Waller M, Barkley S, Harrison T
Sheffield Teaching Hospitals NHS Foundation Trust, UK.
Ann R Coll Surg Engl. 2025 Sep;107(7):469-472. doi: 10.1308/rcsann.2021.0296. Epub 2022 Feb 17.
Hyponatraemia has a prevalence of up to 30% after orthopaedic surgery and is associated with poor outcomes, including around 20% mortality and longer hospital stays. This study assessed the prevalence of hyponatraemia following total hip and knee replacement, the causes, further tests, management, effect on length of stay, intensive care admissions and the impact of an endocrinology hyponatraemia protocol.
Day one postoperative urea and electrolyte results for patients undergoing elective total hip and knee replacements were reviewed. Retrospective data was gathered through the web-based requesting and reporting system ICE. Parameters included demographics, procedure, sodium pre- and postoperatively, endocrine input, high-dependency admissions and length of hospital stay. Next, a hyponatraemia protocol based on NICE guidance was developed with the endocrinology department and a second audit cycle was initiated. SPSS software was used to analyse the data.
Hyponatraemia occurred in 12% of patients, resulted in a significantly longer stay (7.7 days vs 4.6, -4.6, < 0.00001) and multiple critical care admissions (8 days). It was more common in total knee replacement (chi square 5.5194, = 0.018807) and older age ( -2.81083, = 0.002619). Prior to implementation of the endocrine pathway, hyponatraemia was under-investigated (38%). The precipitating factors such as age and use of diuretics corroborated with prior research. Implementation of the hyponatraemia protocol resulted in quicker endocrinology referrals (2.3 vs 3.6 days), reduced length of stay by 0.7 days ( -2.40973, = 0.008144) and reduced intensive care days to 0 (chi square 4.6189, = 0.031622).
This study found a similar incidence of hyponatremia as earlier research with the same precipitating factors, the only exception being an increased incidence in patients undergoing knee compared with hip replacemenr The introduction of the direct endocrine pathway proved to be safe and effective without increasing local workload significantly. The main limitation in this project was the fact that it was carried out in a single unit, although this process could be easily replicated should other units wish to adopt it and compare results over a wider cohort.
This endocrine pathway is easily reproducible for other departments. It may help reduce waiting times and improve outcomes for total hip and knee replacements within the NHS.
骨科手术后低钠血症的发生率高达30%，且与不良预后相关，包括约20%的死亡率和更长的住院时间。本研究评估了全髋关节和膝关节置换术后低钠血症的发生率、病因、进一步检查、管理、对住院时间的影响、重症监护病房入住情况以及内分泌科低钠血症诊疗方案的影响。
回顾了接受择期全髋关节和膝关节置换术患者术后第一天的尿素和电解质结果。通过基于网络的申请和报告系统ICE收集回顾性数据。参数包括人口统计学资料、手术、术前和术后钠水平、内分泌科会诊情况、高依赖病房入住情况和住院时间。接下来，与内分泌科根据英国国家卫生与临床优化研究所（NICE）的指南制定了低钠血症诊疗方案，并启动了第二个审核周期。使用SPSS软件分析数据。
12%的患者发生了低钠血症，导致住院时间显著延长（7.7天对4.6天，-4.6，<0.00001）以及多次重症监护病房入住（8天）。在全膝关节置换术中更常见（卡方值5.5194，P = 0.018807），且在老年患者中更常见（-2.81083，P = 0.002619）。在内分泌科诊疗路径实施之前，低钠血症的检查不足（38%）。年龄和利尿剂使用等诱发因素与先前的研究结果一致。低钠血症诊疗方案的实施导致内分泌科会诊更快（2.3天对3.6天），住院时间缩短0.7天（-2.40973，P = 0.008144），重症监护天数降至0（卡方值4.6189，P = 0.031622）。
本研究发现低钠血症的发生率与早期研究相似，诱发因素相同，唯一的例外是膝关节置换患者的发生率高于髋关节置换患者。直接内分泌科诊疗路径的引入被证明是安全有效的，且未显著增加当地的工作量。本项目的主要局限性在于它是在单个单位进行的，尽管如果其他单位希望采用并在更广泛的队列中比较结果，这个过程可以很容易地复制。
这种内分泌科诊疗路径很容易被其他科室复制。它可能有助于减少英国国家医疗服务体系（NHS）内全髋关节和膝关节置换术的等待时间并改善预后。
