Re-Feeding Syndrome Flashcards
What is the defintion of Re-feeding syndrome?
Potentially fatal shifts in fluid and electrolytes that may occur in malnourished patients following re-feeding (whether enterally or parenterally)’. Leads to
- Hypophosphataemia
- Hypokalaemia
- Hypomagnesaemia
- Hyperglycaemia
- Thiamine deficiency
- Sodium retention
- Fluid overload
What are the hormones released by Prolonged Fasting?
- Glucagon
- Cortisol
- Growth Hormone
- Adrenaline
Who is at risk of Re-feeding syndrome?
- Patients with anorexia nervosa
- Patients with Chronic Alcoholism
- Oncology patients
- Postoperative patients
- Elderly patients (comorbidities, decreased physiological reserve)
- Patients uncontrolled diabetes mellitus
- Patient with Chronic Malnutrition
- Long term users antacids (magnesium and aluminium salts bind phosphate)
- Long term users of diuretics (loss of electrolytes)
What are functions of Phosphate?
- Component of biological molecules: Nucleic acids, Phospholipids, Cellular organelles
- Intracellular messaging – cAMP
- Bone mineralisation (hydroxyapatite)
- Hydrolysis of ATP – aerobic energy source
What are the consequences of Hypophosphataemia?
0.35 – 0.8 mmol/L
- Mild
- Chronic - osteomalacia
<0.35 mmol/L
- Confusion
- Seizure
- Coma
- Impaired muscle contractility
- Rhabdomyolysis
- Ileus
- Red blood cell fragility
- Impaired platelet & leukocyte function
What are the patient at risk of Hypophosphataemia?
Decreased Intake
- Alcoholics
- Severe malnourished
- Eating disorders
Decreased GI Absorption
- Intestinal Failure
- IBD
- Radiation enteritis
Increased Renal Losses
- Hyperparathyroidism
- Fanconi’s
- Chronic diuretic use
- Renal tubular acidosis
- Oncogenic osteomalacia
Genetic
- X-linked hypophosphataemic rickets
- Autosomal dominant hypophosphataemia
- Hereditary hypophosphataemic rickets with hypercalciuria
What are functions of Potassium?
- Protein synthesis
- Glycogen synthesis
- Determinant of resting membrane potential (Em): Muscle contraction
What are Consequences of Hypokalaemia?
- Muscle weakness
- Cramps
- Tetany
- Impaired contractility
- Rhabdomyolysis
- Ileus
- Nausea/vomiting
- Constipation
- Arrythmias
- ECG changes
- Heart block and cardiac arrest
- Impaired urinary concentration
- Increased ammonia production and urinary acidification
- Increased HCO3 reabsorption
What are the patients at risk of Hypokalaemia?
Decreased Intake
- Alcoholics
- Severely malnourished
- Eating disorders
Increased Cellular Uptake
- Metabolic alkalosis
- Insulin – Refeeding
- Periodic paralysis
Increased Extra-Renal Losses
- D + V
- Intestinal fistula
- Chronic laxative abuse
Increased Renal Losses
- Loop / Thiazide diuretics
- Hypomagnesaemia
- Conn’s / Cushing’s
- Barter’s
- Liddle’s
- Gitelman’s
What are functions of Magnesium?
Enzyme co-factor
- Energy metabolism
- Neuromuscular excitability
- Protein/nucleic acid synthesis
- Control Ca/K channels
Co-factor for ATP
Regulation endocrine secretion – PTH, Aldosterone, Insulin
What are consequences of Hypomagnesaemia?
- Muscle weakness
- Cramps
- Tetany
- Impaired contractility
- Ileus
- Nausea/vomiting
- Constipation
- Arrythmias
- Heart block and cardiac arrest
- Hypocalcaemia
- Hypokalaemia
What are patients at risk of Hypomagnesaemia?
Decreased Intake
- Alcoholics
- Severely malnourished
- Eating disorders
Decreased GI Absorption
- IF
- IBD
- Radiation enteritis
- Long term PPI
Increased Cellular Uptake
- Post DKA
- Post MI
- Acute pancreatitis
Increased Renal Losses
- Loop / Thiazide diuretics
- Hyperparathyroidism
- Gitelman’s
- Nephrotoxic drugs:
- Cisplatin. CsA. Gentamycin. Tobramycin
What are the functions of Thiamine?
Thiamine co-factor of thiamine pyrophosphate (TPP). TPP co-factor for
- Transketolase - Pentose phosphate pathway
- Pyruvate Dehydrogenase - Flux from glycolytic pathway through to Kreb’s cycle
- α-Ketoglutarate Dehydrogenase - Kreb’s cycle
During rapid re-feeding, induction of CHO metabolism causes utilisation of already depleted thiamine stores
What are the consequences of Thiamine Deficiency?
Wernicke-Korsakoff Syndrome
- Wernicke’s Encephalopathy - Acute onset
- Korsakoff’s Syndrome - Chronic neurological complications associated with WE
What are signs and symptoms of Wernicke’sEncephalopathy?
Neurological lesions
- Vascular congestion
- Demyelination
- Gliosis
- Haemorrhage
Encephalopathy
- Disorientation
- Indifference
- Agitation
Oculomotor dysfunction
- Nystagmus
Gait ataxia
