Breathing and Shortness of Breath: Pediatric Cancer
Is your child having difficulty breathing or episodes of shortness of breath? If your child has cancer not related to the lungs, you may be wondering why. Cancer and its treatment can impact areas beyond the primary tumor source. As a respiratory therapist, I help people who struggle with breathing. I hope that this blog will help you understand how breathing works and what to do when it gets difficult.
When your child has cancer, you naturally want to research everything you can about their diagnosis. The Sassy Carmen Foundation is a prime resource to read about other families who have fought the same battle. By sharing their experiences, they can help answer questions that you might not even know to ask yet.
Before we discuss how cancer makes breathing harder, let’s take a look at how a normal respiratory system works.
Normal Oxygen Uptake
Every cell in your body needs oxygen to live and do its job. Cells get oxygen from your blood. When you breathe in, air fills your lungs and oxygen flows into your blood. Your blood acts like a delivery truck, bringing oxygen around your whole body. Cells trade oxygen for Co2 (carbon dioxide). Co2 is the leftovers from the cell making energy. Next, your blood changes from a delivery truck into a garbage truck that takes the trash (Co2) away. Your bright red blood that was full of oxygen now turns a darker red when it is full of Co2.
Your blood travels through a highway system of arteries and veins. Starting at your heart, bright red blood loaded with oxygen travels quickly through your arteries to deliver oxygen to your cells. After dropping off oxygen and picking up Co2, your dark blood travels through a highway of veins, slowly making its way back to your lungs. In your lungs, your blood trades Co2 for oxygen, and then you exhale the Co2 when you breathe out. The blood turns bright red again with a new breath of air, passes back through your heart, and gets pumped around your body to deliver its oxygen load again. This cycle repeats itself continuously forever.
When Tumors Get in the Way
A tumor is a collection of abnormal cells that develops without its own blood supply. This makes the tumor low in oxygen (hypoxia). Hypoxia means lack of oxygen. Instead of oxygen, the tumor uses sugar to make its energy so that it can grow. Your body gets a lot of sugar from your food. By using sugar as fuel, the tumor grows out of control. Eventually, the hypoxic tumor tricks your body into making more blood vessels so that it can get oxygen. These hijacked blood vessels bring more blood to the tumor instead of your organs. When your organs don’t get as much blood, they become hypoxic instead of the tumor.
Tumors can cause watery fluid to build up in your chest, around your heart, or in your abdomen. This can make it hard to inhale and can stress your heart. Tumors in your brain can put pressure on places that control breathing, causing irregular or ineffective breathing. If the tumor is large, you might even stop breathing.
Infection
Children with cancer develop infections easily. Chemotherapy weakens the immune system. A healthy child can easily recover from a cold or seasonal virus, but without any immune defense, these germs can settle into the lungs and cause infection.
An infection that invades past your airways and settles in your lungs is pneumonia, where fluid and mucus fill your air sacs (alveoli). When you breathe in, the air travels through your airway like a straw. A straw brings a drink to your mouth, but you do not get the drink until it reaches your mouth. Like a straw, air flows through your airway, but it does not fill your air sacs until it reaches them. If fluid and mucus take up all the space, there is no room for air, so you breathe it all back out.
When blood flows by and there is no oxygen to pick up, it goes back to the heart still full of Co2. This is called shunting. The larger the infection, the more Co2 goes back into your arterial blood. This blood that is supposed to deliver oxygen is still full of Co2. It passes by the organs with nothing to exchange. This makes the organ sick and not able to function like it should.
Chemotherapy
Sometimes the treatment for cancer can cause you to have fewer red blood cells (anemia). The red cells are the ones in your blood that carry oxygen, so anemia means less oxygen in your blood, causing a drop in total blood oxygenation. This can cause you to feel tired, weak, or short of breath because your body is trying to increase oxygen by having you breathe faster and deeper. Chemotherapy drugs can cause permanent lung damage and scarring (pulmonary fibrosis). Scarring can make the lungs stiff and hard to expand when breathing. Any damage to lung tissue makes it easier to develop infections and lifelong recurrent bronchitis and pneumonia.
Treatment for Shortness of Breath
If you check your vital signs and your oxygen is low, you need supplemental oxygen. You will be admitted to the hospital, where you will have a small tube (nasal cannula) close to your nose that gives you more oxygen than regular air. If cancer makes breathing hard, high-flow oxygen can help. A high flow system is like a water hose, but instead of water, it pushes air into your lungs to make breathing easier.
If high flow is not enough and you are still working hard, you can tire out and stop breathing. To prevent this, a mask attached to a machine can give you an extra pressurized push of air in when you take a breath (BiPAP). That helps to open your lungs up and keep the extra pressure inside while you exhale. It makes it easier for you to breathe until the problem can be resolved with medications or treatment. If that is still not enough help for you, a tube can be put into your airway. A machine called a ventilator can take over your breathing for you until you are better.
Cancer can make it hard to breathe, and that is scary. I hope that understanding what is happening and what can be done about it will take some of the fear away. Keep following Sassy Carmen for more articles to learn about how cancer can affect breathing.
References
https://pmc.ncbi.nlm.nih.gov/articles/PMC8003323
https://pmc.ncbi.nlm.nih.gov/articles/PMC9947930
https://pmc.ncbi.nlm.nih.gov/articles/PMC7123817
https://www.thenursingjournal.com/post/pneumonia-pathophysiology
https://www.cancer.org/cancer/managing-cancer/side-effects/low-blood-counts/anemia.html
https://pmc.ncbi.nlm.nih.gov/articles/PMC8348211
