The Many Faces of Sickle Cell Pain

Sickle cell pain syndromes include a triumvirate of acute, chronic and neuropathic pain that occur sequentially or simultaneously with age. Unlike other diseases associated with pain such as osteoarthritis, rheumatoid arthritis, fibromyalgia and complex sympathetic dystrophy, sickle cell acute pain manifests itself in infancy and continues to recur throughout the life span of the affected patient. With age, acute pain retains its unpredictable relapses and spawns chronic pain as a new partner in the rhapsody of pain and suffering. Persistent chronic pain may evolve into neuropathic pain. Acute pain, however, dominates the clinical picture and requires urgent treatment with parenteral opioids in the ER and/or the hospital. Pain that occurs between the acute episodes is usually milder and treated at home with oral analgesics and is often referred to as chronic pain. Although this classification is somewhat arbitrary, nevertheless management of sickle pain is based on these assumptions.

The painful crisis often precedes the onset of other complications of the disease such as acute chest syndrome and acute multi-organ failure. About 50% of cases of acute chest syndrome occur in patients a few days after admission to the hospital with acute painful crises. Moreover, sudden death is known to occur during a painful crisis or shortly after discharge from the hospital. The frequency of acute painful crises in patients varies within and between individuals from rare occurrences during a lifetime to many times a month. About 30% of patients have rare or no pain episodes, 50% have occasional episodes and 20% have weekly or monthly episodes requiring medical attention. The frequency of pain episodes increases late in the second decade of life and decreases in frequency after the fourth decade for reasons that are not understood. Frequency of more than 3 episodes a year is associated with a reduced life expectancy. A small number of patients account for the majority of patients requiring healthcare for acute pain episodes.

Moreover, the resolution of the painful crisis is associated with rebound thrombocytosis, elevated levels of fibrinogen, orosmomucoid, RBC deformability and plasma viscosity indicating the presence of a hypercoagulable state that may cause recurrence of the crisis. About 20% of the patients who discharged from the hospital after the resolution of a crisis had recurrent crises that required treatment with parenteral opioids in the ER or hospital within one week after discharge.

Thus it seems that the prevention of the occurrence of painful crises and the early aggressive treatment to abort a painful crisis could prevent or minimize the complications consequent to poorly managed painful crises. Approaches that may achieve this goal will be presented.