What are common reasons for initiating parenteral nutrition in critically ill patients?

Initiating parenteral nutrition in critically ill patients is often necessary due to certain clinical conditions that impair the ability to tolerate enteral feeding. One of the most significant reasons for initiating parenteral nutrition is hemodynamic instability alongside feeding intolerance.

In critically ill patients, there may be significant challenges in maintaining adequate nutrition through enteral routes due to conditions such as severe hypotension, shock, or other forms of hemodynamic instability, which can compromise gastrointestinal perfusion and, consequently, the ability to digest and absorb nutrients. When patients cannot tolerate enteral feeding, whether from gastrointestinal dysfunction or intolerance, parenteral nutrition ensures that they receive the necessary calories and nutrients intravenously, bypassing the gastrointestinal tract altogether.

Therefore, the combination of hemodynamic instability and feeding intolerance creates a situation where parenteral nutrition becomes a critical intervention to support the patient's nutritional needs while their condition is stabilized. This allows for more comprehensive management of the patient’s overall care, ensuring that nutritional deficits do not compound their critical illness.