Overview of the SCD guidelines and chapters

This report begins with a chapter on comprehensive health maintenance. Many children and adults with chronic diseases such as SCD do not receive the recommended preventive care provided to other children and adults.

Therefore, the guidelines summarize recommendations for health maintenance screening, testing, and immunizations as they apply to infants, children, adolescents, and adults with SCD. Generally speaking, recommendations for screening to facilitate primary and secondary prevention (e.g., asking a teen about smoking behavior or an adult woman about mammography, respectively) are often confused with recommendations for evaluating early symptoms of a disease or condition. For this and most other documents such as the recommendations of the U.S. Preventive Services Task Force (USPSTF), screening is considered testing or evaluation for a relatively common condition for which there is effective therapy prior to symptom recognition or during an asymptomatic phase. Generalized or universal screening is not recommended when existing therapies have not been shown to improve patient outcomes when implemented in this early presymptomatic phase. Information on screening and preventive care is important for all clinicians who work with individuals with SCD, including specialists who may serve as the continuity health care source for them.

Acute complications are common at all ages in individuals with SCD and are addressed in the chapter, Managing Acute Complications of Sickle Cell Disease. Recurrent acute pain crises (also known as vaso- occlusive crises) are the most common manifestation of SCD. These crises occur, usually without warning, when obstructed blood flow results in ischemic tissue injury and pain. The vascular occlusion, generally at the level of capillaries and post-capillary venules, results not only from an accumulation of adherent and sickled erythrocytes, but also from alterations involving the vascular endothelium and adhesive proteins in the plasma and on white blood cells and platelets. The management of acute pain is central to the care of individuals with SCD, yet pain is often poorly or inadequately addressed in all types of health care settings.

These guidelines include recommendations for rapid and effective pain management in people with SCD who present with such pain crises. Other significant acute complications addressed in this chapter include acute chest syndrome (ACS), stroke, splenic sequestration, acute renal failure, and cholecystitis. Neuropsychological, educational, and vocational impairment as well as common mental health issues such as depression and anxiety, which often accompany chronic illness, were considered beyond the scope of this guideline work.

Chronic complications of SCD may occur as a result of acute episodes or as chronic or recurrent events. Several of the most common of the chronic complications—including chronic pain, cholelithiasis, renal dysfunction, pulmonary hypertension, and retinal problems—are addressed in the fourth chapter, Managing Chronic Complications of Sickle Cell Disease.”

Each of the two major therapies used in individuals with SC hydroxyurea and chronic blood transfusions— are described in separate chapters (see “Hydroxyurea Therapy in the Management of Sickle Cell Disease, and Blood Transfusion in the Management of Sickle C’ell Disease). These are the only currently proven disease- modifying treatments for people with SCD. Both therapies are used in primary and secondary stroke prevention. Although neither has been shown to prevent all SCD-related organ damage, these treatment modalities can improve the quality of life for individuals with SCD. Treatment with hydroxyurea is underutilized for many people with SCA who could benefit from it. Blood transfusion therapy has at times been underutilized, overutilized, or prescribed inappropriately for both acute and chronic complications. These two chapters provide guidance regarding the appropriate use of these therapies for SCD.