Enteral tube feeding can be provided via a nasogastric tube (NGT), nasojejunal tube, gastrostomy tube or jejunostomy tube.
Nasogastric feeding
Short-term enteral feeding (2–6 weeks) is normally provided through an NGT as this provides a rela- tively easy means of bypassing the oral cavity while providing direct access to the stomach. Insertion of an NGT can be undertaken at the bedside and generally requires no anaesthetic. Although this is a relatively simple procedure to undertake, there are risks associated with placement of an NGT (Box 4.4). There have been two National Patient Safety Alerts in recent years regarding the placement and checking of NGTs (National Patient Safety Agency [NPSA] 2005, 2011).
A fine-bore NGT should be used as it is more comfortable for the patient and reduces the risk of rhinitis, pharyngitis or oesophageal erosion. It should be radio-opaque throughout its length, so that its position can be monitored on X-ray (if required), and have clear markers to aid measurement during insertion and for bedside checks (NPSA 2011). The NGT is inserted via the nostril, along the nasophar- ynx, down through the oesophagus and into the stomach (Figure 4.1).
Once the tube has been inserted, its gastric positioning needs to be confirmed, which is usually undertaken using pH indicator strips, gastric placement being confirmed by a pH between 1 and 5.5.
Each test result is documented on a chart kept at the patient’s bedside (NPSA 2011). X-rays should only be undertaken if gastric placement cannot be confirmed using pH indicator strips and should only be used following initial NGT placement (NPSA 2011).
Gastrostomy tubes
A gastrostomy provides a more permanent means of access to the stomach to enable longer term enteral feeding (>6 weeks). It provides safe access directly into the stomach through the development of a fistula through the abdominal wall. There are four different types of gastrostomy tube (Table 4.2) of which the percutaneous endoscopic gastrostomy (PEG) tube (Figure 4.2) is the most commonly used.
Postpyloric feeding
Postpyloric feeding may be considered for patients in whom gastric feeding is unsafe or problematic, for example patients with gastroparesis, pancreatitis or aspiration pneumonia. The tip of the feeding
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tube bypasses the stomach and sits in the small intestine. Three types of tube are used for postpyloric feeding (Table 4.3).
Enteral tube feeds
There are many different enteral tube feeds. Some contain fibre, some provide more calories per mil- lilitre than others, and the level of electrolytes may vary between feeds. Feeds are generally presented in sterile ready-to-use containers and can hang for a maximum of 24 hours, after which any remaining feed should be discarded.
Figure 4.1 NGT insertion.
End of nasogastric tube
Nasal cavity
Nasogastric tube
Gullet (oesophagus)
Stomach
Table 4.2 Types of gastrostomy tube
Type of gastrostomy tube Rationale for use
PEG The most common method of primary gastrostomy insertion
Radiologically inserted gastrostomy or fluoroscopically guided
percutaneous gastrostomy
May be the method of choice if endoscopic placement is not available or is inadvisable
Balloon gastrostomy May be used for primary placement or as a percutaneous replacement where further endoscopic or radiological intervention is to be avoided
Button or low-profile device Tend to be used in younger adults and children
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Methods of providing enteral feed
A feed can be delivered through an enteral feeding tube in a number of ways:
•
continuously via a pump providing a set rate of feed over a specified number of hours;•
intermittent infusion (with or without a pump);•
using a syringe to deliver larger volumes of feed (bolus) at agreed timeslots throughout the day.The method of administration used will depend upon the patient’s medical condition, their ability to tolerate the feed, their nutritional requirements and their preferences.
Figure 4.2 PEG tube. Courtesy of Fresenius Kabi.
Table 4.3 Enteral feeding tubes used for postpyloric feeding Type of tube Method of placement
Nasojejunal tube Appears very similar to an NGT. They may be single or dual lumen Dual-lumen tubes have one gastric port for gastric decompression and one jejunal port for feeding
They can be placed endoscopically, radiologically or at the bedside by specially trained healthcare professionals
Some nasojejunal tubes may be assisted into the small bowel using prokinetic drugs to help stimulate gastric emptying and position the tube correctly
Percutaneous endoscopic
gastrojejunostomy Created following the placement of a PEG tube, a long small-gauge tube is passed through the lumen of the PEG and pulled down into the small intestine
Surgical jejunostomy Placed directly into the jejunum at laparotomy
May be tunnelled and secured using a Dacron cuff or held in place by sutures at the abdomen
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Conclusion
Many factors affect the nutritional status of a patient coming into hospital, including increasing age, illness, an inability to cope, drug treatment and socioeconomic factors. As the care of health-related problems is increasingly being managed in primary care settings, patients who are admitted to hospital are often acutely ill before admission and may already have some signs of malnutrition. Once in hos- pital, the risks increase due to episodes where patients are placed on ‘nil by mouth’ for investigations or procedures required to investigate and treat their illness or disease. In addition, appetite often decreases when a person is ill. Therefore it is not surprising that some patients may leave hospital in a more malnourished state that when they arrived.
Providing an appropriate and timely level of nutritional support is essential to maximise the patient’s nutritional status and recovery from illness. The use of a step-by-step approach is often the safest means of progressing – from oral supplementation to parenteral nutrition. However, it is essential to consider the risks that accompany artificial nutritional support as the provision of nutritional care via enteral or parenteral feeding tubes is not without complications. Therefore the balance of risk versus benefit must be considered for each patient before nutritional support is commenced. Nurses play a
Patient monitoring
Enteral feed should be stored and administered at room temperature to avoid gastric discomfort associ- ated with the administration of cold feed. The patient should be positioned with the head and shoul- ders raised to an angle of at least 30° and be monitored closely for any potential side effects (as discussed above) during feeding and for at least an hour on completion of the feed. While nutritional support is being provided, the patient should be monitored to check for:
•
changes in weight;•
changes in oral intake;•
fluid balance;•
electrolyte deficiencies;so that their feeding regimen can be adjusted accordingly.
If a decision is made that nutritional support is no longer required, there is usually a gradual reduc- tion in feed with continued monitoring, to ensure that patients can maintain their nutritional status without support. In the same way that nutritional support is escalated using a step-by-step approach, so it is sensible to reduce it using the same approach.