Pianosi P, Charge T D, Esseltine D W, Coates A L
Respiratory Medicine Service, McGill University-Montreal Children's Hospital Research Institute, Winnipeg, Manitoba, Canada.
Arch Dis Child. 1993 Jun;68(6):735-8. doi: 10.1136/adc.68.6.735.
Patients with sickle cell disease usually have mild hypoxaemia and their oxyhaemoglobin dissociation curve is shifted to the right. It follows that oxygen saturation in sickle cell disease should be lower than normal. Most subjects in this clinic had normal oxygen saturation by pulse oximetry, however. To improve the understanding of this paradox, arterialised capillary oxygen tension (PO2) and oxygen saturation were compared with simultaneously measured pulse oximeter saturation in 20 children with sickle cell disease. In addition, the PO2 at 50% haemoglobin saturation (P50) was compared with saturation measured by pulse oximetry in all 20 patients. It was found that saturation measured by pulse oximetry was, on the whole, similar to that calculated from the sampled blood. Individual deviations were not random, however, and were partly explained by differences in P50 values. It is concluded that pulse oximetry gives variable results in patients with sickle cell disease and should be used with caution to predict arterial saturation in this patient group.
镰状细胞病患者通常有轻度低氧血症，其氧合血红蛋白解离曲线右移。由此可见，镰状细胞病患者的氧饱和度应低于正常水平。然而，该诊所的大多数患者通过脉搏血氧饱和度测定法测得的氧饱和度正常。为了更好地理解这一矛盾现象，对20名镰状细胞病患儿的动脉化毛细血管氧分压（PO2）和氧饱和度与同时测量的脉搏血氧饱和度进行了比较。此外，还对所有20例患者血红蛋白饱和度为50%时的PO2与通过脉搏血氧饱和度测定法测得的饱和度进行了比较。结果发现，通过脉搏血氧饱和度测定法测得的饱和度总体上与从采集的血液中计算得出的饱和度相似。然而，个体偏差并非随机出现，部分原因可由P50值的差异来解释。得出的结论是，脉搏血氧饱和度测定法在镰状细胞病患者中得出的结果存在差异，在该患者群体中使用时应谨慎预测动脉饱和度。
