Nutrition before, during and after critical illness

Area of Science:

• Critical care medicine
• Clinical nutrition
• Intensive care unit (ICU) management

Background:

• Current research on nutrition in intensive care units (ICUs) primarily focuses on the initial 5-7 days of illness in mechanically ventilated patients.
• There is limited consideration for the patient's premorbid nutritional status.
• Significant evidence gaps exist regarding optimal protein intake and the effects of long-term nutrition interventions within the ICU.

Purpose of the Study:

• To review nutrition management considerations across pre-ICU, within-ICU, and post-ICU phases.
• To assess the current literature informing clinical nutrition care for critically ill patients.
• To identify emerging areas and future directions in critical care nutrition.

Main Methods:

• Literature review of studies on nutrition management in critically ill patients.
• Analysis of research focusing on different time periods of critical illness (pre-ICU, within-ICU, post-ICU).
• Identification of evidence gaps and promising future research areas.

Main Results:

• Nutrition management in the ICU is often limited to the early phase of illness, with heterogeneity in patient populations.
• Key evidence gaps include determining optimal protein provision and the impact of extended nutrition interventions.
• Personalized nutrition and post-ICU nutrition are emerging as critical areas of focus.

Conclusions:

• Nutrition for critically ill patients should be viewed as a continuum, encompassing pre-, within-, and post-ICU periods for optimal recovery.
• Future research must investigate the impact of nutrition on clinical and functional outcomes across hospitalization, using biologically plausible interventions.
• Promising future directions include longer-duration interventions, oral nutrition support, individualized regimens, and bedside body composition analysis.