What is a sickle cell crisis, also known as Sickle Cell Disease (SCD) crisis?

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From the Guidelines

Sickle cell crisis, also known as Acute Chest Syndrome (ACS), is a life-threatening complication of Sickle Cell Disease (SCD) that requires early recognition and treatment, characterized by a significant decline in hemoglobin concentration and/or oxygen saturations (SpO2 < 94% or several percentage points below the patient’s baseline) 1.

Clinical Presentation

The clinical spectrum of ACS is variable, and patients may present with severe pain, respiratory distress, and hypoxia. The crisis can occur due to various factors, including infection, dehydration, or low oxygen levels, which cause the abnormal hemoglobin S to become rigid and sickle-shaped, leading to vascular occlusion and tissue ischemia.

Management

Management of ACS includes interventions such as antibiotics, oxygen, invasive and non-invasive respiratory support, bronchodilators, nitric oxide, and corticosteroids 1. Red cell transfusion, either simple or exchange, may be beneficial in improving patient outcomes, although the optimal approach is unclear. Patients with milder degrees of hypoxia may receive simple transfusions if their hemoglobin levels are low enough, whereas exchange transfusion is commonly reserved for more severe cases of ACS, such as those with rapidly falling hemoglobin concentration, severe hypoxia, or requirement for invasive respiratory support 1.

Key Considerations

Key considerations in managing ACS include:

  • Early recognition and treatment to prevent further complications
  • Close monitoring of hemoglobin concentration and oxygen saturations
  • Prompt administration of oxygen and respiratory support as needed
  • Consideration of red cell transfusion, either simple or exchange, based on individual patient needs and severity of disease 1

From the Research

Definition of Sickle Cell Crisis

A sickle cell crisis, also known as Sickle Cell Disease (SCD) crisis, is a condition where the abnormal sickle-shaped red blood cells cause episodes of pain and other complications due to vaso-occlusion and vascular damage 2.

Causes and Triggers of Sickle Cell Crisis

The crisis can be triggered by various factors, including:

  • Blood transfusions, which can increase blood viscosity and lead to sickle cell events, including pain crises, stroke, and acute pulmonary deterioration 3
  • Infections, which can cause a sudden increase in the sickling of red blood cells
  • Dehydration, which can cause the blood to become more concentrated and increase the risk of sickling
  • Cold weather, which can cause the blood vessels to constrict and increase the risk of sickling

Management of Sickle Cell Crisis

The management of sickle cell crisis includes:

  • Blood transfusions to correct anaemia and dilute out the number of red cells able to cause vaso-occlusion and vascular damage 2
  • Pain management using analgesics and other medications
  • Hydration to help prevent dehydration and reduce the risk of sickling
  • Rest and relaxation to help reduce stress and prevent triggering a crisis
  • Exchange transfusions, which involve removing the patient's red blood cells and replacing them with donor red blood cells, can be used to reduce the risk of complications and improve quality of life 4

Complications of Sickle Cell Crisis

The complications of sickle cell crisis include:

  • Acute chest syndrome, which is a life-threatening condition that requires urgent medical attention 2
  • Stroke, which can occur due to the sickling of red blood cells in the blood vessels of the brain 2
  • Acute pulmonary deterioration, which can occur due to the sickling of red blood cells in the blood vessels of the lungs 3
  • Delayed haemolytic transfusion reactions, which can be difficult to diagnose and manage, and potentially fatal 2

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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