Refeeding Syndrome Flashcards
What happens in early starvation
Glucose levels decline and insulin levels decrease
Glucagon levels increase
What does glucagon stimulate
Glycogenolysis in the liver and lipolysis of triacetylglycerol in fat reserves producing fatty acids and glycerol
used by tissues for energy and converted to ketone bodies in liver
What happens as glycogen reserves become depleted
Gluconeogenesis is stimulated in the liver, utilising amino acids (derived from muscle breakdown), lactate and glycerol resulting in the synthesis of glucose for use by brain
Body reduces all energy consuming metabolic pathways including
Action of cellular pumps, allowing electrolytes to leak across cell membranes
Electrolyte changes in starvation
K+, phosphate and Mg2+ move into plasma and are excreted by kidneys
Na+ and fluid leak into cells
Cardiac, intestinal and renal functions become impaired leading to reduced ability to excrete excess sodium and water
The main outcome in starvation is that
Body switches the main energy source from carbohydrate to protein and fat, electrolytes are depleted and water and sodium are retained
Metabolic changes to reintroduction of nutrition
Increased insulin production
Increased cellular uptake of glucose, phosphate, potassium (fall in serum levels)
Decreased glucagon secretion
Electrolyte changes due to reintroduction of nutrition
Reactivation of Na+/K+ membrane pump, more K+ in cells and more Na+ and fluid loss out of cells
Na+/K+ pump utilises magnesium as co-factor, reducing availability
Lowered renal function means lower ability to excrete sodium and fluid resulting in fluid overload
Other metabolic changes due to reintroduction of nutrition
Phosphate used for energy storage in the form of adenosine triphosphate ATP
Increased demand for thiamine as part of carbohydrate metabolism
Increased glucose levels
Stimulation of protein synthesis leads to
Increased anabolic tissue growth which in turn leads to increased cellular demand for phosphate, potassium, glucose and water
The main outcome of the re introduction of nutrition in those with re feeding syndrome is a return to
carbohydrate metabolism and increased uptake of electrolytes intracellularly resulting in low serum levels
Starvation and re feeding syndrome diagram
What would you consider to help determine whether a patient was at high risk of re feeding syndrome
Dietary intake (more than 5 days very little)
BMI (less than 18.5)
Weight loss (unintentional in last 3-6 months)
Electrolyte levels
Malabsorption
Alcohol, insulin, chemo, antacids, diuretics
3 main biochemical markers to assess and monitor a patient at risk of re feeding syndrome
Potassium
Phosphate
Magnesium
How many calories per day when re feeding at risk patient
10kcal a day, increasing slowly to meet full needs by 4-7 days
using only 5kcal a day in extreme cases such as BMI less than 14 or negligible intake for more than 15 days
Monitor cardiac Rhythm
