Villa M P, Rotili P L, Santamaria F, Vania A, Bonci E, Tancredi G, Ronchetti R
4th Cattedra di Clinica Pediatrica, Università La Sapienza, Rome, Italy.
Pediatr Pulmonol. 1996 Jun;21(6):367-72. doi: 10.1002/(SICI)1099-0496(199606)21:6<367::AID-PPUL4>3.0.CO;2-I.
Patients with thalassemia who are on chronic transfusion programs have chronic ventilatory and cardiocirculatory abnormalities. We studied flow-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 subgroups of patients with a questionnaire: 1) those with no history of airway disease; and 2) those with a history of airway obstruction. Patients with no history of airway disease had normal baseline expiratory flows and no posttransfusion changes; those with a history of airway obstruction had lower pretransfusion expiratory flows rates and significantly decreased posttransfusion forced expiratory volume in 1 second (FEV1) and forced expiratory flow at 25-75% of forced vital capacity (FEV25-75%). As a group, TM patients had significantly lower pretransfusion cardiorespiratory function than controls; TM patients' maximum workload was 33% lower, maximum ventilation was 38% lower, maximum oxygen uptake was 25.7% lower, oxygen pulse was 28.6% lower, dyspnea index was 10.6% 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 abnormally high values of PETCO2 (43 mmHg). These results suggest that the transfusion worsened relative hypoventilation at the maximum workload only in the subgroup with a history of airway obstruction.
接受长期输血治疗的地中海贫血患者存在慢性通气和心肺循环异常。我们研究了12例重型地中海贫血（TM）患者输血前及输血后24小时的流量-容积曲线、血气交换和运动时的心肺反应。通过在功率自行车上进行运动耐力测试来评估心肺适能。10名健康对照者按照相同方案进行了两次测试，第一次在基线水平，第二次在24小时后，且未输血。我们通过问卷调查将患者分为两个亚组：1）无气道疾病史者；2）有气道阻塞病史者。无气道疾病史的患者基线呼气流量正常，输血后无变化；有气道阻塞病史的患者输血前呼气流量率较低，输血后1秒用力呼气量（FEV1）和用力肺活量25%-75%时的用力呼气流量（FEV25-75%）显著降低。总体而言，TM患者输血前的心肺功能显著低于对照组；TM患者的最大工作量低33%，最大通气量低38%，最大摄氧量低25.7%，氧脉搏低28.6%，呼吸困难指数低10.6%，氧通气当量比对照组低27.1%。尽管输血后两个亚组的运动心肺反应均有所改善，但有气道阻塞病史的患者输血后呼吸困难指数显著升高（P = 0.05），且其本来就异常高的呼气末二氧化碳分压（PETCO2）（43 mmHg）进一步升高。这些结果表明，输血仅在有气道阻塞病史的亚组中使最大工作量时的相对通气不足恶化。
