POTD- Sickle Cell

In todays POTD were gonna talk Sickle Cell Anemia. Why? Because we don't see it very often at maimo but complications related to SCA present pretty commonly to most EDs... and because I randomly had about 10 Rosh review questions in row about it...

We all know the basics at least vaguely from step 1
  • 100,000 ppl in US, 2mi Carriers. Mc African, Mediterranean, Indian and Middle Eastern
  • AR exchange of Valine for glutamic acid in the B global chain changing the structure so that when deoxygenated it sickles
  • Diagnosed on newborn screen or after 4mos of life (Why? because of the decline in fetal Hb)
So lets talk some of the more common presentations:
  • Remember basic workup should include CBC and retic count plus specific labs/imaging for sx..
  • RFs: High flow velocity on dopler, low Hb, high WBC, HTN, hx TIA, hx ACS
  • Imaging: PEDS: NEED MRI w/ diffusion as CT can miss and early infarct!
  • Trx:
    • Adult: tPA v intraaterial thrombolysis
    • Peds: IVF and exchange transfusion with goal of HgbS < 30%
      • Target MAX HG of 13 or can cause recurrent ischemia
      • 30% have hemorrhagic transformation
      • *** Control BP with labetolol to goal of 50-95th% for age
Acute Chest Syndrome:
  • Fever, cough cp, hemptysis , dyspnea
  • CXR: new infiltrate
  • Some Guidelines:
    • All pts should be hospitalized for pain control and monitoring
    • Trx with IV cephalosporin + oral macrolide
    • Goal O2 >95%
    • Transfuse if Hb is >1g/dL below baseline
    • Higher mortality in adults so should go to ICU as can progress to ARDS
Pain: The somewhat dreaded hard to control complain,
1st and foremost be sympathetic and treat accordingly, they often have their own pain plans and can provide some insight into what works.
  • Think about these dangerous causes and don't just dismiss as "drug seeker"
    • CP: Think ACS v ARDS Vhighoutpt heart failure v PNA v pain crisis
    • HA: Think stroke v meningitis v CVST v ocular pathology
    • Arthralgias: Septic arthritis v actor trauma v avascular necrosis
    • Abd Pain: Splenic sequestration v acute intrahepatic sequestration v pain crisis 2/2 occlusion of mesentery v renal infarct
  • Treating Pain:
    • Should get analgesia w/in 30min of arrival
    • Use NSAIDs as adjunct
    • Follow pts pain plan if available
    • Avoide Meperidine
  • MCC? Viral, But always think of the encapsulated organisms (S pneumonia, HiB, non-typhi Salmonella, Mycoplamsa, C. Pneumonia, Yersinia) which are higher risk in these pts d/t functional asplenia
  • Prophylactic PCN for pts 2mo-5years- check compliance, PCV at 2mos, Influenza vaccine at 6mos
    • Bactermia, Pneumonia--> S pneumonia
    • UTI--> EColi
    • Osteo--> Salmonella
    • TRX: Ceftriaxone +Vanco
  • Some great guidelines from CHOP for pediatric fever: http://www.chop.edu/clinical-pathway/sickle-cell-disease-with-fever-clinical-pathway
A couple others...
RUQ pain: Acute chole v cholelithiasis v acute intrahepatic cholestasis v acute sickle hepatic crisis v acute hepatic sequestration
  • CBC, LFTs, Coags, imaging- CT v US
  • Trx of AHS is simple v exchange transfusion
Splenic Sequestration:
  • Acute drop in hgb >2, splenomegaly, reticulosytosis, intrascaular volume depletion
  • Rapid progress to shock and death
  • MC kids 10-27 mos old
  • IVF + transfusion ( simple v exchange)
and don't forget the beloved board question... Aplastic Crisis... from what Parvovirus B19
  • Pallor, tachycardia, supportive care unless retic < 1-2 then simple transfusion.
A great summary chart!

AND FINALLY... When to transfuse:
JAMA 2014 Sep- Manamge of SCD: summary of the 2014 evidence-based report by expert panel members.  https://www.ncbi.nlm.nih.gov/pubmed/25203083
CHOP clinical guidelines