Medical Nutrition Therapy for Refeeding
Syndrome
Rachel Hammerling
Concordia College, Moorhead MN
Objectives• Be able to describe refeeding syndrome (RFS)
• Be able to describe the pathophysiology of starvation
• Identify the main pathophysiologic features of RFS
• Be able to identify signs & symptoms• Identify recommended treatment & standards of care
• Be able to explain ethical issues involved with treatment & care
Discovery of RFS
• Observed & described after WWII• Victims of starvation experienced cardiac and/or neurologic dysfunction– After being reintroduced to food
• Today, rarely see patients who are severely malnourished, as WWII victims were, in the 1st week– Neurologic signs & symptoms develop later
What is RFS?• Potentially fatal shifts in fluids & electrolytes
• May occur in malnourished patients receiving artificial refeeding– Enterally or parenterally
• Complex syndrome– Sodium & fluid imbalance– Changes in glucose, protein, fat metabolism– Thiamine deficiency– Hypokalemia – Hypomagnesaemia
Understanding Starvation• Glucose = main fuel
– Shifts to protein & fat• Insulin ↓ due to ↓ availability of glucose• Catabolism of protein → loss of cellular & muscle mass → atrophy of vital organs & internal organs
• Respiratory & cardiac function ↓ due to muscular wasting & fluid/electrolyte imbalances
• Body is now surviving by slowly consuming itself
How common is RFS?
• True incidence is unknown• Study of 10,197 patients, incidence of hypophosphatemia = 43 %– Malnutrition one of strongest risk factors
• Parenteral patients = 100% incidence of hypophosphatemia
Pathogenesis
• Electrolytes & minerals involved1) Phosphorus2) Potassium3) Magnesium4) Glucose
Main Pathophysiologic Features
• Disturbances of body-fluid distribution
• Abnormal glucose & lipid metabolisms
• Thiamine deficiency• Hypophosphatemia• Hypomagnesemia• Hypokalemia
Disturbances of Body-Fluid Distribution
• Can influence body functions:1) Cardiac
failure2) Dehydration or
fluid overload3) Hypotension4) Pre-renal
failure5) Sudden death
• CHO refeeding – ↓ water & sodium excretion, resulting in weight gain
• Protein & fat refeeding– Result in weight loss & urinary sodium excretion
– Hypernatremia along with azotemia & metabolic acidosis
Abnormal Glucose & Lipid Metabolisms
• Glucose– Suppress gluconeogenesis → reduced AA usage•Less-negative N balance
– Hyperglycemia
• Glucose → fat (Lipogenesis)– Hypertriglyceridemia, fatty liver, & abnormal liver function tests
Thiamine Deficiency
• Can result in Wernicke’s encephalopathy or Korsakov’s syndrome, associated with:– Ocular disturbance– Confusion– Ataxia
• loss of ability to coordinate muscular movement
– Coma– Short-term memory loss– Confabulation
•Confusion of imagination with memory
Hypophosphatemia• Predominant feature of RFS• Impaired cellular-energy pathways
– Adenosine triphosphate– 2,3-diphosphoglycerate
• Impaired skeletal-muscle function– Including weakness & myopathy
• Seizures & perturbed mental state• Impaired blood clotting processes & hemolysis also can occur
Hypomagnesemia
• Most cases not clinically significant
• Severe cases:– Cardiac arrhythmias – Abdominal discomfort– Anorexia– Tremors, seizures, & confusion– Weakness
Hypokalemia
• Features are numerous:– Cardiac arrhythmias– Hypotension– Cardiac arrest– Weakness– Paralysis– Confusion– Respiratory Depression
Signs & Symptoms
• Electrolyte imbalance– Hypokalemia– Hypophosphatemia– Hypomagnesemia
• REMEMBER: Even an overweight or obese patient can be malnourished & a victim for RFS
Identifying Patients at High Risk of Refeeding Problems
• NICE Guidelines(National Institute for Health & Clinical Excellence)
• Either patient has 1 or more:– BMI <16– Unintentional weight loss >15% in past 3-6 mo– Little/no nutritional intake for 10 days– Low levels of potassium, phosphate, or magnesium before feeding
• Or patient has 2 or more:– BMI <18.5– Unintentional weight loss >10% in past 3-6 mo– Little/no nutritional intake for >5 days– History of alcohol misuse or drugs
Patients at high risk:
• Anorexia nervosa• Chronic alcoholism• Oncology patients• Postoperative patients
• Elderly• Uncontrolled diabetes mellitus
• Chronic malnutrition:– Marasmus– Prolonged fasting or low energy diet
– Morbid obesity with weight loss
• Long term antacid users
• Long term diuretic users
Gastrointestinal Fistula patients
• Usually reveals chronic malnutrition– Due to damaged Gl tract & severe abdominal sepsis
• High risk for RFS• Be aware of condition & treat the same – Diarrhea commonly occurs & can be treated by enteral nutrition
Intervention: Objectives
1) Gradually correct starvation– Use less than full levels of calorie & fluid requirements
2) Advance calories & volume– Monitor cardiac & respiratory side effects
3) Correct vitamin & mineral deficiencies – Especially with symptoms
Intervention: Objectives Cont.
4) Nutrition support in patients at risk should be increased slowly– Assuring adequate amounts of vitamins & minerals
5) Organ function, fluid balance, & serum electrolytes– Monitor daily during 1st week & less frequently after
Intervention: Objectives Cont.
6) Monitor for neurological, hematological, & metabolic complications – Of hypokalemia, hypophosphatemia, & hyperglycemia
7) Prevent sudden death
Intervention: Food & Nutrition
• Begin 20 kcal/kg for 1st 3 days• Progress to 25 kcal/kg• Gradually ↑ by 7th day• Protein start slow, ↑ gradually
– To protect & restore lean body mass
• Restrict CHO to 150-200 g/day– To prevent rapid insulin surge
• CHO in PN – Initiate at 2 mg/kg/min – Fat calories should make up the difference
Intervention: Food & Nutrition
• Maintain fluid balance– Adjust when edema exists
• Adjust for sodium & potassium– Depending on lab values until normal
• Supplements– Thiamin– Other vitamins & minerals as needed
Common Drugs Used
• Replacement of phosphorus, potassium, & magnesium
• Insulin– Used to correct hyperglycemia levels
– Monitor blood glucose levels during refeeding
Recommendation for Phosphate
Phosphate Dose
Maintenance requirement 0.3-0.6 mmol/kg/day orally
Mild hypophosphatemia (0.6-0.85 mmol/l)
0.3-0.6 mmol/kg/day orally
Moderate hypophosphatemia (0.3-0.6 mmol/l)
9 mmol infused into peripheral vein over 12 hours
Severe hypophosphatemia (<0.3 mmol/l)
18 mmol infused into peripheral vein over 12 hours
Recommendation for Magnesium
Magnesium Dose
Maintenance requirement 0.2 mmol/kg/day intravenously
(or 0.4 mmol/kg/day orally )
Mild to moderate hypomagnesaemia (0.5-0.7 mmol/l)
Initially 0.5 mmol/kg/day over 24 hours intravenously, then 0.25 mmol/kg/day for 5 days intravenously
Severe hypomagnesaemia (<0.5 mmol/l)
24 mmol over 6 hours intravenously, then as for mild to moderate hypomagnesaemia (above)
Intervention: Nutrition Education, Counseling, &
Care Management• Focus on adequate nutrient intake• Consider referral if food insecurity is a concern
• Offer guidelines according to discharge intervention plan
• Physician may suggest long-term medication use or therapies
NICE Guidelines for Management
Ethical Issues with RFS
• Roles between dietitian, counselor, nurse, doctor, and other professionals
• Working with anorexia patients, oncology patients or older patients
• Ethnic & religious differences– Muslim patients– Non-English speaking patients
Summary Points
• RFS is caused by rapid refeeding after a period of undernutrition
• Characterized by hypophosphatemia• Patients at high risk: undernourished, little or no energy intake for > 10 days
• Start refeeding at low levels• Correction of electrolyte & fluid imbalances before feeding IS NOT necessary
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