Acute chest syndrome

Treatment of SCD is aimed at the preventing and/or minimizing acute and chronic complications, including infection, acute chest syndrome, neurologic damage, and the various forms of sickle cell crises, including vaso-occlusive pain, splenic sequestration, and aplastic crisis. The acute and chronic complications are summarized in Tables 65-2,65-3, and 65-4. 

May also reduce pain crisis and acute chest syndrome... 

Hydroxyurea reduced the frequency of hospitalizations and the incidences of pain, acute chest syndrome, and blood transfusions by almost 50% in a landmark trial in adult SCD patients with moderate to severe disease. Hemoglobin and HbF concentrations increased, and hemolysis decreased.22 A follow-up study demonstrated a 40% reduction in mortality over a 9-year period in patients continuing to receive hydroxyurea.23 Not all patients responded equally, so hydroxyurea may not be the answer for all patients. 

Hydroxyurea should be considered in SCD with frequent vaso-occlusive crises, severe symptomatic anemia, repeated history of acute chest syndrome (ACS), or other history of severe vaso-occlusive crisis (VOC) complications.6 The prevention of organ damage or reversal of previous damage has not been shown to occur with chronic use of hydroxyurea. 

Frequent pain crises, acute chest syndrome last year, priapism FH... 

Acute chest syndrome An acute respiratory complication of sicklecell disease characterized by chest pain, fever, and pulmonary infiltrates. 

HU significantly reduced the number of vasoocclusive crisis, hospitalization, rate of transfusion and, most importantly, the incidence of one of the deadly complications of this disease, called Acute chest syndrome [19]. 

Hammerman SI, Kourembanas S, Con-ca TJ, Tucci M, Brauer M, Farber H.W. Endothelin-1 production during the acute chest syndrome in sickle cell disease. Am J Respir Crit Care Med 1997 156 280-285. 

Hydroxyurea, a chemotherapeutic agent, has many effects on blood cells, including the stimulation of HbF production. It is indicated for patients with frequent painful episodes, severe symptomatic anemia, acute chest syndrome, or other severe vasoocclusive complications. The dosage should be individualized based on response and toxicity (Fig. 34-1). 

Patients with acute chest syndrome should receive incentive spirometry appropriate fluid therapy broad-spectrum antibiotics including a mac-rolide or quinolone and, for hypoxia or acute distress, oxygen therapy. Steroids and nitric oxide are being evaluated. 

Transplant and allergy also intersect in indirect ways. Acute chest syndrome is a frequent complication in patients with sickle cell disease and has been recently reported to be exacerbated or precipitated by asthma and respiratory allergies. Since SCT can halt this pulmonary destruction process, ongoing investigation at our and other institutions is focused on determining genetic and cytokine pathways and modulators for asthma in sickle cell disease. 

Over the next several years, she had recurrent episodes of reactive airway disease. At the age of 4 years, she had a life-threatening episode of acute chest syndrome requiring admission to the intensive care unit and exchange transfusion. She was subsequently transfused with red blood cells monthly for 6 months to prevent recurrence. Two years later, she was again admitted to the intensive care unit with acute chest syndrome. During this admission, she was found to have Streptococcus pneumoniae sepsis and pneumonia. She again received RBC transfusions monthly for 6 months. Following this course of transfusion therapy, she was offered therapy with hydroxyurea, but this therapy was never instituted. 

Vichinsky EP, Neumayr LD, Earles AN, et al. Causes and outcomes of the acute chest syndrome in sickle cell disease. National Acute Chest Syndrome Study Group. N Engl J Med 342 1855-1865,2000. 

Several paediatric and adult trials have reported decreases in pain, the incidence of acute chest syndrome and overall mortality with the use of hydroxycarbamide. 

Hydroxyurea (hydroxycarbamide) is the first widely available and affordable agent that provides real benefit. It acts by perturbing the maturation of erythrocytes and promoting HbF production. The mode of action may be more complex reduction in leukocyte counts may reduce vaso-occlusive events reduced red cell and endothelial adhesiveness may be a direct effect. Beneficial effects have been seen in adults, children and mfants. Long-term hydrox5mrea (hydroxycarbamide) (at close to myelotoxic doses) raises FIbF to 15-20% and reduces the frequency of hospitalisation, pain, acute chest syndrome and blood transfusion. Neurological complications e.g. stroke, may not be reduced. Some 10-20% of patients will fail to respond due to the condition of the bone marrow, or genetic effects (see also p. 607,613). 

The cost to society of sickle cell disease is high in terms of human suffering and in the financial burden of providing treatment to alleviate the pain and symptoms of the afflicted individnals and the loss of income to the individnals and their families and communities. Health problems due to sickle cell disease include chronic anemia, vaso-occlnsive crises, splenic sequestration, acute chest syndrome, stroke, splenic and renal dysfunction, and snsceptibility to bacterial infections (2,5,12). In Africa, treatments for sickle cell disease are limited... 

Some of the clinical consequences in SS disease include megaloblastic erythropoiesis, aplastic crisis, stroke, bone pain crisis, proneness to infection particularly by Pneumococcus, Salmonella, and Haemophilus due to hypos-plenism and acute chest syndrome. Prophylactic use of penicillin and antipneumococcal and Haemophilus vaccines has aided in the management of life-threatening infectious complications of SS disease. Neonatal screening has been used in the identification of infants with sickle cell disease so that risk of infection can be modulated by appropriate immunizations and penicillin prophylaxis. The acute chest syndrome characterized by chest pain is due to clogged pulmonary capillaries in a small number of studies, patients have been treated with inhaled nitric oxide, which dilates blood vessels with clinical improvement. 

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