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A Sickle Cell Primer

Priapism is the persistent, painful erection of the penis in post-pubertal SCD males not associated with sexual desire or relieved by orgasm; this condition is typically defined as lasting more than four to six hours.20 It is particularly common in younger males, with a yearly incidence of 6%-27%; the incidence of priapism in adults approaches 42%. In addition to being extremely painful, prolonged or repeated episodes can lead to impotence. Unfortunately, there are few well-studied treatment options; expert opinion suggests supportive care, including IV fluids, oxygen, ice, elevation, narcotic pain control, and even red cell transfusion in selected cases. Medications used include oral terbutaline, pseudoephedrine, and even stilboestrol, as well as injected phenylephrine, epinephrine, methylene blue, and tenecteplase (TNK-tPA). Surgical procedures attempted have included dorsal penile nerve block, cavernous aspiration, and the Winter procedure, which involves creating a vascular shunt from the corpora cavernosa to the glans penis. Urology consultation is often required for severe cases.

Several forms of eye disease occur in SCD patients. They can be broadly grouped into non-proliferative and proliferative diseases. In the former group, ocular trauma should be recognized as a visual emergency because patients are at risk for developing hyphema, occlusion of the trabeculae in the anterior chamber, and acute glaucoma. SCD patients of all ages are also at risk for acute retinal artery occlusion. Older SCD patients are at greatest risk, however, for a proliferative retinopathy similar to that seen in diabetes.21

Though red blood cell transfusions are helpful in many SCD patients, repeated transfusions can result in infections, immunologic consequences, and iron overload. (See Table 4, p. 41.) Infections that may result include parvovirus B19, HIV, human T-lymphotropic viruses (HTLV) I and II, and viral hepatitides. Immunologic consequences include alloimmunization, which occurs in up to 50% of SCD patients, and potentially fatal acute hemolytic reactions.22 Finally, patients who require frequent transfusions develop iron overload, which in turn causes fatigue, cardiomyopathy, diabetes mellitus, and cirrhosis. This necessitates iron chelators such as deferoxamine, which are disappointingly difficult to administer, requiring either IV or subcutaneous infusion over 12-24 hours daily. One bright note is the recent approval of deferasirox, an iron chelator that is taken orally once daily.

Conclusion

SCD is a complex genetic disease that affects multiple organs. Advances in medical care have increased longevity for SCD patients, and there are currently more adults living with the disease than ever before. Though patients often receive their care in academic centers, hospitalists may encounter them in routine practice. It is useful to have an understanding of the complications of SCD commonly seen in adults and to review the evidence base for care. TH

References

  1. Platt OS. Preventing stroke in sickle cell anemia. N Engl J Med. 2005 Dec 29;353(26): 2743-2745.
  2. Quinn CT, Rogers ZR, Buchanan GR. Survival of children with sickle cell disease. Blood. 2004 Jun 1;103(11):4023-4027.
  3. Platt OS, Brambilla DJ, Rosse WF, et al. Mortality in sickle cell disease. Life expectancy and risk factors for early death. [See comment.] N Engl J Med. 1994 Oct 13;331(15):1022-1023.
  4. Platt OS, Thorington BD, Brambilla DJ, et al. Pain in sickle cell disease: rates and risk factors. N Engl J Med. 1991 Jul 4;325(1):11-16.
  5. Platt OS, Thorington BD, Brambilla DJ, et al. Pain in sickle cell disease. rates and risk factors. [See comment.] N Engl J Med. 1991;325(24):1747-1748.
  6. Ballas SK. Pain management of sickle cell disease. Hematol Oncol Clin North Am. 2005 Oct;19(5):785-802.
  7. National Institutes of Health. The Management of Sickle Cell Disease. 4th ed. Washington, DC: National Heart, Lung, and Blood Institute; 2002. NIH publication No. 02-2117.
  8. Charache S, Terrin ML, Moore RD, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. [See comment.] N Engl J Med. 1995 May 18;332(20):1317-1322.
  9. Okpala IE. New therapies for sickle cell disease. Hematol Oncol Clin North Am. 2005 Oct;19(5):975-987, ix. Review.
  10. Johnson CS. The acute chest syndrome. Hematol Oncol Clin North Am. 2005;19(5):857-879, vi-vii.
  11. 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. 2000 Sep 14;342(25):1855-65.
  12. Platt OS. Preventing stroke in sickle cell anemia. N Engl J Med. 2005 Dec 29;353(26): 2743-2745.
  13. Ohene-Frempong K, Weiner SJ, Sleeper LA, et al. Cerebrovascular accidents in sickle cell disease: rates and risk factors. Blood. 1998 Jan;91(1):288-294.
  14. Adams RJ, McKie VC, Hsu L, et al. Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography. [See comment.] N Engl J Med. 1998 Jul;339(20):1477-1478.
  15. Adams RJ, Brambilla D. Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) Trial Investigators. Discontinuing prophylactic transfusions used to prevent stroke in sickle cell disease. [See comment.] N Engl J Med. 2005;353(26):2743-2745.
  16. Aguilar C, Vichinsky E, Neumayr L. Bone and joint disease in sickle cell disease. Hematol Oncol Clin North Am. 2005 Oct;19(5):929-941, viii. Review.
  17. Milner PF, Kraus AP, Sebes JI, et al. Osteonecrosis of the humeral head in sickle cell disease. Clin Orthop Relat Res. 1993;289:136-143.
  18. Castro O, Gladwin MT. Pulmonary hypertension in sickle cell disease: mechanisms, diagnosis, and management. Hematol Oncol Clin North Am. 2005;19(5):881-896, vii.
  19. Saborio P, Scheinman JI. Sickle cell nephropathy. J Am Soc Nephrol. 1999 Jan;10(1):187-192. Review.
  20. Vilke GM, Harrigan RA, Ufberg JW, et al. Emergency evaluation and treatment of priapism. J Emerg Med. 2004 Apr;26(3):325-329. Review.
  21. Charache S. Eye disease in sickling disorders. Hematol Oncol Clin North Am. 1996;10(6): 1357-1362.
  22. Wanko SO, Telen MJ. Transfusion management in sickle cell disease. Hematol Oncol Clin North Am. 2005 Oct;19(5):803-826, v-vi.
  23. Ohene-Frempong K. Indications for red cell transfusion in sickle cell disease. Semin Hematol. 2001 Jan;38(1 Suppl 1):5-13.
  24. Vichinsky EP, Haberkern CM, Neumayr L, et al. A comparison of conservative and aggressive transfusion regimens in the perioperative management of sickle cell disease. The Preoperative Transfusion in Sickle Cell Disease Study Group. [See comment.] N Engl J Med. 1995 Jul 27;333(4):206-213.
  25. Piga A, Galanello R, Cappellini, MD, et al. Phase II study of oral chelator ICL670 in thalassaemia patients with transfusional iron overload: efficacy, safety, pharmacokinetics (PK) and pharmacodynamics (PD) after 6 months of therapy. Blood. 2002;100:5a (abstract).
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