Relationship between the postoperative delirium and dementia in elderly surgical patients: Alzheimer's disease or vascular dementia

Abstract

Delirium is common in elderly surgical patients and the etiologies of delirium are multifactorial. Dementia is an important risk factor for delirium. This study was conducted to investigate the clinical relevance of surgery to the dementia in Alzheimer's disease (AD) or Vascular dementia (VaD). From March 2018 to April 2019, 95 patients, aged ≥56 years and undergoing surgery were retrospectively enrolled. We reviewed 29 patients with previous diagnosed dementia and 66 healthy controls, and the differences in postoperative delirium (POD) between these groups were examined. The patients with dementia were classified into 2 groups: AD and VaD. VaD is a heterogeneous disease, which included poststroke, subcortical VaD, and combined VaD (AD + VaD). This study evaluated risk factors for POD in underlying medical conditions and c-reactive protein (CRP) level. Among 95 surgical patients with a mean age of 77.05 years, 41 (43.2%) developed POD. The frequency of POD was higher in dementia patients compared to no dementia groups {82.80% vs 25.80%; odds ratio (OR) 3.21, [95% confidence interval (CI) 2.06–4.99]; P < .001}. There was no significant difference in POD between AD and VaD. Delirium was not correlated with conditions, such as hypertension (HTN), diabetes mellitus (DM), gender and CRP value {HTN, 42.90% vs 43.60%: DM, 45.50% vs. 33.30%: female, 27.2% of 63.0 vs male 13.8% of 32.0%}. Dementia play a key role in the predisposing factor of POD in elderly surgical patients, but found no clinical difference between dementia two subtypes. The results of our study may help reduce POD incidence through vulnerable patients.