Acute chest syndrome (ACS) is a potential complication of sickle cell disease (SCD). It involves the sudden onset of respiratory symptoms, which may lead to lung injury.
SCD is an inherited disorder that affects red blood cells. In people with SCD, red blood cells are crescent- or sickle-shaped instead of disc-shaped. This impairs their ability to carry oxygen and causes them to stick together.
A person with SCD may develop ACS if sickle cells stick together to form a blood clot in the small blood vessels within the lungs. Other possible causes include viral and bacterial lung infections and postsurgical complications.
The article below takes an in-depth look at ACS, including its causes, treatment, and prevention.
ACS is a serious and potentially life threatening condition involving sudden, severe respiratory symptoms and reduced blood oxygen levels. The condition is a potential complication of SCD.
According to the
- chest pain when breathing
- shortness of breath
- hypoxemia, which is the medical term for a low level of oxygen in the blood
Red blood cells contain a protein called hemoglobin, which binds to oxygen. Healthy red blood cells are disc-shaped, allowing them to move freely through blood vessels to deliver oxygen to the body’s tissues and organs.
In those with SCD, the hemoglobin inside red blood cells is abnormal and causes the cells to take on a characteristic sickle shape. These cells do not move through the blood vessels in the typical way and have a tendency to clump together.
A person with SCD may develop ACS as a result of sickle cells blocking a pulmonary blood vessel within the lungs. The Sickle Cell Disease Association of America notes that oxygen deprivation within the lungs can result in permanent lung damage. In some cases, ACS is life threatening.
Various factors can cause or contribute to ACS in SCD. Examples
- a lung infection, such as viral or bacterial pneumonia
- postsurgical complications
In children, doctors are able to identify the cause of ACS in about
According to the
Some additional factors that may increase a person’s risk of developing ACS include:
- respiratory infections
- smoking or exposure to secondhand smoke
- cold temperatures
A diagnosis of ACS relies on
Clinical symptoms that may indicate a diagnosis of ACS include:
- chest pain
- increased breathing effort
- chest sounds, such as coughing, wheezing, or rales
- fever above 38.5°C
Doctors may perform several tests to help rule out other illnesses and confirm a diagnosis of ACS. Examples include:
- Chest X-ray: This imaging test can help doctors identify pulmonary infiltrates, which are substances within the lungs, such as pus, blood, or protein.
- CT scan: Doctors can also use this test to look for the presence of new pulmonary infiltrates, which must be in
at least onelung segment for a person to receive a diagnosis of ACS.
- Blood gas analysis: This test measures oxygen levels in the blood. It can help doctors detect hypoxemia.
Without treatment, ACS may progress rapidly. Early treatment reduces the risk of complications and death.
Most people with ACS require hospitalization for careful respiratory monitoring and treatment. According to a
- IV fluids
- pain medication
- incentive spirometry, which is a technique to encourage deep breathing
- oxygen therapy
- respiratory support, such as using a ventilator for impaired breathing
- a blood transfusion
An individual cannot eliminate all risk factors for ACS. For example, people with certain genotypes of SCD have an increased risk of developing ACS. This is a nonpreventable risk factor.
However, people can take steps to reduce their risk of developing ACS. These include:
- taking precautions to reduce the risk of lung infections, such as staying up to date on vaccinations for pneumonia and influenza
- working with a doctor to develop an effective treatment plan for preventing asthma attacks, if asthma is present
- using an incentive spirometry device during hospitalization
A 2017 study notes that almost half of all ACS cases develop during hospitalization. In this study, the frequency of an ACS diagnosis decreased from 22% to 12% after implementing a protocol for using incentive spirometry during hospital stays.
Among people with SCD, ACS is the second most common cause of hospitalization and one of the most common causes of death. The condition has a
The outlook for people with ACS varies according to the nature and extent of any complications. Possible complications include:
- respiratory failure
- acute respiratory distress syndrome
- damage to the lung tissue
- severe pain
The condition can also be fatal.
According to the British Society for Haematology (BSH), a person who develops ACS will require follow-up treatment, which may include blood transfusions or the chemotherapy agent hydroxycarbamide, which is also known as hydroxyurea.
Acute chest syndrome is a complication of sickle cell disease. People with ACS develop sudden respiratory symptoms, including chest pain and breathing difficulties, along with coughing, wheezing, or rales.
A person with SCD may develop ACS as a result of sickle cells sticking together and forming a blood clot within a pulmonary blood vessel. The condition can also occur due to a viral or bacterial infection, asthma, or complications following surgery.
ACS is a severe and potentially life threatening condition. However, people who receive prompt treatment tend to have a much more favorable outlook. As such, it is important that people with SCD familiarize themselves with the symptoms of ACS so that they can recognize and act on the warning signs, should they occur.