Page 443 - Small Animal Clinical Nutrition 5th Edition

Enteral-Assisted Feeding 457

generally occurred after six to 12 weeks of supplementation. The two methods, enteral and parenteral, are not mutually
VetBooks.ir In dogs, however, investigators found plasma fatty acid pro- exclusive; supplementing what the patient consumes voluntari-
ly with parenteral calories and protein infusion is possible in
file changes within two weeks after the onset of omega-3
many veterinary practices. Therefore, overall patient assess-
dietary supplementation (Campbell and Dorn, 1992). Thus,
there may not be enough time for dietary omega-3 fatty acid ment, including evaluating a patient’s ability to eat and assimi-
therapy to affect an acute inflammatory process, depending late food, is the first step in developing a feeding plan because
on the affected tissue unless the fatty acids were incorporat- it dictates the route, enteral, parenteral or both, for providing
ed into the patient’s dietary regimen before the onset of dis- assisted feeding.
ease. The dietary dose that favors a less inflammatory cas- The food choice should be made based on a food’s key nutri-
cade during a disease process is still not standardized across tional factor profile and form of the food (i.e., liquid, moist)
veterinary patients, but is suggested as an omega-6:omega-3 that best accommodates the specific nutritional support feeding
fatty acid ratio ranging between 5:1 to 1:1, depending on method. For example, if a small nasogastric feeding tube were
patient assessment. to be used, a liquid food of appropriate viscosity and key nutri-
On the other hand, chronic suppression of the inflammatory ent make-up would be selected. This is an added consideration
and/or immune response by feeding high levels of omega-3 fatty compared to developing feeding plans for patients that do not
acids should be done cautiously and is not warranted in disease require assistance.
states in which a fully competent immune system is essential for
survival and recovery. Studies in which mice were pre-fed (two Select the Feeding Method
to four weeks) extremely high levels of omega-3 fatty acids (40% Enteral Feeding Routes
of calories as fish oil) compromised their resistance in an infec- ORAL FEEDING
tious disease state (Chang et al, 1992). Platelet function was sig- Several routes exist for enteral feeding, but the first attempt
nificantly diminished in healthy cats fed an enriched omega-3 usually should be oral feeding. Placing a bolus of food in the
fatty acid food (omega-6:omega-3 ratio of 1.3:1) for eight weeks proximal portion of the mouth may stimulate the swallowing
(Saker et al, 1998). As with many other nutrients, excessive lev- reflex and, if the patient offers no resistance, is a good method
els of omega-3 fatty acids can be detrimental. as long as the patient receives enough food to meet its RER.
Simple syringe feeding of a liquid product is also a good
method, if tolerated. For dogs, the syringe tip is placed between
FEEDING PLAN the molar teeth and cheek with the head held in a normal or
lowered position; for cats, the syringe tip is placed between the
The feeding plan discussion assumes that the health care team four canine teeth (Box 25-4). The patient may choose to swal-
has determined that the patient is a candidate for nutritional low the liquid or allow it to flow from the mouth down the
support (see History and Physical Examination section, above). esophagus by gravity. Some patients refuse to swallow boluses
Nutrients can be supplied enterally or parenterally (Figure of food; therefore, forced feeding may increase the risk of food
25-5). Enteral feeding provides adequate nutrition simply and aspiration. Oral feeding should be discontinued if the patient
cost effectively whether done orally or by feeding tube. Enteral does not swallow food voluntarily. Appetite stimulants may be
feeding is usually preferred to parenteral feeding because it is used to induce food consumption in some patients; however,
less expensive, stimulates the systemic and GI immune systems, voluntary food intake rarely continues and their RER is often
helps to maintain GI mucosal integrity and avoids most meta- not met (Table 25-6).
bolic complications. However, nutrients must be administered Orogastric tubes require placement at each feeding but may
parenterally when the GI tract is inaccessible or not function- provide a useful option for one or two days of feeding.They can
ing adequately enough to meet the patient’s nutrient require- be used as long as there is no nasal, pharyngeal or esophageal
ments enterally. Chapter 26 covers parenteral-assisted feeding. trauma or disease. Anesthesia is not required; therefore, this
Enteral-assisted feeding is providing nutrients to the patient route can be used in patients that are an anesthetic risk.
using some portion of the GI tract. Patients that cannot or will Neonates appear to tolerate multiple daily oral tube feedings
not eat but who can digest and absorb nutrients from the small better than adults. A red rubber or polyvinyl chloride tube (8 to
b
intestine should receive enteral-assisted feeding. Feeding via 24 Fr.) may be used with the tip placed in either the caudal
the GI tract is often the simplest, fastest, easiest, safest, least esophagus or stomach. An indwelling feeding tube is the
expensive and most physiologic method of feeding patients. method of choice if enteral-assisted feeding is necessary for
Prior knowledge that a patient requires other medical and sur- more than two days.
gical procedures should also be considered when formulating an Feeding through an indwelling tube is easier and less stress-
enteral assisted-feeding plan. For example, feeding tubes can ful on the patient than forced feeding or repeated placement of
easily be placed at the end of a procedure requiring anesthesia an orogastric tube. Nasoesophageal, pharyngostomy, esoph-
or tranquilization. Feeding tube placement must consider the agostomy, gastrostomy and enterostomy are potential place-
treatment plan and owners’ expectations. Some feeding tubes ment sites. Tubes should be placed in the most proximal func-
can only be used when the patient is in the hospital whereas tioning portion of the GI tract possible by the least invasive
other tubes may also be used for at-home feeding. method. The stomach should be used whenever possible.