Objective: Recognize various Sickle cell situations and deal with them appropriately:

Sickle cell disease, in the USA, we know is a disease primarily affecting the African American patient.

It is due to a substitution of an amino acid (Valine for Glutamate at position 6) on the beta chain of hemoglobin.

Patients range from asymptomatic disease to acute chest/infarctive/embolic syndromes that are life threatening.

There are three main types of sickle cell disorders: 
Sickle cell anemia
Hemoglobin SC disease & (for sickle SC disease, remember that hematuria is more commonly found in it)
Sickle beta-thalassemia

Patients can develop many types of problems due to sickle cell disease.

• Anemia leads to fatigue
• Aplastic crisis. Pallor is an important sign. One should also be alert after a non-specific fever that may be due to Parvovirus B19. Parvovirus infection can precipitate Aplastic crisis.
• Hand-and-foot syndrome. This is usually one of the earliest signs due to infarction in the digital bones and blood vessels..
• Painful episodes called "sickling crisis" usually requires opiates to abort the pain.
• Severe infections. Due to sickling in the splenic vessels, the spleen slowly dies due to multiple infarcts. These patients have reduced immunity (because spleen introduces antigens to the lymphocytes to evoke good antibody response). Encapsulated organisms including Streptococcus pneumoniae and Hemophilus influenzae are particularly left unchecked.
• Splenic sequestration crisis. Spleen goes crazy and suddenly pools in and holds on to a large number of blood cells. Characterized by LUQ pain and abdominal pain.
• Stroke. This again is due to sickling and clogging up of capillaries.
• Acute chest syndrome. Fast or difficult breathing, chest pain, high fever, and coughing are symptoms of Acute Chest Syndrome.15% to 43% of sickle cell population will contract ACS.

• one can find hypoxia (paO2<60 and sats <90%). One would also find infiltrates in the lungs. Usually bilateral.

• once diagnosed with the acute chest syndrome, patients: should be given OXYGEN, hydration, broad-spectrum antibiotics, including a macrolide & should receive treatment with bronchodilators.
• if they are at high risk for complications (adults and those who have a history of cardiac disease and severe pain in the arms and legs), patients should be given early transfusions.

One drug that has improved the quality of life for sickle cell patients is Hydroxyurea. It is known to increase the level of fetal hemoglobin in the patient and prevents excessive deoxygenation. It also decreases the level of sickle hemoglobin.

Peculiar problems of sickle cell disease also include Salmonella osteomyelitis, proliferative retinopathy and avascular necrosis. It is important though to remember that the commonest type of osteomyelitis in a sickle cell patient still remains Staphylococcal (like general population).

Preventive strategies useful to a sickle patient include Vaccinations against H.influenzae and Pneumovax. Hepatitis B vaccine also may be useful because of the frequent transfusions they receive.