What You Need to Know About Acute Chest Syndrome By Susan Hernandez, RN, CNN, BSN, and G. Elaine Patterson, RN-C, EdD, MA, Med, FPN-C Nursing2009, June 2009 Online: © 2009 by Lippincott Williams & Wilkins. All world rights reserved.

Acute chest syndrome (ACS) Potentially life-threatening complication of sickle-cell disease Potentially life-threatening complication of sickle-cell disease Can lead to respiratory failure Can lead to respiratory failure ACS is the leading cause of death among patients with sickle-cell disease ACS is the leading cause of death among patients with sickle-cell disease

Acute chest syndrome (ACS) Sickle-cell disease affects 80,000 Americans Sickle-cell disease affects 80,000 Americans Inherited disorder Inherited disorder Seen in equatorial African descent, Mediterranean, East Indian, Middle Eastern lineage Seen in equatorial African descent, Mediterranean, East Indian, Middle Eastern lineage

Background of sickle-cell disease Hemoglobin is oxygen-carrying protein in RBCs Normal adult hemoglobin is designated hemoglobin A. A patient with sickle-cell disease has abnormal hemoglobin (designated hemoglobin S), alone or in combination with other abnormal hemoglobin (typically hemoglobin C)

Background of sickle-cell disease Homozygous form of sickle-cell disease (hemoglobin SS, or sickle-cell anemia) is most severe, accounts for about 65% of cases Other types are sickle-cell thalassemia and sickle-cell disease with hemoglobin SC

Background of sickle-cell disease Signs and symptoms of sickle-cell disease are caused by elongated and rigid hemoglobin S Abnormal RBCs cause vascular occlusions, creating a cycle of more deoxygenation, sickling, and sluggish blood flow. This ultimately leads to ischemia and infarction in distal organs

Background of sickle-cell disease Abnormal hemoglobin also means RBC has shorter life (16 days vs. 120 for normal); leads to chronic intravascular and extravascular hemolysis 30 years ago, life expectancy was 14 years; now patients are living into 40s and 50s. Acute complications experienced by adult patients include vaso-occlusive crisis, ACS, renal failure

Vaso-occlusive crisis Low oxygen tension causes red blood cells (RBCs) to lose their round shape Low oxygen tension causes red blood cells (RBCs) to lose their round shape RBCs adhere to each other and the endothelium RBCs adhere to each other and the endothelium Causes pain, edema, fever, tissue ischemia Causes pain, edema, fever, tissue ischemia

Vaso-occlusive crisis Can be triggered by cold, excessive physical exertion, late pregnancy, infection, dehydration, emotional or mental stress Can be triggered by cold, excessive physical exertion, late pregnancy, infection, dehydration, emotional or mental stress Many patients hospitalized with vaso- occlusive crisis develop ACS Many patients hospitalized with vaso- occlusive crisis develop ACS

ACS defined Acute complication Acute complication New pulmonary infiltrate on chest X-ray New pulmonary infiltrate on chest X-ray Accompanied by at least one other new sign or symptom: fever, chest pain, coughing, wheezing, tachypnea Accompanied by at least one other new sign or symptom: fever, chest pain, coughing, wheezing, tachypnea

Possible causes of ACS Fat embolism - more common in adults, diagnosis confirmed with bronchoscopy, can progress to ARDS Fat embolism - more common in adults, diagnosis confirmed with bronchoscopy, can progress to ARDS Infection - Chlamydia pneumoniae, Mycoplasma pneumoniae Infection - Chlamydia pneumoniae, Mycoplasma pneumoniae Atelectasis - secondary to hypoventilation and poor respiratory effort with opioid use Atelectasis - secondary to hypoventilation and poor respiratory effort with opioid use

Diagnostics Chest X-ray is cornerstone of diagnosis Chest X-ray is cornerstone of diagnosis Hemoglobin levels Hemoglobin levels White blood cell count White blood cell count SpO 2 SpO 2

Caring for patients with ACS Improving oxygenation is first priority; supplemental oxygen may be given (incentive spirometry, nebulizer treatments) Improving oxygenation is first priority; supplemental oxygen may be given (incentive spirometry, nebulizer treatments) Administer opioids as ordered for pain; be careful of hindering respiratory effort Administer opioids as ordered for pain; be careful of hindering respiratory effort Continue to assess respiratory, neurologic, and oversedation status Continue to assess respiratory, neurologic, and oversedation status

Caring for patients with ACS Administer antibiotics as ordered Administer antibiotics as ordered Administer I.V. fluids to reverse dehydration and decrease blood viscosity Administer I.V. fluids to reverse dehydration and decrease blood viscosity Monitor intake and output to prevent fluid overload, which can worsen pulmonary status Monitor intake and output to prevent fluid overload, which can worsen pulmonary status

Treatment with hydroxyurea In patients with three or more episodes of ACS or acute painful sickle cell crisis in the previous year In patients with three or more episodes of ACS or acute painful sickle cell crisis in the previous year Used long-term to treat adults with moderate to severe sickle cell disease Used long-term to treat adults with moderate to severe sickle cell disease Has cytotoxic effects on RBCs Has cytotoxic effects on RBCs

Treatment with hydroxyurea Reduces WBCs and platelets, which reduces vascular injury, incidence of ACS Reduces WBCs and platelets, which reduces vascular injury, incidence of ACS Blood counts monitored every 2 weeks to establish optimal dose; decreases pain, increases hemoglobin, provides patient well-being Blood counts monitored every 2 weeks to establish optimal dose; decreases pain, increases hemoglobin, provides patient well-being Monitor for bone marrow suppression Monitor for bone marrow suppression

Treatment with hydroxyurea All patients should be on reliable contraception during therapy All patients should be on reliable contraception during therapy If patient’s condition continues to deteriorate, may need mechanical ventilation and RBC exchange therapy; done in ICU If patient’s condition continues to deteriorate, may need mechanical ventilation and RBC exchange therapy; done in ICU