Develop a Clinical Prediction Model for Postoperative Cognitive Dysfunction after Major Noncardiac Surgery in Elderly Patients: A Protocol for a Prospective Observational Study

Polydopamine-Coated Kaempferol-Loaded MOF Nanoparticles: A Novel Therapeutic Strategy for Postoperative Neurocognitive Disorder

Purpose

The primary objective of this study was to develop an innovative nanomedicine-based therapeutic strategy to alleviate Postoperative Neurocognitive Disorder (PND) in patients undergoing surgery.

Patients and Methods

To achieve this goal, polydopamine-coated Kaempferol-loaded Metal-Organic Framework nanoparticles (pDA/KAE@ZIF-8) were synthesized and evaluated. The study involved encapsulating Kaempferol (KAE) within ZIF-8 nanoparticles, followed by coating with polydopamine (PDA) to enhance biocompatibility and targeted delivery. The characterization of these nanoparticles (NPs) was conducted using various techniques including Scanning Electron Microscopy, Fourier-Transform Infrared Spectroscopy, X-ray Diffraction, and Ultraviolet-Visible spectroscopy. The efficacy of pDA/KAE@ZIF-8 NPs was tested in both in vitro and in vivo models, specifically focusing on their ability to penetrate the blood-brain barrier and protect neuronal cells against oxidative stress.

Results

The study found that pDA/KAE@ZIF-8 NPs efficiently penetrated the blood-brain barrier and were significantly taken up by neuronal cells. These nanoparticles demonstrated remarkable Reactive Oxygen Species (ROS) scavenging capabilities and stability under physiological conditions. In vitro studies showed that pDA/KAE@ZIF-8 NPs provided protection to HT-22 neuronal cells against H2O2-induced oxidative stress, reduced the levels of pro-inflammatory cytokines, and decreased apoptosis rates. In a PND mouse model, the treatment with pDA/KAE@ZIF-8 NPs significantly improved cognitive functions, surpassing the effects of KAE alone. This improvement was substantiated through behavioral tests and a noted reduction in hippocampal inflammation.

Conclusion

The findings from this study underscore the potential of pDA/KAE@ZIF-8 NPs as an effective nanotherapeutic agent for PND. This approach offers a novel direction in the postoperative care of elderly patients, with the potential to transform the therapeutic landscape for neurocognitive disorders following surgery. The application of nanotechnology in this context opens new avenues for more effective and targeted treatments, thereby improving the quality of life for patients suffering from PND.

Prediction model protocols indicate better adherence to recommended guidelines for study conduct and reporting

BACKGROUND AND OBJECTIVE

Protocols are invaluable documents for any research study, especially for prediction model studies. However, the mere existence of a protocol is insufficient if key details are omitted. We reviewed the reporting content and details of the proposed design and methods reported in published protocols for prediction model research.

METHODS

We searched MEDLINE, Embase, and the Web of Science Core Collection for protocols for studies developing or validating a diagnostic or prognostic model using any modeling approach in any clinical area. We screened protocols published between Jan 1, 2022 and June 30, 2022. We used the abstract, introduction, methods, and discussion sections of The Transparent Reporting of a multivariable prediction model of Individual Prognosis Or Diagnosis (TRIPOD) statement to inform data extraction.

RESULTS

We identified 30 protocols, of which 28 were describing plans for model development and six for model validation. All protocols were open access, including a preprint. 15 protocols reported prospectively collecting data. 21 protocols planned to use clustered data, of which one-third planned methods to account for it. A planned sample size was reported for 93% development and 67% validation analyses. 16 protocols reported details of study registration, but all protocols reported a statement on ethics approval. Plans for data sharing were reported in 13 protocols.

CONCLUSION

Protocols for prediction model studies are uncommon, and few are made publicly available. Those that are available were reasonably well-reported and often described their methods following current prediction model research recommendations, likely leading to better reporting and methods in the actual study.

Delirium after Cardiac Surgery-A Narrative Review

Postoperative delirium (POD) after cardiac surgery is a well-known phenomenon which carries a higher risk of morbidity and mortality. Multiple patient-specific risk factors and pathophysiologic mechanisms have been identified and therapies have been proposed to mitigate risk of delirium development postoperatively. Notably, cardiac surgery frequently involves the use of an intraoperative cardiopulmonary bypass (CPB), which may contribute to the mechanisms responsible for POD. Despite our greater understanding of these causative factors, a substantial reduction in the incidence of POD remains high among cardiac surgical patients. Multiple therapeutic interventions have been implemented intraoperatively and postoperatively, many with conflicting results. This review article will highlight the incidence and impact of POD in cardiac surgical patients. It will describe some of the primary risk factors associated with POD, as well as anesthetic management and therapies postoperatively that may help to reduce delirium.

Incidence and Factors Related to Prolonged Postoperative Cognitive Decline (POCD) in Elderly Patients Following Surgery and Anaesthesia: A Systematic Review

Aim

The aim of this systematic review is to explore the current literature to provide evidence regarding the incidence and risk factors of prolonged POCD in elderly patients following cardiac and non-cardiac surgical interventions.

Methods

The PubMed and Google Scholar databases were searched using appropriate keywords and search engines for adequate evidence from studies meeting the inclusion criteria so as to reveal the end-point, which was the presence of prolonged POCD in elderly patients following surgery and anaesthesia. The incidence of POCD at different time intervals and the variables predicting the occurrence of POCD were analysed.

Results

The results of 23 articles covering 5077 patients (3694 non cardiac and 1383 cardiac surgeries) were carefully analysed. POCD occurs from the first postoperative day and lasts for potentially long periods. The incidence of POCD in this review ranged from 2.2% to 35.7%. More specifically, it ranged from 2.2% to 31.5% in non-cardiac surgeries and 11.8% to 35.7% in patients who had undergone cardiac surgeries. Some of the independent risk factors (predictors) for the development of POCD were advanced age, high concentration of neuroinflammatory mediators detectable in plasma, low SpO2, longer anaesthetic and surgical duration, and depth of anaesthesia.

Conclusion

This review can only provide limited evidence of prolonged POCD (more than a year) and further research that involves better study designs, larger samples, involving longer follow-up, and at different sites (multicentre) is highly advised. This in turn may help researchers and clinicians to discover the actual causes and risk factors and develop appropriate preventive and treatment protocols to tackle POCD in the ageing surgical population.

Propofol Versus Remimazolam on Cognitive Function, Hemodynamics, and Oxygenation During One-Lung Ventilation in Older Patients Undergoing Pulmonary Lobectomy: A Randomized Controlled Trial

OBJECTIVES

To investigate the effects of remimazolam on postoperative cognitive function, intraoperative hemodynamics, and oxygenation in older patients undergoing lobectomy.

DESIGN

A prospective, double-blind, randomized, controlled study.

SETTING

A university hospital.

PARTICIPANTS

Eighty-four older patients with lung cancer who underwent lobectomy, aged ≥65 years.

INTERVENTIONS

Patients were divided randomly into the remimazolam (group R) and propofol (group P) groups. Group R underwent remimazolam anesthesia induction and maintenance, whereas group P underwent propofol anesthesia induction and maintenance. Cognitive function was assessed with neuropsychological tests 1 day before surgery and 7 days after surgery. The Clock Drawing Test, Verbal Fluency Test (VFT), Digit Symbol Switching Test (DSST), and Auditory Verbal Learning Test-Huashan (AVLT-H) assessed visuospatial ability, language function, attention, and memory, respectively. The systolic blood pressure (SBP), heart rate, mean arterial pressure (MAP), and cardiac index were recorded 5 minutes before induction of anesthesia (T0), 2 minutes after sedation (T1), 5 minutes after intubation with two-lung ventilation (T2), 30 minutes after one-lung ventilation (OLV) (T3), 60 minutes after OLV (T4), and at the end of surgery (T5), and the incidences of hypotension and bradycardia were recorded. The PaO2, oxygenation index (OI), and intrapulmonary shunt (Qs/Qt) were assessed at T0, T2, T3, T4, and T5. The levels of S-100β and interleukin 6 were measured by enzyme-linked immunosorbent assay at T0, T5, 24 hours after surgery (T6), and on day 7 after surgery (T7).

MEASUREMENTS AND MAIN RESULTS

The VFT, DSST, immediate recall AVLT-H, and short-delayed recall AVLT-H scores were significantly higher in group R than in group P on day 7 after surgery (p < 0.05). The SBP and MAP at T2 to T5 were significantly higher in group R than in group P, the incidence of hypotension was significantly lower in group R (9.5%) than in group P (35.7%) (p = 0.004), and remimazolam significantly reduced the dose of phenylephrine used (p < 0.05). The PaO2 and OI at T4 were significantly higher in group R than in group P, and Qs/Qt was significantly lower in group R than in group P. The levels of S-100β at T5 were significantly lower in group R than in group P (p < 0.05).

CONCLUSION

The results showed that remimazolam (versus propofol) may lessen the degree of short-term postoperative cognitive dysfunction measured by standard neuropsychological tests, better optimize intraoperative hemodynamics, and lead to improved oxygenation during OLV.

Effect of transcutaneous electrical acupoint stimulation on postoperative cognitive function in older patients with lung cancer: A randomized, double-blind, placebo-controlled trial

Objective

This trial was to examine the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive function in older patients who underwent thoracoscopic pulmonary resection.

Methods

This was a prospective, randomized, double-blind, placebo-controlled study. 128 patients scheduled for surgery were randomly assigned to the TEAS group and sham-TEAS group. A standardized intervention of TEAS or sham-TEAS on the acupoints of Baihui (DU20) and bilateral Neiguan (PC6), Hegu (LI4), and Zusanli (ST36) from 30 min before anesthesia induction until the end of the surgery, combined with a general anesthetic protocol performed in the two groups respectively. The primary outcome was the incidence of postoperative cognitive dysfunction (POCD) assessed via the Montreal Cognitive Assessment (MoCA) scale at each time point. The secondary outcomes included the results of the Mini-Mental State Examination (MMSE) score, the Numerical Rating Scale (NRS) on pain and sleep, the European Organization for Research and Treatment of Cancer Quality of Life (EORTC-QLQ-C30), and a chronic pain questionnaire at relative time points.

Results

Participants who completed the 12-month trial of the two groups were well-matched in baseline demographic and clinical parameters. At postoperative day 1, day 7, and day 30 time points, the incidence of POCD in the sham-TEAS group was always significantly higher than in the TEAS group (65.4% vs 20%, 43.6% vs 7.3%, 40% vs 3.6%, all P < 0.001). Also, the TEAS group showed better scores of MMSE, sleep, and pain compared with the sham-TEAS group (all P < 0.001). At 6 and 12 months points, the global health scores of the TEAS group were still significantly higher than the sham-TEAS group, and the prevalence of chronic pain was significantly lower than the sham-TEAS group (all P < 0.05).

Conclusion

TEAS could effectively improve the postoperative cognitive function and long-term life quality of geriatric patients with lung cancer.

Effects of LncRNA GAS5/miR-137 general anesthesia on cognitive function by TCF4 inflammatory bodies in patients undergoing lumbar spinal canal decompression

Lumbar spinal stenosis is a common orthopedic disease in clinical practice at present. Postoperative cognitive dysfunction (POCD) refers to the phenomenon of impaired memory. However, whether long noncoding RNA (LncRNA) GAS5 contributes to the mechanism of cognitive function in undergoing lumbar spinal canal decompression remains unknown. Thus, the present study investigated the precise details of LncRNA GAS5 involvement in Postoperative cognitive dysfunction of patients undergoing lumbar spinal canal decompression. Patients undergoing lumbar spinal canal decompression with cognitive function and Normal healthy volunteers were obtained. C57BL/6 mice were maintained with a 2% concentration of sevoflurane in 100% oxygen at a flow rate of 2 L minute-1 for 4 hours. LncRNA GAS5 gene expression were up-regulated in patients undergoing lumbar spinal canal decompression. In mice model, LncRNA GAS5 gene expression also increased. LncRNA GAS5 promoted neuroinflammation in vitro model. LncRNA GAS5 raised cognitive impairment and increased neuroinflammation in mice model. LncRNA GAS5 suppressed miR-137 in vitro model. MiR-137 reduced neuroinflammation in vitro model. MiR-137 suppressed TCF4 protein expression in vitro model. Transcription factor TCF4 activates the expression of bHLH. Taking together, this experiment provide the first experimental and clinical evidence that LncRNA GAS5/miR-137 promoted anesthesia-induced cognitive function to increase inflammatory bodies in patients undergoing lumbar spinal canal decompression, suggesting it may be a biomarker of POCD and a potential therapeutic target for POCD.

Which Predictor, SctO2 or SstO2, Is more Sensitive for Postoperative Cognitive Dysfunction in Spine Surgery: A Prospective Observational Study?

OBJECTIVE

Patients undergoing spinal surgery in the prone position may experience venous stasis, often resulting in edema in dependent areas of the body, including the head, and increased postoperative cognitive dysfunction (POCD). Not only does POCD present challenges for post-operative care and recovery, it can also cause permanent damage to the patient's brain and increase mortality and social costs. We aimed to clarify the incidence of POCD in patients with hypertension after prone spine surgery and to further determine the association between intraoperative somatic tissue oxygen saturation (SstO2)/cerebral tissue oxygen saturation (SctO2) and POCD.

METHODS

Patients with hypertension scheduled for open prone spine surgery from January 2020 to April 2021 were included in this single-center, prospective, observational study. SctO2 and SstO2 were monitored by near-infrared spectroscopy continuously throughout the surgery. The primary outcome was POCD assessed using the Mini-Mental Status Examination (MMSE). The association of SstO2 and SctO2 with POCD was evaluated with unadjusted analyses and multivariable logistic regression.

RESULTS

One hundred and one of 112 identified patients were included, 28 (27.8%) of whom developed POCD. None of the investigated SctO2 indices were predictive of POCD. However, the patients with POCD had greater decreases in intraoperative absolute SstO2 and relative SstO2 than the patients without POCD (P = 0.037, P = 0.036). Moreover, three SstO2 indices were associated with POCD, including a greater absolute SstO2 decrease (P = 0.021), a greater relative SstO2 decrease (P = 0.032), and a drop below 90% of the baseline SstO2 (P = 0.002), independent of ASA III status, preoperative platelets and postoperative sepsis. In addition, there was no correlation between intraoperative SctO2 and intraoperative SstO2 or between their respective absolute declines.

CONCLUSION

Twenty-eight (27.7%) of 101 patients developed POCD in patients with hypertension undergoing prone spine surgery, and intraoperative SstO2 is associated with POCD, whereas SctO2 shows no association with POCD. This study may initially provide a valuable new approach to the prevention of POCD in this population.