The acute chest syndrome is a

vaso-occlusive crisis A vaso-occlusive crisis is a common painful complication of sickle cell anemia in adolescents and adults. It is a form of sickle cell crisis. Sickle cell anemia – most common in those of African, Hispanic, and Mediterranean origin – leads to s ...

of the

pulmonary The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of th ...

vasculature The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

commonly seen in people with

sickle cell anemia Sickle cell disease (SCD) is a group of blood disorders typically inherited from a person's parents. The most common type is known as sickle cell anaemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blo ...

. This condition commonly manifests with a new opacification of the lung(s) on a chest

x-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

Signs and symptoms

The crisis is a common complication in sickle-cell patients and can be associated with one or more symptoms including fever, cough, excruciating pain,

sputum Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). In medicine, sputum samples are usually used for a naked eye examination, microbiological investigation of respiratory infections and cytological investigations ...

production,

shortness of breath Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing disc ...

, or low oxygen levels.

Cause

Acute chest syndrome is often precipitated by a lung infection, and the resulting

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

and loss of oxygen saturation leads to further sickling of red cells, thus exacerbating pulmonary and systemic hypoxemia, sickling, and vaso-occlusion.

Diagnosis

The diagnosis of acute chest syndrome is made difficult by its similarity in presentation with pneumonia. Both may present with a new opacification of the lung on chest x-ray. The presence of fevers, low oxygen levels in the blood, increased respiratory rate, chest pain, and cough are also common in acute chest syndrome. Diagnostic workup includes chest x-ray, complete cell count, reticulocyte count, ECG, and blood and sputum cultures. Patients may also require additional blood tests or imaging (e.g. a CT scan) to exclude a heart attack or other pulmonary pathology.

Prevention

Hydroxyurea Hydroxycarbamide, also known as hydroxyurea, is a medication used in sickle-cell disease, essential thrombocythemia, chronic myelogenous leukemia, polycythemia vera, and cervical cancer. In sickle-cell disease it increases fetal hemoglobin and d ...

is a medication that can help to prevent acute chest syndrome. It may cause a low white blood cell count, which can predispose the person to some types of infection.

Treatment

Broad spectrum antibiotics to cover common infections such as ''

Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They are ...

'' and

mycoplasma ''Mycoplasma'' is a genus of bacteria that, like the other members of the class ''Mollicutes'', lack a cell wall around their cell membranes. Peptidoglycan (murein) is absent. This characteristic makes them naturally resistant to antibiotics ...

, pain control, and

blood transfusion Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mo ...

. Acute chest syndrome is an indication for exchange transfusion.

Bronchodilators A bronchodilator or broncholytic (although the latter occasionally includes secretory inhibition as well) is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs ...

may be useful but have not been well studied.

Prognosis

It may result in death, and it is one of the most common causes of death for people with sickle cell anemia.Kumar, Abbas, Fausto. Robbins and Cotran: The Pathologic Basis of Disease, Page 631

References

External links

{{DEFAULTSORT:Acute Chest Syndrome Red blood cell disorders Syndromes