常温体外循环心脏手术的钾离子平衡

Potassium metabolism in warm heart surgery

作者对连续２６例常温体外循环心脏手术患者的术中、术后钾离子动态变化进行了分阶段观察分析，发现体外循环过程中钾离子随持续灌注的温氧合血心停搏液大量进入体内，复苏时血浆钾显著增高；术后第１日早７时前补钾量较低温体外循环后同期明显为少；体外循环过程钾离子向细胞内转移显著；自手术当日晚６时始钾离子开始向细胞外转移，至术后第２日早７时钾离子出入达到平衡。复苏时的高钾血症常使心脏复跳延迟，但心脏自动复跳率却很高（９６％）。作者还就高钾血症的预防提出了几条措施。

AbstractThe dynamic balance of potassium getting in andout the body during and after operation was surveyed in26adult patients who underwent cardiac surgery withnormothermic cardiopulmonary bypass(CPB),Wefound that during CPB,because of the continous perfu-sion of warm oxygenated blood cardioplegia solution,alarge volume of potassium entered the body; mean-while,only a little potassium removed from the body inurine。At the moment of CPB finish,the volume ofresidual potassium in the body was as large as74.5mmol(mean)’that was l.2mmol/kg body weight。The mean plasma potassium level at the poirits of aortacross clamp release and CPB finish were 6.8mmol/Land 5.5mmol/Lrespectively,and all in normal rangeat severaI times measured from the end of operation(usually 12～2pm)to the second postoperative day7am。 The volume of potassium replenishment accord-ing to urine output in this group was much less thanthose in hypothermic CPB patients from the end of op-eration to the first postoperative day 7am. During CPBextracellular potassium shifted into intracellular fluid,but the shifting became opposite around the operativeday 6pm , and the final equilibrium of potassiummetabolism was achieved at the second postoperativeday 7am。 The remarkble hyperkalemia at the point ofaorta cross clamp release may delay the heart rebeating(>5min,35%),but the automatic rebeating rate wasstill very high (96%).With regard to the prevention ofhyperkalemia during CPB, we also、give some sugges-tions in this paper。