What is Refeeding Syndrome?
Refeeding syndrome can occur when a person who has been starving for a long time suddenly gets a lot of food. This syndrome is marked by medical complications that happen due to changes in the body’s fluids and electrolytes, which are essential minerals in your body, as a result of fast and aggressive reintroduction to proper nutrition. This condition is often seen in people who are at high risk of being malnourished, such as patients with eating disorders or kidney failure patients undergoing a treatment called hemodialysis.
This metabolic upset can lead to problems in the heart and lungs, blood, and nervous system of these patients. A key sign of refeeding syndrome is a drop in the levels of phosphates in the blood, a condition known as hypophosphatemia. However, other electrolytes can also be affected, such as decreased levels of magnesium, potassium, and a vitamin called thiamine.
Despite recognizing refeeding syndrome as a serious medical issue with a high risk of death that requires immediate medical attention, there’s still a lack of solid scientific research on the cause and how to manage this syndrome. This syndrome was first noted during World War II, when people living in famine suddenly fell ill after their diet improved. In 1951, a study reported that about one-fifth of Japanese prisoners who were starved in prison camps died suddenly after their diets were improved and they received vitamins.
What Causes Refeeding Syndrome?
Refeeding syndrome is a complicated condition that happens due to multiple reasons. One main cause is when someone who hasn’t been eating well, suddenly starts eating a lot. If you’ve been poorly nourished and then start getting lots of nutrition, you could be at a higher risk for this syndrome.
It’s often seen in people with eating disorders or those who excessively consume alcohol. Conditions that hinder the body’s ability to properly absorb nutrients, like inflammatory bowel disease, can also lead to refeeding syndrome. People who are chronically malnourished, unable to control their diabetes efficiently, dealing with cancer, or are in recovery after surgery may also encounter this issue.
Risk Factors and Frequency for Refeeding Syndrome
Refeeding syndrome is a condition often seen in patients who are at high risk, such as those with eating disorders, depression, kidney failure, diseases that interfere with nutrient absorption, history of weight loss surgery, and alcohol abuse. The National Institute for Health Care and Excellence provides guidelines to help identify and treat refeeding syndrome, pointing out risk factors such as low body mass index (BMI), unintentional weight loss, starvation, history of alcohol abuse, and low levels of electrolytes.
It’s tough to say exactly how often refeeding syndrome occurs, mainly because there’s no standard definition or method for studying it. One way doctors have tried to track it is by looking for low phosphate levels in the blood, which is a common marker of the condition. In a study observing patients who had not eaten for at least 48 hours, this marker showed up in 34% of patients about 1.9 days after they started eating again. Estimates suggest refeeding syndrome could affect anywhere from 0.43% to 18% of hospital patients.
Refeeding syndrome is also seen in critical care settings where patients are given nutrition through IVs, a method known as total parenteral nutrition (TPN). However, this can lead to high blood sugar and increased insulin levels, which can make the electrolyte imbalances of refeeding syndrome even worse.
Signs and Symptoms of Refeeding Syndrome
Refeeding syndrome is a serious condition that occurs as a result of drastic changes in a person’s diet, specifically when a person who is malnourished begins to eat again. This syndrome can lead to a variety of symptoms that can affect numerous parts of the body. These symptoms are typically caused by changes in the levels of certain chemicals in the body, which can disrupt cell function and stability. Symptoms can range from something as mild as feeling nauseous to severe conditions like low blood pressure.
Some other issues that people with refeeding syndrome might experience include cardiovascular changes such as irregular heart rhythms, low blood pressure, heart muscle disease, shock, and even heart arrest. Kidney problems like damage to the tubes within the kidneys, kidney failure, and changes in the blood that can lead to acidosis, are also associated with refeeding syndrome. The syndrome can also cause breathing problems that lead to the failure of the respiratory system, fluid build-up in the lungs, and hypoventilation, or slow and shallow breathing.
Those with refeeding syndrome can also have muscle-related symptoms like rhabdomyolysis (a harmful disease that can damage the kidney), muscle aches, fatigue, muscle twitches, and weakness in the diaphragm, the main muscle involved in breathing. There can also be problems with the digestive system as potassium and magnesium levels drop; symptoms may include fluctuating between diarrhea and constipation, feeling nauseous and vomiting, and experiencing a paralyzed small intestine, which can cause an obstruction.
It’s important to note that many people with refeeding syndrome also have other health problems. For instance, they may have an imbalance of electrolytes and vitamins, which can get worse if they also have an alcohol use disorder.
Testing for Refeeding Syndrome
The American Society for Parenteral and Enteral Nutrition (ASPEN), a professional group of nutrition experts, has created a task force to agree on how to define and recognize refeeding syndrome. Refeeding syndrome is a set of symptoms that can happen when someone who is malnourished starts to eat again. Because the symptoms can vary and there are no agreed-upon diagnosis criteria, it can be challenging for doctors to identify.
ASPEN recommended that refeeding syndrome should be diagnosed and categorized according to three levels of severity – mild, moderate, and severe. This framework is based on the amount these three key nutrients – phosphorus, potassium, and magnesium – decrease in someone’s blood:
- Mild is considered if there’s a decrease between 10% to 20% in any one, two, or all three of these nutrients.
- Moderate if there’s a decrease between 20% to 30% in any of the three nutrients/items.
- Severe condition is when any of these nutrients decrease by more than 30% or if there’s a problem with the functioning of organs due to a deficiency in any of these nutrients, or deficiency in thiamine (a vitamin). This should occur within five days after the person starts eating again.
However, while these guidelines from ASPEN give us a good place to start, they do have some limitations. The guidelines look specifically at changes in lab test results, not how the person is feeling or other symptoms they might have. Plus, markers often used to evaluate a person’s nutritional status such as albumin and prealbumin (types of proteins in our blood), are not always reliable, especially since they can change rapidly—prealbumin has a half-life, meaning it can be reduced by half, in just a few days while the half-life of albumin is about 20 days.
Refeeding syndrome can be dangerous, and even life-threatening, and so easy recognition is important to make sure patients at risk are correctly diagnosed and properly treated. The complexity of refeeding syndrome and the lack of consistent standards for diagnosis make it particularly challenging to treat high-risk patients who require extra nutritional support. This highlights the need for more studies on refeeding syndrome to improve the way we diagnose and prevent it.
Treatment Options for Refeeding Syndrome
Traditionally, doctors monitor patients individually for refeeding syndrome, a potentially serious condition that can occur in people who’ve been in a state of extreme malnutrition or starvation and then start eating again. Recent guidelines propose watching these patients closely, making sure not to overload them with calories and carefully replacing essential minerals, or electrolytes, that may have become imbalanced during their malnourished state. These guidelines also recommend that, if patients are able to tolerate it, they should be fed through their digestive tract rather than through a vein. Certain supplements, such as glutamine and L-arginine, can also help these patients fight bacterial infections, support their immune systems, and maintain healthy gut bacteria.
There are currently a few different sets of recommendations available for managing refeeding syndrome, but they’re somewhat controversial because there’s not enough clear data or standard ways of measuring some things. The ASPEN guidelines, for example, suggest checking levels of magnesium, phosphorus, and potassium before giving any nutrition. They say patients with a high risk of refeeding syndrome should have their electrolyte levels checked every 12 hours for the first 3 days, and that any imbalances should be corrected according to usual medical practice. For food replacement, these guidelines recommend starting with a specific amount of calories in the first 24 hours and then gradually increasing that amount over the next few days.
The National Institute for Health and Clinical Excellence (NICE) agrees with ASPEN on the issue of replacing electrolytes at the same time as starting to feed patients again. However, they also point out that in especially high-risk patients who have really severe electrolyte imbalances, it might be a good idea to hold off on food until these imbalances have been corrected. This could be the case, for instance, when a patient has dangerously low levels of potassium, phosphorous, or magnesium.
Both ASPEN and NICE suggest that all patients with a high risk of refeeding syndrome should undergo a detailed nutritional assessment. This includes screening for previous history of serious alcohol use and recent changes in weight. In addition to a clinical evaluation, this initial assessment should also include checks of baseline mineral or electrolyte levels. NICE provides a more detailed plan for replacing each individual electrolyte. Per these guidelines, electrolytes should be monitored daily in the first week of replenishment and three times in the following week. However, both the ASPEN and NICE guidelines lack strong research evidence.
As part of the refeeding process, the replacement of thiamine, a vitamin that supports the brain and nervous system, is recommended before any food is given. It is proposed that Thiamine should be administered at a dose of 100 mg at least 30 minutes before starting feeding and should continue twice daily for 7 to 10 days to prevent potential neurological complications. This practice can help identify those patients at highest risk and allow careful monitoring of electrolytes. Such an approach helps to minimize complications associated with refeeding syndrome and sudden feeding.
What else can Refeeding Syndrome be?
When it comes to diagnosing refeeding syndrome, a condition that can occur when someone who is malnourished begins to eat again, it’s essential to first rule out other serious conditions. This makes it a unique type of diagnosis that is determined by excluding other possible causes of the symptoms.
One condition that needs to be ruled out is fluid overload. This can lower many of the electrolytes in the bloodstream, leading to very low levels of sodium, potassium, magnesium or phosphorus.
- Conditions caused by refeeding syndrome also need to be checked for.
- Heart rhythm abnormalities, which can be caused by imbalances in electrolytes, have to be ruled out as well. For example, long QT syndrome is a potentially serious condition that can occur from these imbalances.
Once these other possibilities have been considered and ruled out, then a diagnosis of refeeding syndrome can be made.
What to expect with Refeeding Syndrome
The future health outcomes for patients diagnosed with refeeding syndrome can vary greatly, often depending on how severely their body’s chemical balances and electrolyte levels are disturbed. It is crucial to note that patients with refeeding syndrome often have other health concerns, such as deficiencies in crucial vitamins and electrolytes, which can become worse if the patient struggles with an alcohol use issue. This could, in turn, worsen their overall condition.
In cases where patients have only slight disturbances in their electrolyte levels, they often may not display any noticeable symptoms. This makes it very important for patients who are at risk of developing refeeding syndrome to maintain a heightened sense of vigilance. Refeeding syndrome can develop quickly and unpredictably.
Possible Complications When Diagnosed with Refeeding Syndrome
When someone suffers from Refeeding Syndrome, they can experience a variety of complications due to an imbalance of electrolytes in the body. Each type of electrolyte can cause different problems.
Key Electrolyte Imbalances:
- Potassium imbalances: This can cause irregular heart rhythms, QT prolongation (a measure of time it takes for heart to recharge after a heartbeat), weakness, fatigue, paralysis, and difficulty breathing.
- Phosphorus imbalances: It can lead to irregular heart rhythms, decreased 2,3 diphosphoglycerate (a compound that helps deliver oxygen to tissues) production, and weaker respiratory muscles.
- Magnesium imbalances: This can cause difficulties with coordination (ataxia), dizziness (vertigo), prickling or tingling sensations (paresthesia), seizures, depression, and QT prolongation.
- Thiamine deficiency: A lack of thiamine (vitamin B1) could cause heart problems and Wernicke-Korsakoff syndrome (a brain disorder related to vitamin B1 deficiency).
Preventing Refeeding Syndrome
Identifying those at a high risk for developing refeeding syndrome is critical to prevent it and its potential problems. The high-risk characteristics are talked about earlier in this article. Once a high-risk person has been identified, NICE (National Institute for Health and Care Excellence) has set rules for preventing refeeding syndrome. These rules involve conducting a nutrition check before replenishment, checking the baseline levels of minerals in your body and keeping a close eye on them for two weeks, and looking out for recent changes in weight, alcohol consumption, or dietary changes. Learning more about the causes and traits of refeeding syndrome could be helpful, especially in a critical care setting like an Intensive Care Unit (ICU).
