Explain the pathophysiology of acute SCD crisis. Why is pain the predominate feature of acute crises?

Explain the pathophysiology of acute SCD crisis. Why is pain the predominate feature of acute crises?

SCD crises occur intermittently and are precipitated by fever, viral infection, and local trauma. Vaso-occlusive or pain crisis is the most common type of SCD crisis. It is caused by tissue hypoxia, causing ischemia and infarction, primarily in the bones, as well as in the lungs, spleen, or kidneys (Inusa et al., 2019). A plastic SCD crisis occurs when bone marrow erythropoiesis delays during acute infection secondary to human parvovirus, during which an acute erythroblastopenia can occur. A painful vaso-occlusive crisis causes excruciating pain in long bones, hands, feet, back, and joints. Hip pain can be caused by avascular necrosis of the femoral head (Inusa et al., 2019).

QUESTION 4

Scenario 2: Sickle Cell Disease (SCD)

A 15-year-old male with known sickle cell disease (SCD) present to the ER in sickle cell crisis. The patient is crying with pain and states this is the third acute episode he has had in the last 10-months. Both parents are present and appear very anxious and teary eyed. A diagnosis of acute sickle cell crisis was made.

Question

1. Discuss the genetic basis for SCD.

SCD is a genetic disease that is inherited through an autosomal recessive pattern. SCD represents all genotypes having at least one sickle gene, in which HbS makes up at least half the hemoglobin present. A patient with SCD usually has two HbS gene alleles, one inherited from each parent (Inusa et al., 2019). This results in 80-100% of the total hemoglobin being HbS. If a person with SCD gets children, each child inherits one of the two abnormal gene alleles and has a sickle cell trait. As a result, individuals with the sickle cell trait have one normal and one abnormal gene allele for hemoglobin, which are inherited (Inusa et al., 2019). Consequently, half of the hemoglobin chains they produce are abnormal.

QUESTION 5