The Inappetent Hospitalised Cat: clinical approach to maximising nutritional support

Abstract

Practical relevance: Inappetence is one of the most common presenting complaints in clinically ill cats requiring hospitalisation. When prolonged, poor food intake can lead to malnutrition and may be associated with impaired metabolic function, immunosuppression, compromised wound healing, and increased morbidity and mortality. It is important to recognise that inappetence or anorexia is always secondary to another condition, and that treatment goals should be targeted at the primary condition. The current emphasis in the nutritional support of hospitalised inappetent cats is to provide more effective means of increasing nutritional intake--for example, by initiating enteral nutrition via feeding tubes-- rather than rely solely on traditional approaches such as increasing palatability of foods or using appetite-stimulating drugs.

Clinical challenges: Cats that are ill enough to require hospitalisation are at increased risk of becoming malnourished because of the combined catabolic effects of their disease and poor nutritional intake. This article highlights some of the problems encountered in treating inappetent cats and discusses a clinical approach to providing better nutritional support.

Patient group: Inappetence and anorexia are associated with a myriad of clinical conditions in cats and can be seen in individuals of any age or breed.

Equipment: Provision of nutritional support to cats may involve the use of feeding tubes such as naso-oesophageal or oesophagostomy tubes. In cases where enteral nutrition is not feasible (eg, cats with gastrointestinal failure), parenteral nutrition should be considered.

Evidence base: Various studies have documented the high prevalence of inappetence or anorexia in clinically ill cats. Additional studies have linked poor food intake in cats with serious sequelae such as immunosuppression and hepatic lipidosis. More recently, techniques for providing more effective nutritional support, such as oesophagostomy tubes, have been clinically evaluated and shown to be associated with minimal complications.

FIG 1

A candidate for nutritional support? Factors such as recent weight loss, poor haircoat and muscle wasting are not specific to malnutrition, hence an appropriate nutritional assessment should be conducted before implementing a nutritional plan

Naso-oesophageal tube

Oesophagostomy tube, (inset) As with all feeding tubes, the exit site should be monitored carefully for irritation or, more significantly, infection

Gastrostomy tube

Step 1

Proper placement of an oesophagostomy feeding tube (O tube) requires the distal tip to be placed in the distal oesophagus at a level no further than the ninth intercostal space. This may require premeasurement of the tube. Rather than cutting the distal tip and creating a sharp edge, the exit hole should be elongated using a small blade

Step 2

The patient should be anaesthetised and preferably intubated. While in right lateral recumbency, the left side of the neck should be clipped and a routine surgical scrub performed

Step 3

A curved Rochester-Carmalt clamp is placed into the mouth and down the oesophagus to the mid-cervical region. The jugular vein should be identified and avoided

Step 4

The tip of the Carmalt clamp is then pushed dorsally, elevating the oesophagus towards the skin. Having confirmed the location of the tip of the instrument by palpating over the skin, an incision is made through the skin onto the tip of the Carmalt in the oesophagus. The mucosa of the oesophagus is relatively more difficult to incise than the skin

Step 5

The tip of the instrument is then forced through the incision, which can be slightly enlarged with the blade to allow the tips of the Carmalt to be opened and the O tube to be grasped

Step 6

The Carmalt is then clamped closed and pulled from the oral cavity

Step 7

The tips of the Carmalt are disengaged and the tip of the O tube is curled back into the mouth and fed into the oropharynx. As the curled tube is pushed into the oesophagus, the proximal end is gently pulled simultaneously. This results in a subtle ‘flip’ as the tube is redirected within the oesophagus. The tube should easily slide back and forth a few millimetres, confirming that the tube has straightened

Step 8

The oropharynx is visually inspected to confirm that the tube is no longer present within it

Step 9

The incision site should be briefly re-scrubbed before a purse-string suture is placed followed by a Chinese finger trap suture, further securing the tube in place. A light wrap is then applied to the neck

Step 10

Correct O tube placement is confirmed using either radiography or fluoroscopy