Refeeding syndrome occurs when electrolyte and fluid shifts happen in malnourished patients undergoing refeeding. It was first described after WWII in prisoners of war who were malnourished in captivity and then cared for by U.S. personnel. Refeeding syndrome is defined as severe electrolyte and fluid shifts associated with metabolic abnormalities in malnourished patients undergoing refeeding. Clinical features include cardiovascular, gastrointestinal, neurological and respiratory symptoms. Risk factors include decreased nutrient intake from conditions like eating disorders, decreased absorption from diseases, and increased catabolism from illnesses. Close monitoring of electrolytes and fluid status is important to prevent complications from refeeding syndrome.

1. Refeeding Syndrome
“Slow and Low”
Vishal Bagchi MBA, RD, LD
Director of Medical and Scientific Affairs
Patient Care America

2. Objectives
After a sustained state of malnutrition or under-nutrition
patients tend to exhibit symptoms of refeeding syndrome
secondary to nutrition support received from oral or
parenteral nutrition.
• Define refeeding syndrome
• Identify causes of refeeding syndrome with subjective
and objective analysis
• Acquire skills to manage refeeding syndrome during
and after oral and/or parenteral nutrition support

3. History
• The syndrome was first described after World
War II in Americans who, held by the Japanese
as prisoners of war, had become malnourished
during captivity and who were then released to
the care of United States personnel in the
Philippines
• A clinical study of malnutrition in Japanese
prisoners of war. -SCHNITKER MA, MATTMAN
PE, BLISS TL. Dec 2nd 1949

4. Prisoners of war
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5. Definition
• Severe electrolyte and fluid shifts associated with
metabolic abnormalities in malnourished patients
undergoing refeeding, whether orally, enterally,
or parenterally.
– Incidence of RS is unclear due to a lack of strict
definition
– Absence of accepted diagnostic criteria or
internationally agreed guidelines for detecting RS
Crook et al.-2001

6. Starvation and Semi-starvation
• State of Negative Protein-Energy Balance
– Absence of nutrient intake
– Intake below requirements
• Dialysis KDOQI/ASPEN
– Calories 25-35 kcal/kg/day
– Protein 1.2-1.4 gm/kg/day

7. Metabolic Adaptation to Starvation
Post Absorptive state --- Overnight fast after a meal
Fast lasting 12-24 Hours
Fast lasting > 3days
Prolonged Starvation

8. Post-Absorptive State
 The Brain Must receive Glucose
 Insulin levels fall
 Glucose delivery to Tissues 8-10 g/hr
– Increased Glycogenolysis 50%
– Continued Gluconeogensis 50%
 Lactate and Pyruvate 50%
 Amino acids 50%
 Muscle uses mainly fatty acids
– 2/3 fuel oxidation is derived from fatty acids

9. Fasting ~ 2-4 days
 Liver glycogen depleted
 Insulin levels fall
 Glucose production by Gluconeogenesis:
– Lactate and Pyruvate
– Amino acids
 Nitrogen loss from amino acid is 10-12 g/day
 Branched chain aminoacids released by muscle and
oxidized
 Ketone production increases
 Brain reduces glucose utilization and increases Ketone
body oxidation

10. Prolonged Starvation 5+days
• Metabolic rate falls
• Nitrogen losses decrease to 4-5 g/day
• Brain now uses ketones as the sole source of
energy
• Muscle uses fatty acid and spares branched-
chain amino acid oxidation

11. Clinical Effects of Starvation
• Resting Energy Expenditure fall by about 25-35%
by 3 weeks
• Serum Albumin Concentrations remain normal
• Serum Prealbumin falls
• Death occurs when body fat is depleted
• Obese persons can withstand prolonged
starvation

12. Pathophysiology
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13. Journal of Gastroenterology and Hepatology 2013; 28 (Suppl. 4): 113–117

15. Pathophysiology
• Marked increase in insulin secretion in response to
nutrient delivery/intake.
• Intracellular shift of glucose
• Uptake of phosphate, magnesium, potassium
• Expansion of extracellular fluid compartment
– Fluid overload
– Pulmonary edema
– Cardiac decompensating

16. Criteria for the determination of refeeding syndrome risk
*National Institute for Health and Clinical Excellence. Nutrition support in adults. CG32, London, England.
One of the following: Two of the following:
• BMI < 16 (kg/m2 )
• Unintentional weight loss >15% in the
preceding three – six months
• Very little or no nutritional intake for
more than 10 days
• Low levels of serum potassium,
phosphate or magnesium prior to
feed
• BMI < 18.5 (kg/m2 )
• Unintentional weight loss >10% in the
preceding three – six months
• Very little or no nutritional intake for
more than 5 days
• History of alcohol or drug abuse

17. Criteria for confirmation of RS-King’s College
1)Electrolytes Refeeding Syndrome Criteria Dialysis/Normal Reference Range
Potassium < 2.5 mmol/L < 2.5 mEq/L 3.5 to 5.0 mEq/L
Phosphorus < 0.32 mmol/L < 0.99 mg/dL 2.6 – 4.5 mg/dL
Magnesium < 0.5 mmol/L < 1.22 mg/dL 1.7 to 2.2 mg/dL
2)Peripheral edema or acute circulatory fluid overload.
3)Disturbance to organ function including respiratory failure, cardiac failure, pulmonary edema
Adopted from:
Occurrence of refeeding syndrome in adults commenced on artificial nutrition and hydration:
prospective cohort study. Alan Rio, Kevin Whelan, Louise Goff, Dianne Reidlinger, Nigel Smeeton. 01-Oct-2012

18. Monitoring patients at risk of developing RFS
Clinical monitoring
• Early identification of high risk
patients
• Monitor blood pressure and pulse
rate
• Monitor feeding rate
• Meticulously document fluid intake
and output
• Monitor change in body weight
• Monitor for neurologic signs and
symptoms
• Patient education
Biochemical monitoring
• Monitor biochemistry and electrolyte
levels
• Monitor blood glucose levels
• ECG monitoring in severe cases
• Account other sources of energy
(dextrose, propofol, medications)
Gastroenterol Res Pract. 2011; 2011:
410971.
Published online 2010 Aug 25.

19. Study 1
• Rio A et al. BMJ Open 2013;3e002173.
doi:10.1136/bmjopen-2012-002173
• 243 adults prospective cohort study at UK teaching hospital
– BMI < 16 kg/m2
– 15% weight loss 3-6 mos
– No nutritional intake > 10 days
• 2% developed severe electrolyte shifts, acute circulatory
fluid overload, organ failure
• No deaths attributed to RS

20. Study 2
• Zeki S et al. Clin Nutr 2011;30:365-368
• Retrospective 321 patients enterally vs parenterally
• At risk EN patients more likely to develop RH than PN
patients (p = 0.03)
• Death more common in EN group vs PN (p < 0.001)
• No association between development of RH and death
within 7 days

21. Study 3
• Owers EL et al. Clin Nutr. 2015;34:134-139.
• Retrospective 1661 Adults
– 9% documented at risk of refeeding syndrome
– 7% had very low levels of K, Mg, P
– 52% had low levels of K, Mg, P
• Patients at risk of refeeding syndrome had
– 4 days longer hospital LOS
– Weighed 13 kg less

22. IDPN Monitoring Guidelines
• Hypophosphatemia < 2.6 mg/dL
– May add potassium phosphate or sodium phosphate
• Hypokalemia < 2.5 mEq/dL
– Adjust dialysate bath 3k
• Abnormal Intradialytic cramping
– Indicative of hyponatremia or excessive fluid removal
– Administer normal saline
– May add 70-150 mEq to IDPN formula
Renal Care: Resources and Practical Applications By Kerri Lynn Wiggins

23. Questions
• Who Walks into ER with 7,7,7,7?

24. Refeeding on IDPN? Not likely
• IDPN Composition low in dextrose mainly AA
– Week 1 – 25% to goal
– Week 2 – 50% to goal goal as tolerated
– Week 3 – 75-100% to goal as tolerated
• Might see a mild decrease in Phosphorus, potassium and magnesium
– Patient’s baseline higher vs non dialysis population
Calories From 3.5 hrs 4 hrs Volume mL Prosol 20% Clinisol 15%
Weight(kg)
Amino
Acids(gm)
Dextrose
(gm) Dextrose AA Total Kcal NPC
GIR
(mg/kg/
min)
GIR
(mg/kg/
min) NPC:N
Prosol
20%
Clinisol
15% Final % CHO Final % CHO
45 60 60 204 240 444 204 6.35 5.56 21.25 386 486 15.6 12.4
55 75 75 255 300 555 255 6.49 5.68 21.25 482 607 15.6 12.4
65 85 85 289 340 629 289 6.23 5.45 21.25 546 688 15.6 12.4
75 100 100 340 400 740 340 6.35 5.56 21.25 643 810 15.6 12.4
85 115 115 391 460 851 391 6.44 5.64 21.25 739 931 15.6 12.4

25. Clinical Features
• CVS: arrhythmia, HT, CHF
• GI: abdo pain, constipation, vomiting, anorexia
• MUSC: weakness, myalgias, rhabdomyolysis,
osteomalacia
• RESP: SOB, ventilator dependence, respiratory muscle
weakness -> requiring intubation and ventilation
• NEURO: weakness, paraesthesia, ataxia, delirium, coma,
central pontine myelinosis, seizures, Korsakoff’s
syndrome or Wernicke’s encephalopathy (confusion,
ataxia, ophthalmoplegia)
• METABOLIC: infections, thrombocytopaenia, haemolysis,
anaemia
• HAEM: reduced 2,3 DPG production -> left shift of oxyHb
dissociation curve
• OTHER: ATN, Wernicke’s encephalopathy, liver failure
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26. Risk Factors
• Decreased intake
– eating disorders (especially anorexia nervosa)
– alcoholism
– depression
– fasting
– vomiting
– dysphagia
– chemotherapy
– prolonged NBM
– post-operative
– chronic malnutrition
• Decreased absorption
– inflammatory bowel disease,
– chronic pancreatitis,
– cystic fibrosis,
– short bowel syndrome
• Decreased absorption
– Oncology patients
– Postoperative patients
– Elderly patients (comorbidities, decreased physiological reserve)
– uncontrolled diabetes mellitus (electrolyte depletion, diuresis)
– chronic malnutrition:
– Marasmus
– Prolonged fasting or low energy diet
– -Morbid obesity with profound weight loss
– High stress patient unfed for >7 days
– Long term users of antacids (magnesium and aluminium salts
bind phosphate)
– Long term users of diuretics (loss of electrolytes)
• Increased catabolism
– inflammatory process (infectious and non-infectious)
– cancer