Refeeding syndrome

Background

Mostly an issue with TPN, risk of death.

Pathophysiology

When a severely malnourished patient is given glucose, the following cascade of events takes place:

• Insulin is released
  • this stimulates drive to produce ATP
  • As ATP is produced, phosphorus is depleted
  • As ATP is produced, the cellular Na/K ATPase is activated, leading to transcellular movement of potassium and eventually other electrolytes, including magnesium, phosphorus and calcium into the cell.
  • this leads to hypokalemia, hypomagnesemia, and hypophosphatemia.
  • Metabolic acidosis also develops.
• Electrolyte abnormalities can cause prolonged QTc
• Rapid phosphorus depletion can lead to hemolysis, hypotension, altered mental status.

Clinical Features

• Fluid overload, CHF
• Altered mental status
• Seizure
• Rhabdomyolysis
• Hemolysis
• Symptomatic from hypophosphatemia, hypokalemia, hypomagnesemia

Differential Diagnosis

• Fluid overload
  • Insulin secretion
  • Loss of myocardium
  • Na absorption
• Mineral Depletion:
  • Phosphorus
  • K
  • Na
  • Mg
• Glucose Intolerance
• Cardiac arrhythmias
  • 1st wk
  • Long QT

Evaluation

Workup

• CBC
• Chemistry
• Magnesium
• Phosphorus
• ECG

Findings

• Hypokalemia, hypomagnesemia
• Metabolic acidosis
• ECG: May cause prolonged QTc
• Hypophosphatemia
  • Leading to hemolysis, hypotension, altered mental status

Management

Adults

Aspect of Care	Recommendation
Initiation of calories	Initiate with 100–150 g of dextrose or 10–20 kcal/kg for the first 24 hours; advance by 33% of goal every 1 to 2 days. This includes enteral as well as parenteral glucose.
	In patients with moderate to high risk of RS with low electrolyte levels, holding the initiation or increase of calories until electrolytes are supplemented and/or normalized should be considered.
	Initiation of or increasing calories should be delayed in patients with severely low phosphorus, potassium, or magnesium levels until corrected.
	Calories from IV dextrose solutions and medications being infused in dextrose should be considered in the limits above and/or initiated with caution in patients at moderate to severe risk for RS. If a patient has received significant amounts of dextrose for several days, from maintenance IV fluids and/or medications in dextrose, and has been asymptomatic with stable electrolytes, calories from nutrition may be reintroduced at a higher amount than recommended above.
Fluid restriction	No recommendation.
Sodium restriction	No recommendation.
Protein restriction	No recommendation.
Electrolytes	Check serum potassium, magnesium, and phosphorus before initiation of nutrition.
	Monitor every 12 hours for the first 3 days in high-risk patients. May be more frequent based on clinical picture.
	Replete low electrolytes based on established standards of care.
	No recommendation can be made for whether prophylactic dosing of electrolytes should be given if prefeeding levels are normal.
	If electrolytes become difficult to correct or drop precipitously during the initiation of nutrition, decrease calories/grams of dextrose by 50% and advance the dextrose/calories by approximately 33% of goal every 1–2 days based on clinical presentation. Recommendations may be changed based on practitioner judgment and clinical presentation, and cessation of nutrition support may be considered when electrolyte levels are severely and/or life-threateningly low or dropping precipitously.
Thiamin and multivitamins	Supplement thiamin 100 mg before feeding or before initiating dextrose-containing IV fluids in patients at risk.
	Supplement thiamin 100 mg/d for 5–7 days or longer in patients with severe starvation, chronic alcoholism, or other high risk for deficiency and/or signs of thiamin deficiency.
	Routine thiamin levels are unlikely to be of value.
	MVI is added to PN daily, unless contraindicated, as long as PN is continued. For patients receiving oral/enteral nourishment, add complete oral/enteral multivitamin once daily for 10 days or greater based on clinical status and mode of therapy.
Monitoring and long-term care	Recommend vital signs every 4 hours for the first 24 hours after initiation of calories in patients at risk.
	Cardiorespiratory monitoring is recommended for unstable patients or those with severe deficiencies, based on established standards of care.
	Daily weights with monitored intake and output.
	Evaluate short- and long-term goals for nutrition care daily during the first several days until the patient is deemed stabilized (eg, no requirement for electrolyte supplementation for 2 days) and then based on institutional standards of care.

Pediatrics

Aspect of Care	Recommendation
Initiation of nutrition	Initiate nutrition at a maximum of 40%–50% goal, but usually starting the glucose infusion rate around 4–6 mg/kg/min and advancing by 1–2 mg/kg/min daily as blood glucose levels allow until you reach a max of 14–18 mg/kg/min. This includes enteral as well as parenteral glucose.
	Calories from IV dextrose solutions and medications being infused in dextrose should be considered in the limits above and/or initiated with caution in patients at moderate to severe risk for RS. If the patient is already receiving IV dextrose for several days and/or medications in dextrose and has been asymptomatic with stable electrolytes, calories from nutrition may be reintroduced at a higher amount than recommended above.
Fluid restriction	No recommendation
Sodium restriction	No recommendation
Protein restriction	No recommendation
Electrolytes	Check serum potassium, magnesium, and phosphorus before initiation of nutrition.
	Monitor every 12 hours for the first 3 days in high-risk patients. May be more frequent based on clinical picture.
	Replete low electrolytes based on established standards of care.
	No recommendation can be made for whether prophylactic dosing of electrolytes should be given if prefeeding levels are normal.
	If electrolytes become difficult to correct or drop precipitously during the initiation of nutrition, decrease calories/grams of dextrose by 50% and advance the dextrose/calories by approximately 33% of goal every 1–2 days based on clinical presentation. Recommendations may be changed based on practitioner judgment and clinical presentation, and cessation of nutrition support may be considered when electrolyte levels are severely and/or life-threateningly low or dropping precipitously.
Thiamin and multivitamins	Thiamin 2 mg/kg to a max of 100–200 mg/d before feeding commences or before initiating IV fluids containing dextrose in high-risk patients.
	Continue thiamin supplementation for 5–7 days or longer in patients with severe starvation, chronic alcoholism, or other high risk for deficiency and/or signs of thiamin deficiency.
	Routine thiamin levels are unlikely to be of value.
	MVI is added to PN daily, unless contraindicated, as long as PN is continued. For patients receiving oral/enteral nourishment, add complete oral/enteral multivitamin once daily for 10 days or greater based on clinical status and mode of therapy.
	Once patient is within adult weight ranges, refer to adult multivitamin recommendations.
Monitoring and long-term care	Recommend vital signs every 4 hours for the first 24 hours after initiation in those at risk.
	Cardiorespiratory monitoring is recommended for unstable patients or those with severe deficiencies, based on established standards of care.
	Daily weights with monitored intake and output.
	Estimation of energy requirements as needed for oral feeding patients.
	Evaluate short- and long-term goals for nutrition care daily during the first several days until the patient is deemed stabilized (eg, no requirement for electrolyte supplementation for 2 days) and then based on institutional standards of care.

See Also

• Nutrition (main)

External Links

• ASPEN Consensus guidelines

References

1. Bhraonain, Sinead, et al. “Chronic malnutrition may in fact be an acute emergency.” The Journal of Emergency Medicine, 2013, Vol 44, issue 1, pages 72-74
2. Bjelakovic, Goran, et al. “Antioxidant Supplements for prevention of mortality in healthy participants and patients with various diseases.” Sao Paula Med J 2015; 133(2):164-165.