I’m starting a series of posts on medical and traumatic conditions which the paramedic or EMT will frequently encounter. One could say that we are going to shine the spotlight on one lucky condition each week. However, this is Gotham City. And in Gotham City, a simple spotlight will not do. Oh no. We have the “Bat Signal.” So, each week we will shine the Bat Signal on a different condition and discuss what causes it, what its signs and symptoms are, and how we as pre-hospital providers should begin to treat it. So, without further ado, let’s shine the Bat Signal on…
Sickle Cell Anemia
Sickle Cell Anemia sounds complicated, but it is actually very simple. Red blood cells are responsible for carrying oxygen to all the tissues of the body. They do this by bonding oxygen molecules to a protein called hemoglobin, which also gives blood its distinctive red color. Normal red blood cells are disk-shaped, with a sunken center. They look a bit like donuts. Red blood cells (from here on, I’m going to refer to them as “RBC’s,” mostly so I don’t have to keep writing out the term) do not have a cell nucleus, which gives them their distinct donut shape.
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In this picture, you can graphically see the difference. |
In patients with sickle cell anemia, a tiny change in the DNA which contains the instructions for building hemoglobin causes the whole hemoglobin protein to change shape. This change causes the whole RBC to collapse and become dehydrated. The end result is that the RBC’s with the different hemoglobin become shaped like crescents, or “sickles.”
When RBCs sickle, they cannot carry oxygen to the tissues of the body. This causes anemia and the feeling of shortness of breath. Anemia is simply a condition caused by not having enough red blood cells to carry the oxygen required by your body’s tissues. Sickle RBCs also become stiff and sticky, which causes them to stick together. These cells can block blood flow in the blood vessels which perfuse the patient’s limbs and internal organs. These blockages cause pain, organ damage, and increased risk of infection.
How is Sickle Cell Anemia Transmitted?
Sickle Cell Anemia is a genetic disorder, passed from parents to children.
Before we go much further, we should take a moment and differentiate between “Sickle Cell Disease” and “Sickle Cell Trait.” In your DNA, you have genes. Each gene is a chunk of DNA which contains the instructions for one protein. You have two copies of each gene; one from your father, and one from your mother. Only one of those copies is used; we call that gene the dominant trait. The other gene, the recessive trait, is not used.
Patients with Sickle Cell Trait have two genes which contain instructions for building hemoglobin. One has the the change that causes blood cells to become sickle shaped. The other gene is normal and usually dominant, and does not cause sickle shaped RBCs. Patients with Sickle Cell Trait typically make both normal RBCs and some sickle-shaped RBCs. Many do not have any complications from sickle cell trait; some, however, do experience pain and other symptoms.
On the other hand, patients with Sickle Cell Disease have two copies of the gene that causes RBCs to sickle, one from each parent. Because the gene which causes RBCs to sickle is the only gene available, these patients are far more likely to have problems associated with sickled RBCs.
Who Gets Sickle Cell Anemia? And How is it Diagnosed?
All states require every newborn to be screened for sickle cell anemia and for sickle cell trait. All that is required is a simple blood test at birth.
Individuals most at risk are:
- Those of African or African-American heritage.
- Those from Central and South America, especially natives of Panama.
- Individuals from the Caribbean Islands.
- Individuals from Turkey, Greece, Italy, India, and Saudi Arabia.
Some facts and figures:
- Sickle cell anemia effects 70.000 to 100.000 individuals in the USA. Most of these are African-American.
- 2,000 children are born every year in the USA with sickle cell anemia.
- Sickle cell anemia is present in 1 of every 500 African-American babies.
- Sickle cell anemia is present in 1 of every 36,000 Hispanic babies.
- Sickle cell trait is present in 1 out of every 12 African-Americans.
Based on these numbers, the chance of you getting someone with either sickle cell anemia or sickle cell trait in the back of your ambulance is extraordinarily high.
Let’s Talk About Some Signs and Symptoms
Sickle cell anemia may be present at birth. However, most patients don’t show symptoms until they are at least four months old.
Symptoms to pay attention to:
- Shortness of breath.
- Dizziness.
- Headaches.
- Cold hands and feet.
- Paler than normal skin or mucosa (in the mouth or nose, and around the eyes).
- Jaundice (yellowing of the skin or sclera of the eyes).
- Sudden pain throughout the body.
A sickle cell crisis is an acute episode of sudden pain through the body, which often affects the bones, lungs, abdomen, and joints. Sickle cell crises are caused by sickled RBCs blood blood flow to the limbs and organs, and are the most frequent cause of EMS calls related to sickle cell anemia. Patients who are dehydrated are at increased risk of experiencing sickle cell crises, as loss of fluid volume increases the chances of blood cells clumping up and causing blockages.
EMS providers should bear in mind that patients with sickle cell disease are at increased risk for a variety of associated conditions. Big ones are:
- Hand-Foot Syndrome: This is mostly found in young children, especially younger than four, and is caused by sickle cells blocking capillaries in the extremities. This causes pain, swelling in the extremities, and fever.
- Splenic Crisis: The spleen is responsible for filtering dead cells and other “junk” out of the blood. Sometimes, the spleen traps RBCs that should be in circulation, which causes the spleen to swell. If too many RBCs are trapped by the spleen, the body can become anemic due to lack of RBCs carrying oxygen to the body’s tissues. This can require blood transfusions to correct the anemia until the body can make more blood cells.
- Chronic Infections: Due to spleen disfunction, patients with sickle cell anemia are more prone to infection. When infections do occur, these patients have a harder time fighting them off.
- Acute Chest Syndrome: Acute chest syndrome is caused by either an infection in the chest, or by sickled RBCs trapped in the lungs. It can be similar to pneumonia, and typically presents with chest pain, shortness of breath, and fever. These patients may also have low SPO2 values, and will have chest abnormalities visible on chest x-rays.
- Pulmonary Hypertension: When RBCs sickle, they cause damage to the blood vessels in the lungs. This damage makes it harder to pump blood through the lungs and increases cardiac workload. This causes increased blood pressure in the lungs, which in turn causes shortness of breath and fatigue.
- Stroke: Patients with sickle cell disease are at increased risk of ischemic stroke (due to blockages which prevent oxygenated blood from reaching portions of the brain) and hemorrhagic stroke (caused by sickled RBCs causing damage to blood vessels, which eventually bleed into the brain).
- Eye Problems: Sickle cells can damage the blood vessels which perfuse the retina, causing vision problems and blindness.
- Priapism: Sickle cells can also block blood flow out of the penis, which causes prolonged and painful erections. Persistent erections can lead to vascular damage, which can lead to impotence.
- Gallstones: The body breaks hemoglobin down into a protein called bilirubin. Elevated bilirubin levels lead to the formation of gallstones.
- Sickle Cell Ulcers: Not much is known about what causes ulcers to form in patients with sickle cell anemia. They typically occur in males rather than in females, and are typically found in patients older than 10.
- Multiple Organ Failure: Multiple organ failure occurs when at least two major organs fail at the same time due to damage caused by sickled RBCs. Sighs that this has occurred are fever, rapid heart rate, shortness of breath or other breathing problems, and altered mental status.
How is Sickle Cell Disease Treated?
The long-term goal of treatment in patients with sickle cell disease is to relieve pain, prevent infections, organ damage, and strokes, and to control complications and associated disorders. Patients are encouraged to remain hydrated, as this helps prevent blockages. Patients are also typically prescribed antibiotics, especially when an infection has occurred. Some patients are prescribed antibiotics to prevent infection. Patients with sickle cell disease are typically prescribed medication for pain management; these can range from over the counter options like tylenol and NSAIDs to strong opioid analgesics such as dilauded. Many patients also take a drug called hydroxyurea. Hydroxyurea causes the body to make a version of hemoglobin found in infants, called fetal hemoglobin. Fetal hemoglobin helps keep RBCs from sickling. Patients with sickle cell disease should also get routine head ultrasounds, to detect strokes. Finally, blood transfusions may be necessary to correct anemia.
Prehospital Treatment
When EMS is called for a patient with sickle cell disease, its typically because the patient is experiencing a sickle cell crisis. Remember, sickle cell crises are caused by sickled RBCs causing blockages in organs and limbs, which then causes lack of perfusion to tissues.
You should take a good set of vitals, and take several more during transport to an appropriate facility so that you can establish a trend. This is a no-brainer.
If the patient is experiencing chest pain or shortness of breath, put them on a cardiac monitor and a 12 Lead EKG. This is also a no-brainer; most agencies require a 12 lead for any mention of chest pain. This will allow you to see any cardiac ischemia, or at very least to rule out a STEMI. I always take at least two EKG’s; one at the beginning of transport, and one at the end. This allows me to see if there has been any changes.
If you can, establish an IV. We have lots of folks with sickle cell anemia and sickle cell trait in Gotham City, and many have crappy veins. Do your best. If you are able to get an IV, start running normal saline. Dehydration makes sickle cell crises worse. Keep in mind that you don’t want to give too much fluid to patients with renal or heart failure.
If the patient is hypoxic, or says that oxygen therapy is helpful for pain, give the patient supplemental oxygen. Oxygen administration also maximizes the amount of oxygen in the patient’s blood stream; remember, they’re anemic, which means they don’t have enough blood cells to carry the oxygen their body requires. By giving them oxygen, we’re trying to do an end-run around the anemia and beat it using quality rather than quantity. Typically, I give my patients four liters/minute by nasal cannula.
You can consider pain meds. Bear in mind, most patients who have been diagnosed with sickle cell disease are already on pain meds, and require much larger doses of analgesic than we can give pre-hospital. Most EMS systems carry either fentanyl or morphine; hypothetically, some might carry diluted. If you decide that you should give some medication to take the edge off, the doses are:
- Fentanyl: 1-3 mcg/kg slow IV push, every 20-30 minutes as needed; pediatric dose is 1 mcg/kg slow IV push, also every 20-30 minutes as needed.
- Morphine: 2.5-5 mg slow IV push, every 5-10 minutes as needed; pediatric dose is 0.1-0.2 mg/kg slow IV push, every 5-10 minutes as needed.
- Dilauded: 1-4 mg slow IV push every 3-6 hours; pediatric dose is 1-2 mg slow IV push every 3-6 hours.
Provide symptomatic relief as needed. Put the patient in a position of comfort. If your patient is nauseous, consider giving them some Zofran (its better then cleaning vomit out of the back of the truck); dosage is 4 mg slow IV push.
Transport your patient to an appropriate facility; typically, patients with sickle cell disease know what sorts of treatments work best for them, and have history with one particular facility.
As always, if you have any questions or comments, feel free to share them in the comments or email me. Enjoy your weekend! I’ll be out on the streets of Gotham City for the next two days.