RESUMEN
BACKGROUND: Malnutrition is common in hospitalized patients, especially in critically ill patients and affects their mortality and morbidity. However, the correlation between malnutrition and poor outcome is not fully understood. Our hypothesis is that the nutritional effect on the patient's prognosis would differ depending on the severity of the disease. METHODS: 3,758 patients admitted to the intensive care unit (ICU) were observed retrospectively. Patients were divided into well, moderate and severe groups, according to their nutritional status as assessed by their serum albumin level and total lymphocyte count (TLC). The severity of the disease was assessed by the Acute Physiologic and Chronic Health Evaluation (APACHE II score). All patients were followed clinically until discharge or death and ICU days, hospital days, ventilator days, and mortality rates were recorded. RESULTS: Depending on the definition used, the prevalence of hospital malnutrition is reported to be 68.3%. Hospital days, ICU days, as well as ventilator days of moderate and severe groups were longer than the well group. In patients exhibiting mild severity of disease, moderate and severe malnutrition groups have 3-5 times the mortality rate than the well group. CONCLUSIONS: Malnutrition affects the prognosis of patients who have an APACHE II score ranging from 4-29 points. Active nutritional support may be more effective for patients with a disease of mild severity.