The Impact of Anaesthesia Method on the Use of Anaesthesia Department Resources in Total Knee Arthroplasty

BACKGROUND: Spinal and general anaesthesia seem to lead to similar health-related outcomes in total knee arthroplasty. However, to produce economically and environmentally sustainable health care, we should also consider other factors. Current guidelines recommend preferring regional anaesthesia and total intravenous anaesthesia to reduce environmental impact. In this study, we analysed time, costs, and disposable materials associated with spinal anaesthesia and total intravenous anaesthesia during total knee arthroplasty. METHODS: A total of 395 patients undergoing total knee arthroplasty were randomised to spinal or general anaesthesia. Outcomes were total operating room time, non-operative operating room time, post-anaesthesia care unit time, use of drugs affecting haemodynamics, and the need for arterial cannulation and urinary catheterisation. In addition, we evaluated the financial costs and waste produced by single-use equipment and medicines in both anaesthesia methods. RESULTS: Anaesthesia method did not affect operating room time (median 152 min [interquartile range 136-168 min] vs. 150 min [137-165 min], Hodges-Lehmann estimate 2 min [95% CI -3 to 6 min], p = 0.49). However, after spinal anaesthesia, patients appeared to spend more time in the postanaesthesia care unit than after general anaesthesia (median 104 min [71-148 min] vs. 73 min [49-98 min], Hodges-Lehmann estimate 32 min [95% CI 23-42 min], p < 0.001). Medication for hypotension was more common in the general anaesthesia group, whereas medication for hypertension was more common in the spinal anaesthesia group. General anaesthesia generated more disposable material (1252 vs. 611 g), and both medicine and equipment expenses were higher (total costs €83 vs. €36). CONCLUSION: With this anaesthesia regimen, knee arthroplasty patients occupied the operating room for a similar duration regardless of anaesthesia method, but patients required longer recovery in the postanaesthesia care unit after spinal anaesthesia. Regarding disposable material and medicine use, spinal anaesthesia appeared to be more economical and material-sparing than total intravenous anaesthesia. Furthermore, spinal anaesthesia appeared to cause less hypotension requiring haemodynamic interventions than general anaesthesia. EDITORIAL COMMENT: This health-economic analysis estimates for how different aspects of general or spinal anaesthesia care contribute to process flow and item costs. Findings suggest that there may be measurably more costs associated with one of the anaesthesia type choices compared with the other, though this will depend on choices for materials and more. TRIAL REGISTRATION: EudraCT (2016-002035-15).