PHYSICAL PERFORMANCE IN PATIENTS WITH THALASSEMIA BEFORE AND AFTER TRANSFUSION

Patients with thalassemia who are on chronic transfusion programs have chronic ventilatory and cardiocirculatory abnormalities. We studied f low-volume curves, blood gas exchange, and cardiorespiratory responses to exercise in 12 patients with thalassemia major (TM) before and 24 hours after transfusions. Cardiorespiratory fitness was assessed with an exercise tolerance test on a cycle-ergometer. Ten healthy controls underwent the same protocol twice, first at baseline and then 24 hours later, without having had transfusions. We identified two subgr,ups o f patients with a questionnaire: 1) those with no history of airway di sease; and 2) those with a history of airway obstruction. Patients wit h no history of airway disease had normal baseline expiratory flows an d no posttransfusion changes; those with a history of airway obstructi on had lower pretransfusion expiratory flows rates and significantly d ecreased posttransfusion forced expiratory volume in 1 second (FEV(1)) and forced expiratory flow at 25-75% of forced vital capacity (FEV(25 -75)). As a group, TM patients had significantly lower pretransfusion cardiorespiratory function than controls; TM patients' maximum workloa d was 33% lower, maximum ventilation was 38% lower, maximum oxygen upt ake was 25.7% lower, oxygen pulse was 28.6% lower, dyspnea index was 1 0.6% lower, and ventilatory equivalent for oxygen was 27.1% lower than in control subjects. Although cardiorespiratory responses to exercise improved in both subgroups after transfusion, patients with a history of airways obstruction had a significant posttransfusion increase in their dyspnea index (P = 0.05) and further increased their already abn ormally high values of PETCO2 (43 mmHg). These results suggest that th e transfusion worsened relative hypoventilation at the maximum workloa d only in the subgroup with a history of airway obstruction. (C) 1996 Wiley-Liss, Inc.