Sickle Cell Disease in the Emergency Department: Atypical Complications and Management

Abstract

Sickle cell disease is the most common inherited blood disorder in the United States. This disorder of hemoglobin structure leads to a chronic hemolytic anemia and complex chronic disease manifested by sudden, severe, and life-threatening complications. These acute complications can occur in any organ system beginning in early childhood and lasting throughout life. The intermittent nature and acuity of these complications lend the emergency department to be an important site of care. The hallmark of sickle cell disease is the vasoocclusive painful event. Other more “typical” complications include fever, acute chest syndrome, priapism, and ischemic stroke. Children with sickle cell disease can also present with other “atypical” complications that can have devastating consequences if they are unrecognized. Detailed discussion of these “atypical” sickle cell disease complications, organized by organ system involved, will be the focus of this article.

The utility of routine reticulocyte count in uncomplicated vaso-occlusive events due to sickle cell disease

“…This change causes a compensatory erythropoiesis to replace the red blood cells (RBCs), and subsequently introduces reticulocytes (immature RBCs) into the system. Individual reticulocytes are transient, lasting only a few days before maturation, but reticulocytes serve as a marker for bone marrow function [5,6]. When bone marrow fails to respond with increased RBC production the reticulocyte count drops, this condition is known as transient red cell aplasia, aplastic crisis, or reticulocytopenia [3].…”

“…While the pathophysiology of SCD is complex, it is generally agreed that it is a chronic inflammatory condition which results in varying degrees of anemia, hemolysis, and pain which are intimately tied to the distinctive changes in erythrocyte morphology and intravascular behavior [2,3,6,9]. This change causes a compensatory erythropoiesis to replace the red blood cells (RBCs), and subsequently introduces reticulocytes (immature RBCs) into the system.…”

“…When reticulocytopenia occurs, SCD patients are at risk for life-threatening anemia secondary to precipitous drops in hemoglobin from a baseline anemic state. In its most severe form, reticulocytopenia can lead to cardiovascular collapse and death [3,5,6]. Reticulocytopenia is one of several SCD-specific complications that must be considered during evaluation for VOE and is typically suspected only after laboratory values consistent with the diagnosis are seen [2,3,6,8].…”

“…An uncomplicated VOE is defined as sickle cell pain without associated clinical indicators such as fever, acute chest syndrome, etc. The task of the Emergency Physician is to diagnose lifethreatening complications while also treating the VOE [2,6,8]. Because many of the more serious complications present similarly to VOE or have nonspecific signs and symptoms, a high index of suspicion must be maintained as there is an increased risk of morbidity and mortality associated with delays in diagnosis and treatment [2,8].…”

“…Approximately 1 in 400 or an estimated 100,000 African Americans in the US have SCD [2,6]. Individuals with SCD are routinely encountered in the clinical practice of Emergency Medicine (EM) [2,3].…”