From the Guidelines
Sickle cell crises are acute complications of sickle cell disease that occur when abnormally shaped red blood cells block blood vessels, causing pain and organ damage, with acute chest syndrome (ACS) being one of the leading causes of death in patients with SCD, as stated in the 2020 American Society of Hematology guidelines 1. The clinical spectrum of ACS is variable, and although there are no specific markers of disease severity, a significant decline in the hemoglobin concentration and/or oxygen saturations (SpO2 # 94% or several percentage points below the patient’s baseline) can suggest severe disease 1. Some key points about sickle cell crises include:
- The most common type is the vaso-occlusive crisis, characterized by severe pain in the chest, abdomen, joints, or bones, often requiring strong pain medications
- Other types include acute chest syndrome (resembling pneumonia), splenic sequestration (blood trapped in the spleen), and aplastic crisis (temporary halt in red blood cell production)
- Treatment typically involves pain management with opioids, hydration with IV fluids, oxygen therapy if needed, and sometimes blood transfusions, with the benefit of red cell transfusion for ACS described in case series and observational studies, but whether simple or exchange transfusion results in improved patient outcomes is unclear 1. The management of ACS may include antibiotics, oxygen, invasive and non-invasive respiratory support, bronchodilators, nitric oxide, and corticosteroids, with simple transfusions often used for milder degrees of hypoxia and red cell exchange (RCE) commonly reserved for more severe cases of ACS 1.
From the Research
Types of Sickle Cell Crises
- Acute recurrent painful crises: the hallmark of the disease and the most common cause of hospitalization and treatment in the emergency department 2
- Chronic pain syndromes: associated with or accompany avascular necrosis and leg ulcers 2
- Neuropathic pain: not well studied in patients with sickle cell disease but has been modeled in the transgenic sickle mouse 2
Characteristics of Sickle Cell Crises
- Recurrent episodes of pain that range in severity from mild to severe, usually occur very abruptly and are often localized around joints 3
- Caused by vaso-occlusions in the vascular bed of the bone marrow, leading to necrosis, edema and increased pressure 3
- Evolve through 4 phases: prodromal, initial, established, and resolving 2
- Each acute painful episode is associated with inflammation that worsens with recurrent episodes, often culminating in serious complications and organ damage 2
Management of Sickle Cell Crises
- Guidelines for management have been produced, but are often not followed, and acute care in emergency departments and on acute medical wards is suboptimal 4
- Effective analgesia with morphine or morphine analogues is often required 3
- Treatment should be based on the pathophysiologic mechanisms of sickle cell pain, rather than borrowing guidelines from other nonsickle pain syndromes 2
- Hydroxyurea can be used to increase fetal hemoglobin levels and reduce the frequency and severity of pain crises 5
- Bone marrow or stem cell transplants can cure select individuals with severe SCD 5