Enteral nutrition in veterinary surgery and serious illness
Parenteral or enteral nutrition is commonly used to meet the needs of perioperative or seriously ill patients. In this post we discuss hospital situations involving malnutrition and the administration parameters and circumstances necessary for enteral and parenteral feeding.
How is recovery affected by malnutrition?
Malnutrition is defined as a progressive loss of lean body mass and adipose tissue due to increased protein and calorie requirements or an inadequate intake thereof.
More specifically, severe protein–calorie malnutrition can have important implications in terms of the body functioning correctly, such as muscle and organ atrophy, a compromised immune system, impaired wound healing, less resistance to infections, and so forth. All of these factors reduce the animal’s chances of survival.
What can lead to malnutrition?
Malnutrition affects about 20–60% of severely ill animals. Some causes, particularly those associated with surgery, may increase the risk of malnutrition:
- Surgery
- Postoperative complications
- Surgery-induced anorexia
- Sepsis
- Burns
- Anorexia
Nutritional risk factors during hospitalisation
A recent study1 by the Autonomous University of Barcelona conducted in a hospital setting revealed the leading nutritional risk factors that result in poorer survival rates.
Body weight is affected by:
- Duration of hospitalisation: the longer the stay, the greater the risk of weight loss.
- Vomiting on admission: is associated with an increased risk of weight loss, especially in the case of heavier animals.
- Percentage consumption of resting energy requirements: the higher the percentage ingested, the more likely the patient is to maintain body weight.
Dogs that consumed their required energy intake, had a higher body condition index or which received nutritional interventions presented better results (in terms of survival at time of discharge).
Nutritional supplementation associated with surgery
As might be expected, the treatment objectives in malnourished patients comprise adequate supplementation to correct any deficiencies detected and resolution of the primary condition as soon as possible. In this regard we can talk about hyperalimentation, referring exclusively to the administration of appropriate nutrients for malnourished patients.
As with humans, cats and dogs that undergo surgery need to receive perioperative enteral or parenteral nutrition.
- Enteral hyperalimentation: supplies food at a functional level directly into the digestive tract through a tube. The tube can be placed orally or naso-oesophageally, or via a pharyngostomy, oesophagostomy, gastrostomy or enterostomy.
- Parenteral hyperalimentation: supplies nutrients directly via an intravenous line. Indicated when the intestine cannot absorb nutrients properly. Also applicable for cases of prolonged pancreatitis or severe malnutrition.
Which is better: parenteral or enteral?
Insofar as possible, enteral nutrition is preferable, if tolerated by the patient, and the tube should be placed as close to the digestive system as possible to avoid atrophy due to organ dysfunction. However, if enteral feeding is not possible, the parenteral route should be used.
Enteral nutrition is more efficient, easier and safer, plus it allows for greater flexibility in the composition of the dietary formulation. The more akin the route is to oral administration, the greater the potential for varying the formula.
Can I use a normal diet for enteral nutrition?
Enteral diets must be well tolerated, highly digestible, easily absorbed and contain essential nutrients. They must also be readily available, competitively priced, easy to use and have a long shelf life.
In terms of cost–effectiveness, the best option is to prepare the enteral nutrition by liquefying a prescription or home-made diet. If you choose this option, please note that the tubes for liquid diets must have a diameter of at least 8 Fr.
If you need to use a narrower tube, you will have to use a liquid diet especially designed for enteral feeding.
We hope you have found today’s post informative and updated your understanding of enteral nutrition in veterinary surgery. If you would like to know more about nutrition, visit Vetsaffinity.com and check out our nutritional consultant.
Bibliography:
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Molina J, Hervera M, Manzanilla E, Torrente C, Villaverde C. Nutrition related risk factors for malnutrition and negative outcome in hospitalized dogs. Journal of Animal Physiology and Animal Nutrition 99 (2015) 810-824
