Nutrition in a Patient Flashcards
1
Q
Why is Malnutrition a Problem?
A
- The metabolic responses to illness or severe injury are complex and place critically ill animals at high risk for malnutrition and its deleterious effects.
- These effects, which are likely to negatively impact overall survival, loss of muscle mass, decrease in protein synthesis, compromised immune function, and decreased wound healing.
- One of the major facets of the metabolic alterations associated with critical illness involves whole body protein metabolism, in which protein turnover rates may become markedly elevated (usually referred to as ‘catabolism’).
- Whereas healthy animals primarily lose fat when deprived of sufficient calories (simple starvation), sick or traumatised patients catabolise lean muscle mass when they are not provided with sufficient calories (stressed starvation).
- Muscle catabolism that occurs during stress provides the liver with glucogenic precursors and other amino acids for glucose and acute-phase protein production.
- Due to the metabolic alterations associated with critical illness, and in part due to an inability or reluctance of many critically ill dogs and cats to take in sufficient calories, this patient population is at increased risk for rapid development of malnutrition.
- Given the serious sequelae of malnutrition, preservation or reversal of deteriorating nutritional status via nutritional support is paramount and is the justification for thinking about nutritional support whenever dealing with a sick hospitalised patient.
2
Q
Body Condition in Dogs
A
- Ribs
- Tummy
- Waistline
- There are a few methods described to evaluate body condition in dogs.
- One that has been validated involves scoring dogs in a scale from 1 to 9, where 5 is ideal. Look at the chart and appreciate that it not just a visual assessment - you need to feel and palpate the animal. This is the scheme that is used at our teaching hospital and on our medical records.
- The other schemes involve a 1-5 scale, where 3 is ideal and even a 1-7 scale. However, validation of these schemes is lacking which is why it is not used by most veterinary nutritionists.
3
Q
Body Condition Score Chart
A
4
Q
How does one evaluate body condition in cats?
A
- Again, there is also a validated system in cats which is also from 1-9.
5
Q
Important: Not all malnourished pets will be….
A
Emaciated
- Complete anorexia in obese patients is just as important, and in some cases like cats, more important to address early on.
6
Q
Good Diet Choice for Hyperthyroidism Cat
A
- Hypothyroidism is not disease that was typically managed with a diet change. This was because although cats have weight loss and muscle loss, this could not be reversed by simply feeding more calories. The increase in metabolism is caused by the disease (over-production of thyroid hormones).
- There is now a new approach that does involve dietary management. A new prescription diet has been developed for cats with hyperthyroidism (this is only one of various approaches) that can help control the disease by depriving iodine in the diet.
- Without iodine, the cat’s over-active thyroid gland cannot synthesize thyroid hormone and this can alleviate the condition. So while diet may play a role in controlling the disease, it is via decreasing the production of thyroid hormones, rather than by increase calories and protein intake.
7
Q
Possible Reasons for Poor Food Intake
A
- Ulcerations in the mouth, severe dental disease, jaw or facial fractures are examples of physical causes
- Animals may also have metabolic reasons for poor intake. Nausea is a very important cause for loss of appetite as is vomiting, abdominal cramping or abdominal pain (notice that pain plays a factor here as well).
- PAIN IS COMMONALITY
8
Q
Signs of Nausea in SA
A
- This cat which is hypersalivating is showing a classical sign of nausea.
- Dogs tend to lick their lips repeatedly
9
Q
A
Normal Cat tongue
10
Q
A
- This cat with ulceration of his tongue actually tried to ingest a caustic agent (it was aromatic potpourri oil).
- This led to significant pain which is a reason to prevent eating.
11
Q
Orogastric Feeding Tube
A
- This technique is not used very often as most conscious animals would not tolerate this method of feeding (basically the feeding tube is inserted orally and passed all the way down to the stomach).
- However, in neonates (ie, hours to days old) that are not suckling – which can happen with complicated whelping or queenings, premature births, post anaesthesia of the queen or bitch for caesareans, then this is really the only way to provide nutrition to these neonates.
- At this age, there is not much resistance to this type of feeding and could mean the difference in maintaining hydration and providing the energy and nutrients for survival.
12
Q
Naso-oesophageal Feeding Tubes
A
- These are by far the most commonly used feeding tube in practice, however, not necessarily the most effective for providing all of the animal’s nutritional needs.
- This feeding tube which is easily placed with local rather than general anaesthetic instilled within the nares. The lubricated small feeding tube (3.5 – 5 Fr sized tube) is inserted into the nostril, within the most medial and ventral nasal meatus and fed down into the nasal passage all the way to the caudal oesophagus. After placement, a radiograph should be taken to confirm proper location.
- Unfortunately, because of the small diameter, these tubes only allow liquid diets to be used, which limits choice and are generally fairly expensive compared to normal pet food. Another limitation is that it is not always well tolerated by the animals, and they will try to remove them, so buster collars are sometimes necessary.
13
Q
Oesophagostomy Tubes
A
- This is actually one of the most effective feeding tubes that can be used.
- The tubes are well tolerated by animals and allow more significant amounts of food to be fed because these are at least 14 Fr in diameter.
- Advantages of this technique include ease of placement and requiring only brief anaesthesia (although it does require a general anaesthetic).
14
Q
Percutaneous Endoscopic-Guided Gastrostomy Tube
A
- These tubes do require special equipment and skills with an endoscope. This procedure does require full general anaesthesia. This tube is appropriate when the oral cavity AND oesophagus has to be bypassed.
- This is appropriate for long term use (months) and are quite large (20 Fr) and accommodate gruel food.
15
Q
How do you choose the right feeding tube for each situation?
A
- How long will the animal need feeding assistance? With less than 3 days, naso-oesophagostomy tubes may be sufficient. Both oesophagostomy and PEG tubes can be used for long term (both can be used for months).
- Your ability and expertise with technique are also considerations.
- Knowing which parts of the GI tract that need to be bypassed is also important.
- And finally, what are the owners’ ability to perform the feeding at home - remember that nutritional support is sometimes a long-term process and animals have to be fed at home for several weeks until the animal can eat on their own.
17
Q
What to do with cases that don’t tolerate feeding
A
- Unfortunately there will be cases in which tube feeding does not work.
- In such cases, the only way to feed these patients is to use parenteral nutrition. (via IV fluids)
- Parenteral nutrition (PN) is a way to deliver nutrients such as amino acids, glucose and lipids directly into the bloodstream.
- Although this sounds convenient there are issues to contend with.
