Nutritional Adequacy in Mechanically Ventilated Patient: Are We Doing Enough?

Critically ill patients are under stress, leading to a catabolic response and higher energy expenditure. The associated malnutrition leads to adverse outcomes.

This study aims to assess the nutritional adequacy (>80% of prescribed calories) in mechanically ventilated (MV) patients and its effects on patients' outcomes. It also aims to identify the causes of deviation from the nutrition prescription.

This is a prospective observational study involving all adult critically ill patients requiring MV for >48 hours. Patients were prescribed enteral nutrition (EN) targeted to achieve 25 kcal/kg (IBW) of energy and 1.2 g/kg of proteins daily. Standard polymeric formula feeds were initiated as continuous infusion as per the feeding protocol in the intensive care unit (ICU). Data were collected on demography, body mass index (BMI), indication for ICU admission, admission category, and admission APACHE II and SOFA scores, and nutritional risk was captured with mNUTRIC score. Nutritional data on type of feed initiated, amount of calories prescribed/achieved, time taken to initiate feeds, reasons for not starting/delay in the initiation of feeds, time taken to achieve the prescribed calories, and reasons for interruptions of feeds were collected. Primary outcome analyzed was adequacy of nutrition (>80% prescribed dose), and secondary outcomes analyzed were ventilator days and ICU LOS.

A total of 622 MV patients were analyzed. 36.1% of patients were at nutritional risk (mNUTRIC χ5). 89% of patients received EN, and the time taken to start EN in these patients was 10 hours (6-20) (median [IQR]). Only 29.6% of patients achieved nutritional adequacy. Time taken for this was 36 hours (median). On average, patients on MV received 63% (1025 kcal) and 57% (41 g) of their prescribed calories and proteins, respectively. The most common reasons for withholding feeds were airway-related procedures (68.2%) followed by GI intolerance (15%). Frequent interruptions of EN, patients on >1 vasopressors, and surgical admissions were reasons for nutritional inadequacy. Nutritional adequacy had no impact on clinical outcomes.

Despite following guidelines and feeding protocols, there exists a wide gap between prescribed nutrition and what is actually delivered in MV patients.

Kalaiselvan MS, Arunkumar AS, Renuka MK, Sivakumar RL. Nutritional Adequacy in Mechanically Ventilated Patient: Are We Doing Enough? Indian J Crit Care Med 2021;25(2):166-171.