CLINICAL
NUTRITION
Ensuring compliance in enteral feeding Pamela Rogers RON, is Nutritional Support Sister, Department of Clinical Surgery, Royal Infirmary of Edinburgh.
i L*
The problem of incompatibility between connections. A piece of oxygen tubing lias been inserted between the nasogastric tube and the giving set. This might solve the problem in the short term, but long term difficulties are likely to occur.
trass
Enteral feeding provides a lifeline for some patients, but is not without its own hazards and risks. The complications include blocking of tubes and gas trointestinal intolerance, and may inhibit and delay the patient’s recoveryfrom illness. This article discusses the difficulties, and offers some potential solutions to them.
Enteral nutrition, and in particular nasogas tric feeding, has become an accepted method of providing nutritional support to patients with a functioning gastrointestinal tract. In terms of feed delivery, the most common method is an infusion over a 24 hour period using an enteral feeding pump. In addition to the mode ofdelivery in enter al nutrition, nurses must also consider the individual’s nutritional requirements. These are influenced by factors such as age, sex, height, weight and the presence of disease. Despite these unique influences on nutritional requirements, most patients receive a standard feeding regimen in terms of nutritional con tent and rate of delivery. Published literature has shown that because
of a number of factors, patients may not always receive their nutritional prescription (1) and therefore do not receive adequate amounts of nitrogen and caloric intake (2). This may have the consequence of exacerbating any pre existing malnutrition as patients move into an increased energy and nitrogen deficit. The reasons for nutritional deficit may be multifactorial, and include mechanical prob lems, gastrointestinal complications, reduced mobility, ongoing investigations and fluid restriction regimes. Mechanical problems Complications such as inadvertent removal of the tube by the patient, tube blockage, incompatibility of equipment and delay between feed changes may all con tribute to inadequate feed delivery. A variety of nasogastric tubes is currently available. They vary in both length and inter nal diameter . Fine bore tubes are widely used in hospital and at home, but it is important that the chosen tube suits the patient's needs. In a trial carried out by Fawcett (3), she noted that some tubes were more effective than others, with reduced incidences of blockage, September 16/Volume 6/Number 52/1992 Nursing Standard 25
CLINICAL
NUTRITION
slippage and inadvertent removal by patients. Weighted tubes were marketed with claims of being beneficial in terms of ease of inser tion and in the facilitation of long term duodenal feeding, but investigations by Silk el al (4) and Levenson (5) have not shown any advantages in using weighted tubes. Tube occlusion is a regular problem, and may lead to several feeding interruptions which result in a deficit between the enteral prescription and the amount received by the patient. There are several causes of obstruc tion; a common one is the inappropriate administration of medicines (6), with tablets which have been inadequately crushed caus ing feed residue to adhere to the lumen of the tube. Alternatively, there may be an interac tion between the feed and medication. By adopting simple preventive measures, however, tube occlusions can be avoided. Wherever possible, liquid medicinal prepara tions should be given and if tablets must be used, they should be crushed to a fine powder before being mixed with water. It is worth A commonly used feeding pump in operation.
n>j
Free fluids
EC « ti
i }1
I
)
noting that potassium and iron preparations are incompatible when mixed with many enteral formulas (7). The importance of flushing the tube can not be over emphasised. Feeding tubes must be flushed between feed changes and after administration of medicines, thus preventing residue adhering to the tube lumen. Despite adopting these measures, recurrent occlusions may continue to present a problem. One pos sible explanation for this has been cited by Marcaud (7), who suggested that there may be reflux ofgastric acid into the tube causing feed precipitation. Various methods of regaining patency in an occluded tube have been suggested. These vary from injecting 30mls of water (7), to giv ing pancreatic enzymes or carbonated soft drinks (6). Unfortunately, if the tube is com pletely occluded, it is almost impossible to instil an adequate volume of these fluids, and the tube usually has to be removed. Nursing workload also presents potential difficulties in ensuring a regimen is properly adhered to. As nursing workload varies, the time between removal of the tube and the insertion of another may vary. This is also true of the time between the changing of empty feed reservoirs. If the patient requires X ray confirmation of tube position, the time that feeding is commenced may be dependent on the workload in the X-ray and portering departments. Gastrointestinal complications Nausea, vomit ing, abdominal pain and diarrhoea can present major setbacks and are common causes of interruption and, in some cases, discontinua tion of feeding. By identifying the underlying causes, these complications may be prevented or overcome.
Slow rate infusion ') i; ■ >.
I
/r
»>■
26 Nursing Standard September 16/Volume 6/Number 52/1992
< r
Nausea and vomiting may stem from rapid feeding rates. Administration should start with a continuous infusion at a slow rate (for example, 50ml an hour) with undiluted feed. The rate may then be increased as tolerated over the next two to three days (75mls an hour, then 100mIs an hour). Keohane el al(8) demonstrated that the use of starter regimens (quarter strength and half strength feeds) are not successful in relieving nausea, vomiting or diarrhoea, but result in reduced intakes of nitrogen and protein. Diarrhoea not only results in a deficit in the prescribed amount of feed, but is distressing for the patient . The two main causes are bac terial contamination or causes that are related to the formula in use.
CLINICAL
NUTRITION
Jr
) Gastronomy tube in situ. These should be considered for use in patients who require long term enteral feeding. With good care, they can remain in situ for months, and are relatively free of problems. References 1. Robertson S. I low much of the prescribed volume of enteral feed does the hospitalised patient actually receive? Journal oj Human Nutrition and Dietetics. 1990. 3, 165 - 170. 2. Abernathy (i B et aJ. Efficacy of rube feeding in supplying energy requirements of hospitalised patients. Journal oj Parenteral and Enteral Nutrition. 1989- 13, 4, 387 - 370. 3. Fawcett 11 A tube- ro suit all N G needs? Evaluation of fine bore nasogastric tubes. Professional Nurse. 1989. 9, 6, 324- 329. 4. Silk D et al. Clinical efficacy and design changes of Fine Bore nasogastric feeding tubes: A seven year experience involving 809 intubations in 403 patients. Journal of Parenteral and Enteral Nutrition. 1987. 11,4, 378 - 383. 5. Levenson R N et al. Do weighted nasoenteric tubes facilitate duodenal i ntubations ? Journal oj Parenteral and Enteral Nutrition. 1988. 12, 2,135 137. 6. Kohn C, Keithley T. Potential complications and patient monitoring. Nursing Clink f Of North \ ....... 1989. 24, 2, 339 - 353. 7. Marcuad S, Perkins A. Clogging of feeding tubes. Journal of Parenteral and Enteral Nutrition. 1988. 12, 4, 403 405. 8. Keohane P et al. Relation between osmolality of diet and gastrointestinal side-effects in enteral nutrition. British MedicalJournal. 1984. 288, 678-680. 9. Edes T et al. Diarrhoea in tube fed patients: feeding formula not necessarily the cause. American Journal of Medicine. 1990. 88, 91 - 9.3. 10 Hill D et al. Osmotic diarrhoea induced by sugar free theophylline solution in critically ill patients. Journal of Parenteral and Enteral Nutrition. 1991. 15, 3, 332 - 336.
V
Elemental formulas, which are higher in osmolaricy, have been implicated as possible causes of diarrhoea. This may be an important factor in patients who are malnourished or who have malabsorption problems (6). In this patient group, the use of a peptide regimen (osmolarity approximately 220 mosm per litre) may be beneficial in improving tolerance. Although most formulas are commercially prepared, bacterial contamination can still occur during transfer from the proprietary packing to the administration device. Hand hygiene is important, both in the diet kitchen and at ward level. Administration devices should be changed regularly, following manufacturers’ recommendations. The administration device should be labelled with the date and time of transfer. In warm weath er, the length of time the formula is exposed to room temperature is significant; the longer the exposure, the greater the chance of prob lems occurring. Powder feeds that require reconstitution should be changed more often than the ready to use delivery systems. In a study of tube-fed patients (9), only 21 per cent had diarrhoea which was related to the feed formula. Medications were responsi ble in 61 per cent, and the organism Clostridium difficile in the remaining 17 per cent of cases. Patients receiving tube feeding will often be given elixirs, some of which will contain the sweetener sorbitol (10), which act as an osmotic agent and can cause diarrhoea. Antibiotics are also a common cause of diar rhoea. If antibiotic related diarrhoea is suspected, it is important to consider the pos sibility that the patient may have pseudomembraneous colitis and screening should be carried out by a microbiologist before any antidiarrhoeal drugs are prescribed.
Mobility An important milestone in any patient’s rehabilitation is the recovery of inde pendent mobility, especially following a long period of illness. Continuous enteral feeding may to some extent hamper the efforts of the patient and various health care disciplines to achieve this. By increasing the rate of administration or administering a more concentrated formula in a shorter time and therefore creating periods when no feeding is in progress, patients can still receive the prescribed amount of feed and have periods free of the restrictions of equip ment for mobilisation. Investigations During almost any period of hospitalisation for the patient on nutritional support, investigations which require periods of fasting must be carried out. This may result in a reduced amount of prescribed feed being administered and, if continued for a period of a week or more, will result in a significant deficit in energy and nitrogen balance. Consideration should be given to increasing the rate of administration or using a more con centrated feed during the period when fasting is not required. fluid restriction If fluid restriction is necessary, administering concentrated feeds (if tolerat ed) will increase the nitrogen and calorie intake while keeping the patient’s fluid intake to a minimum. Conclusion Patients who are dependent upon nutritional support are subject to a variety of problems and hazards, some of which have been explained in this article. Nurses can be instrumental in reducing the incidence of these problems. By careful monitoring and being aware of potential problems, patients can be fed via the nasogastric route safely and effectively. September 16/ Volume 6/Number 52/1992 Nursing Standard 27
NUTRITION
Ensuring compliance in enteral feeding Pamela Rogers RON, is Nutritional Support Sister, Department of Clinical Surgery, Royal Infirmary of Edinburgh.
i L*
The problem of incompatibility between connections. A piece of oxygen tubing lias been inserted between the nasogastric tube and the giving set. This might solve the problem in the short term, but long term difficulties are likely to occur.
trass
Enteral feeding provides a lifeline for some patients, but is not without its own hazards and risks. The complications include blocking of tubes and gas trointestinal intolerance, and may inhibit and delay the patient’s recoveryfrom illness. This article discusses the difficulties, and offers some potential solutions to them.
Enteral nutrition, and in particular nasogas tric feeding, has become an accepted method of providing nutritional support to patients with a functioning gastrointestinal tract. In terms of feed delivery, the most common method is an infusion over a 24 hour period using an enteral feeding pump. In addition to the mode ofdelivery in enter al nutrition, nurses must also consider the individual’s nutritional requirements. These are influenced by factors such as age, sex, height, weight and the presence of disease. Despite these unique influences on nutritional requirements, most patients receive a standard feeding regimen in terms of nutritional con tent and rate of delivery. Published literature has shown that because
of a number of factors, patients may not always receive their nutritional prescription (1) and therefore do not receive adequate amounts of nitrogen and caloric intake (2). This may have the consequence of exacerbating any pre existing malnutrition as patients move into an increased energy and nitrogen deficit. The reasons for nutritional deficit may be multifactorial, and include mechanical prob lems, gastrointestinal complications, reduced mobility, ongoing investigations and fluid restriction regimes. Mechanical problems Complications such as inadvertent removal of the tube by the patient, tube blockage, incompatibility of equipment and delay between feed changes may all con tribute to inadequate feed delivery. A variety of nasogastric tubes is currently available. They vary in both length and inter nal diameter . Fine bore tubes are widely used in hospital and at home, but it is important that the chosen tube suits the patient's needs. In a trial carried out by Fawcett (3), she noted that some tubes were more effective than others, with reduced incidences of blockage, September 16/Volume 6/Number 52/1992 Nursing Standard 25
CLINICAL
NUTRITION
slippage and inadvertent removal by patients. Weighted tubes were marketed with claims of being beneficial in terms of ease of inser tion and in the facilitation of long term duodenal feeding, but investigations by Silk el al (4) and Levenson (5) have not shown any advantages in using weighted tubes. Tube occlusion is a regular problem, and may lead to several feeding interruptions which result in a deficit between the enteral prescription and the amount received by the patient. There are several causes of obstruc tion; a common one is the inappropriate administration of medicines (6), with tablets which have been inadequately crushed caus ing feed residue to adhere to the lumen of the tube. Alternatively, there may be an interac tion between the feed and medication. By adopting simple preventive measures, however, tube occlusions can be avoided. Wherever possible, liquid medicinal prepara tions should be given and if tablets must be used, they should be crushed to a fine powder before being mixed with water. It is worth A commonly used feeding pump in operation.
n>j
Free fluids
EC « ti
i }1
I
)
noting that potassium and iron preparations are incompatible when mixed with many enteral formulas (7). The importance of flushing the tube can not be over emphasised. Feeding tubes must be flushed between feed changes and after administration of medicines, thus preventing residue adhering to the tube lumen. Despite adopting these measures, recurrent occlusions may continue to present a problem. One pos sible explanation for this has been cited by Marcaud (7), who suggested that there may be reflux ofgastric acid into the tube causing feed precipitation. Various methods of regaining patency in an occluded tube have been suggested. These vary from injecting 30mls of water (7), to giv ing pancreatic enzymes or carbonated soft drinks (6). Unfortunately, if the tube is com pletely occluded, it is almost impossible to instil an adequate volume of these fluids, and the tube usually has to be removed. Nursing workload also presents potential difficulties in ensuring a regimen is properly adhered to. As nursing workload varies, the time between removal of the tube and the insertion of another may vary. This is also true of the time between the changing of empty feed reservoirs. If the patient requires X ray confirmation of tube position, the time that feeding is commenced may be dependent on the workload in the X-ray and portering departments. Gastrointestinal complications Nausea, vomit ing, abdominal pain and diarrhoea can present major setbacks and are common causes of interruption and, in some cases, discontinua tion of feeding. By identifying the underlying causes, these complications may be prevented or overcome.
Slow rate infusion ') i; ■ >.
I
/r
»>■
26 Nursing Standard September 16/Volume 6/Number 52/1992
< r
Nausea and vomiting may stem from rapid feeding rates. Administration should start with a continuous infusion at a slow rate (for example, 50ml an hour) with undiluted feed. The rate may then be increased as tolerated over the next two to three days (75mls an hour, then 100mIs an hour). Keohane el al(8) demonstrated that the use of starter regimens (quarter strength and half strength feeds) are not successful in relieving nausea, vomiting or diarrhoea, but result in reduced intakes of nitrogen and protein. Diarrhoea not only results in a deficit in the prescribed amount of feed, but is distressing for the patient . The two main causes are bac terial contamination or causes that are related to the formula in use.
CLINICAL
NUTRITION
Jr
) Gastronomy tube in situ. These should be considered for use in patients who require long term enteral feeding. With good care, they can remain in situ for months, and are relatively free of problems. References 1. Robertson S. I low much of the prescribed volume of enteral feed does the hospitalised patient actually receive? Journal oj Human Nutrition and Dietetics. 1990. 3, 165 - 170. 2. Abernathy (i B et aJ. Efficacy of rube feeding in supplying energy requirements of hospitalised patients. Journal oj Parenteral and Enteral Nutrition. 1989- 13, 4, 387 - 370. 3. Fawcett 11 A tube- ro suit all N G needs? Evaluation of fine bore nasogastric tubes. Professional Nurse. 1989. 9, 6, 324- 329. 4. Silk D et al. Clinical efficacy and design changes of Fine Bore nasogastric feeding tubes: A seven year experience involving 809 intubations in 403 patients. Journal of Parenteral and Enteral Nutrition. 1987. 11,4, 378 - 383. 5. Levenson R N et al. Do weighted nasoenteric tubes facilitate duodenal i ntubations ? Journal oj Parenteral and Enteral Nutrition. 1988. 12, 2,135 137. 6. Kohn C, Keithley T. Potential complications and patient monitoring. Nursing Clink f Of North \ ....... 1989. 24, 2, 339 - 353. 7. Marcuad S, Perkins A. Clogging of feeding tubes. Journal of Parenteral and Enteral Nutrition. 1988. 12, 4, 403 405. 8. Keohane P et al. Relation between osmolality of diet and gastrointestinal side-effects in enteral nutrition. British MedicalJournal. 1984. 288, 678-680. 9. Edes T et al. Diarrhoea in tube fed patients: feeding formula not necessarily the cause. American Journal of Medicine. 1990. 88, 91 - 9.3. 10 Hill D et al. Osmotic diarrhoea induced by sugar free theophylline solution in critically ill patients. Journal of Parenteral and Enteral Nutrition. 1991. 15, 3, 332 - 336.
V
Elemental formulas, which are higher in osmolaricy, have been implicated as possible causes of diarrhoea. This may be an important factor in patients who are malnourished or who have malabsorption problems (6). In this patient group, the use of a peptide regimen (osmolarity approximately 220 mosm per litre) may be beneficial in improving tolerance. Although most formulas are commercially prepared, bacterial contamination can still occur during transfer from the proprietary packing to the administration device. Hand hygiene is important, both in the diet kitchen and at ward level. Administration devices should be changed regularly, following manufacturers’ recommendations. The administration device should be labelled with the date and time of transfer. In warm weath er, the length of time the formula is exposed to room temperature is significant; the longer the exposure, the greater the chance of prob lems occurring. Powder feeds that require reconstitution should be changed more often than the ready to use delivery systems. In a study of tube-fed patients (9), only 21 per cent had diarrhoea which was related to the feed formula. Medications were responsi ble in 61 per cent, and the organism Clostridium difficile in the remaining 17 per cent of cases. Patients receiving tube feeding will often be given elixirs, some of which will contain the sweetener sorbitol (10), which act as an osmotic agent and can cause diarrhoea. Antibiotics are also a common cause of diar rhoea. If antibiotic related diarrhoea is suspected, it is important to consider the pos sibility that the patient may have pseudomembraneous colitis and screening should be carried out by a microbiologist before any antidiarrhoeal drugs are prescribed.
Mobility An important milestone in any patient’s rehabilitation is the recovery of inde pendent mobility, especially following a long period of illness. Continuous enteral feeding may to some extent hamper the efforts of the patient and various health care disciplines to achieve this. By increasing the rate of administration or administering a more concentrated formula in a shorter time and therefore creating periods when no feeding is in progress, patients can still receive the prescribed amount of feed and have periods free of the restrictions of equip ment for mobilisation. Investigations During almost any period of hospitalisation for the patient on nutritional support, investigations which require periods of fasting must be carried out. This may result in a reduced amount of prescribed feed being administered and, if continued for a period of a week or more, will result in a significant deficit in energy and nitrogen balance. Consideration should be given to increasing the rate of administration or using a more con centrated feed during the period when fasting is not required. fluid restriction If fluid restriction is necessary, administering concentrated feeds (if tolerat ed) will increase the nitrogen and calorie intake while keeping the patient’s fluid intake to a minimum. Conclusion Patients who are dependent upon nutritional support are subject to a variety of problems and hazards, some of which have been explained in this article. Nurses can be instrumental in reducing the incidence of these problems. By careful monitoring and being aware of potential problems, patients can be fed via the nasogastric route safely and effectively. September 16/ Volume 6/Number 52/1992 Nursing Standard 27
