Sickle Cell Disease Oversimplified II: Sickle Cell Crisis
Hello, welcome to the second instalment of our sickle cell oversimplified series. In part one, we heard the sad but true story of brilliant Kweku, who spent his growing years frequenting hospital wards. The question, why? The answer, Sickle Cell Crisis! Three words that strike fear and panic in the hearts of relatives and patients of sickle cell disease alike.
What is Sickle cell crisis?
One RBC (Red Blood Cell – that blood cell that kind of looks like a doughnut and carries oxygen we mentioned previously) contains about 270 million haemoglobin. The haemoglobin is a marvellous work of art. It is designed in a highly specific conformation to allow it to carry out its job – transporting oxygen – perfectly. When there are no mutations, none of these 270 million haemoglobins interact with each other (only if our nosey neighbours were like this). A different story, however, is told in the presence of HbS mutations. HbS is like that boyfriend who can’t let go of his bros. Once you (oxygen) are out of town, HbS quickly invites the bros (other HbS molecules) home. These HbS bro molecules interact with each other and form rigid structures (polymers) which give the RBCs their characteristic sickle shape.
These sickling of RBCs, from time to time, result in sudden, occasionally severe and life-threatening events known as ‘crisis.’ Throughout their lifetime, people with the disease are plagued by these crises; some more commonly than others.
The crises may be largely grouped into 4:
You know how it’s not such a big deal when you drop a seed through the sink but dropping a coin is going to clog the drains? Well, that’s what happens with a vaso-occlusive crisis.
The shape of regular RBCs allows them to move around easily through blood vessels. However, rigid sickle cells tend to get stuck in small blood vessels. This may occur in any organ of the body and leads to severe pain and/or dysfunction.
The most common manifestations of vaso-occlusive crisis are acute (rapid-onset) painful events. Pain is usually in the long bones of the arms or legs but may occur in smaller bones of the hands or feet in infancy (remember dactylitis?) or in the abdomen. When these vaso-occlusive events occur in the thigh bone, they may lead to an inadequate supply of blood to the head of the thigh bone. This lack of proper blood supply causes the head of the thigh bone to eventually die off, leading to the shortening of the limb (leg). Professionals dub this phenomenon as avascular necrosis of the femoral head.
Another very important manifestation of the vaso-occlusive crisis is priapism. This is the sudden onset of painful, unrelenting erections when sickle cells block the blood vessels of the penis. It usually occurs in males between 6 and 20 years old and can lead to impotence.
This is by far the least common crisis in SCD. We already know the sickle cell breaks down faster than the normal RBC. In a haemolytic crisis, there is an acute acceleration of this process. This leads to anaemia (drop in blood levels) and jaundice (yellowing of the eyes). It is more common when there is an associated G6PD deficiency.
In an aplastic crisis, a virus known as Parvovirus B-19 attacks the building blocks of RBCs in the bone marrow and induces transient failure of the RBCs to develop fully or to function normally. Therefore, in this case, there is also anaemia. However, this anaemia is due is a defect from the production line unlike in haemolytic crisis.
Splenic Sequestration crisis
This occurs when there is pooling of the RBCs within the spleen. There is a drop in blood volume and the spleen becomes enlarged.
How do I know I have a sickle cell crisis?
The most common symptom is pain which is felt commonly in the long bones (arms and legs) and in other places such as the belly, chest and lower back. It can come on suddenly and be mild or severe. The pain can last for a few hours, a few days, or sometimes longer. The duration and severity of pain vary among different people and different crises. While some people experience crises occasionally, others may have them every month.
Other symptoms (mostly symptoms of anaemia) include:
- Breathing problems
- Extreme tiredness
- Headache or dizziness
- Lethargy (Generalized body weakness)
- Jaundice (Yellowish colour of skin/sclera)
What triggers a sickle cell crisis?
Sickle cell crises are usually precipitated by factors such as;
- High altitude (think mountain climbing or a flight)
- Hypoxic conditions (Low oxygen such as from intense bursts of exercise, running swimming, etc.)
- Dehydration (not drinking enough water)
- Infection/ illness
- Sudden change in temperature
- Rigorous exercise
- Stressful emotional and physical conditions.
How can I prevent a Crisis?
Though you can’t always prevent a crisis, there are ways of lowering the odds:
- Take all medications recommended by your doctor.
- Try to drink lots of water (about 3 litres daily), especially in hot weather or during exercise.
- Wash your hands often (and carry a hand sanitizer) to help prevent infection
- Avoid strenuous exercise (Stick to light or moderate exercise)
- Dress warmly in cold weather, and carry an extra layer just in case.
- Limit time spent at high altitudes (Avoid mountain climbing or flying in an unpressurized cabin (non-commercial flights) above 10,000 feet.)
- Get all recommended vaccinations.
- Take a folic acid supplement, which your bone marrow needs to make new RBCs.
- Learn to manage stress properly or seek professional assistance.
- Don’t smoke, drink alcohol, or use drugs.
How is it treated?
Treatment depends on the severity of pain and how long it lasts. Occasionally, you can manage pain crisis at home by drinking lots of fluids and taking non-prescription, or over-the-counter, pain relievers such as ibuprofen. Other times, however, the pain requires stronger pain relief medicine that is prescribed by a doctor. Some painful episodes may need intravenous fluid therapy and powerful pain medicines, such as morphine, to ease the pain.
Here at Thetropicalmd, we advise that you report all episodes of crises to you family doctor, attend regular sickle cell clinics and prepare in advance for a crisis by creating a pain management plan with your doctor.