Oka Tatsujiro, Itoi Toshiyuki, Hamaoka Kenji
Department of Pediatrics Cardiology and Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Pediatr Int. 2007 Dec;49(6):898-902. doi: 10.1111/j.1442-200X.2007.02481.x.
It has been shown that acute hypoxia induces the transient elevation of blood hemoglobin concentration ([Hb]) as a consequence of sympathetic-mediated splenic contraction to maintain the supply of oxygen, and splenectomy abolishes this phenomenon. The purpose of the present paper was to determine, retrospectively, whether the ability of transient elevation of [Hb] against acute hypoxia would be impaired in neonates with asplenia.
Eleven neonates who underwent surgery from 1998 to 2003 were enrolled in this retrospective study. They were divided into two groups: (i) five patients with asplenia syndrome with cyanotic congenital heart disease (asplenia group); and (ii) six patients with hypoplastic left heart syndrome who needed nitrogen gas inhalation therapy (HLHS group). In the asplenia group simultaneous data of arterial oxygen saturation (Sao(2)) and [Hb] were obtained before and after the temporary unexpected decrease of percutaneous arterial oxygen saturation. In the HLHS group they were obtained before and after nitrogen gas administration therapy. The arterial oxygen content (Cao(2)) changes and the ratio of Cao(2) change (Cao(2) after hypoxia divided by Cao(2) before hypoxia) were also calculated.
In the asplenia group [Hb] was unchanged (12.9 +/- 1.6 g/dL to 12.8 +/- 1.4, n.s.) and Cao(2) was decreased (14.5 +/- 1.6 mL/dL to 11.9 +/- 1.1, P = 0.018). In the HLHS group [Hb] was increased (14.6 +/- 1.3 g/dL to 15.4 +/- 1.5, P = 0.028), but Cao(2) was changed (18.2 +/- 2.2 mL/dL to 16.7 +/- 3.0, P = 0.043). The ratio of Cao(2) change for the HLHS group was significantly different from that of the asplenia group (0.92 +/- 0.10, 0.83 +/- 0.10, respectively, P = 0.02).
Patients with asplenia syndrome have some disadvantage regarding this protective mechanism against acute hypoxia.
研究表明，急性缺氧会导致血血红蛋白浓度（[Hb]）短暂升高，这是交感神经介导的脾脏收缩以维持氧气供应的结果，而脾切除会消除这种现象。本文的目的是回顾性地确定无脾新生儿对急性缺氧时[Hb]短暂升高的能力是否受损。
本回顾性研究纳入了1998年至2003年接受手术的11例新生儿。他们被分为两组：（i）5例患有青紫型先天性心脏病的无脾综合征患者（无脾组）；（ii）6例需要氮气吸入治疗的左心发育不全综合征患者（HLHS组）。在无脾组中，在经皮动脉血氧饱和度意外暂时降低前后获取动脉血氧饱和度（Sao₂）和[Hb]的同步数据。在HLHS组中，在氮气给药治疗前后获取这些数据。还计算了动脉血氧含量（Cao₂）的变化以及Cao₂变化率（缺氧后Cao₂除以缺氧前Cao₂）。
在无脾组中，[Hb]无变化（从12.9±1.6 g/dL至12.8±1.4，无统计学意义），而Cao₂降低（从14.5±1.6 mL/dL至11.9±1.1，P = 0.018）。在HLHS组中，[Hb]升高（从14.6±1.3 g/dL至15.4±1.5，P = 0.028），但Cao₂有变化（从18.2±2.2 mL/dL至16.7±3.0，P = 0.043）。HLHS组的Cao₂变化率与无脾组显著不同（分别为0.92±0.10和0.83±0.10，P = 0.02）。
无脾综合征患者在这种针对急性缺氧的保护机制方面存在一些劣势。
