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Basics in Clinical Nutrition: Nutritional support in different clinical situations
e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism 5 (2010) e153–e154
Contents lists available at ScienceDirect
e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism journal homepage: http://www.elsevier.com/locate/clnu
Educational Paper
Basics in Clinical Nutrition: Nutritional support in different clinical situations Lubos Sobotka Charles University, Hradec Kralove, Czech Republic
a r t i c l e i n f o Article history: Received 4 June 2009 Accepted 4 June 2009 Keywords: Severe malnutrition Nutritional therapy Oral nutritional support
Learning objectives To characterize the metabolic situation in severely malnourished patient To know methods of nutritional support in severely malnourished patients To be aware of possible risks connected with nutritional support in severely malnourished patients
1. Pathophysiology Severe malnutrition is always a result of inadequate intake of energy and basic nutrients or it can be a result of increased energy expenditure, which is not matched by an adequate intake. It often develops relatively slowly over a long period, as a result of somatic or psychiatric disease (see related chapters). However, it can develop quickly during a short period of stress starvation. Regardless of the aetiology, severe malnutrition is associated with depletion of body protein, fat, glycogen, potassium, phosphate, magnesium, zinc, selenium, vitamin A, vitamin E, vitamin C, thiamine, pyridoxine, riboflavin and other vitamins. As malnutrition is commonly associated with an increased risk of infection, delayed wound healing and surgical complications, the severely malnourished subject must receive nutritional support, given preferably by the oral or enteral route. Only in the presence of gastrointestinal dysfunction is parenteral nutrition indicated. When starting nutritional support in a severely malnourished patient, one must remember:
E-mail address: [email protected] (Editorial Office).
Severe malnutrition causes secondary gastrointestinal dysfunction with impaired pancreatic secretion and small and large bowel mucosal atrophy, with consequent maldigestion, malabsorption and risk of diarrhoea with enteral feeding. There is a risk of refeeding syndrome unless this is anticipated in the feed formulation and administration rate. Sodium and water content should not be excessive but extra potassium, phosphate and magnesium should be given to avoid clinically dangerous reductions in their plasma concentrations, as avid cellular uptake of these elements follows from restoration of substrate supply. The problem is particularly acute with parenteral nutrition.
2. Goals of nutritional therapy Two basic goals should be kept in mind when starting nutrition support in severely malnourished patients: to restore cellular function – short-term goal to replete lost tissue – long-term goal The depleted patient’s cells behave like those of the growing child, being avid for energy and amino acids to restore tissue. Feeding formulae should not only aim to repair immediate nutrient deficits and meet basic requirements, but also provide sufficient extra energy and protein to restore lost tissue during the convalescent or anabolic phase of illness. Remember that nutritional care is only one part of the patient’s management and can be negated unless other aspects of management are of a high standard and well coordinated.
1751-4991/$36.00 Ó 2009 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.eclnm.2009.06.015
e154
L. Sobotka / e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism 5 (2010) e153–e154
3. Oral nutritional support If the patient is able to eat, nutritional support should start using this route. A well balanced diet should be given and an experienced dietician should control its composition and tolerance. Additional potassium, magnesium and phosphate may need to be infused peripherally during the first week of realimentation to prevent clinically dangerous falls in their plasma levels. The patient should be monitored regularly and plasma levels of the above-mentioned electrolytes should be checked. Vitamins (especially water soluble ones) should also be given during the first days of realimentation because a deficit can be expected (e.g. a deficit of thiamine can impair glucose metabolism and cause lactic acidosis). On the first day of refeeding the patient should receive only half the recommended daily dosage of energy, carbohydrates, fat and proteins. Subsequently, the dose of nutrients should be increased gradually to obtain the full recommended intake within 3–5 days or as soon as tolerated. If intake remains inadequate then supplementary enteral or parenteral feeding may be needed.
Daily body weight and fluid balance charts to measure water balance Examination for any known signs of excess or deficit of electrolytes, vitamins and trace elements Blood sugar to monitor tolerance to glucose in the feed and to control sliding scale insulin administration Frequent (daily to weekly depending on the clinical situation) measurements of creatinine, urea, electrolytes (particularly K, P, Ca and Mg). Weekly albumin levels are helpful with, sometimes, the shorter half life proteins e.g. transthyretin and transferrin Liver function tests and INR to detect early signs of hepato biliary complications of TPN Folate and vitamin B12 (infrequently) and full micronutrient screen (long-term feeding only) where this is available; selenium and zinc levels should be checked It may also be useful once a week to examine serum for lipid clearance and to check cholesterol and triglycerides levels 4 h after the infusion has been stopped
4. Enteral nutrition 7. Rehabilitation If a particular patient is not able to eat or swallow and bowel function is sufficient, he/she should be fed enterally via a feeding tube introduced into the stomach or jejunum. The formula should be chosen to meet tolerance and requirements. The rate of administration should be increased gradually from 20–30 ml per hour until full requirements are met or maximum tolerance is reached – usually over 3–5 days. Standard formulae contain only the basic requirement for electrolytes, minerals and trace elements. In severely depleted patients, therefore, parenteral or enteral supplements of electrolytes, vitamins and trace elements may be necessary (see above). Clinical and biochemical monitoring should be performed regularly. 5. Parenteral nutrition This is indicated when gastrointestinal dysfunction prevents nutritional needs being met by the oral or enteral route. Some care should be taken with the feed prescription to ensure that it meets the needs of the patient, avoiding both deficit and excess. Additional salt and water may be needed in the patient with excess losses from vomiting, diarrhoea or fistulae. Conversely these may need to be restricted in the patient with oedema since both severe malnutrition and acute illness confer an inability to excrete a salt and water load. Special attention should be paid to any possible mineral or micronutrient deficiency particularly following prolonged gastrointestinal disorders. Acute falls in potassium and phosphate should be anticipated with extra amounts of these. An energy supply of 35 kcal/kg/day and protein equivalent of 1.5 g/kg/day should be the initial aim, although these can be increased slightly once mobility and convalescence are established. When gastrointestinal function begins to recover, oral or enteral nutrition can be introduced cautiously and parenteral feeding gradually withdrawn, always making sure that total nutrient requirements continue to be met by whatever route or combination of routes is available. 6. Monitoring At the beginning of nutritional support in severely malnourished patients the effects of nutritional support should be monitored carefully using:
Mobility and exercise are important for restoration of muscle. Restoration of nutrition rapidly improves mental state and cellular function including muscle strength and respiration, thereby accelerating rehabilitation. Real tissue gain is usually minimal in the short term and usually has to await discharge from hospital to normal condition of activity and home feeding. 8. Summary Severely malnourished patients need more K, P, Mg, Zn, and vitamins than well-nourished subjects. Final energy and protein needs are also higher (up to 40–45 kcal/kg/day and 1.5 g/kg/day, respectively) in order to accelerate repletion of deficits. If possible, oral and/or enteral nutrition is advocated for severely malnourished patients. The administration of standard formulae for enteral nutrition may be supplemented with parenteral infusion of electrolytes, minerals and vitamins. The early goal of feeding is improved function and accelerated rehabilitation. Restoration of lean mass is a longer term objective over weeks and months.
Conflict of interest There is no conflict of interest. Further reading 1. Payne-James J, Grimble G, Silk D, editors. Artificial nutrition support in clinical practice. London: Edward Arnold; 1995. 2. Birmingham CL, Alothman AF, Goldner EM. Anorexia nervosa: refeeding and hypophosphatemia. Int J Eat Disord 1996;20:211. 3. Maier-Dobersberger T, Lochs H. Enteral supplementation of phosphate does not prevent hypophosphatemia during refeeding of cachectic patients. JPEN 1994;18:182. 4. Rossouw JE, Pettifor JM. Protein-energy malnutrition. In: Cohen RD, Lewis B, Alberti KGMM, Denman AM, editors. The metabolic and molecular basis of acquire disease. Bailliere Tindall; 1990. p. 514. 5. Scherbaum V, Furst P. New concepts on nutritional management of severe malnutrition: the role of protein. Curr Opin Clin Nutr Metab Care 2000;3:31.
Contents lists available at ScienceDirect
e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism journal homepage: http://www.elsevier.com/locate/clnu
Educational Paper
Basics in Clinical Nutrition: Nutritional support in different clinical situations Lubos Sobotka Charles University, Hradec Kralove, Czech Republic
a r t i c l e i n f o Article history: Received 4 June 2009 Accepted 4 June 2009 Keywords: Severe malnutrition Nutritional therapy Oral nutritional support
Learning objectives To characterize the metabolic situation in severely malnourished patient To know methods of nutritional support in severely malnourished patients To be aware of possible risks connected with nutritional support in severely malnourished patients
1. Pathophysiology Severe malnutrition is always a result of inadequate intake of energy and basic nutrients or it can be a result of increased energy expenditure, which is not matched by an adequate intake. It often develops relatively slowly over a long period, as a result of somatic or psychiatric disease (see related chapters). However, it can develop quickly during a short period of stress starvation. Regardless of the aetiology, severe malnutrition is associated with depletion of body protein, fat, glycogen, potassium, phosphate, magnesium, zinc, selenium, vitamin A, vitamin E, vitamin C, thiamine, pyridoxine, riboflavin and other vitamins. As malnutrition is commonly associated with an increased risk of infection, delayed wound healing and surgical complications, the severely malnourished subject must receive nutritional support, given preferably by the oral or enteral route. Only in the presence of gastrointestinal dysfunction is parenteral nutrition indicated. When starting nutritional support in a severely malnourished patient, one must remember:
E-mail address: [email protected] (Editorial Office).
Severe malnutrition causes secondary gastrointestinal dysfunction with impaired pancreatic secretion and small and large bowel mucosal atrophy, with consequent maldigestion, malabsorption and risk of diarrhoea with enteral feeding. There is a risk of refeeding syndrome unless this is anticipated in the feed formulation and administration rate. Sodium and water content should not be excessive but extra potassium, phosphate and magnesium should be given to avoid clinically dangerous reductions in their plasma concentrations, as avid cellular uptake of these elements follows from restoration of substrate supply. The problem is particularly acute with parenteral nutrition.
2. Goals of nutritional therapy Two basic goals should be kept in mind when starting nutrition support in severely malnourished patients: to restore cellular function – short-term goal to replete lost tissue – long-term goal The depleted patient’s cells behave like those of the growing child, being avid for energy and amino acids to restore tissue. Feeding formulae should not only aim to repair immediate nutrient deficits and meet basic requirements, but also provide sufficient extra energy and protein to restore lost tissue during the convalescent or anabolic phase of illness. Remember that nutritional care is only one part of the patient’s management and can be negated unless other aspects of management are of a high standard and well coordinated.
1751-4991/$36.00 Ó 2009 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.eclnm.2009.06.015
e154
L. Sobotka / e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism 5 (2010) e153–e154
3. Oral nutritional support If the patient is able to eat, nutritional support should start using this route. A well balanced diet should be given and an experienced dietician should control its composition and tolerance. Additional potassium, magnesium and phosphate may need to be infused peripherally during the first week of realimentation to prevent clinically dangerous falls in their plasma levels. The patient should be monitored regularly and plasma levels of the above-mentioned electrolytes should be checked. Vitamins (especially water soluble ones) should also be given during the first days of realimentation because a deficit can be expected (e.g. a deficit of thiamine can impair glucose metabolism and cause lactic acidosis). On the first day of refeeding the patient should receive only half the recommended daily dosage of energy, carbohydrates, fat and proteins. Subsequently, the dose of nutrients should be increased gradually to obtain the full recommended intake within 3–5 days or as soon as tolerated. If intake remains inadequate then supplementary enteral or parenteral feeding may be needed.
Daily body weight and fluid balance charts to measure water balance Examination for any known signs of excess or deficit of electrolytes, vitamins and trace elements Blood sugar to monitor tolerance to glucose in the feed and to control sliding scale insulin administration Frequent (daily to weekly depending on the clinical situation) measurements of creatinine, urea, electrolytes (particularly K, P, Ca and Mg). Weekly albumin levels are helpful with, sometimes, the shorter half life proteins e.g. transthyretin and transferrin Liver function tests and INR to detect early signs of hepato biliary complications of TPN Folate and vitamin B12 (infrequently) and full micronutrient screen (long-term feeding only) where this is available; selenium and zinc levels should be checked It may also be useful once a week to examine serum for lipid clearance and to check cholesterol and triglycerides levels 4 h after the infusion has been stopped
4. Enteral nutrition 7. Rehabilitation If a particular patient is not able to eat or swallow and bowel function is sufficient, he/she should be fed enterally via a feeding tube introduced into the stomach or jejunum. The formula should be chosen to meet tolerance and requirements. The rate of administration should be increased gradually from 20–30 ml per hour until full requirements are met or maximum tolerance is reached – usually over 3–5 days. Standard formulae contain only the basic requirement for electrolytes, minerals and trace elements. In severely depleted patients, therefore, parenteral or enteral supplements of electrolytes, vitamins and trace elements may be necessary (see above). Clinical and biochemical monitoring should be performed regularly. 5. Parenteral nutrition This is indicated when gastrointestinal dysfunction prevents nutritional needs being met by the oral or enteral route. Some care should be taken with the feed prescription to ensure that it meets the needs of the patient, avoiding both deficit and excess. Additional salt and water may be needed in the patient with excess losses from vomiting, diarrhoea or fistulae. Conversely these may need to be restricted in the patient with oedema since both severe malnutrition and acute illness confer an inability to excrete a salt and water load. Special attention should be paid to any possible mineral or micronutrient deficiency particularly following prolonged gastrointestinal disorders. Acute falls in potassium and phosphate should be anticipated with extra amounts of these. An energy supply of 35 kcal/kg/day and protein equivalent of 1.5 g/kg/day should be the initial aim, although these can be increased slightly once mobility and convalescence are established. When gastrointestinal function begins to recover, oral or enteral nutrition can be introduced cautiously and parenteral feeding gradually withdrawn, always making sure that total nutrient requirements continue to be met by whatever route or combination of routes is available. 6. Monitoring At the beginning of nutritional support in severely malnourished patients the effects of nutritional support should be monitored carefully using:
Mobility and exercise are important for restoration of muscle. Restoration of nutrition rapidly improves mental state and cellular function including muscle strength and respiration, thereby accelerating rehabilitation. Real tissue gain is usually minimal in the short term and usually has to await discharge from hospital to normal condition of activity and home feeding. 8. Summary Severely malnourished patients need more K, P, Mg, Zn, and vitamins than well-nourished subjects. Final energy and protein needs are also higher (up to 40–45 kcal/kg/day and 1.5 g/kg/day, respectively) in order to accelerate repletion of deficits. If possible, oral and/or enteral nutrition is advocated for severely malnourished patients. The administration of standard formulae for enteral nutrition may be supplemented with parenteral infusion of electrolytes, minerals and vitamins. The early goal of feeding is improved function and accelerated rehabilitation. Restoration of lean mass is a longer term objective over weeks and months.
Conflict of interest There is no conflict of interest. Further reading 1. Payne-James J, Grimble G, Silk D, editors. Artificial nutrition support in clinical practice. London: Edward Arnold; 1995. 2. Birmingham CL, Alothman AF, Goldner EM. Anorexia nervosa: refeeding and hypophosphatemia. Int J Eat Disord 1996;20:211. 3. Maier-Dobersberger T, Lochs H. Enteral supplementation of phosphate does not prevent hypophosphatemia during refeeding of cachectic patients. JPEN 1994;18:182. 4. Rossouw JE, Pettifor JM. Protein-energy malnutrition. In: Cohen RD, Lewis B, Alberti KGMM, Denman AM, editors. The metabolic and molecular basis of acquire disease. Bailliere Tindall; 1990. p. 514. 5. Scherbaum V, Furst P. New concepts on nutritional management of severe malnutrition: the role of protein. Curr Opin Clin Nutr Metab Care 2000;3:31.