What is the difference between enteral nutrition and parenteral nutrition?

Difference between Enteral Nutrition and Parenteral Nutrition

The choice of enteral nutrition, parenteral nutrition or the combination of the two depends to a great extent on the patient's gastrointestinal tube function and tolerance to the way of nutrition supply. It usually depends on the nature of the disease, the state of the patient and the judgment of the attending doctor. If the patient's cardiopulmonary function is unstable, most of the gastrointestinal absorption function is lost or the nutritional metabolism is unbalanced, and compensation is urgently needed, parenteral nutrition should be chosen. If the patient's gastrointestinal tract is functional or partially functional, safe and strict enteral nutrition should be selected. Enteral nutrition is a physiological feeding method, which not only avoids the possible risks caused by central venous intubation, but also contributes to the recovery of intestinal function. Its advantages are simplicity, safety, economy, high efficiency, physiological function, and a variety of different enteral nutrition agents. However, it is not easy for patients with gastrointestinal diseases to choose the right time and safe way to give enteral nutrition, and it may potentially aggravate the primary disease. Some clinical symptoms, such as nausea, satiety, abdominal pain and signs, such as diarrhea, decreased bowel sounds and abdominal distension, limit the application of enteral nutrition. In addition, if patients can't tolerate nasogastric tube placement, nasogastric tube placement is not smooth or the original anatomical position changes after esophageal and gastric surgery, the application of enteral nutrition will also be limited. At the same time, there will be complications of enteral nutrition, including tracheal aspiration, nausea, diarrhea, intestinal blood supply disorder and so on. Therefore, enteral nutrition should not be given when the patient's heart function is in a marginal state or the hemodynamics is unstable; Patients with poor enteral nutrition should change the supply mode in time to avoid delaying nutritional treatment. In a word, the key and most important principle of enteral nutrition is to strictly grasp the indications, accurately calculate the amount and duration of nutritional treatment, and reasonably choose the way of nutritional treatment.

Parenteral nutrition plays an active and effective role in the adjuvant treatment of almost any digestive system disease that is insufficient, inappropriate or impossible for oral intake, and is an important progress in the treatment of human diseases. This therapy has brought great benefits to patients with digestive system diseases such as malnutrition and gastrointestinal dysfunction.

Parenteral nutrition can produce satiety syndrome and inhibit gastric peristalsis. Therefore, before the transition to enteral nutrition, we advocate mild starvation for a few days, only intravenous infusion of liquid to maintain water and electrolyte balance, stimulate gastrointestinal activities, and at the same time, use conditioned reflex to stimulate appetite or have dinner with family members to get pleasure. The proper combination of tube feeding and oral feeding is helpful to the transition from parenteral nutrition to enteral nutrition. The transition from long-term tube feeding to oral normal enteral nutrition should also follow this principle.

Long-term parenteral nutrition can lead to decreased gastrointestinal function. Therefore, the transition from parenteral nutrition to enteral nutrition must be gradual and cannot be stopped suddenly. Otherwise, it will increase the intestinal burden, which is not conducive to recovery. This change can be roughly divided into four stages: ① the combination of parenteral nutrition and tube feeding; ② Simple tube feeding; ③ Combination of tube feeding and oral administration; ④ Routine enteral nutrition. That is to say, it is necessary to gradually transition to enteral nutrition to adapt to intestinal cells. When enteral feeding can be tolerated, low concentration, slow infusion of essential or non-essential enteral nutrition preparations is used to monitor the water-electrolyte balance and nutrient intake (including parenteral and enteral nutrition), then enteral nutrition is gradually increased and decreased until enteral nutrition can meet the metabolic needs, then parenteral nutrition is completely cancelled, and finally normal enteral nutrition is achieved by combining tube feeding and oral administration.