis (such as the aforementioned guidelines), and in addition to the "restricted low calorie feeding", the concept of "increasing protein supply" has also been put forward 。 It is one of the important principles of nutritional support for severe patients to give high protein feeding, which can reduce the decomposition of body muscle and visceral protein by supplementing exogenous amino acids However, protein supplementation is still very particular: it is mainly suitable to be supplemented through the gut, and due to the reduction of protein synthesis such as various normal digestive enzymes during the acute stress period, protein supplementation should be mainly carried out in the form of short peptide and amino acid forms of pre digestion With the patient's stable condition, it will gradually transition to the whole protein dosage form Whether it is enteral nutrition or parenteral nutrition, it is necessary to monitor the changes of blood urea nitrogen and other indicators when supplementing protein substrate If the blood urea nitrogen increases continuously, it often indicates the accumulation of nitrogen products in the blood, and many kinds of amino acids cannot be effectively used At this time, it is necessary to appropriately reduce the supplement of protein (amino acid), or select the necessary amino acid and other preparations, and then increase the supplement of protein (amino acid) after the nitrogen products in the blood are gradually used and the level returns to the normal range Similarly, serum triglyceride and glucose levels must be monitored during nutritional therapy It is worth pointing out that in recent years, with the increase of diabetes patients and the attention to stress hyperglycemia, many enteral nutrition formulations reduce the sugar content, greatly increase the proportion of fat, and deliberately increase the heat ratio of unit volume preparations, resulting in the high level of serum triglyceride in some patients Imagine that there are too many triglycerides floating in the serum, and the exchange of blood gas and substance between blood and tissue will be affected However, in severe patients, because of tissue edema, lymphatic reflux disorder, and the liver is difficult to clear in time, the excessive fat in their serum will increase the fat deposition of the tissue and aggravate the damage of organ function Stress hyperglycemia is one of the self defense mechanisms of stress By down regulating the insulin receptor of peripheral muscle and adipose tissue, it supplies the "saved" glucose to nerve cells, red blood cells and other vital cells for energy However, this self-defense mechanism must be "moderate", that is, to keep the hard-earned saved glucose in the blood rather than losing it out of the blood vessels or even in vitro Clinically, the important sign of glucose loss out of the blood vessels is that the blood glucose level is higher than the "renal glucose threshold" (9mmol / L) and urine glucose is positive Therefore, it is not necessary to reduce the blood glucose to a completely normal level in the early stage of acute stress in severe patients, but it should be avoided that the blood glucose level exceeds 9mmol / L and is lost out of the blood vessels In addition, among the various measures to control blood glucose level, it is more important to continuously and uniformly give glucose than to rely on a large amount of insulin to reduce blood glucose after a significant increase in blood glucose Because a large number of insulin itself can not directly reduce blood sugar level, but through stimulating liver or muscle cells to try to synthesize glycogen to reduce blood sugar, fast adding insulin hypoglycemic treatment to sugar will increase the metabolic burden of liver in severe patients For severe patients, nutrition therapy should be given, but the principle of "no monitoring and careful nutrition" must be adhered to Monitor the utilization of internal and external nutrient substrates in the blood, know what is insufficient and what is surplus, so that the patients can not only make full and effective use of various nutrient substrates in the blood, but also do not increase the metabolic burden of each organ 3 The latest nutrition guidelines or consensus of feeding bacteria first and then people all emphasize the status of enteral nutrition in severe patients, but it is also pointed out that it is not necessary to pursue the goal of full quantity of calories in the early stage of stress in severe patients In fact, this is to "set things right" and return to the essence of enteral nutrition The essence of enteral nutrition is the regulation of immune function The largest contact and communication organ between human and environment is the gastrointestinal tract In the whole process of human biological evolution, we have gradually learned to eat clean food and reduce the load of pathogens that may invade the body, but at the same time, the immune defense function of our gastrointestinal tract is also gradually changing We often say that people are easily "acclimatized" when they are in a foreign country The so-called "soil and water" is actually the relationship between the microorganisms carried by our bodies and the environment and food The number of microbes in the body cavity and surface is nearly 100 times of the number of human cells These microbes play an extremely important role in our physical and mental health Each person's environment of birth and growth determines the dominant composition of microorganisms in the body cavity, which not only forms a regional taste, but also affects the material absorption and metabolism of the host organism In severe patients with stress, once the patient stops eating or is insufficient in a short period of time, the body can still rely on its energy storage to maintain cell metabolism, but the short-lived and fast-growing intestinal flora will die in large numbers due to the lack of food, resulting in the disorder of organic intestinal absorption and material metabolism At this time, the pathogenic flora may damage the patient's Immune function, and lead to systemic infection and organ dysfunction Therefore, the essence of enteral nutrition, especially in the early stress stage of severe patients, is not to provide enough calories to "feed people", but more importantly to provide food to protect the basic survival needs of intestinal microorganisms to "feed bacteria" The essence of "feeding bacteria first, then people" is to avoid the risk of increasing the metabolism burden of organ cells in the past by simply pursuing the "heat target", and to provide basic food for patients' intestinal flora to maintain survival, so as to protect the largest immune system of the body Because the intestinal flora has its own habitual food, the early enteral nutrition for severe patients should choose the daily diet that the patients are accustomed to in addition to commercial preparations For most of the severe patients in China who are accustomed to rice and white noodles as the main food, 100-200ml rice soup or batter per day should be the initial choice of enteral nutrition in the stress stage On this basis, other commercial preparations or food can be added Finally, the author hopes to publish some opinions on the concepts of "clinical nutrition support" and "clinical nutrition treatment" The so-called "nutritional support" is to meet physiological needs Its basis should be that the patient's body still retains the basic ability to utilize and metabolize the nutrient substrate, but it is difficult to ingest enough substrate to maintain the metabolism and organ function (repair) of the body due to diseases and other reasons Therefore, it is important to provide the patient with the required nutrient substrate and heat through the enteral or parenteral pathway However, the premise of this "nutritional support" is that the patient's body can still moderately regulate its own organ function and absorption metabolism, that is, the organ function of the body has not yet been decompensated, and the role of clinical nutrition at this time is mainly to provide substrate to meet the physiological needs of the patient's body, so as to support the material metabolism and organ function repair of the body "Nutritional therapy" is aimed at regulating the pathological evolution of severe patients Because of the presence of severe patients