Introduction and objectives: The critically ill patient is especially susceptible to malnutrition due to his/her hypermetabolic state that leads to an increase in the nutritional requirementes, which many times are not compensated with the administered enteral formulas. The assessment of nutritional intake is essential in this kind of patients to know to what level their energetic and nutritional requirements are fulfilled, improving and monitoring in the most individualized possible way to indicated clinical and nutritional therapu.
Methodology: This is a retrospective study in which all patients admitted to the Intensive Care Unit of Virgen de las Nieves Hospital were studied from January to December of 2003, aged more than 18 years, and on enteral nutrition. A total of 90 patients (52 men and 38 women) were studied, 81% of which were older than 50 years, and 57% had hospital stays longer than 8 days, with a 21% mortality rate. Intake was assessed from time of admission and throughout the whole hospitalization period. Energetic requirements were calculated according to the modified Long's formula and micronutrients intakes were compared to existing general recommendations for the Spanish, European and American populations, and to vitaminic requirements in critically ill patients.
Results: Percentages of mean energy and nutrients intakes in relation to theoretical calculated requirements for both genders are presented in figure 1. Mean energy intake was 1,326 cal in men and 917 cal in women. With regards to micronutrients intake, the values found for proteins, falts, and carbohydrates were lower than 50% of the requirements for both genders. The percentage of adequacy as referred to requirements for vitamins and minerals intake is shown in figure 2. Reference recommendations used correspond to sufficient intakes to cover the healthy individual requirements, therefore, the values obtained in our study show and adequacy greater than 75%, with the exception of particular elements such as vitamin A and magnesium. However, by taking a look at figure 3, which shows the adequacy of vitamins intake at recommended does for sick patients, the intake is lower than 25% of the requirements in all cases, and these deficiencies significantly interfere with wound healing, the immune, cardiovascular and nervous systems, as well as with metabolism of the remaining macronutrients leading to an unbalanced situation of the antioxidant system, worsening the patient's clinical status.
Conclusions: The present study confirms the need for monitoring individually the nutritional requirements in the critically ill patient and adapting recommendations to his/her metabolic changes, since currently these recommendations are not clearly defined for these situations. It is necessary to provide micronutrients doses closer to the patient's demands, so that the nutritional status and the balance of the antioxidant system may be preserved or improved, making the adopted clinical treatment more effective.