Desnutrição como preditor de desfechos clínicos desfavoráveis em pacientes graves internados em uma unidade de terapia intensiva: um estudo de coorte prospectivo

Abstract

Critically ill patients are at high risk of developing malnutrition, a consequence of hypermetabolism, which is a common characteristic of critical illness. In addition, it is common for these patients to only partially meet their nutritional needs during hospitalization due to adverse clinical conditions that require periods of fasting or reduced energy intake. Malnutrition appears to be associated with unfavorable clinical outcomes in critically ill patients, such as increased mortality and length of hospital stay, although studies have shown contradictory results. Therefore, this study aimed to assess the association between malnutrition and clinical outcomes in critically ill patients through a prospective cohort study in a clinical, surgical, and non-trauma ICU of a university hospital in Dourados, Mato Grosso do Sul. Adult and elderly patients hospitalized for 48 hours or more were included. Nutritional status was assessed within the first 48 hours of ICU admission by a previously trained dietitian using the Subjective Global Assessment (SGA). Sociodemographic and clinical data were collected through interviews and medical record reviews. Patients were followed until death or hospital discharge, with mortality as the primary outcome. Secondary outcomes included ICU length of stay, duration of mechanical ventilation, and infection rate. The association between malnutrition and dichotomous outcomes (mortality and infections) was assessed using Poisson regression with robust variance, while for discrete outcomes (ICU length of stay and duration of mechanical ventilation), negative binomial regression was used. The significance level was set at 5%. The sample consisted of 201 individuals, mostly male (54.2%), elderly (60.7%), non-smokers (51.7%), non-drinkers (60.7%), with at least two comorbidities (63.7%), and with a predominance of respiratory (37.6%), infectious (16.9%), and cardiovascular (15.4%) diseases as primary admission diagnoses. Overall, 70.6% were malnourished, and the overall ICU mortality rate was 31.8%. The mortality rate among malnourished patients was 63.8% higher compared to the non-malnourished group (36.6% vs. 20.3%). In the adjusted analysis, total malnutrition (moderate and severe) was not significantly associated with mortality, infections, or duration of mechanical ventilation. However, total malnutrition was associated with a 2.84 day reduction in ICU length of stay (p = 0.018) due to early mortality. No significant associations were found for moderate malnutrition. The group with severe malnutrition had an 80% higher risk of death (RR 1.80; 95% CI 1.02–3.20; p = 0.042) and a 238% higher risk of developing infections (RR 3.38; 95% CI 1.17–9.78; p = 0.025), in addition to an average reduction of 4.03 ICU days (p = 0.011), compared to the non-malnourished group. There was no significant change in mechanical ventilation duration in any of the analyses (p > 0.05). In conclusion, malnutrition diagnosed at the beginning of ICU admission was significantly associated with ICU mortality, the development of infections, and ICU length of stay.