Hemolytic Anemia


https://sites.google.com/a/imreference.com/main/hemolytic-anemia/Screen%20Shot%202015-10-30%20at%205.16.24%20AM.pngHarrison's Principles of Internal Medicine, 19e; 129. Hemolytic Anemias and Anemia Due to Acute Blood Loss
SSA and its complications
  • Pulmonary Complications:
    • From a clinical perspective, pulmonary complications — namely, the acute chest syndrome and pulmonary hypertension — are the most common causes of death in patients with sickle cell disease 
    • Basic pathogenesis of Sickle Cell Complication is divided into 2 groups.
      • the vaso-occlusive process, and
      • the deleterious effects of intravascular hemolysis on endothelial-cell and vascular function 
        • Note: These complications including Pulmonary HTN, Leg Ulceration, Priapism also occur in other hemolytic diseases. 

    • Pulmonary Complications of Sickle Cell Disease NEJM 2008
    • Fat from bone marrow, which is typically infarcted during acute pain episodes, embolizes to the lungs and, in its most extreme form, fat embolism syndrome may involve the brain, kidneys, and the liver15 with substantial mortality. It may be that, as with trauma, fat emboli occur commonly with acute bone infarction, and clinical severity is a reflection of site and volume of marrow infarction. 
      Blood. 2011;117(20):5297-5305 
    • 2 common causes of ACS, Chlamydia pneumoniae and Mycoplasma pneumoniae, are associated with a severe clinical course in children with sickle cell disease-rather than the “walking pneumonia” that typifies infection in othersMacrolide therapy, or use of another antibiotic to which atypical bacteria are susceptible, is clearly indicated in patients diagnosed as having ACS, regardless of their age or location when diagnosed. 
    • Parvovirus B19 infection, the common cause of aplastic crisis, is a notable viral cause of ACS, perhaps via its association with bone marrow infarction/necrosis and potentially PFE. 

    • Pulmonary Complications of Sickle Cell Disease NEJM 2008
SSA and Acute Chest Syndrome 
    • tachypnea is sometimes overlooked and misreported by house staff and nurses 

    • Radiographic changes may lag behind clinical findings, and therapy should commence once a clinical diagnosis is made. 
    • It is important to note that nearly 50% of ACS occurs in patients hospitalized for other causes (notably pain) 
    • continuously monitored by pulse oximetry to detect any decrease in oxygenation. 
    • Because of a right-shifted oxygen dissociation curve and the increased presence of hemolysis-related carboxyhemoglobin, pulse oximetry may indicate spurious oxygen saturation values  and, particularly because some children may have baseline hypoxemia, treatment of ACS should not be initiated solely on the basis of low pulse oximetry readings. 
    • Blood. 2011;117(20):5297-5305 
    • Although 20% of patients examined at the bedside for forced expiratory volume in 1 second had improvement after bronchodilator therapy,we do not routinely give bronchodilators to patients without asthma. We will give a therapeutic trial if wheezing is present; we do not, however, use a bronchodilator as adjunctive treatment of all ACS, as has been recommended on the basis of a favorable experience at a single institution 
    • Children with asthma may be at increased risk for ACS, and a diagnosis, with therapy to control exacerbations in children with sickle cell disease, is recommended 
    • Bellet et al  demonstrated that incentive spirometry, given at a prescribed regimen of 10 puffs every 2 hours while the patient is awake, significantly and substantially reduced nosocomial ACS in patients hospitalized for chest or back pain 
    • When one administers opioids, it is tricky in patients with chest and back pain to achieve analgesia adequate to reduce respiratory splinting while avoiding respiratory depression. The nonsteroidal anti-inflammatory drug ketorolac is not a respiratory depressant and may provide analgesia comparable with opioids; however, ketorolac is relatively expensive, can be used for only 5 days 
    • Screening for M pneumoniae infection with the use of a bedside test for cold agglutinins offers good specificity if agglutination persists after rewarming and repeat cooling of the specimen. 
    • Hydration is generally given intravenously at approximately a maintenance rate.  Patients with ACS may be at risk for pulmonary edema, especially if aggressive hypotonic fluid management is given 
    • In a retrospective review, patients admitted with ACS and transfused within 24 hours had a prompt recovery relative to those who were not. transfusion therapy increases oxygenation beyond that attributable to the increase in hemoglobin alone 

    • Blood. 2011;117(20):5297-5305 
    • SSA and pulmonary htn
    • Although a more traditional definition of pulmonary hypertension would be a tricuspid regurgitant jet velocity of 3.0 m per second or more, values between 2.5 and 2.9 m per second are associated with an increased risk of death among patients with sickle cell disease. 
    • It is clear that pulmonary pressures rise acutely during vaso-occlusive crisis and even more so in the acute chest syndrome . Acute pulmonary hypertension and right heart dysfunction are major coexisting conditions in the acute chest syndrome 
    • In pulmonary hypertension — both idiopathic and the type associated with sickle cell disease — the level of brain natriuretic peptide correlates with the degree of pulmonary vascular resistance and the risk of death (risk ratio, 5.1; 95% CI, 2.1 to 12.5; P<0.001) 
    • Approximately 60% of catheterized patients with a tricuspid regurgitant jet velocity that is 3.0 m per second or more meet the definition of pulmonary-artery hypertension, indicating that vasculopathy primarily involves the pulmonary arterial system 
    • In the other 40% of patients, the left ventricular end diastolic pressures are greater than 15 mm Hg, indicating a component of left ventricular diastolic dysfunction. 
    • Pulmonary Complications of Sickle Cell Disease NEJM 2008
    • How I treat acute chest syndrome in children with sickle cell disease Blood 2011

  • Neurology Complications:
  • Clinical Immunology
    • A concern specific to patients with sickle cell disease who undergo transfusion is the delayed hemolytic transfusion reaction/ hyperhemolysis syndrome.89 Within 6-10 days of transfusion, patients present with fever, hemoglobinuria, and often pain. Because of “bystander” hemolysis, the hemoglobin concentration is frequently decreased to less than pretransfusion levels, and additional transfusion may exacerbate the destruction of transfused and autologous red cells even if completely matched phenotypi- cally. Although presumed to be allo- or auto-immune, new antibodies often are not detectable. Treatment with intravenous immunoglobulin, corticosteroids, and recombinant erythropoietin has been effective .  Blood. 2011;117(20):5297-5305 
    • Red blood cell alloimmunization in sickle cell disease: pathophysiology, risk factors, and transfusion management Blood 2011
  • Liver Disease
    • What does Sickle hepatopathy entail?
      • Sickle hepatopathy is an umbrella term covering a wide variety of pathologies, both acute and chronic, that occur as a consequence of the sickling process, including gallstone disease, hypoxic liver injury, hepatic sequestration, venous outflow obstruction, viral hepatitis (especially in the multitransfused patient), hepatic crises, and SCIC. Some clinicians, however, consider sickle hepatopathy as a term reserved for SCIC. 
    • How is SC intrahepatic cholestasis (SCIC) and its pathogenesis?
      • Clinically, it comprises severe right upper quadrant pain, acute hepatomegaly, coagulopathy, extreme hyperbilirubinemia (mainly conjugated in contrast to the typical unconjugated hyper- bilirubinemia seen in hemolytic anemias), but moderately elevated liver enzymes, with occasional progression to acute hepatic failure. 
      • Pathologically, it involves sickling within hepatic sinusoids leading to vascular stasis and localized hypoxia. The hypoxic injury results in ballooning of the hepatocytes causing a direct back pressure effect, with resultant intracanalicular cholestasis, its defining feature. 

    • Summary: 
    • How we treat sickle hepatopathy and liver transplantation in adults Blood 2014
  • Treatment:

Microangiopathic HA


AIHA : Diagnosis 
Blood. 2010;116(11):1831-1838 

Blood. 2010;116(11):1831-1838

Blood. 2010;116(11):1831-1838

Blood. 2010;116(11):1831-1838