Comprehensive geriatric assessment for older orthopedic patients and analysis of risk factors for postoperative complications.

BACKGROUND: The comprehensive geriatric assessment (CGA) has been proposed as a supplementary tool to reduce perioperative complications of geriatric patients, however there is no universally accepted standardization of CGA for orthopedic surgery. In this study, a novel CGA strategy was applied to evaluate the conditions of older patients undergoing orthopedic surgery from a broad view and to identify potential risk factors for postoperative complications. METHODS: A prospective cohort study was conducted from March 2019 to December 2020.The study enrolled patients (age > 75 years) for elective or confined orthopedic surgery. All patients were treated by a multidisciplinary team. A structured CGA was conducted to identify high-risk older patients and to facilitate coordinated multidisciplinary team care by a geriatric team. The basic patient characteristics, CGA results, postoperative complication and mortality rates were collected. Multivariate logistic regression analysis was used to identify risk factors for postoperative complications. RESULTS: A total of 214 patients with an age of 81.07 ± 4.78 (range, 75-100) years were prospectively enrolled in this study. In total, 66 (30.8%) complications were registered, including one death from myocardial infarction (mortality rate, 0.5%). Poor Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) were accompanied by frailty, worse perioperative risk, pain, and nutritional status. Poor ADL was also associated with higher risks of falling, polypharmacy, and cardiac and respiration complications. Poor IADL was associated with a higher risk of cardiac and respiration complications. Higher stroke risk was accompanied by higher risks of cardiac complications, delirium, and hemorrhage. Worse American Society of Anesthesiologists (ASA) score was associated with worse ADL, IADL, frailty, and higher delirium risk. Multivariate logistic regression analysis showed that spinal fusion (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.65 to 0.83; p = 0.0214), blood loss(OR, 1.68; 95% CI, 1.31 to 2.01; p = 0.0168), ADL (severe dysfunction or worse) (OR, 1.45; 95% CI, 1.16 to 1.81; p = 0.0413), IADL (serious dependence) (OR, 1.08; 95% CI, 1.33 to 1.63; p = 0.0436), renal function (chronic kidney disease (CKD) ≥ stage 3a) (OR, 2.01; 95% CI, 1.54 to 2.55; p = 0.0133), and malnutrition(OR, 2.11; 95% CI, 1.74 to 2.56; p = 0.0101) were independent risk factors for postoperative complications. CONCLUSION: The CGA process reduces patient mortality and increases safety in older orthopedic surgery patients. Spinal fusion, blood loss, ADL (severe dysfunction or worse), IADL (serious dependence), renal function (CKD ≥ stage 3a) and nutrition mini nutritional assessment (MNA) (malnourished) were independent risk factors of postoperative complications following orthopaedic surgery in older patients.

Risk factors for acute kidney injury after major abdominal surgery in the elderly aged 75 years and above.

OBJECTIVES: The study aimed to investigate the incidence and risk factors of acute kidney injury (AKI) in elderly patients (aged ≥ 75 years) undergoing major nonvascular abdominal surgery. METHODS: The study was a retrospective study that evaluated the incidence of AKI in patients within 48 h after major abdominal surgeries. Patients' preoperative characteristics and intraoperative management, including the use of nephrotoxic medications, were evaluated for associations with AKI using a logistic regression model. RESULTS: A total of 573 patients were included in our analysis. A total of 33 patients (5.76%) developed AKI, and 30 (90.91%), 2 (6.06%) and 1 (3.03%) reached the AKI stages 1, 2 and 3, respectively. Older age (adjusted OR, aOR 1.112, 95% confidence interval, CI 1.020-1.212), serum albumin (aOR 0.900, 95% CI 0.829-0.977), baseline eGFR (aOR 3.401, 95% CI 1.479-7.820), the intraoperative occurrence of hypotension (aOR 3.509, 95% CI 1.553-7.929), and the use of hydroxyethyl starch in combination with nonsteroidal anti-inflammatory drugs (aOR 3.596, 95% CI 1.559-8.292) or furosemide (aOR 5.724, 95% CI 1.476-22.199) were independent risk factors for postoperative AKI. CONCLUSIONS: Several risk factors, including intraoperative combined administration of HES and furosemide, are independent factors for AKI during abdominal surgeries. Anesthesiologists and surgeons should take precautions in treating at-risk patients.

Effects of circadian rhythm on Narcotrend index and target-controlled infusion concentration of propofol anesthesia.

BACKGROUND: The effects of circadian rhythms on drug metabolism and efficacy are being increasingly recognized. However, the extent to which they affect general anesthesia remains unclear. This study aims to investigate the effects of circadian rhythms on anesthetic depth and the concentrations of propofol target-controlled infusion (TCI). METHODS: Sixty patients undergoing laparoscopic surgeries were sequentially assigned to four groups. Group ND (n = 15): Propofol TCI with Narcotrend monitor during the day (8:00-18:00), Group NN (n = 15): Propofol TCI with Narcotrend monitor during the night (22:00-5:00), Group CLTD (n = 15): Propofol closed-loop TCI guided by bispectral index (BIS) during the day (8:00-18:00), Group CLTN (n = 15): Propofol closed-loop TCI guided by BIS during the night (22:00-5:00). The Narcotrend index, mean arterial pressure (MAP) and heart rate (HR) were compared between group ND and NN at 7 time points, from 5 min before induction to the end of operation. The propofol TCI concentrations, MAP and HR were compared between group CLTD and CLTN at 7 time points, from 5 min after induction to the end of operation. RESULTS: The Narcotrend index, MAP, and HR in group NN were lower than those in group ND from the beginning of mechanical ventilation to the end of operation (p < 0.05). The propofol TCI concentrations in group CLTN were lower than those in group CLTD from the beginning of operation to the end of operation (p < 0.05). CONCLUSION: Circadian rhythms have a significant effect on the depth of anesthesia and drug infusion concentrations during propofol TCI. When using general anesthesia during night surgery, the propofol infusion concentration should be appropriately reduced compared to surgery during the day. TRIAL REGISTRATION: The present study was registered on the ClinicalTrials.gov website ( NCT02440269 ) and approved by the Medical Ethics Committee of Southwest Hospital of Third Military Medical University (ethics lot number: 2016 Research No. 93). All patients provided informed written consent to participate in the study.

Association of preoperative medication with postoperative length of stay in elderly patients undergoing hip fracture surgery.

BACKGROUND: For elderly patients who are about to undergo surgery, research on the effects of preoperative medication on postoperative outcomes is rare, especially preoperative discontinuation-requiring medication (PDRM) which needed to be discontinued because of its increased risk of postoperative complications. AIM: To investigate whether preoperative medication (PDRM and polypharmacy) is associated with postoperative length of hospital stay (LOS) in elderly patients undergoing hip fracture surgery. METHODS: Patients aged ≥ 65 who were scheduled for hip (limited to femoral tuberosity) fracture surgery were included. Baseline characteristics, preoperative medication and postoperative LOS were collected from the electronic medical record. The primary outcome was postoperative LOS. RESULTS: A total of 369 hip fracture patients were included. There were 188 and 122 patients exposed to PDRM and polypharmacy, respectively. Multivariate analysis models were constructed using significant factors for prolonged postoperative hospital stay from univariate analysis: Model I (body mass index (BMI), Charlson comorbidity index (CCI) ≥ 7, creatinine clearance rate (Ccr) < 60 and PDRM) and Model II (BMI, Ccr ≥ 7, Ccr < 60 and polypharmacy). CCI was the most significant factor. Its adjusted odds ratio was as large as 2.7 and attributable risk was 63%. In preoperative medication use, both polypharmacy and PDRM showed significant association with postoperative LOS. CONCLUSION: The present study supported the impact of PDRM on postoperative LOS in geriatric hip fracture patients. The results added a further aspect to preoperative medication optimization in elderly patients undergoing hip fracture surgery.

An elderly female with adult-onset Still's disease initially misdiagnosed as prosthetic joint infection after total knee arthroplasty: lessons in differential diagnosis and treatment.

BACKGROUND: High fever, knee swelling and pain after knee arthroplasty are often considered as symptoms of acute prosthetic joint infection. However, similar symptoms can also present as primary manifestations of adult-onset Still's disease, which creates some interference in differential diagnosis. To our knowledge, this is the first published case of misdiagnosis of adult Still's disease after total knee arthroplasty, who was initially misdiagnosed as an prosthetic joint infection due to the above-mentioned symptoms. The symptoms of the knee infection was not relieve after several revisions and continous antibiotic treatment. Finally, after several consultations and repeated evaluation it was diagnosed as adult-onset Still's disease. CASE PRESENTATION: A 77-year-old female who underwent bilateral total knee arthroplasty 6 years ago was admitted to our hospital with high fever, right knee effusion and painful knee. Based on the results of joint fluid aspiration and culture, we treated the right knee as acute hematogenous prosthetic joint infection. After three debridement and revision surgeries, the patient's symptoms continued to persist. Subsequent manifestations of other symptoms such as typical rash and sore throat and laboratory examination suggested the possibility of adult-onset Still's disease. So she underwent diagnostic steroid hormone therapy at the recommendation of a rheumatologist, and a final revision was performed after symptom was controlled. At the one-year follow-up, the patient's symptoms completely resolved and the knee revision was functioning well. CONCLUSIONS: When joint swelling and pain occurs after knee arthroplasty, the possibility of joint infection should not only be considered, but rheumatic autoimmune diseases should also be differentiated. Because the manifestations of joint infection and rheumatic immune disease sometimes overlap highly, when reasonable treatment over a period of time fails to relieve symptoms and signs, we should notice subtle differences in symptoms and laborotary tests and look for other diagnostic possibilities in time.

Structural basis for efonidipine block of a voltage-gated Ca2+ channel.

Efonidipine is a dual L-/T- type calcium channel blocker with a slow onset of action and a long lasting effect that exibihits antihypertensive and nephroprotective effects. differs from most other DHPs which can induce reflex tachycardia. Efonidipine reduces blood pressure without decreasing cardiac output and exerts organ-protective effects on the heart and kidney. In order to investigate how efonidipine block voltage-gated Ca2+ channel, we determined the crystal structure of CaVAb in complex with efonidipine at atomic resolution using x-ray crystallography. Our results reveal that efonidipine targets the central cavity of a model voltage-gated calcium channel underneath its selectivity filter and occlude the channel in an inactivated state. Binding of efonidipine does not break down the fourfold symmetry of the quaternary structure and its pore structure. Our work provides the structural basis for efonidipine block of a voltage-gated Ca2+ channel at the molecular level.

Risk Factors for Postoperative Cognitive Decline After Orthopedic Surgery in Elderly Chinese Patients: A Retrospective Cohort Study.

Purpose: We aimed to identify the risk factors for postoperative cognitive decline (POCD) by evaluating the outcomes from preoperative comprehensive geriatric assessment (CGA) and intraoperative anesthetic interventions. Patients and Methods: Data used in the study were obtained from the Aged Patient Perioperative Longitudinal Evaluation-Multidisciplinary Trial (APPLE-MDT) cohort recruited from the Department of Orthopedics in Xuanwu Hospital, Capital Medical University between March, 2019 and June, 2022. All patients accepted preoperative CGA by the multidisciplinary team using 13 common scales across 15 domains reflecting the multi-organ functions. The variables included demographic data, scales in CGA, comorbidities, laboratory tests and intraoperative anesthetic data. Cognitive function was assessed by Montreal Cognitive Assessment scale within 48 hours after admission and after surgery. Dropping of ≥1 point between the preoperative and postoperative scale was defined as POCD. Results: We enrolled 119 patients. The median age was 80.00 years [IQR, 77.00, 82.00] and 68 patients (57.1%) were female. Forty-two patients (35.3%) developed POCD. Three cognitive domains including calculation (P = 0.046), recall (P = 0.047) and attention (P = 0.007) were significantly worsened after surgery. Univariate analysis showed that disability of instrumental activity of daily living, incidence rate of postoperative respiratory failure (PRF) ≥4.2%, STOP-Bang scale score, Caprini risk scale score and Sufentanil for maintenance of anesthesia were different between the POCD and non-POCD patients. In the multivariable logistic regression analysis, PRF ≥ 4.2% (odds ratio [OR] = 2.343; 95% confidence interval [CI]: 1.028-5.551; P = 0.046) and Sufentanil for maintenance of anesthesia (OR = 0.260; 95% CI: 0.057-0.859; P = 0.044) was independently associated with POCD as risk and protective factors, respectively. Conclusion: Our study suggests that POCD is frequent among older patients undergoing elective orthopedic surgery, in which decline of calculation, recall and attention was predominant. Preoperative comprehensive geriatric assessments are important to identify the high-risk individuals of POCD.

Fabrication of a micro/nanocomposite structure on the surface of high oxygen concentration titanium to promote bone formation.

This study investigated the properties of the micro/nano composite structure on the surface of high oxygen concentration titanium (HOC-Ti) after anodic oxidation modification (HOC-NT) and evaluated its biocompatibility as a dental implant material in vitro and in vivo. HOC-Ti was produced by titanium powders and rutile powders using the powder metallurgy method. Its surface was modified by anodic oxidation. After detecting the electrochemical characteristics, the surface properties of HOC-NT were investigated. MC3T3 and MLO-Y4 cells were employed to evaluate the biocompatibility of HOC-NT and cocultured to study the effects of the changes in osteocytes induced by HOC-NT on osteoblasts. While, its possible mechanism was investigated. In addition, osseointegration around the HOC-NT implant was investigated through in vivo experiments. The results showed that a unique micronano composite structure on the HOC-Ti surface with excellent hydrophilicity and suitable surface roughness was created after anodic oxidation promoted by its electrochemical characteristics. The YAP protein may play an important role in regulating bone remodeling by ß-catenin and Rankl/OPG Signaling Pathways. An in vivo study also revealed an accelerated formation rate of new bone and more stable osseointegration around the HOC-NT implant. In view of all experimental results, it could be concluded that the unique morphology of HOC-NT has enhanced physicochemical and biological properties. The promotion of bone formation around implants indicated the feasibility of HOC-NT for applications in oral implants.

Hyperbranched polymer functionalized flexible perovskite solar cells with mechanical robustness and reduced lead leakage.

Perovskite solar cells (PSCs) are multilayer structures. The interface between electron transport layer and perovskite is the mechanical weakest point in flexible PSCs due to its low fracture energy. Herein, we develop a highly adhesive polyamide-amine-based hyperbranched polymers to reinforce the interface. The interface fracture energy is improved from 1.08 to 2.13 J·m-2 by the hyperbranched polymers with adhesive groups and dynamic hydrogen bond networks. The polymer functionalized perovskite solar cells achieve superior power conversion efficiencies of 25.05% and 23.86% for rigid and flexible devices, respectively. Furthermore, the hyperbranched polymer contains abundant intramolecular cavities that can capture Pb2+. Pb leakage after solar cell damage is effectively suppressed. Our findings provide insights on designing adhesive interface layers towards high-efficiency, mechanical-stable and environment-friendly flexible perovskite solar cells.

Extraordinary Antiwear Properties of Graphene-Reinforced Ti Composites Induced by Interfacial Decoration.

The expected excellent lubricant effect of graphene in metals during friction and wear is rarely achieved because of the difficulty in synthesizing suitable interfaces. Particularly, the situation is more challenging in titanium (Ti) matrix composites (TMCs) because of the high chemical-interface-reaction tendency between graphene and Ti during composite fabrication. In this study, few-layered graphene (FLG) decorated with SiC nanoparticles (SiCp) was synthesized as reinforcement in Ti-6Al-4V alloy to improve the interface of the composites. It was found that interfacial SiCp not only strengthened the interface bonding by the Si solid solution but also inhibited the chemical reaction between FLG and the Ti matrix with reduced sp3 defects. The composite with 30 wt % SiC-decorated FLG showed an 86.8% decrement in wear rate compared to the unreinforced matrix, resulting in exceptionally high antiwear enhancing efficiency, which was around fourfold of the available values of other TMCs in the literature. The antiwear mechanism was investigated by thorough characterization of the interfaces and microstructures of the composites. The idea of interfacial decoration can be potentially applied to other nanocarbon/metal composites with the advantages of retaining the function performance of nanocarbon materials.

Mechanical properties and biocompatibility of titanium with a high oxygen concentration for dental implants.

In order to improve the strength of commercially pure Ti (CP-Ti) for oral implants, the high oxygen content Ti (HOC-Ti) was prepared via powder metallurgy. Its composition and mechanical properties were then characterized. After surface treatment by sandblasting and acid etching (SLA), the surface morphology, wettability and roughness of the HOC-Ti and CP-Ti sample were examined. In an in vitro test that followed an evaluation of the protein adsorption capacity of HOC-Ti, the mouse preosteoblast cells were inoculated onto the specimens to evaluate their biocompatibility, in comparison with those of CP-Ti. The oxygen concentration of the HOC-Ti increased to 0.62 wt%, which is higher than the 0.26 wt% of the CP-Ti, while their compositions and microstructures were very similar. The tensile and compressive yield strength of the HOC-Ti (800 MPa) was improved significantly in comparison to that of the CP-Ti (530 MPa). After surface treatment, a unique structure of micropores with a diameter of 380 nm was observed on the entire surface of the HOC-Ti that facilitates cell adhesion and proliferation. The wettability of the HOC-Ti was obviously superior (p < 0.05). The in vitro study showed that the MC3T3-E1 cells inoculated on the surface of HOC-Ti exhibited a homogeneous microstructure, and the viability was higher than that of the control group on days 4 and 7 (p < 0.05). In addition, the number and differentiation activity of cells that adhered to the surface of the HOC-Ti increased significantly on day 7 (p < 0.05). The experimental results showed that, in view of its mechanical properties and biocompatibility, HOC-Ti is superior to CP-Ti and is promising for oral implant applications.

Dynamic self-strengthening of a bio-nanostructured armor - conch shell.

Bio-nanowire structured armors - conch shells, which are often collected as art pieces, possess a special function - an unusual resilience against high speed predatory attacks. Under high-strain-rate compression (strain rate ~103 s-1) conch shells highlight significantly high fracture strength vis-à-vis under quasi-static loading (strain rate ≤ 10-2/s). The dynamic fracture strength reaches a strikingly high value of 600 MPa, 67% enhancement with reference to that of quasi-static loading with the fracture strength 360 MPa. Upon dynamic impact loading, conch shells ingeniously activated a new defense mechanism - intra-lamella fracture, which differs from the inter-lamella fracture damage under quasi-static loading. The lengthy third-order lamellae with a length of hundreds of micrometers were pulverized into rods with the length ranging from 0.4 µm and 2.5 µm upon dynamic loading, whereas the third-order lamellae in the quasi-statically fractured segments maintained the length of hundreds of micrometers. Multiple energy-dissipating mechanisms - intra-lamella fracture, nanoparticle rotation and dislocation enabled nanoparticle deformation in a synergistical fashion contribute to the high strain rate fracture strength of conch shells. This dynamic self-strengthening strategy provides a new guideline for designing dynamically robust materials.

Development of a list of high-risk perioperative medications for the elderly: a Delphi method.

Objectives: There is a lack of direct evidence for the management of perioperative medications in elderly patients. Therefore, the authors aimed to develop a list of high-risk medications for the elderly population in China to provide indicators for clinicians to identify medication-related factors contributing to potential adverse events during the perioperative period. Methods: The initial list of high-risk perioperative medications was developed by studying all the publications that described specific high-risk medications and their risk profiles in the elderly. Delphi consultations were performed to form a consensus among the group of experts and the list was finalized. Results: The expert panel consisted of 36 experts from 29 tertiary hospitals and 18 provinces or municipalities. The consensus was reached after two Delphi rounds. Finally, a total of 86 medications of 13 medication classes and 120 screening items were included in the final list, along with perioperative risk profiles and risk aversion recommendations for each drug. Conclusion: This is the first study to establish a high-risk perioperative medication list in China, which can be used as a reference for intervention and evaluation of perioperative medications for the elderly population.