Table of Contents
Causes of Acute Chest Syndrome. Primary causes of acute chest syndrome include:
- Infection. Infection from viruses or small atypical organisms (Chlamydia and Mycoplasma) is the most common cause of the oxygen deprivation that leads to acute chest syndrome.
- Blockage of blood vessels. Blockage in the blood vessels (called infarction) that cuts off oxygen in the lungs is another important cause of acute chest syndrome. Blockage may be produced by blood clots or fat embolisms. (Fat embolisms are particles formed from fatty tissue in the bone marrow that enter and travel through the blood vessels.)
- Asthma. Asthma can increase the frequency and pain of acute chest syndrome episodes in children. Children with sickle-cell disease who have frequent acute chest syndrome attacks should be evaluated for asthma.
Some cases of acute chest syndrome may result from treatments of the crisis, including from administration of opioids (which reduce oxygen) or excessive use of intravenous fluids. Other lung diseases may also trigger ACS.
Severity of Acute Chest Syndrome. The mortality rates for ACS are around 2% in children and 4% in adults. The syndrome and its long-term complications are the major causes of death in older patients. The longer a patient survives, the more repetitive sickle cell crises damage the chest and lungs.
The following destructive effects can occur:
- Damage in the chest area from recurrent episodes increases susceptibility to invading infections, even those that are ordinarily not harmful.
- Lung damage over time can lead to obstruction in the airways in lungs, causing asthma-like conditions.
Infections
Infections are common and an important cause of severe complications. Before early screening for sickle cell disease and the use of preventive antibiotics in children, 35% of infants with sickle cell died from infections. Fortunately, with screening tests for sickle cell now required for newborns, and with the use of preventive antibiotics and immunizations in babies who are born with the disease, the mortality rate has dropped significantly.
Infections in Infants and Toddlers with Sickle Cell Disease. The most common organisms causing infection in children with sickle cell disease include:
- Streptococcus pneumoniae (can cause pneumonia, blood infections, or meningitis)
- Haemophilus influenza (also a cause of pneumonia, blood infections, and meningitis)
Such infections pose a grave threat to infants and very young children with sickle cell disease. They can progress to fatal pneumonia with devastating speed in infants, and death can occur only a few hours after onset of fever. The risk for pneumococcal meningitis, a dangerous infection of the central nervous system, is also significant.
Infections in Children and Adults. Infections are also common in older children and adults with sickle cell disease, particularly respiratory infections such as pneumonia, kidney infections, and osteomyelitis, a serious infection in the bone. (The organisms causing them, however, tend to differ from those in young children.) Infection-causing organisms include:
- Chlamydia and Mycoplasma pneumoniae. These are the important infections in acute chest syndrome (see above).
- Gram-negative bacteria. This group of bacteria mostly infects hospitalized patients and can cause serious pneumonias and other infections.
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Review Date: 01/13/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
