Nutrition in the critically ill patient

Area of Science:

• Critical care medicine
• Nutritional science

Background:

• Critically ill patients exhibit hypermetabolism, increasing their nutritional demands.
• The benefits of nutritional support in critically ill patients lack robust clinical trial evidence, relying on clinical judgment.
• Lean tissue loss in catabolic patients (20-40g nitrogen/day) suggests critical depletion may occur within 14 days.

Purpose of the Study:

• To review the rationale and evidence for nutritional support in critically ill patients.
• To highlight the importance of early nutritional intervention for wound healing and immune function.
• To identify limitations in current research regarding optimal nutritional strategies.

Main Methods:

• Review of existing literature and clinical trials on nutritional support in critically ill and surgical patients.
• Analysis of the impact of nutritional support on complications, length of stay, and recovery.
• Evaluation of study designs in randomized controlled trials of enteral and parenteral feeding.

Main Results:

• Total parenteral nutrition (TPN) for 7-10 days pre-surgery in malnourished cancer patients reduced complications by approximately 10%.
• Early feeding is hypothesized to decrease length of stay and complication rates.
• Current enteral and parenteral feeding regimens in critically ill patients are often sub-optimal, with excessive calorie intake and variable study designs hindering comparisons.

Conclusions:

• Nutritional support is essential for critically ill patients, impacting wound healing and immune response.
• Commencing nutritional support as early as possible is recommended.
• Further well-designed clinical trials are needed to establish optimal nutritional requirements and strategies for critically ill patients.