Frimley Guidelines

Management of refeeding syndrome in adults

Key Points

  • To enable healthcare professionals to recognize patients at risk of refeeding syndrome and adhere to the Trust protocol in place

  • To safely restore nutrition whilst minimising risks of complications associated with refeeding syndrome and prolonged starvation.

Version:1.0
Date Issued:21/11/2025
Review Date:01/09/2028
Key words:nutrition support, nutrition oral supplement, refeeding syndrome, nutrition screening tool, out of hours

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Abbreviations

BDTwice daily
ECGElectrocardiogram
IVIntravenous
ODOnce daily
PNParenteral nutrition
TDSThree times daily
NEWSNational early warning score

Introduction

Refeeding Syndrome is a serious condition characterized by significant fluid and electrolyte imbalances, along with metabolic disturbances. This can develop in malnourished individuals when nutrition is reintroduced.

This may cause blood levels of phosphate, potassium, and magnesium to drop, even if they were normal prior to the start of feeding. Such imbalances can lead to complications affecting the heart, lungs, muscles, kidneys, metabolism, blood, liver, and digestive system (Parenteral and Enteral Nutrition Group of the British Dietetic Association, 2019).

It is therefore vital that refeeding syndrome is identified, prevented and managed safely and appropriately within Frimley Health NHS Foundation Trust.

‘Refeeding syndrome can be defined as a group of biochemical shifts and clinical symptoms that can occur in the malnourished or starved individual upon the reintroduction of oral, enteral or parenteral nutrition (Solomon and Kirby 1990) (PENG 2018).’ This can occur within 72 hours after feeding is commenced, with a range of 1-5 days but in some cases, it can occur late and therefore close monitoring is advised (Friedli, N., et al 2020). Refeeding syndrome is associated with increased mortality in malnourished medical inpatients.

Aim & Objectives

  • To enable healthcare professionals to recognize patients at risk of refeeding syndrome and adhere to the Trust protocol in place

  • To safely restore nutrition whilst minimising risks of complications associated with refeeding syndrome and prolonged starvation.

Identification of Refeeding Syndrome

Criteria for defining the risk of Refeeding Syndrome (NICE Guidelines 2006)


At risk; Any patient who has had very little or no food intake for more than 5 days



High Risk if one or more of the following:



- Body Mass Index less than 16kg/m²



- Unintentional weight loss greater than 15% within the last 3-6 months



- Little or no nutritional intake for more than 10 days



- Low levels of potassium, phosphate or magnesium prior to feeding


High Risk if two or more of the following:



- Body Mass Index less than 18.5 kg/m²



- Unintentional weight loss greater than 10% within the last 3-6 months



- Little or no nutritional intake for more than 5 days



- A history of alcohol abuse or drugs including insulin, chemotherapy, antacids or diuretics

Extremely High Risk of Refeeding Syndrome

  • Very low Body Mass Index < 14kg/m2
  • Not eaten for > 15 days

*Please note that NICE criteria serve as a guide to identify those who may be at risk and should be considered in conjunction with clinical assessment

Biochemical shifts and clinical symptoms of Refeeding Syndrome may present as:

  • Hypophosphataemia

  • Hypokalaemia

  • Hypomagnesaemia

  • Altered glucose metabolism

  • Fluid balance abnormalities

  • Thiamine deficiency

These may lead to cardiac, respiratory, neuromuscular, renal, metabolic, haematologic, hepatic and gastrointestinal symptoms.

For patients with eating disorders please see the Trust eating disorder guideline for management of refeeding syndrome.

Management of Refeeding Syndrome

Step 1 - Biochemistry

Check baseline urea and electrolyte biochemistry including; potassium, phosphate, magnesium, adjusted calcium, urea and sodium and replace as necessary prior to commencing feeding. Consult your ward Pharmacist for guidance on electrolyte replacement.

Caution should be taken with patients who are severely malnourished, dehydrated or have renal impairment as normal or elevated baseline plasma levels of electrolytes can decrease rapidly following introduction of nutrition or be misinterpreted.

Biochemistry should be repeated daily or twice daily in extremely high risk or unstable patients until patient is at goal rate of nutrition support with regular electrolyte replacement where required.

Step 2 – Micronutrient supplementation

Prescribe micronutrient supplementation as appropriate:


Oral Nutrition
Enteral Nutrition
Parenteral Nutrition

Initial dose should be given 30 minutes prior to
eating/drinking:


Thiamine 100mg BD-TDS

Vitamin B co strong 1-2 tablets TDS


Continue daily for around 10 days or until
patients are fully established on nutrition support.
Dietitians to advise on duration of prescription.

Do not discharge on ongoing prescription.


Additionally prescribe a balanced multivitamin
& mineral supplement. Liaise with pharmacy
on available products.
Initial dose should be given 30 minutes before
starting feeding:


IV Thiamine 250mg injection OD.

Vitamin B co strong 1-2 tablets TDS once enteral
route available

Continue daily for 3-5 days until patients are
fully established on goal rate of enteral feeding
or until dietitian specifies.

Alternatively oral thiamine & Vitamin B co strong
tablets can be crushed into fine powder and mixed
with water, then flushed through an enteral feeding
tube. *

Feeds may be nutritionally complete in micronutrients
and may not be needed in all patients, therefore
prescribe a balanced multivitamin & mineral supplement
if recommended by dietitians.

Initial dose should be given 30 minutes before
starting feeding:


IV Thiamine 250mg injection OD

Continue daily for 3-5 days until patients are
fully established on goal rate of parenteral
feeding or until dietitian specifies.









PN bags usually consist of multivitamin and mineral
therefore may not require an additional prescription.
However, confirm with the dietitian.

*Tablets need to be thoroughly crushed and flushed with sufficient water to prevent blocking of enteral feeding tubes.

Step 3 – Observation and Monitoring

Observation and monitoring of the patient including:

  • Cardiac and respiratory observations, e.g. ECG, NEWS. a. ECG Monitoring - Patients at extremely high risk of Refeeding Syndrome, e.g., very low body mass index < 14kg/m2 and/or not eaten for > 15 days, are recommended to have ECG monitoring.

  • 4 x Daily blood glucose monitoring until established on goal nutrition support.

  • Daily fluid balance monitoring, i.e. avoid prescribing additional IV glucose/dextrose as it may exacerbate refeeding syndrome.

  • Clinical observations, e.g., muscular weakness/cramps, tetany, oedema, bowels or vomiting

  • Daily weight

Step 4 – Slow re-introduction of nutrition

Introduction of nutrition should not be delayed provided any baseline derangement in electrolytes are corrected; however, emphasis should be placed on a slow and cautious reintroduction of food, nutritional supplements or enteral nutrition or parenteral nutrition.