[Clinical importance of hypocaloric parenteral feeding]

Hypocaloric parenteral nutrition (HPN) is mainly and frequently used in surgical medicine since it allows a reliable and standardized supply of nutrients. Ready-mix solutions which are suitable for peripheral venous nutrition generally contain about 50 g carbohydrates (glucose and/or xylitol), 25 g amino acids and electrolytes per liter. The osmolarity of the solutions averages between 600 and 800 mosmol/l. HPN has two distinct advantages: firstly the minimal effects on carbohydrate metabolism and secondly the good improvement in nitrogen balance. If 2 g/kg and day glucose are administered, even postoperatively, the mean blood sugar levels are only just above the normal range and an amino acid dosage of 1 g/kg and day, compared with liquid substitution alone or the administration of small amounts of carbohydrates, leads to an approximately 60% improvement in postoperative N-balance. Experience gained with HPN in surgical medicine to date permits the following recommendation: 1. HPN should not be used after small and moderate interventions with short nutritional abstinence; it is not necessary to administer nutrients in such cases. 2. HPN may be used after moderate to serious surgical interventions; e.g. after gastrointestinal resections in the case of elective surgery on patients with a normal nutritional status. However, studies have yet to prove the clinical efficacy of HPN, e.g. as evidenced by shorter hospitalization or a reduced perioperative morbidity or mortality, although this reservation equally applies to the routinely administered complete parenteral or enteral nutrition.(ABSTRACT TRUNCATED AT 250 WORDS)