Hatherill M, Salie S, Waggie Z, Lawrenson J, Hewitson J, Reynolds L, Argent A
Division of Critical Care & Children's Heart Disease, School of Child & Adolescent Health, University of Cape Town, South Africa.
Arch Dis Child. 2005 Dec;90(12):1288-92. doi: 10.1136/adc.2005.078006. Epub 2005 Sep 13.
To describe acid-base derangements in children following open cardiac surgery on cardiopulmonary bypass (CPB), using the Fencl-Stewart strong ion approach.
Prospective observational study set in the paediatric intensive care unit (PICU) of a university children's hospital. Arterial blood gas parameters, serum electrolytes, strong ion difference, strong ion gap (SIG), and partitioned base excess (BE) were measured and calculated on admission to PICU.
A total of 97 children, median age 57 months (range 0.03-166), median weight 14 kg (range 2.1-50), were studied. Median CPB time was 80 minutes (range 17-232). Predicted mortality was 2% and there was a single non-survivor. These children showed mild metabolic acidosis (median standard bicarbonate 20.1 mmol/l, BE -5.1 mEq/l) characterised by hyperchloraemia (median corrected Cl 113 mmol/l), and hypoalbuminaemia (median albumin 30 g/l), but no significant excess unmeasured anions or cations (median SIG 0.7 mEq/l). The major determinants of the net BE were the chloride and albumin components (chloride effect -4.8 mEq/l, albumin effect +3.4 mEq/l). Metabolic acidosis occurred in 72 children (74%) but was not associated with increased morbidity. Hyperchloraemia was a causative factor in 53 children (74%) with metabolic acidosis. Three (4%) hyperchloraemic children required adrenaline for inotropic support, compared to eight children (28%) without hyperchloraemia. Hypoalbuminaemia was associated with longer duration of inotropic support and PICU stay.
In these children with low mortality following open cardiac surgery, hypoalbuminaemia and hyperchloraemia were the predominant acid-base abnormalities. Hyperchloraemia was associated with reduced requirement for adrenaline therapy. It is suggested that hyperchloraemic metabolic acidosis is a benign phenomenon that should not prompt escalation of haemodynamic support. By contrast, hypoalbuminaemia, an alkalinising force, was associated with prolonged requirement for intensive care.
采用芬克尔 - 斯图尔特强离子方法描述小儿体外循环心脏直视手术后的酸碱紊乱情况。
在一家大学儿童医院的儿科重症监护病房（PICU）进行前瞻性观察研究。在患儿入住PICU时测量并计算动脉血气参数、血清电解质、强离子差、强离子间隙（SIG）和分区碱剩余（BE）。
共研究了97例儿童，中位年龄57个月（范围0.03 - 166个月），中位体重14千克（范围2.1 - 50千克）。中位体外循环时间为80分钟（范围17 - 232分钟）。预测死亡率为2%，仅有1例死亡。这些儿童表现为轻度代谢性酸中毒（中位标准碳酸氢盐20.1毫摩尔/升，BE为 - 5.1毫当量/升），其特征为高氯血症（中位校正氯113毫摩尔/升）和低白蛋白血症（中位白蛋白30克/升），但未发现明显过量的未测定阴离子或阳离子（中位SIG为0.7毫当量/升）。净BE的主要决定因素是氯和白蛋白成分（氯效应为 - 4.8毫当量/升，白蛋白效应为 + 3.4毫当量/升）。72例儿童（74%）发生代谢性酸中毒，但与发病率增加无关。53例代谢性酸中毒儿童（74%）中高氯血症是一个致病因素。3例（4%）高氯血症儿童需要肾上腺素进行强心支持，而无高氯血症的儿童中有8例（28%）需要。低白蛋白血症与强心支持时间延长和PICU住院时间延长有关。
在这些心脏直视手术后死亡率较低的儿童中，低白蛋白血症和高氯血症是主要的酸碱异常情况。高氯血症与肾上腺素治疗需求减少有关。提示高氯性代谢性酸中毒是一种良性现象，不应促使增加血流动力学支持。相比之下，作为一种碱化力量的低白蛋白血症与重症监护需求延长有关。
