The frequency, severity , and duration of these crises vary tremendously, however. No magic number exists to trigger treatment with hydroxyurea. The MSH study used a baseline of 3 painful vaso-occlusive crises per year as an enrollment criterion. This number is probably low for practical purposes. Patients who are hospitalized more than 4 or 5 times per year with painful vaso-occlusive crises are good candidates for hydroxyurea therapy.
Some patients have frequent painful crises that are managed at home with rest and analgesia.
In some instances, this pattern of illness may interfere with normal activities, such as work or school. Hydroxyurea should be considered as an option in the management of these patients as well. Acute Chest Syndrome. Patients who survive the syndrome are more likely to suffer a recurrent episode than are people who have never been affected. About half the patients in the MSH study were ACS survivors.