Characterization of lung function impairment and pathological changes induced by chronic lead and cadmium inhalation: Insights from a mouse model study.

Exposure to environmental heavy metals such as lead (Pb) and cadmium (Cd) is a global concern due to their widespread presence. However, the specific pulmonary effects of inhaled exposure, especially related to long-term effects, remain poorly understood. In this study, we developed a novel mouse model of Pb and Cd inhalation to mimic real-world conditions and investigate pulmonary effects. Mice were exposed to Pb and Cd inhalation for 6 months using a whole-body exposure system, resulting in decreased lung compliance and progression from emphysematous changes to fibrosis. In addition, the blood Pb/Cd levels of mice exposed to Pb/Cd for 6 months are like those of humans occupationally exposed to heavy metals. Histology revealed inflammation and collagen deposition. Transcriptomic analysis highlighted immune responses and macrophage activity in developing fibrosis. These results confirm an association between Pb/Cd exposure and emphysema and fibrosis, reflecting clinical findings. The study highlights the importance of long-term exposure assessment and time-course analysis for understanding Pb/Cd-induced lung disease. The relevance of the mouse model in replicating human exposure scenarios underscores its value in studying fibrosis and emphysema simultaneously. These findings provide a basis for targeted therapeutic interventions against heavy metal-induced lung injury.

Clinical and Radiological Outcomes in C2 Recapping Laminoplasty for the Pathologies in the Upper Cervical Spine.

OBJECTIVE: To evaluate C2 muscle preservation effect and the radiological and clinical outcomes after C2 recapping laminoplasty. METHODS: Fourteen consecutive patients who underwent C2 recapping laminoplasty around C1-2 level were enrolled. To evaluate muscle preservation effect, the authors conducted a morphological measurement of extensor muscles between the operated and nonoperated side. Two surgeons measured the cross-sectional area (CSA) of obliquus capitis inferior (OCI) and semispinalis cervicis (SSC) muscle before and after surgery to determine atrophy rates (ARs). Additionally, we examined range of motion (ROM), sagittal vertical axis (SVA), neck visual analogue scale (VAS), Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) score to assess potential changes in alignment and consequent clinical outcomes following posterior cervical surgery. RESULTS: We measured the CSA of OCI and SSC before surgery, and at 6 and 12 months postoperatively. Based on these measurements, the AR of the nonoperated SSC was 0.1% ± 8.5%, the AR of the operated OCI was 2.0% ± 7.2%, and the AR of the nonoperated OCI was -0.7% ± 5.1% at the 12 months after surgery. However, the AR of the operated side's SSC was 11.2% ± 12.5%, which is a relatively higher value than other measurements. Despite the atrophic change of SSC on the operated side, there were no prominent changes observed in SVA, C0-2 ROM, and C2-7 ROM between preoperative and 12 months postoperative measurements, which were 11.8 ± 10.9 mm, 16.3° ± 5.9°, and 48.7° ± 7.7° preoperatively, and 14.1 ± 11.6 mm, 16.1° ± 7.2°, and 44.0° ± 10.3° at 12 months postoperative, respectively. Improvement was also noted in VAS, NDI, and JOA scores after surgery with JOA recovery rate of 77.3% ± 29.6%. CONCLUSION: C2 recapping laminoplasty could be a useful tool for addressing pathologies around the upper cervical spine, potentially mitigating muscle atrophy and reducing postoperative neck pain, while maintaining sagittal alignment and ROM.

A smart device application for acute pain service in surgical patients at a tertiary hospital in South Korea: a prospective observational feasibility study.

Background: Pain assessment and patient education are essential for successful postoperative pain management. However, the provision of personnel for performing these tasks is often insufficient. Recently, attempts have been made to implement smartphone applications for educating and monitoring surgical patients. We developed a smartphone application (app) for postoperative pain management, and conducted a feasibility study. Methods: This single-center prospective observational study included 60 patients aged < 70 years who underwent elective surgery. This study evaluated the SmartAPS application, which offers tools for postoperative pain assessment and educational materials for pain management. The primary outcome was the active usage rate, defined as responding at least twice daily on postoperative days (PODs) 1 and 2. Additionally, we investigated patient satisfaction with the app and educational videos as well as any challenges encountered during use. Results: Sixty patients were enrolled in the study and active app use was achieved in 56.7% of them. Response rates peaked at 85.0% for pain intensity and 83.3% for opioid-related side effects at 14:00 on POD 1 but dropped to 56.7% and 58.3%, respectively, at 18:00 on POD 2. Among the patients who responded to the survey regarding the app usage, 84.0% reported satisfaction with the app and 80% found it beneficial for managing postoperative pain. Furthermore, 92.0% did not encounter difficulties using the app, indicating a generally positive user experience. Conclusions: Our findings support the utility of the SmartAPS application in acute pain services, highlighting its potential for improving postoperative pain management.

Neighbor effect on conformational spaces of alanine residue in azapeptides.

The conformational properties of Alanine (Ala) residue have been investigated to understand protein folding and develop force fields. In this work, we examined the neighbor effect on the conformational spaces of Ala residue using model azapeptides, Ac-Ala-azaGly-NHMe (3, AaG), and Ac-azaGly-Ala-NHMe (4, aGA1). Ramachandran energy maps were generated by scanning (φ, ψ) dihedral angles of the Ala residues in models with the fixed dihedral angles (φ = ±90°, ψ = ±0° or ±180°) of azaGly residue using LCgau-BOP and LCgau-BOP + LRD functionals in the gas and water phases. The integral-equation-formalism polarizable continuum model (IEF-PCM) and a solvation model density (SMD) were employed to mimic the solvation effect. The most favorable conformation of Ala residue in azapeptide models is found as the polyproline II (ßP), inverse γ-turn (γ'), ß-sheet (ßS), right-handed helix (αR), or left-handed helix (αL) depending on the conformation of neighbor azaGly residue in isolated form. Solvation methods exhibit that the Ala residue favors the ßP, δR, and αR conformations regardless of its position in azapeptides 3 and 4 in water. Azapeptide 5, Ac-azaGly-Ala-NH2 (aGA2), was synthesized to evaluate the theoretical results. The X-ray structure showed that azaGly residue adopts the polyproline II (ßP) and Ala residue adopts the right-handed helical (αR) structure in aGA2. The conformational preferences of aGA2 and the dimer structure of aGA2 based on the X-ray structure were examined to assess the performance of DFT functionals. In addition, the local minima of azapeptide 6, Ac-Phe-azaGly-NH2 (FaG), were compared with the previous experimental results. SMD/LCgau-BOP + LRD methods agreed well with the reported experimental results. The results suggest the importance of weak dispersion interactions, neighbor effect, and solvent influence in the conformational preferences of Ala residue in model azapeptides.

Preoperative COVID-19 and Postoperative Mortality in Cancer Surgery: A South Korean Nationwide Study.

BACKGROUND: We evaluated the impact of preoperative COVID-19 on early postoperative mortality in patients undergoing time-sensitive cancer surgery. METHODS: This retrospective, nationwide cohort study included adult patients who underwent various cancer (thyroid, breast, stomach, colorectal, hepatobiliary, genitourinary, lung, and multiple cancer) surgeries under general anesthesia in South Korea in 2022. Patients were grouped according to the duration from the date of COVID-19 confirmation to the date of surgery (0-2 weeks, 3-4 weeks, 5-6 weeks, and ≥7 weeks). Patients without preoperative COVID-19 also were included. Multivariable logistic regression analysis with Firth correction was performed to investigate the association between preoperative COVID-19 and 30-day and 90-day postoperative mortality. The covariates encompassed sociodemographic factors, the type of surgery, and vaccination status in addition to the aforementioned groups. RESULTS: Of the 99,555 patients analyzed, 30,933 (31.1%) were preoperatively diagnosed with COVID-19. Thirty-day mortality was increased in those who underwent surgery within 0-2 weeks after diagnosis of COVID-19 (adjusted odds ratio [OR], 1.47; 95% confidence interval [CI], 1.02-2.12; P = 0.038); beyond 2 weeks, there was no significant increase in mortality. A similar pattern was observed for 90-day mortality. Full vaccination against COVID-19 was associated with reduced 30-day (OR 0.38; 95% CI 0.29-0.50; P < 0.001) and 90-day (OR 0.39; 95% CI 0.33-0.46; P < 0.001) mortality. CONCLUSIONS: Cancer surgery within 2 weeks of COVID-19 diagnosis was associated with increased early postoperative mortality. These findings support current guidelines that recommend postponing elective surgery for at least 2 weeks after the diagnosis of COVID-19.

Volatile Anesthetic Use Versus Total Intravenous Anesthesia for Patients Undergoing Heart Valve Surgery: A Nationwide Population-Based Study.

BACKGROUND: Many studies have suggested that volatile anesthetic use may improve postoperative outcomes after cardiac surgery compared to total intravenous anesthesia (TIVA) owing to its potential cardioprotective effect. However, the results were inconclusive, and few studies have included patients undergoing heart valve surgery. METHODS: This nationwide population-based study included all adult patients who underwent heart valve surgery between 2010 and 2019 in Korea based on data from a health insurance claim database. Patients were divided based on the use of volatile anesthetics: the volatile anesthetics or TIVA groups. After stabilized inverse probability of treatment weighting (IPTW), the association between the use of volatile anesthetics and the risk of cumulative 1-year all-cause mortality (the primary outcome) and cumulative long-term (beyond 1 year) mortality were assessed using Cox regression analysis. RESULTS: Of the 30,755 patients included in this study, the overall incidence of 1-year mortality was 8.5%. After stabilized IPTW, the risk of cumulative 1-year mortality did not differ in the volatile anesthetics group compared to the TIVA group (hazard ratio, 0.98; 95% confidence interval, 0.90-1.07; P = .602), nor did the risk of cumulative long-term mortality (hazard ratio, 0.98; 95% confidence interval, 0.93-1.04; P = .579) at a median (interquartile range) follow-up duration of 4.8 (2.6-7.6) years. CONCLUSIONS: Compared with TIVA, volatile anesthetic use was not associated with reduced postoperative mortality risk in patients undergoing heart valve surgery. Our findings indicate that the use of volatile anesthetics does not have a significant impact on mortality after heart valve surgery. Therefore, the choice of anesthesia type can be based on the anesthesiologists' or institutional preference and experience.

Effect of an intravenous acetaminophen/ibuprofen fixed-dose combination on postoperative opioid consumption and pain after video-assisted thoracic surgery: a double-blind randomized controlled trial.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) often induces significant postoperative pain, potentially leading to chronic pain and decreased quality of life. This study aimed to evaluate the acetaminophen/ibuprofen combination effectiveness in reducing analgesic requirements and pain intensity in patients undergoing VATS. STUDY DESIGN: This is a double-blinded randomized controlled trial. METHODS: Adult patients scheduled for elective VATS for lung resection were randomized to receive either intravenous acetaminophen and ibuprofen (intervention group) or 100 mL normal saline (control group). Treatments were administered post-anesthesia induction and every 6 h for three cycles. The primary outcome was total analgesic consumption at 24 h postoperatively. Secondary outcomes were cumulative analgesic consumption at 2 and 48 h; analgesic-related side effects at 2, 24, and 48 h; quality of recovery at 24 h and 48 h postoperatively; pain intensity at rest and during coughing; and rescue analgesics use. Chronic postsurgical pain (CPSP) was assessed through telephone interviews 3 months postoperatively. RESULTS: The study included 96 participants. The intervention group showed significantly lower analgesic consumption at 24 h and 48 h postoperatively (24 h: median difference: - 100 µg equivalent intravenous fentanyl [95% confidence interval (CI) - 200 to - 5 µg], P = 0.037; 48 h: median difference: - 140 µg [95% CI - 320 to - 20 µg], P = 0.035). Compared to the controls, the intervention group exhibited a significantly lower quality of recovery 24 h post-surgery, with no significant difference at 48 h. All pain scores except for coughing at 48 h post-surgery were significantly lower in the intervention group compared to the controls. No significant differences were observed between the groups in postoperative nausea and vomiting occurrence, hospital stay length, and CPSP. CONCLUSION: Perioperative administration of acetaminophen/ibuprofen significantly decreased analgesic needs in patients undergoing VATS, providing an effective postoperative pain management strategy, and potentially minimizing the need for stronger analgesics.

siRNA treatment targeting integrin α11 overexpressed via EZH2-driven axis inhibits drug-resistant breast cancer progression.

BACKGROUND: Breast cancer, the most prevalent cancer in women worldwide, faces treatment challenges due to drug resistance, posing a serious threat to patient survival. The present study aimed to identify the key molecules that drive drug resistance and aggressiveness in breast cancer cells and validate them as therapeutic targets. METHODS: Transcriptome microarray and analysis using PANTHER pathway and StemChecker were performed to identify the most significantly expressed genes in tamoxifen-resistant and adriamycin-resistant MCF-7 breast cancer cells. Clinical relevance of the key genes was determined using Kaplan-Meier survival analyses on The Cancer Genome Atlas dataset of breast cancer patients. Gene overexpression/knockdown, spheroid formation, flow cytometric analysis, chromatin immunoprecipitation, immunocytochemistry, wound healing/transwell migration assays, and cancer stem cell transcription factor activation profiling array were used to elucidate the regulatory mechanism of integrin α11 expression. Tumour-bearing xenograft models were used to demonstrate integrin α11 is a potential therapeutic target. RESULTS: Integrin α11 was consistently upregulated in drug-resistant breast cancer cells, and its silencing inhibited cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) while restoring sensitivity to anticancer drugs. HIF1α, GLI-1, and EZH2 contributed the most to the regulation of integrin α11 and EZH2 expression, with EZH2 being more necessary for EZH2 autoinduction than HIF1α and GLI-1. Additionally, unlike HIF1α or EZH2, GLI-1 was the sole transcription factor activated by integrin-linked focal adhesion kinase, indicating GLI-1 as a key driver of the EZH2-integrin α11 axis operating for cancer stem cell survival and EMT. Kaplan-Meier survival analysis using The Cancer Genome Atlas (TCGA) dataset also revealed both EZH2 and integrin α11 could be strong prognostic factors of relapse-free and overall survival in breast cancer patients. However, the superior efficacy of integrin α11 siRNA therapy over EZH2 siRNA treatment was demonstrated by enhanced inhibition of tumour growth and prolonged survival in murine models bearing tumours. CONCLUSION: Our findings elucidate that integrin α11 is upregulated by EZH2, forming a positive feedback circuit involving FAK-GLI-1 and contributing to drug resistance, cancer stem cell survival and EMT. Taken together, the results suggest integrin α11 as a promising prognostic marker and a powerful therapeutic target for drug-resistant breast cancer.

Challenging issues of implementing enhanced recovery after surgery programs in South Korea.

This review discusses the challenges of implementing enhanced recovery after surgery (ERAS) programs in South Korea. ERAS is a patient-centered perioperative care approach that aims to improve postoperative recovery by minimizing surgical stress and complications. While ERAS has demonstrated significant benefits, its successful implementation faces various barriers such as a lack of manpower and policy support, poor communication and collaboration among perioperative members, resistance to shifting away from outdated practices, and patient-specific risk factors. This review emphasizes the importance of understanding these factors to tailor effective strategies for successful ERAS implementation in South Korea's unique healthcare setting. In this review, we aim to shed light on the current status of ERAS in South Korea and identify key barriers. We hope to encourage Korean anesthesiologists to take a leading role in adopting the ERAS program as the standard for perioperative care. Ultimately, our goal is to improve the surgical outcomes of patients using this proactive approach.

The impact of preoperative coronavirus disease 19 infection on early postoperative mortality during the vaccination era: a nationwide retrospective cohort study.

BACKGROUND: We aimed to investigate the optimal surgical timing in patients with preoperative coronavirus disease 2019 (COVID-19) infection to minimize postoperative morbidity and mortality during the COVID-19 vaccination era. METHODS: The Korean nationwide data on patients who underwent standard surgery under general anesthesia in 2021 were analyzed. Patients were categorized based on the time from COVID-19 diagnosis to surgery: 0-4, 5-8, > 8 weeks, and those without preoperative COVID-19 infection. Multivariable logistic regression analysis, considering preoperative COVID-19 vaccination status (fully vaccinated vs. unvaccinated or partially vaccinated), was performed to associate the preoperative COVID-19 infection timing with 30- and 90-day postoperative mortality and 30-day respiratory complications. RESULTS: Among the 750,175 included patients, 28.2% were preoperatively fully vaccinated. Compared with patients without prior COVID-19 infection, those who had surgery 0-4 weeks (adjusted odds ratio [OR]: 4.28, 95% CI [1.81, 10.13], P = 0.001) and 5-8 weeks (adjusted OR: 3.38, 95% CI [1.54, 7.44], P = 0.002) after COVID-19 infection had a significantly increased risk of 30-day mortality. Preoperative full vaccination was significantly associated with a decrease in 90-day mortality (adjusted OR: 0.93, 95% CI [0.89, 0.98], P = 0.007) and 30-day respiratory complications (adjusted OR: 0.85, 95% CI [0.82, 0.87], P < 0.001), but not with 30-day mortality (P = 0.916). CONCLUSIONS: COVID-19 infection eight weeks preoperatively was associated with an increased 30-day postoperative mortality. Preoperative full vaccination was not associated with 30-day mortality but was related to lower risk of 90-day mortality and 30-day respiratory complications.

Randomized controlled trial of the effect of general anesthetics on postoperative recovery after minimally invasive nephrectomy.

BACKGROUND: General anesthetic techniques can affect postoperative recovery. We compared the effect of propofol-based total intravenous anesthesia (TIVA) and desflurane anesthesia on postoperative recovery. METHODS: In this randomized trial, 150 patients undergoing robot-assisted or laparoscopic nephrectomy for renal cancer were randomly allocated to either the TIVA or desflurane anesthesia (DES) group. Postoperative recovery was evaluated using the Korean version of the Quality of Recovery-15 questionnaire (QoR-15K) at 24 h, 48 h, and 72 h postoperatively. A generalized estimating equation (GEE) was performed to analyze longitudinal QoR-15K data. Fentanyl consumption, pain severity, postoperative nausea and vomiting, and quality of life three weeks after discharge were also compared. RESULTS: Data were analyzed for 70 patients in each group. The TIVA group showed significantly higher QoR-15K scores at 24 and 48 h postoperatively (24 h: DES, 96 [77, 109] vs. TIVA, 104 [82, 117], median difference 8 [95% CI: 1, 15], P = 0.029; 48 h: 110 [95, 128] vs. 125 [109, 130], median difference 8 [95% CI: 1, 15], P = 0.022), however not at 72 h (P = 0.400). The GEE revealed significant effects of group (adjusted mean difference 6.2, 95% CI: 0.39, 12.1, P = 0.037) and time (P < 0.001) on postoperative QoR-15K scores without group-time interaction (P = 0.051). However, there were no significant differences in other outcomes, except for fentanyl consumption, within the first 24 h postoperatively. CONCLUSIONS: Propofol-based TIVA showed only a transient improvement in postoperative recovery than desflurane anesthesia, without significant differences in other outcomes.

Pulmonary artery catheter monitoring versus arterial waveform-based monitoring during liver transplantation: a retrospective cohort study.

Although pulmonary artery catheter (PAC) has been used during liver transplantation surgery, the usefulness of PAC has rarely been investigated. We evaluated whether the use of PAC is associated with better clinical outcomes compared to arterial waveform-based monitoring after liver transplantation. A total of 1565 cases undergoing liver transplantation were reviewed. We determined whether patients received PAC or not and divided our cohort into the PAC with hemodynamic monitoring using PAC and the non-PAC with arterial waveform-based monitoring using FloTrac-Vigileo. Propensity score matching was performed. Acute kidney injury (AKI), early allograft dysfunction (EAD) and 1-year all-cause mortality or graft failure were compared in the matched cohorts. Logistic regression analysis was performed in the inverse probability of treatment-weighted (IPTW) cohort for postoperative EAD and AKI, respectively. Five-year overall survival was compared between the two groups. In the matched cohort, there was no significant difference in the incidence of AKI, EAD, length of hospital or ICU stay, and 1-year all-cause mortality between the groups. In the IPTW cohort, the use of PAC was not a significant predictor for AKI or EAD (AKI: odds ratio (95% confidence interval) of 1.20 (0.47-1.56), p = 0.229; EAD: 0.99 (0.38-1.14), p = 0.323). There was no significant difference in the survival between groups after propensity score matching (Log-rank test p = 0.578). In conclusion, posttransplant clinical outcomes were not significantly different between the groups with and without PAC. Anesthetic management without the use of PAC may be possible in low-risk patients during liver transplantation. The risk should be carefully assessed by considering MELD scores, ischemic time, surgical history, previous treatment of underlying liver disease, and degree of portal and pulmonary hypertension.Registration: https://clinicaltrials.gov/ct2/show/NCT05457114 (registration date: July 15, 2022).

Surgical technique of combined minimally invasive anterior column realignment at L1-L2 with open extension of prior fusion.

Surgical correction of fixed kyphotic deformity or severe sagittal imbalance traditionally involves three column osteotomies, which are associated with high morbidity rates. Anterior column realignment (ACR) has emerged as a minimally invasive alternative for restoring segmental lordosis. This technique involves a lateral approach and release of the anterior longitudinal ligament (ALL), followed by placement of a hyperlordotic interbody cage. In this study, we present a successful case of minimally invasive ACR for the treatment of flatback deformity and adjacent segment disease in a patient with prior L2-S1 fusion. Imaging revealed a flatback deformity, sagittal vertical axis elevation, and spinopelvic disharmony. The patient underwent a multistage procedure involving a lateral retropleural approach for ACR and interbody fusion, followed by open posterior instrumented fusion and vertebroplasties. Postoperatively, the patient experienced significant pain relief and improvement in lumbar lordosis, pelvic tilt, and pelvic incidence-lumbar lordosis mismatch. ACR combined with posterior release allows for manipulation of all three spinal columns, leading to spine reconstruction and improved spinopelvic harmony. We discuss the advantages of ACR, including its minimally invasive nature and potential benefits for patients with sagittal deformities. The presented surgical technique demonstrates the feasibility and efficacy of minimally invasive ACR in addressing flatback deformity and adjacent segment disease.

Correlation Between Pain Intensity and Quality of Recovery After Video-Assisted Thoracic Surgery for Lung Cancer Resection.

Purpose: The Quality of Recovery-15 (QoR-15) questionnaire provides a multifaceted assessment of postoperative recovery, and the resulting score is recommended as an endpoint in clinical studies focused on postoperative pain. We aimed to investigate the correlation between the QoR-15 score and postoperative pain intensity in surgical patients. Patients and Methods: Adult patients who underwent video-assisted thoracoscopic surgery (VATS) for lung cancer resection and were enrolled in a prospective registry or in a previous prospective study were included in this study. Baseline and perioperative data, including the results of assessment using the Korean version of the QoR-15 (QoR-15K) questionnaire at 48 hours postoperatively, were collected from the database. Correlations between the QoR-15K total score, questionnaire dimensions, and postoperative pain intensity at 48 hours postoperatively were determined using the Spearman correlation coefficient (ρ). Results: We analyzed a total of 137 eligible patients. Significant negative correlations were noted between the QoR-15K total score and pain intensity at rest (ρ = -0.45, 95% confidence interval [CI]: -0.57 - -0.31, P < 0.001) and during coughing (ρ = -0.55, 95% CI: -0.65 - -0.42, P < 0.001) at 48 hours postoperatively. The pain dimension and pain intensity at 48 hours postoperatively showed significant correlations with physical comfort, emotional state, and physical independence dimensions. Multivariable logistic regression revealed a significant negative association between the pain score at 24 hours postoperatively and good or excellent postoperative recovery. Conclusion: The results support the impact of postoperative pain on the overall postoperative quality of recovery in patients who underwent VATS for lung cancer resection. Moreover, the QoR-15K score may be considered as a primary endpoint in clinical studies on postoperative pain control.

The effect of high perioperative inspiratory oxygen fraction for abdominal surgery on surgical site infection: a systematic review and meta-analysis.

Guidelines from the World Health Organization strongly recommend the use of a high fraction of inspired oxygen (FiO2) in adult patients undergoing general anesthesia to reduce surgical site infection (SSI). However, previous meta-analyses reported inconsistent results. We aimed to address this controversy by focusing specifically on abdominal surgery with relatively high risk of SSI. Medline, EMBASE, and Cochrane CENTRAL databases were searched. Randomized trials of abdominal surgery comparing high to low perioperative FiO2 were included, given that the incidence of SSI was reported as an outcome. Meta-analyses of risk ratios (RR) were performed using a fixed effects model. Subgroup analysis and meta-regression were employed to explore sources of heterogeneity. We included 27 trials involving 15977 patients. The use of high FiO2 significantly reduced the incidence of SSI (n = 27, risk ratio (RR): 0.87; 95% confidence interval (CI): 0.79, 0.95; I2 = 49%, Z = 3.05). Trial sequential analysis (TSA) revealed that z-curve crossed the trial sequential boundary and data are sufficient. This finding held true for the subgroup of emergency operations (n = 2, RR: 0.54; 95% CI: 0.35, 0.84; I2 = 0%, Z = 2.75), procedures using air as carrier gas (n = 9, RR: 0.79; 95% CI: 0.69, 0.91; I2 = 60%, Z = 3.26), and when a high level of FiO2 was maintained for a postoperative 6 h or more (n = 9, RR: 0.68; 95% CI: 0.56, 0.83; I2 = 46%, Z = 3.83). Meta-regression revealed no significant interaction between SSI with any covariates including age, sex, body-mass index, diabetes mellitus, duration of surgery, and smoking. Quality of evidence was assessed to be moderate to very low. Our pooled analysis revealed that the application of high FiO2 reduced the incidence of SSI after abdominal operations. Although TSA demonstrated sufficient data and cumulative analysis crossed the TSA boundary, our results should be interpreted cautiously given the low quality of evidence.Registration: https://www.crd.york.ac.uk/prospero (CRD42022369212) on October 2022.

The safety and effectiveness of lumbar drainage for cerebrospinal fluid leakage after spinal surgery.

PURPOSE: Cerebrospinal fluid (CSF) leakage is a frequent complication after spinal surgery. The lumbar drainage procedure (LDP) is the preferred method for early closure of a dural tear. This study was conducted to assess the safety and effectiveness of LDP after spinal surgery. MATERIALS AND METHODS: We retrospectively reviewed 122 patients (55 male and 67 female) who underwent LDP after spinal surgery between January 2010 and June 2021. LDP was performed on patients with suspected CSF leakage due to a dural tear during spinal surgery or in whom mixed-color CSF was observed in the hemo-drain after surgery. LDP was performed aseptically by a resident according to our institution's protocol, and the amount drained was from 200cc to 300cc per day. Absolute bed rest was maintained during the lumbar drainage period. The hemo-drain was opened to confirm that CSF was no longer mixed or oozing, at which time the lumbar drain was removed. Culture was performed at the drain tip when the lumbar drain was removed. RESULTS: The spinal surgery level was cervical in 23 patients, thoracic in 27 patients, and lumbar in 72 patients. The mean duration of the indwelling lumbar drain was 7.2 days (2 days-18 days), and the mean amount of drainage was 1198.2cc (100cc-2542cc). Among the 122 patients, the CSF leakage in 101 patients was resolved with the initial procedure, but 21 patients required re-insertion. Of those 21 patients, improper insertion due to a technical problem occurred in 15 patients, poor line fixation occurred in 2 patients, and CSF leakage was again observed after removal of the lumbar drain in 4 patients. In only 1 case was open surgery done after LDP because follow-up magnetic resonance imaging showed a suspected infection. During lumbar drainage, 76 patients used antibiotics, and 46 patients did not. Four patients showed bacterial growth in the tip culture, and 3 of them had been using antibiotics. All 4 of those patients were treated without complications and discharged. Among the 122 patients, 1 patient was discharged with left hemiparesis due to cerebral venous infarction (CVI) and hemorrhage after LDP, and 1 patient underwent re-operation because the CSF collection was not resolved. CONCLUSIONS: No major complications such as systemic infection, deep vein thrombosis, or aspiration pneumonia occurred during the lumbar drainage, except for 1 patient (0.8%) with CVI caused by over-drainage. One patient (0.8%) required open surgery after LDP, but no cases of systemic infection occurred while maintaining lumbar drainage, irrespective of antibiotic use. In conclusion, LDP is a safe and effective treatment for CSF leakage after spinal surgery.

Computational Investigation of Conformational Properties of Short Azapeptides: Insights from DFT Study and NBO Analysis.

Azapeptides have gained much attention due to their ability to enhance the stability and bioavailability of peptide drugs. Their structural preferences, essential to understanding their function and potential application in the peptide drug design, remain largely unknown. In this work, we systematically investigated the conformational preferences of three azaamino acid residues in tripeptide models, Ac-azaXaa-Pro-NHMe [Xaa = Asn (4), Asp (5), Ala (6)], using the popular DFT functionals, B3LYP and B3LYP-D3. A solvation model density (SMD) was used to mimic the solvation effect on the conformational behaviors of azapeptides in water. During the calculation, we considered the impact of the amide bond in the azapeptide models on the conformational preferences of models 4-6. We analyzed the effect of the HB between the side-chain main chain and main-chain main-chain on the conformational behaviors of azapeptides 4-6. We found that the predicted lowest energy conformation for the three models differs depending on the calculation methods. In the gas phase, B3LYP functional indicates that the conformers tttANP-1 and tttADP-1 of azapeptides 4 and 5 correspond to the type I of ß-turn, the lowest energy conformation with all-trans amide bonds. Considering the dispersion correction, B3LYP-D3 functional predicts the conformers tctANP-2 and tctADP-3 of azapeptide 4 and 5, which contain the cis amide bond preceding the Pro residue, as the lowest energy conformation in the gas phase. The results imply that azaAsx and Pro residues may involve cis-trans isomerization in the gas phase. In water, the predicted lowest energy conformer of azapeptides 4 and 5 differs from the gas phase results and depends on the calculational method. For azapeptide 6, regardless of calculation methods and phases, tttAAP-1 (ß-I turn) is predicted as the lowest energy conformer. The results imply that the effect of the side chain that can form HBs on the conformational preferences of azapeptides 4 and 5 may not be negligible. We compared the theoretical results of azaXaa-Pro models with those of Pro-azaXaa models, showing that incorporating azaamino acid residue in peptides at different positions can significantly impact the folding patterns and stability of azapeptides.

Norepinephrine preserved flap blood flow compared to phenylephrine in free transverse rectus abdominis myocutaneous flap breast reconstruction surgery: A randomized pilot study.

BACKGROUND: Vasopressors are used in up to 85% of cases during free flap surgery. However, their use is still debated with concerns of vasoconstriction-related complications, with rates up to 53% in minor cases. We investigated the effects of vasopressors on flap blood flow during free flap breast reconstruction surgery. We hypothesized that norepinephrine may preserve flap perfusion better than phenylephrine during free flap transfer. METHODS: A randomized pilot study was performed in patients undergoing free transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. Patients with peripheral artery disease, allergies to study drugs, previous abdominal operations, left ventricular dysfunction, or uncontrolled arrhythmias were excluded. Twenty patients were randomized to receive either norepinephrine (0.03-0.10 µg/kg/min) or phenylephrine (0.42-1.25 µg/kg/min) (each n = 10) to maintain a mean arterial pressure of 65-80 mmHg. The primary outcome was differences in mean blood flow (MBF) and pulsatility index (PI) of flap vessels after anastomosis measured using transit time flowmetry in the two groups. Secondary outcomes included flap loss, necrosis, thrombosis, wound infection, and reoperation within 7 days postoperatively. RESULTS: After anastomosis, MBF showed no significant change in the norepinephrine group (mean difference, -9.4 ± 14.2 mL/min; p = 0.082), whereas it was reduced in the phenylephrine group (-7.9 ± 8.2 mL/min; p = 0.021). PI did not change in either group (0.4 ± 1.0 and 1.3 ± 3.1 in the norepinephrine and phenylephrine groups; p = 0.285 and 0.252, respectively). There were no differences in secondary outcomes between the groups. CONCLUSION: During free TRAM flap breast reconstruction, norepinephrine seems to preserve flap perfusion compared to phenylephrine. However, further validation studies are required.

Serum neutrophil gelatinase-associated lipocalin and lactate level during surgery predict acute kidney injury and early allograft dysfunction after liver transplantation.

Early allograft dysfunction (EAD) and acute kidney injury (AKI) are common and clinically important complications after liver transplantation. Serum lactate level at the end of surgery could predict EAD and neutrophil gelatinase-associated lipocalin (NGAL) is known as a biomarker for AKI after liver transplantation. The authors investigated whether the combination of these two laboratory tests could be used as an early predictor of these two complications of EAD and AKI. We reviewed cases undergoing living donor liver transplantation (n = 353). Lactate-adjusted NGAL level, a combination of these two predictors, was calculated as the sum of each value multiplied by the odds ratio for EAD or AKI. We evaluated whether this combined predictor at the end of surgery is significantly associated with both postoperative AKI or EAD. We compared the area under the receiver operating characteristic curve (AUC) between our multivariable regression models with and without NGAL, lactate, or lactate-adjusted NGAL. NGAL, lactate and lactate-adjusted NGAL are significant predictors for EAD and AKI. The regression model for EAD or AKI including lactate-adjusted NGAL showed a greater AUC (for EAD: odds ratio [OR] 0.88, 95% confidence interval [CI] 0.84-0.91; for AKI: OR 0.89, 95% CI 0.85-0.92) compared to the AUC of the models including lactate (for EAD: OR 0.84, 95% CI 0.81-0.88; for AKI: OR 0.79, 95% CI 0.74-0.83) or NGAL alone (for EAD: OR 0.82, 95% CI 0.77-0.86; for AKI: OR 0.84, 95% CI 0.80-0.88) or the model without lactate or NGAL (for EAD: OR 0.64, 95% CI 0.58-0.69, for AKI: OR 0.75, 95% CI 0.70-0.79). In conclusion, lactate-adjusted NGAL level at the end of surgery could be a reliable combined laboratory predictor for postoperative EAD or AKI after liver transplantation with a greater discriminative ability than lactate or NGAL alone.