Overview of Ultrafiltration in Acute Decompensated Heart Failure
Acute decompensated heart failure (ADHF) is a major reason why people are admitted to hospitals and has a significant impact on the healthcare system. Causes can include not taking prescribed medication, other health conditions, diet, lifestyle factors, the disease getting worse, or treatment not working. The usual treatment involves medication, specifically drugs given through a vein (intravenous or IV) that helps get rid of excess water in the body, usually loop diuretics.
However, long term use of these diuretics can have negative effects on the nervous system and hormones in the body, which can make them less effective over time and worsen kidney function. This may lead to more severe health problems and even increase the risk of death. Because of this, there is interest in finding other ways to manage the body’s fluid balance in patients with ADHF. The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) suggest using both drug treatments and non-drug treatments for managing fluid overload.
One method gaining interest for treating fluid overload in patients with ADHF is extracorporeal ultrafiltration (UF). Extracorporeal refers to a procedure or treatment occurring outside the body. In UF, blood is passed through a machine that filters out excess fluid, before returning it back to the body. This is proving to be a promising alternative.
Anatomy and Physiology of Ultrafiltration in Acute Decompensated Heart Failure
Loop diuretics are the go-to treatment for patients with acute decompensated heart failure (ADHF) who are in the hospital. These medications work on a part of the kidney called the loop of Henle to decrease the amount of sodium and chloride that the body absorbs, resulting in increased urination. This helps to get rid of excess fluid in the body and can help to ease symptoms like shortness of breath and high pressure in the lungs.
However, recent studies have shown that these medications sometimes don’t get rid of enough fluid – a problem that may be more common than we thought. This can be a significant problem for those with heart failure who also have kidney problems, as more than half of heart failure patients do. The reason for this is that other molecules can interfere with the way the medication works on the kidneys, and so higher doses of the medication may be needed in these patients.
Unfortunately, as heart failure gets worse, these medications become less efficient, a situation often referred to as diuretic resistance. This means that even higher doses of the medication are needed to achieve the same effect, or that the same doses no longer have an effect. Long-term use of loop diuretics can also lead to something known as the “braking phenomenon.” Essentially, the body overcompensates for the fluid loss by overactivating certain responses and causing cells in the kidney to grow larger and work harder, which ultimately makes the medication less effective.
There are ways to work around this resistance to diuretics, one of which is a treatment called ultrafiltration. This involves filtering the blood to remove excess fluid and waste products. Research suggests that this could be a highly effective way to manage fluid buildup in patients with acute decompensated heart failure.
Why do People Need Ultrafiltration in Acute Decompensated Heart Failure
When someone has a severe case of ADHF (Acute Decompensated Heart Failure) that doesn’t get better with standard drug treatment such as IV diuretics, there’s another option called UF (Ultrafiltration). This condition happens when the heart can’t pump enough blood to the rest of the body, and in severe cases, patients can have too much fluid buildup in their body, which can cause further complications.
Ultrafiltration can help to remove this excess water from a patient’s body, which can be especially helpful when their body cannot handle standard treatments. In fact, UF can actually improve the body’s nitrogen balance―a critical part of maintaining a healthy body function. UF might also be used in patients who need to increase their calorie intake but can’t because of the fluid overload.
This treatment might also be used to help patients undergoing heart-lung machine surgery (also known as cardiopulmonary bypass) if they show signs of having too much fluid in their bodies, to prevent any further fluid buildup.
When a Person Should Avoid Ultrafiltration in Acute Decompensated Heart Failure
Ultrafiltration (UF), which is a procedure that cleanses the blood of excess fluid and salts, may not be suitable for all patients. There are numerous reasons why a doctor might decide not to use this procedure, including:
If a patient’s blood pressure is unstable or if they have a heart condition called acute coronary syndrome, which includes heart attacks or chest pain due to insufficient blood flow to the heart. In both these cases, UF could potentially be harmful.
Patients with a serum creatinine higher than 3.0 mg/dL, which indicates that the kidneys may not be working properly, should also avoid this procedure. Similarly, UF may not be right for patients who have a hematocrit (the proportion of red blood cells in the blood) of over 45%, as it can lead to more concentrated blood and increase the risk of clot formation.
Finally, appropriate access to the veins is necessary for UF. So, if it’s inadvisable or impossible to insert a catheter into a patient’s veins, perhaps because they are too narrow or due to other health problems, UF won’t be possible.
Equipment used for Ultrafiltration in Acute Decompensated Heart Failure
The equipment used for ultrafiltration (UF), a medical treatment that removes extra fluid from your body, is quite similar to that used for hemodialysis, a treatment that cleans your blood when your kidneys are not working properly. The UF system is basically made up of a device called a dialyzer, a special fluid called dialysate, tubes to carry the blood and the dialysis fluid, and a machine to control and keep an eye on the process.
The dialyzer, which might also be referred to as an “artificial kidney,” is usually made of a material called polyurethane. Within the dialyzer, there are tiny tube-like structures known as hollow fiber membranes. These membranes are suspended in the dialysate; they act like a sieve, helping to separate and remove the extra fluid from your blood.
Preparing for Ultrafiltration in Acute Decompensated Heart Failure
Research has been conducted to look at the various methods used to carry out ultrafiltration, a process during which excess water and salts are removed from the blood. This is usually done on a long-term basis or intermittently. Common factors to think about when choosing the method include cost and the complexity of the procedure.
In ultrafiltration, the treatment typically requires central venous access. This is where doctors create a pathway to a large vein in the body, preferably in the internal jugular neck veins. However, providing this type of access, especially over a long period of time, can increase the possibility of unwanted side effects.
In most cases, patients going through long-term dialysis (another way to clean the blood) have an arteriovenous communication. This is a kind of connection between an artery and a vein, usually in the arm or leg. This connection is also used in ultrafiltration but can sometimes result in issues such as increased heart workload and heart failure.
An alternative option is peritoneal dialysis access. This method uses the lining of the abdomen to filter the blood. However, it may occasionally cause a rare but serious infection called peritonitis.
How is Ultrafiltration in Acute Decompensated Heart Failure performed
Dialyzer fibers are like tiny tubes that have an important job in the dialysis process. They are filled with blood and surrounded by a cleansing fluid called dialysate. To cleanse the blood, the dialysate and blood flow in opposite directions, creating a crossing current, which helps remove waste from the blood.
During dialysis, waste and extra fluid are removed from your blood using two main principles: diffusion and convection. The process is a bit like making a cup of tea – when you place a tea bag (filled with tea leaves) into hot water, the tea flavor diffuses into the water, producing a cup of tea. Similarly, in dialysis, the waste in the blood moves from an area of high concentration (your blood) to an area of low concentration (the dialysate) through the dialyzer fibers.
Besides this, some extra fluid is also removed from the blood through a process called ultrafiltration. This works due to pressure differences created by the dialysis machine across the dialyzer membrane (the ‘wall’ of the tiny tubes we mentioned earlier). This pressure difference is like the push you need on a swing to get you up in the air. In this case, it forces some fluid to move from the high-pressure area (blood) to the low-pressure area (dialysate) across the tiny tubes or fibers.
So, put simply, during dialysis, your blood moves into the tiny tubes, waste is removed and then your cleaned blood flows back into your body.
Possible Complications of Ultrafiltration in Acute Decompensated Heart Failure
Ultrafiltration (UF), a medical procedure that removes excess water and salt from the body, can sometimes have side effects. These can include blood clots in UF filters, temporary discomfort where a tube has been inserted into a vein, infection around this tube, problems with the tube’s function, low blood pressure, bleeding, and kidney damage. In rare cases, patients might have problems getting rid of excess fluid in their bodies even with UF.
Despite these possible side effects, recent research indicates that UF is generally safe to use for patients with acute decompensated heart failure (ADHF), a condition where the heart can’t pump enough blood to meet the body’s needs. One large analysis of previous studies didn’t find any serious side effects in patients who had UF compared to those who were given IV diuretics, which are drugs that help remove excess water from the body. This same analysis also found fewer bleeding events with UF than standard therapy. While some studies noted more low blood pressure events with UF, they were generally not a major concern.
In terms of kidney damage, the rate was similar for UF and diuretic therapy. The Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF) trial was a study that looked at how UF and diuretic therapy affect kidney function in patients with heart failure and ongoing fluid retention and worsening kidney function. According to this study, UF initially caused a higher increase in a chemical in the blood (serum creatinine) that indicates kidney function. However, in the long run, patients who received UF had lower serum creatinine levels compared to those who received standard diuretic therapy.
What Else Should I Know About Ultrafiltration in Acute Decompensated Heart Failure?
Ultrfiltration (UF) therapy is a type of treatment that helps remove excess fluid from the body. It does this by lowering the pressure in the veins without affecting the amount of fluid coursing through your body. UF therapy works by creating a pressure difference that moves fluid through a filter, separating it from the blood, and removing it from the body. This therapy can be useful in managing fluid overload condition in patients who don’t respond well to conventional water pill treatments.
A research trial known as the UNLOAD trial revealed that UF therapy was not just a good alternative for people with severe heart condition who weren’t responding to water pills, but it also aided in reducing body weight and fluid volume more than the conventional intravenous water pills. Plus, it reduced chances of readmission to hospital for heart-related illnesses over a 90-day period.
Three recent studies comparing outcomes between UF therapy and conventional water pill treatments in managing fluid overload in patients with severe heart condition found that patients who could tolerate UF experienced a substantial reduction in fluid overload and body weight as compared to using just water pills.
UF therapy provides several other benefits to patients with severe heart condition who don’t respond to standard water pill treatments. It removes excess fluid in a way that doesn’t disturb the balance of electrolytes (minerals that have electric charge) in your body. Plus, it causes the greatest loss of sodium (a key electrolyte) for each unit of fluid removed, compared to intravenous water pills. UF might also change how substances involved in controlling functions of the heart behave, and this could be beneficial in treating heart disease.
What’s more, UF therapy has been found to help restore sensitivity to water pills. This means that this treatment could help heart patients who have stopped responding to water pill treatments start responding to them again.