Refeeding syndrome
Encyclopedia
Refeeding syndrome is a syndrome
consisting of metabolic disturbances that occur as a result of reinstitution of nutrition to patients who are starved
or severely malnourished. Renourishment is the process of avoiding refeeding syndrome. The syndrome was first described after the Second World War in Americans who, held by the Japan
ese as prisoners of war, had become malnourished during captivity and who were then released to the care of United States personnel in the Philippines
.
disorders, especially hypophosphatemia
, along with neurologic, pulmonary, cardiac, neuromuscular, and hematologic complications.
During prolonged fasting the body aims to conserve muscle and protein breakdown by switching to ketone bodies
derived from fatty acids as the main energy source. The liver decreases its rate of gluconeogenesis
thus conserving muscle and protein. Many intracellular minerals become severely depleted during this period, although serum levels remain normal. Importantly, insulin secretion is suppressed in this fasted state and glucagon
secretion is increased.
During refeeding, insulin secretion resumes in response to increased glycemia
; resulting in increased glycogen, fat and protein synthesis. This process requires phosphates, magnesium and potassium which are already depleted and the stores rapidly become used up. Formation of phosphorylated carbohydrate compounds in the liver and skeletal muscle depletes intracellular ATP and 2,3-diphosphoglycerate in red blood cells, leading to cellular dysfunction and inadequate oxygen delivery to the body's organs. Refeeding increases the basal metabolic rate
. Intracellular movement of electrolytes occurs along with a fall in the serum
electrolytes including phosphate
, potassium
and magnesium
. Glucose
, and levels of the B vitamin thiamine
may also fall. Cardiac arrhythmias are the most common cause of death from refeeding syndrome, with other significant risks including confusion, coma
and convulsions and cardiac failure.
This syndrome can occur at the beginning of treatment for anorexia nervosa
when patients are reintroduced to a healthy diet.
The shifting of electrolytes and fluid balance increases cardiac workload and heart rate. This can lead to acute heart failure. Oxygen consumption is also increased which strains the respiratory system and can make weaning from ventilation more difficult.
is often the refeeding food of choice in this early period as it is naturally high in phosphate and easily tolerated by those who have been starved. If potassium
, phosphate
or magnesium
are low then this should be corrected via the oral route, or if severe with parenteral
treatment. Prescribing thiamine
, vitamin B complex (strong) and a multivitamin
and mineral is recommended. Biochemistry should be monitored regularly until it is stable. Energy intake
should remain only 50-70% that of normally required for the first 3–5 days.
Patients who have been starved for some time often experience gastrointestinal disturbance during refeeding, in particular colicky abdominal pain, reflux
symptoms, nausea and early satiety. To help manage this patients are often prescribed pro-kinetic agents such as domperidone
or metoclopramide
, as well as acid suppressants such as omeprazole
. This may be of particular importance in patients suffering from anorexia nervosa
, who can find these symptoms particularly distressing.
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
consisting of metabolic disturbances that occur as a result of reinstitution of nutrition to patients who are starved
Starvation
Starvation is a severe deficiency in caloric energy, nutrient and vitamin intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death...
or severely malnourished. Renourishment is the process of avoiding refeeding syndrome. The syndrome was first described after the Second World War in Americans who, held by the Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese as prisoners of war, had become malnourished during captivity and who were then released to the care of United States personnel in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
.
Syndrome
Any individual who has had negligible nutrient intake for 5 consecutive days is at risk of refeeding syndrome. Refeeding syndrome usually occurs within four days of starting to feed. Patients can develop fluid and electrolyteElectrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
disorders, especially hypophosphatemia
Hypophosphatemia
Hypophosphatemia is an electrolyte disturbance in which there is an abnormally low level of phosphate in the blood. The condition has many causes, but is most commonly seen when malnourished patients are given large amounts of carbohydrates, which creates a high phosphorus demand by cells,...
, along with neurologic, pulmonary, cardiac, neuromuscular, and hematologic complications.
During prolonged fasting the body aims to conserve muscle and protein breakdown by switching to ketone bodies
Ketone bodies
Ketone bodies are three water-soluble compounds that are produced as by-products when fatty acids are broken down for energy in the liver and kidney. They are used as a source of energy in the heart and brain. In the brain, they are a vital source of energy during fasting...
derived from fatty acids as the main energy source. The liver decreases its rate of gluconeogenesis
Gluconeogenesis
Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids....
thus conserving muscle and protein. Many intracellular minerals become severely depleted during this period, although serum levels remain normal. Importantly, insulin secretion is suppressed in this fasted state and glucagon
Glucagon
Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...
secretion is increased.
During refeeding, insulin secretion resumes in response to increased glycemia
Glycemia
Glycemia means the presence, or the level, of glucose in one's blood. Related words include:* Hyperglycemia, an unusually high concentration of sugar in the blood* Hypoglycemia, an unusually low concentration of sugar in the blood...
; resulting in increased glycogen, fat and protein synthesis. This process requires phosphates, magnesium and potassium which are already depleted and the stores rapidly become used up. Formation of phosphorylated carbohydrate compounds in the liver and skeletal muscle depletes intracellular ATP and 2,3-diphosphoglycerate in red blood cells, leading to cellular dysfunction and inadequate oxygen delivery to the body's organs. Refeeding increases the basal metabolic rate
Basal metabolic rate
Basal Metabolic Rate , and the closely related resting metabolic rate , is the amount of daily energy expended by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state...
. Intracellular movement of electrolytes occurs along with a fall in the serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
electrolytes including phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
, potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
and magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
. Glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, and levels of the B vitamin thiamine
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...
may also fall. Cardiac arrhythmias are the most common cause of death from refeeding syndrome, with other significant risks including confusion, coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
and convulsions and cardiac failure.
This syndrome can occur at the beginning of treatment for anorexia nervosa
Anorexia nervosa
Anorexia nervosa is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight. Although commonly called "anorexia", that term on its own denotes any symptomatic loss of appetite and is not strictly accurate...
when patients are reintroduced to a healthy diet.
The shifting of electrolytes and fluid balance increases cardiac workload and heart rate. This can lead to acute heart failure. Oxygen consumption is also increased which strains the respiratory system and can make weaning from ventilation more difficult.
Treatment
Refeeding syndrome can be fatal if not recognized and treated properly. An awareness of the condition and a high index of suspicion are required in order to make the diagnosis. Refeeding syndrome occurs most commonly in those who have lost weight rapidly. The electrolyte disturbances of the refeeding syndrome can occur within the first few days of refeeding, which can be undertaken through the oral or nasogastric routes. Close monitoring of blood biochemistry is therefore necessary in the early refeeding period. MilkMilk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
is often the refeeding food of choice in this early period as it is naturally high in phosphate and easily tolerated by those who have been starved. If potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
, phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
or magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
are low then this should be corrected via the oral route, or if severe with parenteral
Parenteral
Parenteral is a route of administration that involves piercing the skin or mucous membrane. Parenteral nutrition refers to providing nutrition via the veins.-Etymology:...
treatment. Prescribing thiamine
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...
, vitamin B complex (strong) and a multivitamin
Multivitamin
A multivitamin is a preparation intended to supplement a human diet with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, and injectable formulations...
and mineral is recommended. Biochemistry should be monitored regularly until it is stable. Energy intake
Energy balance (biology)
In biology, energy balance is the biological homeostasis of energy in living systems. It is measured with the following equation: Energy intake = internal heat produced + external work + storage. It is also an aspect of bioenergetics, concerning energy flow through living systems.It generally uses...
should remain only 50-70% that of normally required for the first 3–5 days.
Patients who have been starved for some time often experience gastrointestinal disturbance during refeeding, in particular colicky abdominal pain, reflux
Reflux
Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations...
symptoms, nausea and early satiety. To help manage this patients are often prescribed pro-kinetic agents such as domperidone
Domperidone
Domperidone is an antidopaminergic drug, developed by Janssen Pharmaceutica, and used orally, rectally or intravenously, generally to suppress nausea and vomiting, or as a prokinetic agent...
or metoclopramide
Metoclopramide
Metoclopramide is an antiemetic and gastroprokinetic agent. It is commonly used to treat nausea and vomiting, to facilitate gastric emptying in people with gastroparesis, and as a treatment for the gastric stasis often associated with migraine headaches.-Medical uses:Metoclopramide is commonly...
, as well as acid suppressants such as omeprazole
Omeprazole
Omeprazole is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease , gastroesophageal reflux disease , laryngopharyngeal reflux and Zollinger–Ellison syndrome...
. This may be of particular importance in patients suffering from anorexia nervosa
Anorexia nervosa
Anorexia nervosa is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight. Although commonly called "anorexia", that term on its own denotes any symptomatic loss of appetite and is not strictly accurate...
, who can find these symptoms particularly distressing.
General references
- Shils, M.E., Shike, M., Ross, A.C., Caballero, B. & Cousins, R.J. (2006). Modern nutrition in health and disease, 10th ed. Lippincott, Williams & Wilkins. Baltimore, MD.
- Mahan, L.K. & Escott-Stump, S.E. (2004) Krause’s Food, Nutrition, & Diet Therapy, 11th ed. Saunders, Philadelphia, PA.