McCall B B, Mazzei W J, Scheller M S, Thomas T C
Department of Anesthesiology, University of California, San Diego School of Medicine 92103.
J Cardiothorac Anesth. 1990 Oct;4(5):571-6. doi: 10.1016/0888-6296(90)90406-6.
The effects of central venous bolus injections of potassium chloride (KCl) on arterial potassium concentration were studied in patients undergoing cardiopulmonary bypass. Ten subjects were studied, and each received a rapid bolus injection of KCl, 33 microEq/kg, both before and after cardiopulmonary bypass. Injections were delivered through the proximal infusion port of a 7.5F pulmonary artery catheter, which was situated in either the superior vena cava or the right atrium. Monitored variables included the electrocardiogram, mean arterial, central venous, and pulmonary artery pressures, end-tidal carbon dioxide and inspired oxygen concentrations, and temperature. Blood was sampled continuously at either the radial artery alone or both the radial artery and aortic root at 2 mL/4.3 s. The difference in magnitude between the maximal potassium concentration achieved and the prebolus baseline potassium concentration (delta K) was correlated with cardiac output, stroke volume, and prebolus baseline potassium concentration (baseline [K+]), using simple linear regression analysis. Although significant hyperkalemia (eg, 7 to 9 mEq/L) developed in both the aortic root and radial artery, this was of no electrocardiographic or hemodynamic consequence, presumably because of the transient nature of the hyperkalemic response, following bolus injection of KCl. There was no significant correlation between delta K and cardiac output or stroke volume; however, delta K did correlate significantly with the Baseline [K+] in a direct linear relationship. It is concluded that central bolus injections of KCl through the proximal infusion port of the pulmonary artery catheter at 33 microEq/kg are safe. This technique should be used cautiously in patients with extremely low cardiac outputs or where intracardiac shunting of blood may exist, as these situations could potentially result in greater hyperkalemic responses than those observed in the current study.
在接受体外循环的患者中，研究了经中心静脉大剂量注射氯化钾（KCl）对动脉血钾浓度的影响。研究了10名受试者，每位受试者在体外循环前后均接受了33微当量/千克氯化钾的快速大剂量注射。注射通过位于上腔静脉或右心房的7.5F肺动脉导管的近端输注端口进行。监测变量包括心电图、平均动脉压、中心静脉压、肺动脉压、呼气末二氧化碳和吸入氧浓度以及体温。仅在桡动脉或同时在桡动脉和主动脉根部以2毫升/4.3秒的速度连续采血。使用简单线性回归分析，将达到的最大钾浓度与注射前基线钾浓度之间的差值（ΔK）与心输出量、每搏输出量和注射前基线钾浓度（基线[K+]）进行相关性分析。尽管主动脉根部和桡动脉均出现了显著的高钾血症（例如，7至9毫当量/升），但这并未产生心电图或血流动力学后果，可能是因为注射氯化钾后高钾反应具有短暂性。ΔK与心输出量或每搏输出量之间无显著相关性；然而，ΔK与基线[K+]呈显著的直接线性相关。结论是，通过肺动脉导管近端输注端口以33微当量/千克的剂量中心大剂量注射氯化钾是安全的。对于心输出量极低或可能存在心内血液分流的患者，应谨慎使用该技术，因为在这些情况下可能会导致比本研究中观察到的更大的高钾反应。
