The intensive care unit is a special work unit within the hospital that includes supervision, care, treatment and maintenance of the lives of critically ill or severely injured patients. Intensive care units (ICUs) require proper and properly applied nutrition of patients because quality nutrition and absorption of nutrients from the intestinal cavity are a prerequisite for maintaining the integrity of the organism and keeping homeostasis of all energy and metabolic processes. In most cases, patients in the intensive care unit need partial or complete enteral and/or parenteral nutrition. Before using any method of feeding, it is necessary to assess the patient's nutritional status and condition, with special emphasis on the condition of the gastrointestinal tract. Depending on the condition of the patient's digestive system, we will determine the enteral or parenteral diet. Enteral nutrition is used in patients who have a preserved digestive tract, but cannot naturally ingest a sufficient amount of food. Enteral preparations are administered by feeding tube or stoma directly into the stomach or into the initial parts of the small intestine (duodenum or jejunum). Different types of nasal probes (nasogastric, nasojejunal, nasoduodenal) are used in patients for whom enteral nutrition is indicated for a short period of time. In patients for whom it is indicated for a longer period of time surgical or endoscopic stomas are placed. Parenteral nutrition supplies the body with water, energy nutrients, amino acids and other nutrients through the circulatory system. If the patient's condition requires complete parenteral nutrition, the patient needs to have a central venous catheter inserted into one of the larger central veins and if he needs only partial parenteral nutrition of certain substances, the patient can receive the necessary nutrients peripherally. Infection is a common complication of intravenous catheters, which can lead to fatal results, so it is important to take timely measures and prevent infections in order not to endanger the patient's life. Due to the growing problem of malnutrition of patients in hospitals, today's priority goal of clinical nutrition is to maintain the integrity of the mucosa of the small and large intestine, with emphasis on feeding patients normal food with modifications or enteral preparations, if there are no absolute contraindications. Even small amounts of food in the intestinal lumen can prevent thinning of the intestinal wall and atrophy of the intestinal villi, and thus affect the reduction of the transition of bacteria from the intestine into the systemic bloodstream. In this way, we prevent the occurrence of infection, sepsis and other serious conditions in the body.