Acute kidney injury in patients undergoing elective primary lower limb arthroplasty

European Journal of Orthopaedic Surgery & Traumatology https://doi.org/10.1007/s00590-021-03024-x ORIGINAL ARTICLE Acute kidney injury in patients undergoing elective primary lower limb arthroplasty Luke Farrow1,2 · Stacey Smillie2,3 · Joseph Duncumb2,4 · Brian Chan2 · Karen Cranfield2 · George Ashcroft1,2 · Iain Stevenson2 Received: 29 March 2021 / Accepted: 27 May 2021 © The Author(s) 2021 Abstract Purpose Recent research has outlined the increasing incidence of acute kidney injury (AKI) and its effect on morbidity/ mortality. There is evidence that current rates are significantly under-reported nationally, with uncertainty about pre-operative factors that might influence AKI reduction and the impact on other healthcare outcomes such as mortality and later Chronic Kidney Disease (CKD) development. We set out to help address these current deficiencies in the literature. Methods A retrospective cohort study was undertaken using data collected from patients undergoing elective primary lower limb arthroplasty within our institution from 01/10/16–31/09/17 with a 2-year follow-up. Results 53/782 (6.8%) patients had an AKI during the study time period. This was associated with a longer inpatient stay (p < 0.001). There was no significant difference in 30-day mortality (p = 0.134), 30-day readmission (p = 1.00) or later CKD development (p = 0.63). Independent predictors of AKI were as follows: Diabetes (OR 2.49; 95%CI 1.15–5.38; p = 0.021), CKD (OR 4.59; 95%CI 2.37–8.92; p < 0.001) and Male sex (OR 2.61; 95%CI 1.42–4.78; p = 0.002). Conclusions AKI in those undergoing hip and knee arthroplasty remains under-reported at a national level. AKI development was associated with an increased length of stay, but not long-term healthcare outcomes. This may be due to the mechanism of AKI development or the low absolute numbers of AKI suffered. We have identified three pre-operative factors (Diabetes, CKD & Male Sex) that were independently predictive of AKI. Targeted interventions may reduce the risk of AKI after lower limb arthroplasty. Keywords Acute kidney injury · Chronic kidney disease · Arthroplasty · Orthopaedics · Hip · Knee Introduction Acute kidney injury (AKI) is a sudden deterioration in kidney function usually multifactorial in origin [1]. There is increasing evidence that even a transient AKI can have a subsequent impact on the risk of increased short- and longterm mortality, as well as increased hospital costs and length of stay [1–3]. * Luke Farrow 1 Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK 2 Woodend Hospital, Aberdeen, UK 3 University Hospital of Ayr, Ayr, UK 4 Royal Infirmary of Edinburgh, Edinburgh, UK Although there has previously been little interest in AKI in orthopaedic surgery, recent data from the Scottish Arthroplasty project report have suggested an exponential increase in the incidence of AKI in elective arthroplasty surgery from 0.3 to 0.5% in 2000 to 1.9-2.2% in 2019 [4]. Recent studies focussing on orthopaedic surgery have suggested that AKI is associated with an increased length of stay in elective surgery [5], as well as increased mortality [6] and costs [7]. Whilst other studies have examined potential risk factors for AKI in orthopaedic patients [7–9], there is limited evidence to guide targeted intervention strategies to reduce AKI risk. Identification of patients at high risk of AKI is particularly important in a financially constrained heath system such as the NHS, where the significant increased cost associated with AKI has negative implications for population health and economics. There is evidence in other healthcare settings that the impact of AKI is not just related to short-term complications 13 Vol.:(0123456789) European Journal of Orthopaedic Surgery & Traumatology and outcomes, but also to the development of future Chronic Kidney Disease (CKD) [2, 10]. There has however been limited investigation about how the development of AKI following hip and knee arthroplasty might influence longer term CKD risk. To help address the current deficiencies in the literature, we therefore set out to examine: I. II. III. The rate of AKI within our institution in patients undergoing primary elective lower limb arthroplasty Pre-operative patient factors that may influence AKI risk Impact of AKI development on patient outcomes including the risk of CKD development at two years post-operatively. Methods and Materials A retrospective cohort study was undertaken using data collection from all patients undergoing elective primary lower limb arthroplasty within a single large regional university hospital in Scotland from 01/10/16 to 31/09/17. Eligible patients were identified using an online theatre management system. Individuals were excluded if they were undergoing complex primary (such as that for development hip dysplasia & acetabular fracture) or revision surgery. Patients who had end-stage renal failure (ESRF) requiring renal replacement therapy (RRT) were also excluded. Electronic patient records were used to collect relevant pre-operative patient and outcome variables (determined via prior analysis of relevant literature regarding AKI in Trauma & Orthopaedic surgery) including the following: • Demographic: Age, Sex, Body Mass Index (BMI) • Pre-operative: Serum Creatinine, Diuretic use, Non- Steroidal Anti-Inflammatory (NSAID) use, Angiotensin II Receptor Blocker (ARB) or Angiotensin Enzyme Inhibitor (ACEI) use, significant Cardiovascular Disease (CVD) [previous Stroke, Myocardial Infarction or Peripheral Vascular Disease (PVD)] and Diabetes (medication controlled) • Post-operative: Post-operative serum creatinine, NSAID use, length of stay, 30-day mortality, 30-day readmission and risk of CKD development at a minimum 2-year postoperative follow-up. AKI was classified according to the (AKI Network) AKIN criteria [11]; with a definition of an absolute risk in serum creatinine of > 26.4 micromole per litre or a 150% rise from baseline. Urine output was not utilised as part of the data collection due to concerns over the accuracy of recorded results. The highest post-operative creatinine value 13 in the 5 days following surgery was used for the calculation of AKI. Statistical analysis was performed using SPSS 24 for Windows. The rate of AKI was calculated using the number of individuals undergoing primary elective arthroplasty as the denominator. A Mann–Whitney U test was used to assess the effect of AKI development on length of stay. 30-day mortality and 30-day readmission were examined using Fisher’s exact test. Subsequent CKD development (or worsening of CKD status if a pre-operative diagnosis of CKD was present) was also evaluated at a minimum of 2-year post-operative follow-up, including comparison for those who suffered an AKI versus those who did not. CKD was defined as an eGFR < 60 persistently for 3 months or more. If a patient had only one test in the entire post-discharge period, this was a (...truncated)