Síndrome de realimentação

What is refeeding syndrome?

Refeeding syndrome is a dangerous and life threatening shift of fluids and body salts (electrolytes) that can occur when malnourished patients receive treatment with refeeding. These shifts cause serious complications such as low body phosphate, abnormal sodium and fluid balance, changes in glucose, protein, and fat metabolism, low vitamin levels, particularly thiamine (vitamin B1), low potassium and low magnesium.

Starting to eat again after a period of prolonged starvation can also lead to severe complications, including heart failure and problems with the lungs, liver and brain, which can be fatal. Sudden reversal of prolonged starvation by the reintroduction of food leads to rapid shifts of electrolytes back into cells. Muscle damage (myopathy) and rapid breakdown of muscle (rhabdomyolysis) are also recognised complications.

Refeeding syndrome usually starts within 72 hours of beginning refeeding, with a range of 1-5 days, but can then progress rapidly. However, it can occur late (up to 18 days) in the most severely malnourished. The symptoms of refeeding syndrome include:

• Abdominal pain, bowel changes.

• Confusão.

• Dificuldade para respirar.

• Fadiga.

• Heart palpitations, increased heart rate, low blood pressure.

• Muscle pain, weakness.

• Náusea, vômito.

• Swelling (oedema), rapid weight gain (from fluid retention).

• Paralysis.

• Convulsões.

If not recognised and treated quickly, refeeding syndrome can result in a coma or even death.

The people who are at the highest risk of refeeding syndrome are the elderly and those with:

• Very low body mass index, for example, anorexia nervosa.

• Minimal or no food intake for more than 3-4 consecutive days (the longer the duration the greater the risk and severity of refeeding syndrome).

• Weight loss of over 15% in the past 3 months.

• Abnormal chemical (electrolyte) levels.

• Medical conditions such as pneumonia or other serious infections, heart failure or heart disease, or liver damage (for example, history of alcohol dependence) before refeeding.

• Other risks include poorly controlled diabetes, receiving chemotherapy or recovering from surgery.

Refeeding syndrome is less common in children than adults, but can occur.

Refeeding syndrome occurs in people who are malnourished, most commonly in those who have been in hospital. Other causes of malnutrition include an inability to take food by mouth due to an injury or condition such as dental problems or oral surgery, an inability to swallow, a gastrointestinal disease that impacts digestion (malabsorption), or weight-loss surgery.

In addition, famine, illness, poverty, disability, or old age can cause problems with access to nutritious food and lead to malnutrition. A person can suffer from malnutrition at any weight.

When the body does not get adequate food and water, it is forced to break down fat stores, and eventually muscle, for energy. The longer starvation continues, the more the body will use these stores. Muscle wasting and loss of fat stores weaken the vital body organs, particularly the heart. As malnutrition progresses, a person will also become more vulnerable to injury and illness.

People who are severely malnourished are typically admitted to hospital intensive care to begin refeeding and fluid replacement. This allows for close monitoring of vital signs and blood tests to quickly diagnose refeeding syndrome. Blood tests, such as electrolyte levels, can often show potentially life-threatening complications before symptoms develop. The medical team will closely monitor levels of glucose, sodium, potassium, and other electrolytes.

During refeeding, constant monitoring is needed. Some potentially fatal metabolic changes (such as low potassium levels) can occur suddenly. Nutrition and fluid intake, urine output, weight, and body mass will also be closely monitored during refeeding.

Refeeding and fluid and electrolyte replacement must be slow and deliberate, allowing the body enough time to adjust. Vitamin supplements to correct any deficiencies (especially a thiamine deficiency) will also be needed.

Depending on the underlying cause of malnutrition, other interventions may be needed, such as a treatment for a bowel problem. Treatment may also be need if refeeding syndrome causes any complications, such as heart failure, insulin to control high blood glucose, or correction of low potassium, phosphate or magnesium.

Apart from a team of doctors and nurses, the treatment of refeeding syndrome will need a variety of other healthcare professionals, depending on the needs of each individual person. Dietitians and nutrition specialists will be involved in ensuring that the correct quantity and content of nutrition replacement is being provided.

Long-term follow-up care for people who have been treated for malnutrition will need to include many different healthcare professionals depending on the underlying cause, including mental health professionals, specialists and dieticians.

Keeping to slow and steady fluid and calorie replacement and having an specific fluid and nutrition plan for each individual person is essential. Close monitoring of food and fluid intake, body weight and blood tests will also ensure early recognition of problems and early treatment to prevent refeeding syndrome.