Nutritional needs of the anorectic or debilitated animal are sometimes overlooked, since most of the focus is placed on curing
the disease and not the whole patient. Nutritional support can provide the energy the body needs to help combat disease. Diets
are now being formulated to meet the caloric requirements of the individual patient depending on such factors as disease process,
age, caloric requirements, and route of ingestion. While one canine patient in kidney failure might require a protein restricted
diet, another might require low fat diet. Most of these formulated diets, while nutritionally appropriate, are not palatable
to the patient. So here's the dilemma--how do we feed our patient their correct diet if they are not willing to eat it?
Dietary stimulants such as cyproheptadine and mirtazapine are an option, but only offer temporary support and are minimally
effective, especially in the anorectic animal. TPN (total parenteral nutrition) or PPN (partial parenteral nutrition) can
be very costly and can lead to catheter-related infections. Force feeding is not recommended--most of the food ends up on
the floor or on you instead of in the patient. Patients can also become fractious after several feeding attempts.
Feeding tubes offer the most options for nutritional support. There are many factors to take into consideration when choosing
a feeding tube in regards to the patient -
- Does the patient have a functional gastrointestinal tract?
- How long will the patient need the feeding tube?
- Will the animal's temperament allow for a feeding tube?
- Will the owner be able to maintain and use the feeding tube at home?
One more factor to consider is risk of anesthesia. Your patient may need to be stabilized before a feeding tube can be placed.
This may take several days. In the interim, a short-term option such as a nasoesophageal tube (if not vomiting) or TPN can
be implemented.
The material that your feeding tube is made of is very important. Gastric juices can render some tubes brittle and stiff.
Tubes that are too flimsy or thin may burst if too much pressure is applied. Silicone catheters are usually the best option,
and can withstand the abdominal environment. Latex is another good option. Latex tubes create a reaction on the skin, allowing
a stoma to form and making it easier to replace if needed. Latex tubes can discolor and break in the presence of digestive
juices and should be removed and/or replaced after about 12 weeks. Red rubber feeding tubes (Sherwood Medical) are used frequently
at the VMTH, especially for esophagostomy tube placements. These tubes can also discolor and turn brittle and should be monitored
closely and replace if needed.
Outer diameter of feeding tubes is dependent on where the tube will be placed and the size of the patient. Keep in mind that
the bigger the diameter, the easier it will be to get the food into the patient. Tubes are measured at the outer diameter
using the French (fr.) unit which is equivalent to 0.33 mm per unit.
Nasoesophageal tube placement
These tubes are for short-term use, the simplest to place, and require only topical anesthetic. Only a liquid diet may be
used through these tubes. A functional nasal cavity and GI tract are necessary for these tubes to work properly. A gag reflex
must also be present to prevent reflux. Small diameter catheters such as 5 or 8 fr. infant feeding tube or red rubber catheter
work well for this procedure. Additional materials needed are Proparacaine ophthalmic drops, Lidocaine jelly, tape, and either
suture, tissue glue or staples to secure the tube.
Procedure
- Place 2-3 drops proparacaine into the nasal cavity about 3 minutes apart.
- Measure your tube from the tip of the nose to the ninth rib and mark with a piece of tabbed tape. This will prevent the tube
from entering the stomach and causing GI reflux.
- Lubricate the distal end of your tube with Lidocaine jelly.
- With the patient's head in a normal position, gently direct the tube in a ventromedial direction into the nasal cavity. The
tube should move easily into the esophagus. If you encounter any resistance, retract the tube and try again.
- When the tube is placed with the mark on the tube at the tip of the nose, secure the tube first near the nostril, then either
above the eyes on the forehead or on the side of the face below the ear. You may need to shave a small area to adequately
secure the tube to the skin.
- To check positioning, there are several options-
o Inject 5 ml. of air through the tube while auscultating the stomach and listening for gut sounds.
o Inject 3-5 ml. of saline through the tube. If the patient coughs, this could indicate that the tube might be in the
trachea.
o Performing a lateral thoracic radiograph.
