Perioperative platelet count in peripheral blood is associated with the early stage of PND after major orthopedic surgery: a prospective observational study.

BACKGROUND: Perioperative neurocognitive disorders (PND) are common complications of major surgery among elderly patients, remarkably decreasing patients' life quality. Platelet count has been proved to be an essential factor in inflammation. However, as far as we know, the relationship between platelet count and PND is not clear yet in the orthopedic area. PND could be a long-term disease, which sometimes lasts for several years, and it is meaningful to find a biomarker of PND at the early stage. Thus, we designed this study to find out the association between perioperative platelet count and occurrence of PND, and determine whether preoperative platelet count could be a biomarker of the early stage of PND. METHODS: A prospective observational study was performed on the patients who would take total knee arthroplasty or total hip arthroplasty. Their peripheral platelets were counted by blood routine examination 1 day before and 3 days after the surgery. And we assessed their neurocognitive functions 1 day before and 3 days after the surgery. These data were recorded and analyzed to find out the relationship between platelet count and the occurrence of PND. RESULTS: Eventually, 70 patients finished the whole process, and 14 of them developed PND. The median preoperative platelet count in the PND group was significantly higher than that in the non-PND group (239 vs 168 × 10^9/L, p = 0.009). Preoperative platelet count was an independent risk factor for PND (odds ratio = 1.014, 95% confidence interval [CI] 1.000-1.027, P = 0.043) in the logistic multivariable regression, while the area under the curve of the receiver operating characteristic curve of the prediction model was 0.796 (95% CI 0.676-0.916). CONCLUSIONS: The higher preoperative and postoperative level of platelet count in the peripheral blood were associated with the early stage of PND, and preoperative platelet count could be a potential predictor of the early stage of PND in patients undergoing major orthopedic surgeries. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000033001 , registration date: 17 May 2020.

Evidence for Cognitive Decline in Chronic Pain: A Systematic Review and Meta-Analysis.

Background: People with chronic pain (CP) sometimes report impaired cognitive function, including a deficit of attention, memory, executive planning, and information processing. However, the association between CP and cognitive decline was still not clear. Our study aimed to assess the association of CP as a risk factor with cognitive decline among adults. Methods: We included data from clinical studies. Publications were identified using a systematic search strategy from PubMed, Embase, and Cochrane Library databases from inception to October 10, 2020. We used the mean cognitive outcome data and the standard deviations from each group. The standardized mean difference (SMD) or odds ratio (OR), and 95% confidence intervals (CI) were performed for each cognitive decline outcome. I 2-values were assessed to quantify the heterogeneities. Results: We included 37 studies with a total of 52,373 patients with CP and 80,434 healthy control participants. Because these studies used different evaluative methods, we analyzed these studies. The results showed CP was associated with cognitive decline when the short-form 36 health survey questionnaire (SF-36) mental component summary (SMD = -1.50, 95% CI = -2.19 to -0.81), the Montreal cognitive assessment (SMD = -1.11, 95% CI = -1.60 to -0.61), performance validity testing (SMD = 3.05, 95% CI = 1.74 to 4.37), or operation span (SMD = -1.83, 95% CI = -2.98 to -0.68) were used. However, we got opposite results when the studies using International Classification of Diseases and Related Health Problems classification (OR = 1.58, 95% CI = 0.97 to 2.56), the Mini-Mental State Examination (SMD = -0.42, 95% CI = -0.94 to 0.10; OR = 1.14, 95% CI = 0.91 to 1.42), and Repeatable Battery for the Assessment of Neuropsychological Status memory component (SMD = -0.06, 95% CI = -0.37 to 0.25). Conclusion: There may be an association between CP and the incidence of cognitive decline when some cognitive, evaluative methods were used, such as short-form 36 health survey questionnaire, Montreal cognitive assessment, performance validity testing, and operation span.