Determinants of Post-Operative Cognitive Decline in Elderly People.

BACKGROUND: Surgery and anesthesia can result in temporary or permanent deterioration of the cognitive functions, for which causes remain unclear. OBJECTIVES: In this pilot study, we analyzed the determinants of cognitive decline following a non-emergency elective prosthesis implantation surgery for hip or knee. DESIGN: Prospective single-center study investigating psychomotor response time and changes in MoCA scores between the day before (D-1) and 2 days after (D+2) following surgery at the Lariboisière Hospital (Paris, France). PARTICIPANTS: 60 patients (71.9±7.1-year-old, 72% women) were included. MEASUREMENTS: Collected data consisted in sociodemographic data, treatments, comorbidities and the type of anesthesia (local, general or both). Furthermore, we evaluated pain and well-being before as well as after the surgery using point scales. RESULTS: Post-operative (D+2) MoCA scores were significantly lower than pre-operative ones (D-1) with a median difference of 2 pts [IQR]=4pts, (p<0.001), we found no significant difference between locoregional and general anesthesia. Pre-operative benzodiazepine or anticholinergic treatments were also associated to a drop in MoCA scores (p=0.006). Finally, the use of ketamine during anesthesia (p=0.043) and the well-being (p=0.006) evaluated before intervention, were both linked to a reduced cognitive impact. CONCLUSION: In this pilot study, we observed a post-operative short-term cognitive decline following a lower limb surgery. We also identified pre and perioperative independent factors linked to cognitive decline following surgery. In a next stage, a larger cohort should be used to confirm the impact of these factors on cognitive decline.

Acute pain Factors predictive of post-operative pain and opioid requirement in multimodal analgesia following knee replacement.

BACKGROUND: Despite the development of multimodal analgesia for postoperative pain management, opioids are still required for effective pain relief after knee arthroplasty. We aimed to identify the determinants of post-operative pain intensity and post-operative opioid requirement in this context. METHODS: In this observational prospective study, we recorded patient characteristics, pre-operative pain intensity, anxiety and depression levels, sensitivity and pain thresholds in response to an electrical stimulus, and mu-opioid receptor (OPRM1) and catechol-O-methyltransferase (COMT) single-nucleotide polymorphisms. Multivariate linear regression models were used to identify predictors of post-operative pain at rest and opioid requirement. RESULTS: We included 109 patients. Pre-operative pain at rest (p = 0.047), anxiety level (p = 0.001) and neuropathic pain symptoms (p = 0.030) were independently and positively associated with mean post-operative pain intensity adjusted for mean post-operative morphine equivalent dose (MED). Mean post-operative pain intensity at rest was lower (p = 0.006) in patients receiving celecoxib and pregabalin in the post-operative period, with all other variables constant. Mean post-operative MED over 5 days was low, but highly variable (78.2 ± 32.1 mg, from 9.9 to 170 mg). Following adjustment for mean post-operative pain intensity, it was independently negatively correlated with age (p = 0.004), and positively correlated with associated paracetamol treatment (p = 0.031). No genetic effect was detected in our sample. CONCLUSIONS: Our findings suggest that clinicians could use the pre-operative pain profile, in terms of anxiety levels, neuropathic pain symptoms, and chronic pre-operative pain intensity, to improve the efficacy of pain management after knee surgery.