Children with cystic fibrosis may be at risk of developing what's called a venous thromboembolism. This is essentially a blood clot that forms in the deep veins of the body, most often in the lower legs. These clots can be extremely dangerous because they can dislodge and travel to vital organs, blocking blood supply.
What is a venous thromboembolism?
A venous thromboembolism in children can have very serious consequences. The most severe cases can be fatal and usually involve clots breaking off the original site and traveling through the bloodstream to the lungs. Here, the dislodged clot will block blood from flowing to the lungs where they can pick up oxygen to deliver to the rest of the body. This causes the body's tissues to basically suffocate as they are unable to receive oxygen as the child takes each breath. This phenomenon is known as pulmonary embolism, and is one of the most feared consequences of having a venous thromboembolism.
So what does this all have to do with cystic fibrosis? For some time, doctors and researchers have recognized the fact that deep venous clots are associated with cystic fibrosis. However, the details regarding this relationship are still unclear. It's not certain whether cystic fibrosis directly causes a state where patients have blood with a higher tendency to coagulate. However, it is known that deep vein blood clots in a healthy child are extremely rare. So why are kids with cystic fibrosis forming these clots?
A new study looks at risk factors
A team of researchers decided to look into this matter further. They decided to try to decipher any unique characteristics or comorbidities that might be associated with venous thromboembolism in kids suffering from cystic fibrosis. To do this, they went back and looked at old patient charts dating from 2003 to 2016. They collected extensive information from these charts, including data about the severity of their disease, comorbidities, and any treatments they required.
Researchers reviewed charts of almost 500 children with cystic fibrosis, of which 11 suffered from a venous thromboembolism. The scientists calculated that this rate correlated to an incidence of 53 deep vein clots per 10,000 children with cystic fibrosis.
The researchers found children who developed clots have unique characteristics
The study authors then looked at characteristics that might separate these children who formed clots from those who did not. Using statistical analysis and algorithms, they determined that cystic fibrosis patients who developed clots more often had other diseases such as cystic fibrosis-related diabetes, sinus disease, and Pseudomonas infections. Many of the children who developed a clot were not only older but also had more severe cystic fibrosis as marked by longer and more numerous admissions to the hospital, higher rates respiratory infections.
More inflammation in kids with CF who developed clots
Authors also predicted that higher levels of inflammation. This was measured by blood work using the erythrocyte sedimentation rate test and C-reactive protein test. By measuring these levels, doctors are able to gauge the inflammatory response of the body. The higher these numbers, the more active a person's immune system is. The children who tended to clot were associated with having higher levels of both these inflammatory markers.
Children who were more likely to clot were also on less systemic steroids. This also correlates with the level of inflammation because steroids actually suppress the immune system. That means that the kids who developed clots were less likely to be on medication to suppress their immune system, further supporting the theory that high inflammation is correlated with coagulability of the child's blood.
So what does this all mean for us? If you are a parent of a child with cystic fibrosis, it means that you need to be aware of this potentially deadly health risk. Deep vein clots in cystic fibrosis are still poorly understood, but now we know more about what may put your child at higher risk.
What are the signs and symptoms of a deep vein clot?
If your child has any of these risk factors, it's important to keep in mind that they might develop a deep vein clot in the future. Some of the symptoms of a deep vein clot include swelling and pain because the area affected is deprived of blood flow. Usually, blood clots like these tend to occur one-sided, so be extremely wary if your child complains of redness and swelling in one calf. If you suspect that your child may have a clot, take them immediately to the emergency room or your local doctor if they are available. They will be able to do more tests and evaluate whether or not your child has a clot.
What do doctors do to evaluate for a clot?
The doctors will likely perform blood tests and ultrasounds if they are suspicious that your child has a clot. An ultrasound will use sonar to look at the deep veins within your child's affected limb. The sonar will project images for your physician to evaluate the structure inside the limb, and a clot would be seen if it is present. There are also blood tests that your doctor might recommend if they are worried about a blood clot. These involve platelet counts and a test called the D-Dimer test which evaluates consumption of several molecules in the blood that work to create clots. Levels of these will help your doctor figure out whether or not your child has a clot.
Red flags to look out for in children with venous thromboembolism
Some red flags for a child with leg pain suspicious for deep vein thrombosis would be any symptoms of trouble breathing. As we had discussed earlier, blood clots in the deep veins can become dislodged and travel to the lungs, causing severe symptoms and even death. If your child is having any respiratory distress or pain in his or her chest, it is an emergency. Doctors will have to work very fast to scan your child and evaluate for a clot in the lungs.
What is the treatment for venous thromboembolism?
The treatment of venous thromboembolism is usually in the form of medication. These drugs work to thin the blood and prevent more clots from forming. You may wonder whether treating the cystic fibrosis or comorbidities may decrease your child's risk, but the truth is that no one really knows the answer quite yet. It's possible that cystic fibrosis may simply be a risk factor in itself for developing clots in the veins. However, it's always a good idea to manage disease complications as best as you can, so your child can live healthier and happier with a better quality of life. Adherence to medications and maintaining a close relationship with the medical team will help your child have fewer hospital stays and shorter admissions. Though we don't know if managing these comorbidities can help, it surely doesn't hurt!