Chalwin R P, Moran J L, Peake S I, Flynn S, Pieterse J, Williams P
The Department of Intensive Care, The Queen Elizabeth Hospital, Adelaide, South Australia, Australia.
Anaesth Intensive Care. 2012 May;40(3):433-41. doi: 10.1177/0310057X1204000308.
Hypokalaemia is a common problem in critically ill patients, which if untreated, can result in dysrhythmia or another adverse outcome. We assessed the safety and efficacy of a continuous infusion of potassium chloride versus an existing intermittent infusion regimen. In this open-label randomised parallel-arm active-controlled pilot study, critically ill adults with plasma potassium concentration between 2.5 and 3.8 mmol/l were randomised to receive either a continuous infusion or intermittent infusions of potassium chloride for establishment and maintenance of normokalaemia. The primary outcome was the mean difference in plasma potassium concentration over time between the two study arms as assessed by a linear mixed-effects model. Although a statistically significant difference was observed (0.22 mmol/l; 95% confidence interval 0.17, 0.27; P <0.0001), this did not reach the pre-determined level indicative of a treatment effect (0.5 mmol/l). The continuous group demonstrated less variance in (mean) plasma potassium as reflected in narrower confidence intervals in a prediction-by-time model. The incidence rate ratio of dysrhythmia, assessed by a mixed-effects Poisson model, was similar in each group (0.62; 95% confidence interval 0.32, 1.21; P=0.16). We recorded no adverse events directly attributable to infusion of potassium chloride in either study arm. Although titrated continuous infusion did not demonstrate a clinically important difference by comparison with intermittent infusions for the maintenance of normokalaemia, there was more consistent control of plasma potassium with no observed complications or adverse events. Therefore, this trial showed an acceptable efficacy and safety profile for the continuous infusion regimen, suggesting scope for further study.
低钾血症是重症患者常见的问题，若不治疗，可导致心律失常或其他不良后果。我们评估了氯化钾持续输注与现有间歇输注方案的安全性和有效性。在这项开放标签的随机平行臂活性对照试验性研究中，血浆钾浓度在2.5至3.8 mmol/L之间的成年重症患者被随机分配接受氯化钾持续输注或间歇输注，以建立和维持正常血钾水平。主要结局是通过线性混合效应模型评估的两个研究组之间血浆钾浓度随时间的平均差异。尽管观察到有统计学显著差异（0.22 mmol/L；95%置信区间0.17, 0.27；P<0.0001），但这未达到预先确定的表明治疗效果的水平（0.5 mmol/L）。持续输注组在（平均）血浆钾方面表现出较小的方差，这在时间预测模型中表现为更窄的置信区间。通过混合效应泊松模型评估的心律失常发生率在每组中相似（0.62；95%置信区间0.32, 1.21；P = 0.16）。在任何一个研究组中，我们均未记录到直接归因于氯化钾输注的不良事件。尽管与间歇输注相比，滴定式持续输注在维持正常血钾水平方面未显示出临床重要差异，但血浆钾的控制更为一致，且未观察到并发症或不良事件。因此，该试验显示持续输注方案具有可接受的疗效和安全性，表明有进一步研究的空间。
