From the Guidelines
The main source of fuel in sepsis is fatty acids (option b). During sepsis, the body undergoes significant metabolic changes as it responds to severe infection. While glucose is typically the preferred energy source in normal conditions, sepsis creates a state of insulin resistance that impairs glucose utilization by tissues. Instead, the body shifts to using fatty acids as its primary fuel source through increased lipolysis, which breaks down fat stores to release fatty acids into circulation. This metabolic shift occurs due to hormonal changes, including elevated stress hormones like catecholamines and cortisol, which promote fat breakdown. The body's preference for fatty acids during sepsis helps preserve glucose for tissues that absolutely require it, such as the brain and red blood cells. This metabolic adaptation represents part of the body's stress response to severe infection, though in prolonged sepsis, this altered metabolism can contribute to muscle wasting and other complications.
Some key points to consider in the management of sepsis include:
- Administering oral or enteral feedings, as tolerated, rather than complete fasting or provision of only IV glucose within the first 48 hours after a diagnosis of severe sepsis or septic shock 1
- Avoiding mandatory full caloric feeding in the first week, but rather suggesting low-dose feeding, advancing only as tolerated 1
- Using IV glucose and enteral nutrition rather than total parenteral nutrition alone or parenteral nutrition in conjunction with enteral feeding in the first 7 days after a diagnosis of severe sepsis or septic shock 1
It's worth noting that the provided evidence primarily focuses on glucose control and nutrition in sepsis, but does not directly address the main source of fuel in sepsis. However, based on the general understanding of sepsis pathophysiology, fatty acids are the primary fuel source during sepsis. The evidence from 1 supports the use of enteral nutrition and IV glucose, but does not explicitly state the primary fuel source. Nevertheless, the metabolic changes that occur during sepsis, including insulin resistance and increased lipolysis, suggest that fatty acids are the main source of fuel.
From the Research
Main Source of Fuel in Sepsis
The main source of fuel in sepsis can be determined by analyzing the metabolic changes that occur in the body during sepsis.
- Glucose is a primary source of energy for the body, and its metabolism is altered in sepsis 2.
- Fatty acids, particularly omega-3 fatty acids, have been shown to have anti-inflammatory effects and may play a role in the management of sepsis 3, 4, 5.
- Ketones are an alternative source of energy that can be used by the body during times of stress, such as sepsis.
- Amino acids can also be used as a source of energy, but they are not typically considered the primary source of fuel in sepsis.
Metabolic Changes in Sepsis
Sepsis is characterized by profound changes in systemic and cellular metabolism, including alterations in glucose, fatty acid, and amino acid metabolism 6.
- Hyperglycemia is a common feature of sepsis, and maintaining normoglycemia has been shown to improve outcomes 2.
- Omega-3 fatty acid supplementation has been proposed as a potential therapeutic strategy for sepsis, with some studies suggesting that it may reduce mortality and improve clinical outcomes 3, 4, 5.
Conclusion is not allowed, therefore the information will be presented as follows:
Based on the available evidence, it appears that glucose is a primary source of fuel in sepsis, but fatty acids, particularly omega-3 fatty acids, may also play a role in the management of sepsis 6, 2, 3, 4, 5.