Refeeding syndrome (RFS) is a potentially fatal set of metabolic and electrolyte imbalances that occurs when feeding is restarted in malnourished individuals, highlighted by electrolyte disturbances such as hypophosphatemia. The incidence of RFS is notably high in critically ill patients, especially those with a history of malnutrition or certain risk factors, and proper screening and management are crucial to avoid complications. Recommendations emphasize gradual refeeding, close monitoring of electrolytes, and appropriate supplementation of vitamins like thiamine in high-risk patients.

1. The Hidden enemy
Refeeding syndrom
Emad Zarief MD
Anesthesia & Surgical intensive care Dpt.

2. Agenda
Emad Zarief 2021 2
Definition of RFS
Pathophysiology
Incidence
Screening for
Prevention

3. Refeeding Syndrome (RFS) is a set of metabolic & electrolyte
alterations occurring due to reintroduction of calories through
oral, enteral, parenteral nutrition after a period of consistent
reduction of energy intake or starvation in individuals with pre-
existent malnutrition and/or in a catabolic state.
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ASPEN Consensus recommendations for refeeding syndrome.;2020
Definition

4. Limitations: lack of capturing a patient’s clinical presentation.
 Mild 10% to 20%
 Moderate 20% to 30%
 Sever >30% + organ dysfunction resulting from a ⇟ in any of
these and/or thiamine sever deficiency within 5 d. of a
reintroduction of calories
⇟of serum phosphorus, potassium, and/or magnesium levels
ASPEN Consensus recommendations for refeeding syndrome.;2020
Definition and classification

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ASPEN Consensus recommendations for refeeding syndrome.;2020 https://doi.org/10.1002/ncp.10474
NUTRITION DEPRIVATION THEN, REPLENISHMENT OF NUTRIENTS →
↑↑ INSULIN SECRETION
INTRACELLULAR SHIFT OF P++, K+ , CA++, MG++
↑↑ GLYCOLYSIS, THE SYNTHESIS OF GLYCOGEN, FATS, PROTEINS
↑↑ SODIUM AND WATER RETENTION, AND FINAL ATP DEPLETION
Pathophysiology

6. RFS
Clinical effects
 Myocardial depression and atrophy
 Arrythmias
 Salt &Water retention --> CHF
 Respiratory distress
 Hemolytic anemia, thrombocytopenia, impaired
WBCS activity
 Paresthesia, confusion weakness,
encephalopathy up to seizures
 Muscle weakness, myalgia, up to
rhabdomyolysis
 GIT dysfunction
Mehanna HM, et al. Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008 ;336(7659):1495-8.
Emad Zarief 2021

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8. Emad Zarief 2021 8
The incidence of RFS

9. Emad
Zarief
2021
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 Critically ill patients (nutrition held for 48 h) have a 34% chance of
hypophosphatemia.
 Severe hypophosphatemia has mortality of 18.2% compared with
4.6% among patients without hypophosphatemia.
1996

10. Incidence
of RFS
Emad
Zarief
2021
Because there is no real definition,
the incidence of RFS is unknown !!
11
2008

11. Kraaijenbrink et al. Incidence of refeeding syndrome in internal medicine patients. Neth J Med. 2016;74(3):116-21.
Patients with a malignancy or
previous malignancy at increased
risk of developing refeeding
syndrome
(p < 0.05)
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399
97
At risk
RFS in
14
NICE screening
178
2016

12. Susceptible Personnel
Malabsorption
syndrome
Malignancy
Mentally
affected
CRRT
P. dialysis
Critically ill ED patients
Child abuse &
starvation
Some athletes
ASPEN Consensus recommendations for refeeding syndrome.;2020
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13. Screening for RFS
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14. Screening Tool
Clin Nutr. 2005;24(1):75-82
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15. One of:
- BMI < 18.5 kg/m2
- Recent unintentional weight loss > 10%
- Little/no food intake >5 days
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Moderate
Risk
2006

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One of:
- BMI<16 kg/m2
- Recent unintentional weight loss >15%
- Little/no food intake >10 days
- Levels of K, Mg or PO4 low prior to feeding
Two of:
- BMI<18.5 kg/m2
- Recent unintentional weight loss >10%
- Little/no food intake >5 days
- Alcohol abuse / drugs e.g., insulin, chemotherapy, antacids, or
diuretics
High Risk
2006

17. Refeeding syndrome (RFS)
2020
ASPEN Consensus recommendations for refeeding syndrome.;2020

18. Any
Predictive
Biomarker
s?
 Albumin long t-half
 Prealbumin of short t-half (2 to 3
days).
 These markers are unreliable as they
are acute phase reactants.
 Clinical examination remains crucial
in such patients.
.
Gastroenterol Rep (Oxf). 2016;4(4):272-280.
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19. • The literature is too spare
• Biomarkers have been studied
for risk of malnutrition 
theorized to identify risk for
RFS.
• Insulin-like GF1 & leptin for
malnutrition (weak sensitivity)
ASPEN Consensus recommendations for refeeding syndrome.;2020
Emad Zarief 2021
20
Any
Predictive
Biomarker
s?

20. • History of weight Loss
• History of decrease intake
• History of tube feeding
• History of some medications
• Anthropometric
• Comorbidities
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What are
the Risk
Predictors
?

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RFSManagement / Preventi

22. Avoidance of RFS
• No universal recommendation to now
• Regardless of the route of energy intake,
obtain Caloric goal needs in 3-7 days
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23. https://www.irspen.ie/wpcontent/uploads/2014/10/IrSPEN_Guideline_Document_No1.pdf.
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2014

24. Emad
Zarief
2021
.
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Nutrition 2018;47:13-20
2018

25. https://www.nice.org.uk/guidance/cg32/chapter/1- Guidance#what-to-give-in-hospital-and-the-community. (2019)
 Start with 10 Kcal/Kg/d (max)
 If BMI<14Kg/m2 or lack intake>15 d
 5 Kcal/Kg/d
 Go Slow to Goal over 4-7 d
 Restore circulatory volume
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2019

26. Initiate nutrition at a maximum of 40%–50% goal
Starting the glucose infusion rate 4–6 mg/kg/min
Advancing by 1–2 mg/kg/min daily
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ASPEN Consensus recommendations for refeeding syndrome.;2020
2020

27. ASPEN Consensus recommendations for refeeding syndrome.;2020
• Check electrolytes before initiation of nutrition
• Then / 12 hr. for 1st 3 days
• Replete low electrolytes
• No prophylactic supplements
• If electrolytes become difficult to correct or drop precipitously 
• ⇟
⇟ dextrose/calories by 50% and then,
• ↟
↟ dextrose/calories (33% of goal) / 1–2 days
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2020

28. Supplement thiamin 100 mg before initiating dextrose-
containing IV fluids in patients at risk
Thiamine for 5–7 days or longer in high risk for deficiency
and/or signs of thiamin deficiency.
Iv or oral multivitamins once daily for 10 days or greater
based on clinical status
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ASPEN Consensus recommendations for refeeding syndrome.;2020
2020

29. Avoidance of RFS
• Predict the risk
• Obtain Caloric goal needs in 3-7 days
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30. Thank
you
Emad Zarief 2021 31
emadzarief@aun.edu.eg