Medicine, Manchester Royal Infirmary, Manchester, UK
Barts and The London School of Medicine and Dentistry, London, UK.
BMJ Case Rep. 2022 Nov 14;15(11):e251611. doi: 10.1136/bcr-2022-251611.
Acute hypocalcaemia can be life-threatening and must be diagnosed promptly. The gold-standard investigation is ionised calcium, which is measured on most blood gas analysers. Total calcium measurements are inaccurate in severe depletion even if 'corrected' or 'adjusted' for albumin. We present an illustrative case of a woman in her 30s with symptomatic hypocalcaemia and a very low ionised calcium on VBG analysis. Emergency calcium replacement was delayed due to a falsely reassuring corrected calcium result. Our discussion includes a systematic literature review on the use of ionised calcium in emergency and acute medical settings. We suggest cognitive biases that may explain clinical over-reliance on corrected calcium, and call for the inclusion of ionised calcium values in major treatment guidelines for acute hypocalcaemia.
急性低钙血症可能危及生命，必须迅速诊断。金标准的检查是离子钙，它可以在大多数血气分析仪上测量。即使“校正”或“调整”白蛋白，在严重缺乏时总钙测量也不准确。我们呈现了一个有症状性低钙血症的 30 多岁女性的说明性病例，其 VBG 分析显示离子钙非常低。由于纠正钙结果令人放心，导致紧急补钙被延迟。我们的讨论包括对离子钙在紧急和急性医疗环境中应用的系统文献回顾。我们提出了可能解释临床过度依赖校正钙的认知偏差，并呼吁在急性低钙血症的主要治疗指南中纳入离子钙值。
