Oral Nutritional Intake among Critically Ill Patients Is Grossly Deficient in the Week Following Extubation

Abstract & Commentary

By David J. Pierson, MD. This article originally appeared in the July 2010 issue of Critical Care Alert. It was peer reviewed by William Thompson, MD

Synopsis: In a prospective study of the actual oral nutritional intake of patients with respiratory failure in the first week following extubation, average intake failed to exceed 50% of daily requirements on all seven days.

Source: Peterson SJ, et al. Adequacy of oral intake in critically ill patients 1 week after extubation. J Am Diet Assoc. 2010;110: 427-433.

Peterson and colleagues at Rush University Medical Center carried out an observational study of ICU patients' oral nutritional intake in the seven days following extubation after mechanical ventilation for acute respiratory failure. They included adult patients who were ventilated for at least 24 hours prior to extubation, were advanced to an oral diet once the endotracheal tube was removed, and were not receiving supplementary enteral or parenteral nutrition. Patients were judged by a standard technique to be either well-nourished or suffering from malnutrition of various degrees of severity. Their estimated daily energy requirements were also determined by accepted techniques based on admission body weight and BMI. The investigators evaluated the adequacy of daily oral intake using a modified multiple-pass 24-hour recall technique, essentially consisting of daily structured interviews of the patient and family in reference to the actual meal menus they had used. Oral intake < 75% of daily requirement — a threshold below which previous studies have shown to be associated with significant loss of body weight during illness — was considered inadequate.

During the study period, 64 patients were eligible and 50 were evaluated after exclusion of 14 because of inability or unwillingness to participate. The patients (54% women) had a mean age of 59 years, were evenly distributed between medical and surgical ICUs, and had mean BMIs of 28.7 kg/m2 on admission. They had mean admission APACHE II scores of 22 and had been invasively ventilated for 5.2 ± 4.2 days (mean ± SD). Forty-four percent of the population was classified as moderately or severely malnourished via the Subjective Global Assessment technique.

On post-extubation day 1, only eight patients (16%) consumed at least 75% of their daily requirements. On days 2-7, the proportions were 25%, 26%, 29%, 28%, 5%, and 18%, respectively, of the patients remaining in the study. On day 1, among the majority of patients whose caloric intake was < 75% of requirements, the 24-hour calorie count was 480 ± 282 kcal, with only 22 ± 13 g protein; these values remained roughly the same in the succeeding days. Lack of appetite and the presence of nausea or vomiting were cited most often by patients as reasons for not taking in more nutrition. A substantial proportion of the patients with inadequate oral intake were on therapeutic diets, such as "heart-healthy," diabetic, or renal regimens.

Commentary

Malnutrition is very common among hospitalized patients and is associated with high rates of nosocomial infections, increased hospital costs, prolonged lengths of stay, and higher mortality. More and more attention is being paid to the institution of early and appropriate nutritional support when critically ill patients are first admitted to the ICU. However, almost no previous work has examined the adequacy of nutritional support among patients who have been extubated and are in the recovery phase of critical illness. The results of this modestly sized observational study from a single institution are not very encouraging, and suggest that the actual nutrition delivered to most such patients falls way short of ideal — or even adequate. The authors appropriately note that further research is needed in this area. They also call into question the widespread use of restrictive oral diets (such as special renal or diabetic diets, which may be less appealing to patients) in the early days following extubation, and posit that alternative medical nutrition therapies may be needed in this setting.