Lands L C, Woods S, Katsardis C, Desmond K, Coates A L
Respiratory Medicine Service, McGill University-Montreal Children's Hospital Research Institute, Quebec, Canada.
Pediatr Pulmonol. 1991;11(4):340-4. doi: 10.1002/ppul.1950110411.
Previous pulmonary function studies in subjects with thalassemia major (TM) who were on regular transfusion programs have demonstrated results ranging from small airway obstruction to a restrictive pattern. Ten subjects with TM were studied pre- and postdiuresis, and again 24 hr after transfusion, in order to evaluate the role of possible fluid overload in altering pulmonary function. Subjects underwent spirometry and had lung volume and flow volume curves (MEFVC) measured in a volume displacement plethysmograph while breathing air and a mixture of 80% helium and 20% oxygen (HeO2). Six patients had pulmonary mechanics measured with esophageal balloons in place. Baseline function was normal and no change occurred following diuresis. Following transfusion, the volume of isoflow (VisoV) decreased, but other parameters did not change. Subsequent analysis revealed 5 subjects with an initial VisoV greater than 20 (% FVC) but, paradoxically, less evidence of flow limitation in the small airways than those with a VisoV less than 20 (% FVC). Posttransfusion, in those subjects with an initially high VisoV, the Vmax25(air) tended to fall without a change of MEFVC in HeO2, resulting in a decreased VisoV. This was interpreted as evidence of subtle abnormalities in the small airways caused by volume expansion, raising doubts about the value of the VisoV as a measure of small airway disease. As a group, our subjects did not demonstrate any abnormalities in baseline function. Some subjects had mild flow limitation in small airway while other developed comparable levels of flow limitation following the volume expansion associated with transfusion.
以往对接受定期输血治疗的重型地中海贫血（TM）患者进行的肺功能研究结果显示，从小气道阻塞到限制性模式不等。对10名TM患者在利尿前后以及输血后24小时进行了研究，以评估可能的液体过载对肺功能改变的作用。受试者接受了肺活量测定，并在体积描记仪中测量了肺容积和流量容积曲线（MEFVC），同时呼吸空气以及80%氦气和20%氧气的混合气体（HeO2）。6名患者在放置食管气囊的情况下测量了肺力学。基线功能正常，利尿后未发生变化。输血后，等流量容积（VisoV）降低，但其他参数未改变。随后的分析显示，5名受试者最初的VisoV大于20（%FVC），但矛盾的是，与VisoV小于20（%FVC）的受试者相比，小气道中流量限制的证据更少。输血后，在那些最初VisoV较高的受试者中，Vmax25（空气）倾向于下降，而在HeO2中MEFVC没有变化，导致VisoV降低。这被解释为容量扩张导致小气道存在细微异常的证据，这让人对VisoV作为小气道疾病测量指标的价值产生怀疑。作为一个群体，我们的受试者在基线功能上未表现出任何异常。一些受试者在小气道存在轻度流量限制，而其他受试者在与输血相关的容量扩张后出现了相当程度的流量限制。
