Artificial nutrition

Artificial nutrition (NA) is a therapeutic procedure intended for people in whom oral feeding is not feasible and / or is not sufficient to meet protein caloric needs or is contraindicated. Artificial nutrition is necessary to meet the nutritional needs of patients at risk. The primary objective must be to identify therapeutic protocols that make artificial nutrition safe and try to debunk established myths regarding complications related to this type of treatment, making it known that prevention and monitoring are able to reach the goal of complications “by at zero “(24). Nutritional therapy is indicated in preventing malnutrition and in meeting the increased protein caloric needs typical of hypercadolism conditions (metabolic response to stress secondary to pathological events, such as polytrauma, sepsis, major surgery, characterized by an accentuated muscle proteolysis and from a depletion of visceral proteins). 

NE is defined as the modality that allows to convey the nutrients in the digestive tract (stomach, duodenum or fasting) by means of probes, while parenteral nutrition (NP) is the mode of administration of nutrients through the venous pathway (in the peripheral vein or in the central vein) ( 3). People in NA must be considered in critical condition, as suggested by the Committee for the guidelines of the American Society of Intensive Care which inserts the “serious nutritional problems that require nutritional support” among the critical characteristics (25). NA significantly improves the prognosis of numerous pathological patterns, with reduction of morbidity and mortality, improvement of clinical course and quality of life (26-28). 

Based on the experience of Dudrick et al. (29), the use of NP was introduced in the late 1960s and since then has helped to restore many critical conditions to patients. However, the widespread use of this therapy and the extensive indications have encouraged the appearance of complications and doubts regarding its benefits. At the end of the 1980s animal studies confirmed the concept that enteral nutrition is able to preserve and promote intestinal function and prevent bacterial translocation. Based on these data parenteral nutrition was considered dangerous and this belief led enteral nutrition to be the new standard of care in artificial nutrition. In particular, the review of Stratton, Green and Elia of fifteen years ago showed the great benefits of enteral nutrition (NE):

in 12 randomized clinical trials (RCT) (600 subjects) mortality was reduced (23 vs 11% ) in 17 RCTs (749 subjects) there was a decrease in total complications (48 vs 33%) and in 9 RCTs (442 subjects) the reduction of infectious complications was documented (46 vs 23%). These results are related to the increase in nutritional intake and weight recovery (30). It is now universally accepted that under all conditions in which NA is indicated and there is a normal function of the gastrointestinal tract, with the possibility of covering enteral needs, the NE must be considered the first choice technique with respect to NP as more physiological, able to maintain the anatomical-functional integrity of the intestinal mucosa, burdened by minor side effects and lower effects on blood sugar and even less expensive (31-33). The NE can be difficult to perform in the presence of gastroparesis, a clinical condition that is easy to find in the diabetic that, if not diagnosed, can lead to serious complications:

ab ingestis in unconscious patients. Gastroparesis is secondary not only to autonomic neuropathy, but may also depend on hyperglycemia and as such be reversible. The NP should be used when the NE is not practicable or when it is insufficient to cover the needs of the subject. The anatomo-functional conditions of inability of the digestive tract are contraindications to the use of NE. In particular, the pictures of intestinal insufficiency secondary to short bowel syndrome or to severe enteropathy, the intractable vomiting, the paralytic ileus or the conditions of mechanical occlusion or severe intestinal ischemia and finally the presence of jejunal fistulas or high-flow ileal they lean towards the NP. The latter may be total (NPT, nihil per os) or supplemental to oral or enteral nutrition. 

Both the NE and the NP require precise monitoring protocols since there are various types of complications: metabolic (common to NE and NP), gastrointestinal and mechanical secondary to NE and finally linked to central venous access for NP (1.33) -35). In 2014, Harvey et al. verified early nutritional support in 2400 critically ill adult patients. The results of the study comparing enteral nutrition with parenteral nutrition did not show significant differences between the two types of treatment either as adverse events or as positive outcomes (36). It is true that at the beginning the administration of high doses of glucose with NP often caused hyperglycemia with consequent complications that negatively influenced the prognosis. Today,