Takeaway

More than half of older adult patients had some form of neurocognitive disorder 5 years after elective orthopaedic surgery. Surgery and anaesthesia may be associated with the trajectory of cognitive decline in at-risk older adults, including those with pre-operative cognitive impairment.

Key Points

• Study goal was to use recent nomenclature guidelines to describe the prevalence of neurocognitive disorders (i.e. mild cognitive impairment and dementia) 5 years after elective orthopaedic surgery
• Secondary aim to identify pre-operative factors associated with neurocognitive disorders 5 years postop
• Prospective, longitudinal study with patients scheduled for elective orthopaedic surgery under general anaesthesia with or without regional anaesthesia
• Enrolled 300 adults >60 years old, scheduled for elective, first-time total hip joint replacement surgery
• pre-operative cognitive impairment is associated with poor cognitive outcomes in the long term, emphasising the need for cognitive assessments to be embedded into routine peri-operative care for older adults.

Excerpts

Postoperative cognitive dysfunction is estimated to affect between 14% and 48% of older adults, depending on the surgical population, as well as the type and timing of assessment

Postoperative cognitive disorder is defined as any objective decline on neurocognitive testing occurring after surgery and anaesthesia, although when this decline occurs relative to surgery and on which tests or how many tests the decline is measured (e.g. screening tools vs. neuropsychological test batteries), varies significantly across studies. Additionally, these classifications do not account for the subjective experience of the patient or their functional independence

The prevalence of major neurocognitive disorder (i.e. dementia) after 5 years was 17%. This contrasts with the population prevalence of dementia in Australia which is estimated to be 6.8% in people aged 75–84 y

there is growing evidence that the cognitive trajectory of patients postoperatively is non-linear and may follow an acute disorder or initial decline, followed by a rebound to near pre-operative function and then an accelerated decline

High rates of major neurocognitive disorder at baseline may reflect the higher burden of cardiovascular disease, medical comorbidities and lifestyle characteristics of patients who have surgery

Abstract

Background

Peri-operative neurocognitive disorders are one of the most common complications affecting older adults after anaesthesia and surgery. It is not clear how exposure to surgery and anaesthesia contributes to the prevalence of long-term neurocognitive disorders. This study aimed to report the prevalence of neurocognitive disorders, and explore pre-operative factors associated with neurocognitive disorders 5 years after elective orthopaedic surgery.

Methods

A prospective, 5-year longitudinal, cohort study was performed recruiting patients (aged ≥ 60 y) undergoing elective orthopaedic surgery and a contemporaneous non-surgical control group. Neurocognitive disorder was evaluated and classified at baseline and 5-year review incorporating: self- and informant-reported cognition; functional participation; and performance on neuropsychological tests.

Results

Recruitment at 5-year follow-up included 195 patients and 21 control participants. In the patient cohort the prevalence of neurocognitive disorder was 38.1% (n = 75), with 61 (30.1%) meeting the criteria for mild neurocognitive disorder and 14 (7.1%) for major neurocognitive disorder. At 5-year follow-up, 121 (61.4%) patients were classified with a neurocognitive disorder, with 88 (44.7%) characterised with mild neurocognitive disorder and 33 (16.8%) with major neurocognitive disorder. Age (odds ratio (95%CI) 1.07 (1.02–1.13); p = 0.01) and baseline cognitive impairment (odds ratio (95%CI) 2.1 (1.06–4.15); p = 0.03) were significant predictors of neurocognitive disorder 5 years after surgery.

Conclusion

More than half of older adult patients had some form of neurocognitive disorder 5 years after elective orthopaedic surgery. Surgery and anaesthesia may be associated with the trajectory of cognitive decline in at-risk older adults, including those with pre-operative cognitive impairment. Cognitive screening should be factored into pre-operative assessments of older adults to inform subsequent care.

Citation

Atkins KJ, Silbert B, Scott DA, Evered LA. Prevalence of neurocognitive disorders 5 years after elective orthopaedic surgery. Anaesthesia. 2024 Oct;79(10):1053-1061. doi: 10.1111/anae.16365. Epub 2024 Jul 10. PMID: 38985478.

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