Feeding the hospitalized patient: what technicians need to know
TORONTO, ON – Technicians are largely responsible for patients’ care, and are in a unique position to monitor them and draw the doctor’s attention to potential issues. While literally hundreds to thousands of dollars are spent on antibiotics, IV fluids, etc., very little is spent on nutritional support. It is important for technicians to advocate for their patients, by paying attention to what they are or are not eating. Not allowing a patient to receive adequate and essential nutrients, while receiving numerous other expensive treatments, makes absolutely no sense, said Tammy Owens, DVM, DACVN, speaking at the Veterinary Education today (VET) Conference & Medical Exposition, especially since many of the more common and expensive treatments are less effective when administered in a state of starvation.
What is malnutrition?
Malnutrition is the inadequate consumption of energy (calories), of proteins, and other nutrients. During complicated starvation (i.e. during critical illness), stress hormones are released, which counteract the body’s attempt to lower its metabolic rate, resulting in accelerated starvation and tissue depletion.
As many as half of all hospitalized patients experience malnutrition. Ability to eat can be impaired by stress, anxiety, pain, nausea or vomiting, functional or mechanical impairments to eating (e.g. facial trauma, megaesophagus, gastrointestinal dysmotility), or primary illnesses that impair appetite or the ability to eat.
Dr. Owens explained that nutritional needs are often overlooked due to management issues and treatment needs that can seem more urgent. But patients are often underfed simply because adequate written orders and the monitoring of intake are lacking, or the clinician is uncertain when to intervene or how to proceed when intervention is warranted. There is also the misperception regarding the cost, effect on quality of life, and the consequences of malnutrition. As a result, the benefits of proper nutrition are often overlooked.
Muscle wasting
Muscle wasting occurs before laboratory test changes are detected. It is the result of amino acid demands exceeding dietary intake, resulting in the metabolism of skeletal muscle. Monitoring a patient’s muscle condition is very important; muscle wasting is a clear indication of a serious problem that requires intervention.
Nutritional goals
Short-term
- Address energy and protein needs
- Achieve weight stability
- Prevent loss of body condition or muscle mass
- Support recovery
- Prevent nutritionally-related complications
Long-term
- Improve body condition
- Address/reverse weight loss if needed
- Improve quality of life
- Decrease or prevent disease/complication recurrence
- Prolong life expectancy
Assessing the patient
Patient nutritional assessment should be a routine part of patient evaluation.
This includes obtaining a diet history (what the pet eats and how much, including treats and supplements, and any recent changes to the eating routine), body condition score (BCS), weight, and muscle condition. The exam should help determine any signs of nutritional deficiencies or imbalances (e.g. skin lesions), and physical impairments to eating (dental disease, facial trauma, oral-pharyngeal lesions, etc).
Obtaining the diet history is important because it will help determine the patient’s baseline so that trends can be monitored, and patients identified that are at higher risk of nutrition-related complications. For example, if the diet history includes a raw diet, a diet that contains bones, or a diet that is not complete and balanced (i.e. potential nutrient deficiencies), this may be a possible cause or contributing factor to a patient’s current signs, or may help identify patients at increased risk for complications. Even the misuse of prescription therapeutic diets, or occasional mix-ups, can be problematic. For example, feeding a growing puppy a protein-reduced diet (such as k/d) could explain muscle wasting, etc. Dr. Owens added that it is also useful to have this information on-hand in the event of future problems.
Labwork is used to detect problems such as anemia, hypoproteinemia, electrolyte imbalance, decreased BUN, discordant creatinine, etc. Dr. Owens recommended accessing the WSAVA Nutrition Toolkit for useful information and charts (www.wsava.org).
When a patient won't eat
It is important to identify and minimize any barriers to voluntarily eating early on. If three to five days pass without the patient eating (including time before hospitalization), then intervention is required. However, intervention should happen earlier if higher risk factors for malnutrition are already present, such as poor BCS or muscle condition and/or rapid or progressive weight loss.
Dr. Owens noted that the rule of thumb when deciding how to intervene is “If the gut works, use it”.
Enteral feeding
Enteral feeding is preferred when possible because it is the most physiologic option, is less expensive than parenteral feeding, and may be the safest option. Oral options for patients that won’t eat voluntarily include appetite stimulants, syringe feeding, and the use of oro-esophageal tubes in neonates. Syringe feeding is generally not recommended, however, as it is likely to cause permanent food aversions, increases risk of aspiration, and is generally not effective in meeting patients’ energy needs.
Common assisted feeding devices include nasoenteral, esophagostomy, and gastrostomy tube feeding. Nasoenteral tubes are indicated in cases for relatively short term feeding (i.e. days to weeks) or in cases with anesthetic or surgical risk. Placement usually only requires mild sedation and a few sutures. Dr. Owens said it is important to keep in mind that nasogastric tubes offer the added possibility for gastric decompression in certain cases, and are easier/safer to confirm placement in the stomach with radiographs whereas nasoesophageal and nasotracheal can be confused without sufficient precaution. Overall, they are relatively non-invasive and not expensive, but are generally limited to liquid diets only.
Esophagostomy tubes are minimally invasive and can be placed without special equipment; however anesthesia is required. They can be removed immediately after placement, or can be used for an extended period of time. Complications include local infection, aspiration, and tube misplacement or dislodgement. Dr. Owens stressed the importance of always confirming correct placement using radiographs (orthogonal views required).
Gastrostomy tubes offer direct gastric access, and are larger, offering more dietary options. They can be used for months to years. Contraindications include gastric abnormalities such as masses, pyloric stenosis, or severe functional abnormality.
Enteral options include liquid diets, critical care diets, and blended commercial diets. The route of administration, patient’s signalment and history, cost, and availability dictates the type of diet to be selected, but it is important to remember that you are not limited to the pre-made critical care diets and should select the diet most appropriate for your patient’s condition whenever possible
Daily feeding goals should be based on the patient’s resting energy requirement, determined by the patient’s current body weight, using the formula 70(BWkg)0.75, and then adjusted as needed with changes in weight, body condition, or tolerance of the volume fed. With feeding tubes or in cases of prolonged anorexia, start with 25-33% of resting energy requirement (RER) per day (divided into several meals) and then gradually increase to 100% RER over 3-4 days as tolerated.
Parenteral feeding
This feeding methodis used to by-pass the gastrointestinal tract, by administering nutrients intravenously, when enteral feeding is insufficient or contraindicated. It involves greater expertise to administer, is more expensive, and can have serious complications, such as hyperglycemia and hyperlipidemia.
Summary
Early nutritional intervention improves recovery and prevents complications. Enteral feeding is preferable, and the most appropriate route of administration is selected based on the patient’s signalment and needs. Regardless of the type of feeding, patients must be regularly monitored for complications. The initial goal is to meet the resting energy requirements, and then re-weigh the patient and re-adjust the diet accordingly. The veterinary technician is an integral part of the team, and is routinely relied on to monitor patients and make sure the veterinarian is aware of potential issues. CVT
Useful resources
Nasogastric tube placement: https://youtu.be/VqG3KVX2FdQ
Esophagostomy tube placement
- Part 1: https://youtu.be/5nRcDYP6MWs
- Part 2: https://youtu.be/3v_eGCp7o0w
Esophagostomy tube feeding: https://youtu.be/isKU2OQWBzY
