Efficient Labeling of Vesicles with Lipophilic Fluorescent Dyes via the Salt-Change Method.

Fluorescent labeling allows for imaging and tracking of vesicles down to single-particle level. Among several options to introduce fluorescence, staining of lipid membranes with lipophilic dyes provides a straightforward approach without interfering with vesicle content. However, incorporating lipophilic molecules into vesicle membranes in an aqueous solution is generally not efficient because of their low water solubility. Here, we describe a simple, fast (<30 min), and highly effective procedure for fluorescent labeling of vesicles including natural extracellular vesicles. By adjusting the ionic strength of the staining buffer with NaCl, the aggregation status of DiI, a representative lipophilic tracer, can be controlled reversibly. Using cell-derived vesicles as a model system, we show that dispersion of DiI under low-salt condition improved its incorporation into vesicles by a factor of 290. In addition, increasing NaCl concentration after labeling induced free dye molecules to form aggregates, which can be filtered and thus effectively removed without ultracentrifugation. We consistently observed 6- to 85-fold increases in the labeled vesicle count across different types of dyes and vesicles. The method is expected to reduce the concern about off-target labeling resulting from the use of high concentrations of dyes.

Association between preoperative frontal electroencephalogram alpha asymmetry and postoperative quality of recovery: an observational study.

BACKGROUND: Left-sided frontal alpha asymmetry on electroencephalograms, which indicates decreased relative left-hemispheric activity, has been associated with depression, anxiety, and stress responsivity. We aimed to evaluate the association between perioperative measures of frontal alpha asymmetry and quality of recovery (QoR) after surgery. METHODS: We enrolled 110 female patients undergoing thyroidectomy and recorded perioperative electroencephalograms. The power of the prefrontal alpha band (8-13 Hz) was measured in the Fp1 and Fp2 leads. Left-sided frontal alpha asymmetry was defined as a higher alpha band power in Fp1 than in Fp2 and vice versa. QoR was assessed using the QoR-15 score on the day before surgery and postoperative days 1 and 2. The primary study endpoint was a difference in postoperative global QoR-15 score between preoperative left-sided and right-sided alpha asymmetry groups. The predictability of frontal alpha asymmetry for poor QoR-15 score was also evaluated. RESULTS: The global QoR-15 score showed a significant group-by-time interaction, and post-hoc analysis revealed significantly lower scores on postoperative days 1 (P=0.006) and 2 (P<0.001) in the left-sided frontal alpha asymmetry group. In the multivariate logistic regression analysis, preoperative left-sided frontal alpha asymmetry was associated with a 3.3-fold increased risk of the lowest tertile for the postoperative day 1 QoR-15 score (95% CI: 1.31-8.24; P=0.011). CONCLUSIONS: Preoperative left-sided frontal alpha asymmetry was independently associated with a lower postoperative QoR-15 score in female patients undergoing thyroidectomy, highlighting the potential role of preoperative frontal electroencephalography in predicting patient-centred outcomes after surgery. CLINICAL TRIAL REGISTRATION: KCT0006586 (http://cris.nih.go.kr/).

Comparative Analysis of the Performance of Electroencephalogram Parameters for Monitoring the Depth of Sedation During Remimazolam Target-Controlled Infusion.

BACKGROUND: The changes in hypnotic indicators in remimazolam sedation remain unclear. We investigated the correlation of the electroencephalogram (EEG) parameters with the effect-site remimazolam concentration and the depth of sedation in patients receiving a target-controlled infusion of remimazolam. METHODS: This prospective observational study enrolled 35 patients (32 analyzed) who underwent lower extremity varicose vein surgery or lower extremity orthopedic surgery under spinal anesthesia. We administered remimazolam by target-controlled infusion using the pharmacokinetic model introduced by Schüttler et al. The EEG data were continuously recorded, including the bispectral index (BIS), patient state index (PSI), spectral edge frequency (SEF), and raw EEG signals. The relative beta ratio (RBR), defined as log (spectral power [30-47 Hz]/spectral power [11-20 Hz]), was obtained by analyzing raw EEG. The level of sedation corresponding to each effect-site remimazolam concentration was assessed using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S). The prediction probability (Pk) and Spearman's correlation coefficients (R) were calculated between effect-site remimazolam concentration, MOAA/S, and EEG parameters. RESULTS: BIS and PSI showed significantly higher Pk for effect-site remimazolam concentration (Pk = 0.76 [0.72-0.79], P < .001 for BIS; Pk = 0.76 [0.73-0.79], P < .001 for PSI) compared to RBR (Pk = 0.71 [0.68-0.74], P < .001) and SEF (Pk = 0.58 [0.53-0.63], P = .002). BIS, PSI, and RBR showed significantly higher correlation coefficients for effect-site remimazolam concentration (R = -0.70 [-0.78 to -0.63], P < .001 for BIS; R = -0.72 [-0.79 to -0.66], P < .001 for PSI; R = -0.61 [-0.69 to -0.54], P < .001 for RBR) compared to SEF (R = -0.22 [-0.36 to -0.08], P = .002). BIS and PSI also had significantly higher Pk and correlation coefficients for MOAA/S (Pk = 0.81 [0.79-0.83], P < .001; R = 0.84 [0.81-0.88], P < .001 for BIS) (Pk = 0.80 [0.78-0.83], P < .001; R = 0.82 [0.78-0.87], P < .001 for PSI) compared to RBR (Pk = 0.74 [0.72-0.77], P < .001; R = 0.72 [0.65-0.78], P < .001) and SEF (Pk = 0.55 [0.50-0.59], P = .041; R = 0.13 [-0.01 to 0.27], P = .067). CONCLUSIONS: BIS, PSI, and RBR showed an acceptable correlation with the effect-site remimazolam concentration and depth of sedation in this study, suggesting that these EEG-derived parameters are potentially reliable hypnotic indicators during remimazolam sedation. BIS and PSI showed superior performance as hypnotic indicators to RBR and SEF in patients receiving target-controlled infusion of remimazolam.

Anatomical and Radiological Assessments of Injectate Spread Stratified by the Volume of the Pericapsular Nerve Group Block.

BACKGROUND: The pericapsular nerve group (PENG) block was recently suggested as a regional technique for managing acute pain after hip surgery. However, few anatomical studies have confirmed the spread of injectate during the PENG block. This cadaver study aimed to analyze injectate spread to the target nerves during single-injection ultrasound-guided PENG block. METHODS: Ultrasound-guided PENG block with 3 different injectate volumes (10, 20, or 30 mL) was performed in 18 cadavers. Injectate spread by the volume was first evaluated on computed tomography, followed by cadaver dissection. The spread of the dye over the pelvis and lower limb was evaluated. RESULTS: The articular branches of the femoral nerve were stained nearly sufficiently with 20- and 30-mL specimens. The femoral nerve itself was stained simultaneously in six of 12 (50%) 20-mL specimens and 12 of 12 (100%) 30-mL specimens. The accessory obturator nerve was observed only in three (9%) of 36 specimens. The articular branches of the obturator nerve were rarely affected, regardless of injectate volume (1/12, 10 mL specimens; 2/12, 20 mL specimens; 1/12, 30 mL specimens; P > .999). Rather, the obturator nerve was affected. However, the obturator nerve was not stained consistently even with 30 mL of injectate (50%). CONCLUSIONS: After combining the dissection and radiological findings, the single-injection ultrasound-guided PENG blocks with volumes of 10, 20, and 30 mL do not support motor sparing or selective anterior hip capsule innervation in a clinical setting. If early rehabilitation is needed, high-volume PENG block might not be the ideal option, and persisting pain after PENG block might be attributed in part to the lack of obturator nerve articular branches blockade.

Prognostic role of body composition in peritoneal carcinomatosis patients undergoing cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Bioelectric impedance analysis (BIA)-measured body composition and nutritional status have been used as prognostic indicators in various cancer cohorts. This study investigated whether BIA could provide information on prognosis in peritoneal carcinomatosis patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: We retrospectively analyzed the data of 99 patients with preoperative BIA data among those who underwent CRS and HIPEC. The association between BIA-derived parameters and intraoperative peritoneal cancer index (PCI) score was assessed. Predictive analysis for the occurrence of postoperative morbidities including major complications (Clavien-Dindo classification 3-4) and re-admission within 30 days after surgery as well as 1 year mortality was also performed. RESULTS: BIA-derived mineral (r = 0.224, p = 0.027), fat (r = - 0.202, p = 0.048), and total body water (TBW)/fat-free mass (FFM) (r = - 0.280, p = 0.005) showed significant associations with intraoperative PCI score. Lower TBW/FFM was an independent predictor of major postoperative complications (OR 0.047, 95% CI 0.003-0.749, p = 0.031) and re-admission (OR 0.094, 95% CI 0.014-0.657, p = 0.017) within 30 days after surgery. Higher fat mass was also independently associated with a higher risk of major postoperative complications (OR 1.120, 95% CI 1.006-1.248, p = 0.039) and re-admission (OR 1.123, 95% CI 1.024-1.230, p = 0.013). Intraoperative PCI score > 20 (OR 4.489, 95% CI 1.191-16.917, p = 0.027) and re-admission within 30 days after surgery (OR 5.269, 95% CI 1.288-21.547, p = 0.021) independently predicted postoperative 1-year mortality. CONCLUSIONS: We demonstrate that preoperative BIA-derived TBW/FFM and fat mass were significantly correlated with metastatic extent, assessed by PCI score, in patients with peritoneal carcinomatosis. In addition, BIA-derived TBW/FFM and fat mass showed independent predictability for postoperative 30-day major complications and re-admission in patients undergoing CRS and HIPEC. Our findings suggest that assessment of BIA may improve discrete risk stratification in patients who are planned to receive CRS and HIPEC.

Pharmacodynamic analysis of intravenous bolus remimazolam for loss of consciousness in patients undergoing general anaesthesia: a randomised, prospective, double-blind study.

BACKGROUND: Remimazolam is a new rapid offset benzodiazepine used for procedural sedation and general anaesthesia. This study evaluated the efficacy and safety of i.v. bolus remimazolam during induction of anaesthesia. METHODS: A total of 120 patients undergoing general anaesthesia were randomly allocated into six dose groups (n=20) of i.v. bolus remimazolam (0.02-0.27 mg kg-1). Loss of consciousness, respiratory depression, patient state index (PSI), and haemodynamic variables were evaluated during anaesthetic induction. Parametric time-to-event models were used to identify the 50% effective dose (ED50)/95% effective dose (ED95) associated with loss of consciousness and respiratory depression. Non-linear mixed-effect models analysed the PSI and haemodynamic changes after i.v. bolus remimazolam. RESULTS: Loss of consciousness and respiratory depression onset showed steep dose-responses with ED50/ED95 of 0.11/0.19 and 0.14/0.27 mg kg-1 and Hill coefficients of 5.3 and 4.6, respectively. Older age was significantly associated with lower ED50/ED95 for both endpoints. ED50/ED95 and the Hill coefficient of PSI decline were 0.12/0.68 mg kg-1 and 1.7, respectively. We propose optimal doses of 0.25-0.33, 0.19-0.25, and 0.14-0.19 mg kg-1 in patients aged <40, 60-80, and >80 yr, respectively, based on the ED95 estimates for the corresponding age groups. The maximum percentage reduction of MAP was 27.8% and the ED50/ED95 were 0.14/2.60 mg kg-1. The effect of remimazolam on heart rate was insignificant. CONCLUSIONS: The ED50/ED95s of i.v. bolus remimazolam were successfully estimated from the time to loss of consciousness and respiratory depression. No serious adverse events occurred within the range of tested doses. CLINICAL TRIAL REGISTRATION: NCT04901871.

Effect of Previous Caudal Block to Predict Successful Outcome after Adhesiolysis using a Steerable Catheter in Lumbar Failed Back Surgery Syndrome: A Retrospective Study.

Adhesiolysis is minimally invasive and commonly used for pain associated with adhesion after lumbar spine surgery. Caudal epidural block may be used for radiating pain due to failed back surgery syndrome. We evaluated the predictive value of response to caudal block performed prior to adhesiolysis in failed back surgery syndrome. Between January 1, 2013 and June 30, 2020, 150 patients with failed back surgery syndrome were treated with adhesiolysis using a steerable catheter at the pain clinic of a tertiary hospital after failed conservative treatment (including caudal block). Patient demographics, pain duration, and lumbar magnetic resonance imaging findings were examined. Response to previous caudal block was determined as a binary result (yes or no). Patients were followed up 3 months after adhesiolysis. Successful outcome was defined as a ≥2-point reduction in the numeric rating scale scores for radicular pain 3 months after adhesiolysis, evident in 81/150 (46%) patients. Multivariable logistic regression analysis revealed that caudal block response was an independent predictor of successful adhesiolysis (odds ratio = 4.403; p = 0.015). Response to prior caudal block is a positive predictor of successful adhesiolysis.

Effect of different general anaesthetics on ventricular repolarisation in robot-assisted laparoscopic prostatectomy.

BACKGROUND: Ventricular repolarisation is affected differently by the types of anaesthetics used. This study aimed to compare the effect of different types of anaesthetics on ventricular repolarisation during robot-assisted laparoscopic radical prostatectomy (RALP). METHODS: Sixty-nine patients were randomly assigned in a 1:1:1 ratio to the Sevoflurane (sevoflurane/remifentanil), Desflurane (desflurane/remifentanil) or total intravenous anaesthesia (TIVA [propofol/remifentanil]) groups; however, only 67 patients completed the study. The primary outcome was heart rate-corrected QT (QTc) interval collected at nine time points during RALP. Bazett's (QTcB) and Fridericia's (QTcF) formulae were used for QT interval correction. The secondary outcomes were Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio that were collected at the same time points. RESULTS: The QTcB and QTcF intervals were significantly prolonged during surgery in all groups; however, these values showed significant intergroup differences with time. After assuming the Trendelenburg position, the QTcB and QTcF intervals were significantly longer in the Desflurane group than in the other two groups, and this prolongation continued until the end of surgery. Intra-operatively, the QTcB and QTcF intervals exceeded 450 ms in six and five patients, respectively, in the Desflurane group, but in none in the TIVA group. Moreover, the incidence of intra-operative QTc interval prolongation >20 ms and >60 ms was significantly higher in the Desflurane group than in the TIVA group. There were no significant differences in Tp-e intervals and Tp-e/QT ratio among the three groups during surgery. CONCLUSIONS: To minimise QTc interval prolongation during RALP, TIVA with propofol/remifentanil is recommended for general anaesthesia.

PIM-1 kinase is a novel regulator of proinflammatory cytokine-mediated responses in rheumatoid arthritis fibroblast-like synoviocytes.

Objectives: This study investigated the expression of proviral-integration site for Moloney murine leukaemia virus (PIM) -1 kinase in RA synovium and RA fibroblast-like synoviocytes (FLSs) along with its impact on RA-FLS aggressiveness. Methods: The expression of PIM kinases was assessed in synovial tissues by immunohistochemistry and double IF. After PIM-1 inhibition using either small-interfering RNA or the chemical inhibitor AZD1208, we performed proliferation and migration assays and measured the levels of MMPs and IL-6 released from RA-FLSs under stimulation with proinflammatory cytokines (TNF-α, S100A4 and IL-6/soluble IL-6 receptor). Additionally, PIM-1-associated downstream signalling pathways were analysed by immunoblotting. Results: Three isoforms of PIM kinases were immunodetected in the synovial tissues from patients with RA or OA. Specifically, PIM-1 and PIM-3 were upregulated in RA synovium and PIM-1 was expressed in T cells, macrophages and FLSs. Additionally, upon stimulation of RA-FLSs with TNF-α, S100A4 and IL-6/sIL-6R, PIM-1 and PIM-3, but not PIM-2, were significantly inducible. Moreover, PIM-1 knockdown or AZD1208 treatment significantly suppressed basal or cytokine-induced proliferation and migration of RA-FLS and the secretion of MMPs from stimulated RA-FLSs. PIM-1 knockdown significantly affected the phosphorylation levels of extracellular signal-regulated kinase and cAMP responsive element binding protein in RA-FLSs. Conclusion: PIM-1 was upregulated in RA synovial tissues and RA-FLSs and its inhibition significantly reduced the proliferation, migration and MMP production of RA-FLSs in vitro. These findings suggest PIM-1 as a novel regulator of the aggressive and invasive behaviour of RA-FLSs and indicate its potential as a target for RA treatment.

Effect of intraoperative dexmedetomidine on renal function after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a randomized, placebo-controlled trial.

INTRODUCTION: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) predispose to postoperative renal dysfunction. Dexmedetomidine is an α2 adrenoreceptor agonist, which has renoprotective effects after cardiac surgery. OBJECTIVE: To assess the effect of dexmedetomidine on renal function after CRS and HIPEC. MATERIALS: Thirty-eight patients undergoing CRS and HIPEC were randomized to receive dexmedetomidine (dexmedetomidine group, n = 19, loading 1 µg/kg over 20 min followed by infusion at 0.5 µg/kg/h) or 0.9% sodium chloride (control group, n = 19) during surgery. Creatinine clearance (CrCl) was assessed daily until postoperative day 7. Urine neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule (KIM)-1 were measured for 24 h after surgery. RESULTS: There was no difference in the lowest CrCl value during the first 7 days postoperatively, but the % change from baseline to the lowest value was lower in the dexmedetomidine group than in the control group (p = .037). Urine NGAL and KIM-1 levels were increased over time in both groups, but the increases were significantly less in the dexmedetomidine group (p = .018 and 0.038, respectively). In the dexmedetomidine group, the length of intensive care unit stay was shorter (p = .034). CONCLUSIONS: Intraoperative dexmedetomidine infusion did not improve renal function in terms of serum Cr-related indices following CRS and HIPEC. However, as the decrease in CrCl was attenuated and early tubular-injury markers were lower in the dexmedetomidine group, dexmedetomidine may have protective effects against early tubular injury in CRS and HIPEC. Clinical Trials Registry: http://clinicaltrials.gov (NCT02641938).

Optimization and modeling of reduction of wastewater sludge water content and turbidity removal using magnetic iron oxide nanoparticles (MION).

Economic and rapid reduction of sludge water content in sewage wastewater is difficult and requires special advanced treatment technologies. This study focused on optimizing and modeling decreased sludge water content (Y1) and removing turbidity (Y2) with magnetic iron oxide nanoparticles (Fe3O4, MION) using a central composite design (CCD) and response surface methodology (RSM). CCD and RSM were applied to evaluate and optimize the interactive effects of mixing time (X1) and MION concentration (X2) on chemical flocculent performance. The results show that the optimum conditions were 14.1 min and 22.1 mg L(-1) for response Y1 and 16.8 min and 8.85 mg L(-1) for response Y2, respectively. The two responses were obtained experimentally under this optimal scheme and fit the model predictions well (R(2) = 97.2% for Y1 and R(2) = 96.9% for Y2). A 90.8% decrease in sludge water content and turbidity removal of 29.4% were demonstrated. These results confirm that the statistical models were reliable, and that the magnetic flocculation conditions for decreasing sludge water content and removing turbidity from sewage wastewater were appropriate. The results reveal that MION are efficient for rapid separation and are a suitable alterative to sediment sludge during the wastewater treatment process.

Quality of Postoperative Recovery in Total Intravenous Anesthesia between Remimazolam and Propofol for Intraoperative Neurophysiological Monitoring: A Prospective Double-Blind Randomized Controlled Trial.

This study compared the overall postoperative recovery of patients who underwent total intravenous anesthesia with remimazolam or propofol, using the Quality of Recovery-15 questionnaire (QoR-15). Seventy-two patients who underwent spine surgery with intraoperative neurophysiological monitoring (IONM) were randomly categorized into the remimazolam group (group R) or propofol group (group P). On the first postoperative day, the QoR-15 scores for groups P and R were 114 and 112, respectively, indicating no significant difference (p = 0.691). Similarly, group-time interaction effects on QoR-15 scores were not significantly different. In the post-anesthesia care unit, the pain intensity at rest was notably higher in group P than in group R (3.0 [0.0] vs. 2.8 [0.5], respectively, p = 0.009). Although the intraoperative consumption of remifentanil was higher in group R (1452.4 µg vs. 2066.8 µg, respectively, p < 0.001), the intraoperative use of vasopressors was lower in group R (1705.6 µg vs. 286.1 µg, respectively, p < 0.001) compared to group P. Group R exhibited significantly lower variability in mean blood pressure over time compared to group P. Remimazolam was viewed as a promising intravenous agent for general anesthesia, showing potential to replace propofol in spine surgery with IONM, considering both recovery quality and intraoperative hemodynamic stability.

Comparison of Remimazolam versus Sevoflurane on the Postoperative Quality of Recovery in Cervical Spine Surgery: A Prospective Randomized Controlled Double-Blind Trial.

Purpose: Remimazolam is a newly developed ultra-short-acting benzodiazepine. We compared overall functional recovery, including the postoperative Quality of Recovery-15 (QoR-15) questionnaire scores, between balanced inhalational anesthesia using sevoflurane and total intravenous anesthesia (TIVA) with remimazolam in patients undergoing anterior cervical discectomy and fusion (ACDF). Patients and Methods: Seventy-two patients were randomized to the remimazolam (group R) or sevoflurane (group S) group. The primary outcome was the total QoR-15 score on postoperative day (POD) 1. We also assessed the total QoR-15 score on POD2, sub-scores of the QoR-15, perioperative parameters, and postoperative recovery profiles. Group-time interaction effects on the QoR-15 and its sub-scores were analyzed using a linear mixed model. Results: The total QoR-15 score on POD1 (120.2 in group R vs 114.3 in group S, P=0.189) was not statistically different between the groups. There were no significant group-time interaction effects on total QoR-15 scores. Instead, patients in group R showed significantly better sub-scores in psychological and postoperative nausea and vomiting (PONV) items on POD1, as well as a lower degree of PONV, than those in group S. Among the five dimensions of the QoR-15, a significant group-time interaction effect was observed for psychological support. Group R showed significantly less changeability in blood pressure and heart rate with a lower dose of intraoperatively administered vasopressor than group S. Conclusion: Considering QoR-15, including PONV reduction, and intraoperative hemodynamic stability, remimazolam can be used as the novel and safe anesthetic agent for maintaining general anesthesia instead of sevoflurane in patients undergoing ACDF.

Comparison of the efficacy of dexmedetomidine plus fentanyl patient-controlled analgesia with fentanyl patient-controlled analgesia for pain control in uterine artery embolization for symptomatic fibroid tumors or adenomyosis: a prospective, randomized study.

PURPOSE: To investigate whether dexmedetomidine infusion could reduce opioid consumption and opioid-related side effects after uterine artery embolization (UAE). MATERIALS AND METHODS: Fifty patients undergoing UAE for symptomatic leiomyomas or adenomyosis were randomized into two groups. In 25 patients, dexmedetomidine infusion was started at 0.2 µg/kg/h at 30 minutes before the procedure, followed by 0.4 µg/kg/h for 6 hours after the procedure. In another 25 patients (control group), volume-matched normal saline solution was administered. Both groups received fentanyl-based intravenous patient-controlled analgesia (PCA; fentanyl 10 µg/h with a bolus dose of 20 µg) during the 24 hours after the procedure. Nonspherical polyvinyl alcohol particles were used. Pain scores, fentanyl consumption, need for additional analgesics, and side effects were assessed for 24 hours after UAE. RESULTS: Compared with the control group, patients in the dexmedetomidine group required 28% less PCA fentanyl during the 24 hours after UAE (P = .006). Numeric rating scale scores for pain (5.0±2.4 vs 7.0±2.2; P = .026) and the need for additional analgesics (two of 25 vs 17 of 25; P<.001) were lower in the dexmedetomidine group than in the control group during the first 1 hour after UAE. The incidence and severity of nausea and vomiting during the 24 hours after UAE were lower in the dexmedetomidine group than in the control group (P < .05). CONCLUSIONS: The addition of dexmedetomidine infusion to fentanyl PCA provides better analgesia, fentanyl-sparing effect, and less nausea and vomiting, without significant hemodynamic instability.

Smoking behavior change and the risk of pneumonia hospitalization among smokers with diabetes mellitus.

Smoking patients with diabetes mellitus (DM) are at greater risk of developing pneumonia. How smoking behavior changes affect the risk of pneumonia hospitalization, however, remains unclear. Therefore, we investigated the association between smoking behavior change and the risk of pneumonia hospitalization in patients with DM. From January 1, 2009 and December 31, 2018, we investigated the association between smoking behavior change and the risk of pneumonia hospitalization in patients with DM. A total of 332,798 adult patients with DM from the Korean National Health Insurance System database who underwent health screening examination between 2009 and 2012, and were smokers at the first health examination were included. During a mean follow-up of 4.89 years, 14,598 (4.39%) incident pneumonia hospitalization cases were identified. Reducers had a slightly increased risk of pneumonia hospitalization (aHR 1.06, 95% CI 1.01-1.10) compared to sustainers. Quitters did not have a significant association with incidence of pneumonia hospitalization. However, increasers had 13% higher risk of pneumonia hospitalization (aHR 1.13, 95% CI 1.07-1.18), regardless of whether initial smoking was light, moderate, or heavy. Our study showed that an increase in smoking intensity was associated with an increased risk of pneumonia hospitalization in people with DM. However, a protective effect of smoking reduction or cessation on pneumonia risk was not demonstrated.

Practical role of preoperative echocardiography in low-risk non-cardiac surgery.

Background: Due to increased needs to reduce non-fatal as well as fatal cardiac events, preoperative echocardiography remains part of routine clinical practice in many hospitals. Data on the role of preoperative echocardiography in low-risk non-cardiac surgery (NCS) other than ambulatory surgeries do not exist. We aimed to investigate the role of preoperative echocardiography in predicting postoperative adverse cardiovascular events (CVEs) in asymptomatic patients undergoing low-risk NCS. Methods: The study population was derived from a retrospective cohort of 1,264 patients who underwent elective low-risk surgery at three tertiary hospitals from June 1, 2021, to June 30, 2021. Breast, distal bone, thyroid, and transurethral surgeries were included. Preoperative examination data including electrocardiography, chest radiography, and echocardiography were collected. The primary outcome was a composite of postoperative adverse CVEs including all-cause death, myocardial infarction, cerebrovascular events, newly diagnosed or acutely decompensated heart failure (HF), lethal arrhythmia such as sustained ventricular tachycardia/fibrillation, and new-onset atrial fibrillation within 30 days after the index surgery. Results: Preoperative echocardiography was performed in 503 patients (39.8%), most frequently in patients with breast surgery (73.5%), followed by transurethral (37.7%), distal bone (21.6%), and thyroid surgeries (11.9%). Abnormal findings were observed in 5.0% of patients with preoperative echocardiography. Postoperative adverse CVEs occurred in 10 (0.79%) patients. Although a history of previous HF was an independent predictor of postoperative CVE occurrence (adjusted odds ratio, aOR: 17.98; 95% confidence interval, CI: 1.21-266.71, P = 0.036), preoperative echocardiography did not significantly predict CVE in multivariate analysis (P = 0.097). However, in patients who underwent preoperative echocardiography, the presence of abnormal echocardiographic findings was independently associated with development of CVE after NCS (aOR: 23.93; 95% CI: 1.2.28-250.76, P = 0.008). In particular, the presence of wall motion abnormality was a strong predictor of postoperative adverse CVE. Conclusion: In real-world clinical practice, preoperative echocardiography was performed in substantial number of patients with potential cardiac risk even in low-risk NCS, and abnormal findings were independently associated with postoperative CVE. Future studies should identify patients undergoing low-risk NCS for whom preoperative echocardiography would be helpful to predict adverse CVE.

Comparison of injectate spread and nerve coverage between single-injection intertransverse process block and paravertebral block at the T2 level: a cadaveric study.

BACKGROUND: We compared the spread of an injectate into the thoracic sympathetic chain resulting from a single-injection intertransverse process (ITP) block with that of a single-injection PV block at the T2 level. METHODS: Sixteen soft-embalmed cadavers were used. The right hemithorax was randomly allocated to receive either an ultrasound-guided single-injection ITP block or ultrasound-guided single-injection PV block at the T2 vertebral level, with the opposite block administered to the other side. Approximately 10 mL of latex dye solution was injected into each hemithorax using a random allocation technique. The presence of dye at the nerve root in the sympathetic chain and intercostal nerves at the injection and additional levels was examined by dissection. RESULTS: The injectate spread into the T2 sympathetic ganglion on both ITP (11/16, 68.8%) and PV (16/16, 100%) blocks. The ITP block demonstrated greater uniformity of dye staining in both the dorsal rami and dorsal root ganglion, which contrasts with the less consistent staining outcomes of the PV block in these regions. CONCLUSIONS: At the T2 level, we observed a lower efficacy of the ITP block for analgesic coverage of the sympathetic nerve. This suggested a potential preference by clinicians for the application of the T2 PV block over the ITP block, specifically for the management of sympathetically maintained pain in the upper extremities. In addition, our findings may hint at the potential advantages of the ITP block in specific clinical contexts where targeted nerve involvement, such as the medial branch block or dorsal root ganglion block, is sought.

A pharmacodynamic analysis of factors affecting recovery from anesthesia with propofol-remifentanil target controlled infusion.

AIM: To examine individual patient's demographic parameters and clinical variables related to return of consciousness (ROC) and the pharmacodynamic relationship between propofol effect-site concentration (C(e)) and ROC from propofol-remifentanil anesthesia. METHODS: Ninety-four patients received propofol-remifentanil anesthesia using the effect-site target-controlled infusion (TCI) system. All clinical events were noted, and variables possibly related to propofol C(e) at ROC were examined using linear correlation analyses. Pharmacodynamic modeling incorporating covariates was performed using NONMEM (Nonlinear Mixed Effects Modeling) VII software. RESULTS: The C(e) values of propofol at loss of consciousness (LOC) and ROC were 4.4±1.1 µg/mL and 1.1±0.3 µg/mL, respectively. Age was negatively correlated with propofol C(e) at ROC (r=-0.48, P<0.01). Including age as a covariate in C(e50) (the effect-site concentration associated with 50% probability of return of consciousness) and λ (the steepness of the concentration-versus-response relationship) significantly improved the performance of the basic model based on the likelihood ratio test, with a significant decrease in the minimum value of the objective function. The C(e50) in 25-, 50-, and 75-year-old patients was predicted to be 1.38, 1.06, and 0.74 µg/mL, respectively. The λ in 25-, 50-, and 75-year-old patients was predicted to be 12.23, 8.70, and 5.18, respectively. CONCLUSION: Age significantly affects the relationship between propofol C(e) and ROC, and pharmacodynamic modeling including age could lead to better predictions of ROC during emergence from propofol-remifentanil anesthesia.

The Impact of Air Pollutants and Meteorological Factors on Chronic Obstructive Pulmonary Disease Exacerbations: A Nationwide Study.

Rationale: Chronic obstructive lung disease (COPD) is a chronic progressive disease. Although smoking is the most important risk factor, 30% of patients with COPD are never-smokers, and environmental agents are also influential. The effects of air pollutants and meteorological factors on COPD exacerbations have not been studied extensively. Objectives: We aimed to investigate the air pollutants and meteorological factors that impact the incidence of COPD exacerbations. Methods: We obtained clinical data of COPD exacerbation cases from The National Health Insurance Service and merged it with 24-hour average values of air pollutants and meteorological factors from national databases. Patients who reside in eight metropolitan cities, where observatory stations are densely located, were selected for analysis. Results: In 1,404,505 patients with COPD between 2013 and 2018, 15,282 COPD exacerbations leading to hospitalization or emergency room visits were identified. Among the various air pollutants and meteorological factors, particulate matter ⩽2.5 µm in aerodynamic diameter (PM2.5), particulate matter ⩽10 µm in aerodynamic diameter (PM10), NO2, SO2, CO, O3, average temperature, and diurnal temperature range (DTR) were associated with COPD exacerbations. Generalized additive mode model analysis with cubic splines showed an inverted U-shaped relationship with PM2.5, PM10, CO, NO2, SO2, O3, DTR, and humidity, whereas it displayed a U-shaped pattern with the average temperature. Distinct patterns were found from 2015-2016 to 2017-2018. Conclusions: PM2.5, PM10, CO, NO2, O3, SO2, average temperature, humidity, and DTR affected the incidence of COPD exacerbations in various patterns, up to 10 lag days.