Diaphragm-sparing efficacy of subparaneural upper trunk block for arthroscopic shoulder surgery: A randomised controlled trial.

BACKGROUND: Inter-scalene block (ISB) is associated with an inevitable risk of hemi-diaphragmatic paresis (HDP). To reduce the risk of HDP, an upper trunk block (UTB) has been proposed at the brachial plexus division level. OBJECTIVE: We hypothesised that UTB would be associated with a lower incidence of HDP than ISB while providing sufficient analgesia following arthroscopic shoulder surgery. DESIGN: Randomised controlled trial. SETTING: A tertiary teaching hospital. PATIENTS: Seventy patients aged 20 to 80 years undergoing arthroscopic rotator cuff repair. INTERVENTION: Ultrasound-guided ISB or UTB was performed with 5 ml 0.75% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the incidence of complete HDP, assessed by diaphragm excursion using ultrasound, defined as a decrease to 25% or less of baseline or occurrence of paradoxical movement. Postoperative pulmonary function change, pain scores, opioid consumption and pain-related outcomes were the secondary outcomes. RESULTS: The UTB group had a significantly lower incidence of complete HDP than the ISB group [5.9% (2/34) vs. 41.7% (15/36); absolute difference, 35.8%; 95% confidence interval (CI), 17.8 to 53.7%; P < 0.001]. The postblockade decline in pulmonary function was more pronounced in the ISB group than that in the UTB group. The pain score at 1 h postoperatively was not significantly different between the groups (ISB vs. UTB group: median 0 vs. 1; median difference, -1; 95% CI, -2 to 0.5). No significant difference was observed in any other secondary outcomes. CONCLUSION: UTB was associated with a lower incidence of HDP compared with ISB while providing excellent analgesia in arthroscopic shoulder surgery. TRIAL REGISTRATION: Clinical Trial Registry of Korea (https://cris.nih.go.kr) identifier: KCT0007002. IRB NUMBER: Chungnam National University Hospital Institutional Review Board No. 2021-12-069.

Continuous cardiac output estimation using a new modified Fick method during off-pump coronary artery bypass graft surgery: a retrospective observational study.

PURPOSE: Several technical aspects of the Fick method limit its use intraoperatively. A data-driven modification of the Fick method may enable its use in intraoperative settings. METHODS: This two-center retrospective observational study included 57 (28 and 29 in each center) patients who underwent off-pump coronary artery bypass graft (OPCAB) surgery. Intraoperative recordings of physiological data were obtained and divided into training and test datasets. The Fick equation was used to calculate cardiac output (CO-Fick) using ventilator-determined variables, intraoperative hemoglobin level, and SvO2, with continuous thermodilution cardiac output (CCO) used as a reference. A modification CO-Fick was derived and validated: CO-Fick-AD, which adjusts the denominator of the original equation. RESULTS: Increased deviation between CO-Fick and CCO was observed when oxygen extraction was low. The root mean square error of CO-Fick was decreased from 6.07 L/min to 0.70 L/min after the modification. CO-Fick-AD showed a mean bias of 0.17 (95% CI 0.00-0.34) L/min, with a 36.4% (95% CI 30.6-44.4%) error. The concordance rates of CO-Fick-AD ranged from 73.3 to 87.1% depending on the time interval and exclusion zone. CONCLUSIONS: The original Fick method is not reliable when oxygen extraction is low, but a modification using data-driven approach could enable continuous estimation of cardiac output during the dynamic intraoperative period with minimal bias. However, further improvements in precision and trending ability are needed.

Errors in pressure measurements due to changes in pressure transducer levels during adult cardiac surgery: a prospective observational study.

BACKGROUND: Blood pressure measurement is an essential element during intraoperative patient management. However, errors caused by changes in transducer levels can occur during surgery. METHODS: This single center, prospective, observational study enrolled 25 consecutive patients scheduled for elective cardiac surgery with invasive arterial and central venous pressure (CVP) monitoring. Hydrostatic pressures caused by level differences (leveling pressure) between a reference point (on the center of the left biceps brachii muscle) and the transducers (fixed on the right side of the operating table) for arterial and central lines were continuously measured using a leveling transducer. Adjusted pressures were calculated as measured pressure - leveling pressure. Hypotension (mean arterial pressure < 80, <70, and < 60 mmHg), and CVP (< 6, ≥6 and < 15, or ≥ 15 mmHg) and pulmonary artery pressure (PAP, mean > 20 mmHg) levels were determined using unadjusted and adjusted pressures. RESULTS: Twenty-two patients were included in the analysis. Leveling pressure ≥ 3 mmHg and ≥ 5 mmHg observed at 46.0 and 18.7% of pooled data points, respectively. Determinations of hypotension using unadjusted and adjusted pressures showed disagreements ranging from 3.3 to 9.4% depending on the cutoffs. Disagreements in defined levels of CVP and PAP were observed at 23.0 and 17.2% of the data points, respectively. CONCLUSIONS: The errors in pressure measurement due to changes in transducer level were not trivial and caused variable disagreements in the determination of MAP, CVP, and PAP levels. To prevent distortions in intraoperative hemodynamic management, strategies should be sought to minimize or adjust for these errors in clinical practice. TRIAL REGISTRATION: cris.nih.go.kr (KCT0006510).

Randomised comparison between superior trunk and costoclavicular blocks for arthroscopic shoulder surgery: A noninferiority study.

BACKGROUND: Superior trunk block (STB) provides noninferior analgesia to the interscalene block and reduces the risk of hemidiaphragmatic paralysis (HDP). Recently, supraclavicular spreading has also been shown to occur during costoclavicular block (CCB), presenting as an alternative analgesic technique for shoulder surgery. OBJECTIVE: The aim of this study was to determine whether there is a difference in postoperative pain scores and HDP incidence between STB and CCB. DESIGN: Prospective randomised controlled trial. SETTING: Chungnam National University Hospital in Daejeon from January to July 2021. PATIENTS: Seventy patients, aged 20 to 70 years with ASA Physical Status classifications I to III and scheduled for elective arthroscopic rotator cuff repair were recruited. INTERVENTION: Ultrasound-guided STB or CCB was performed with 20 ml 0.5% ropivacaine. MAIN OUTCOME MEASURES: The primary outcome was the pain score (numeric rating scale, NRS) at 1 h postsurgery. A 1.4 (NRS) noninferiority margin was set a priori . The incidence of HDP, postoperative change of pulmonary function and postoperative opioid use were included as secondary outcomes. RESULTS: The pain score was higher in the CCB group compared with the STB group at 1 h postoperatively (median difference, 2; 95% confidence interval (CI), 1 to 3; noninferiority was not demonstrated). Two patients in the CCB group received a rescue interscalene block due to severe postoperative pain. The incidence of complete HDP was lower in the CCB group (risk difference, -26%; 95% CI, -6 to -45%; P  < 0.001). The median reduction in forced vital capacity and forced expiratory volume in 1 s were also significantly lower in the CCB group. CONCLUSION: Although the incidence of HDP was lower, CCB did not show noninferiority in immediate postoperative analgesia compared with STB in arthroscopic shoulder surgery. CLINICAL TRIAL REGISTRATION: Clinical Trial Registry of Korea (KCT0005822, principal investigator: Boohwi Hong) on 25 January 2021 ( https://cris.nih.go.kr ).

Increasing the interval between repeated anesthetic exposures reduces long-lasting synaptic changes in late post-natal mice.

While recent studies strongly suggest that a single, short anesthetic exposure does not affect neurodevelopment, the effects of multiple exposures remain unclear. Unfortunately, studying "multiple exposures" is challenging as it is an extremely heterogeneous descriptor comprising diverse factors. One potentially important, but unrecognized factor is the interval between anesthetic exposures. In order to evaluate the significance of interval, we exposed post-natal day 16, 17 mice to three sevoflurane exposures (2.5%, 1 hr) with short (2 hr) or long (24 hr) intervals. Changes in synaptic transmission, plasticity, protein expression, and behavior were assessed in male and female mice. We discovered that short-interval exposures induced a female-dependent decrease in miniature inhibitory post-synaptic current (mIPSC) frequency 5 days after the last exposure (control: 18.44 ± 2.86 Hz, sevoflurane:14.65 ± 4.54 Hz). Short-interval sevoflurane exposed mice also displayed long-term behavioral deficits at adult age (hypoactivity, anxiety). These behavioral changes were consistent with the sex-dependent changes in inhibitory transmission, as they were more robust in female mice. Although there was no change in learning and memory, short-interval sevoflurane exposures also impaired LTP in a non-sex-dependent manner (control: 171.10 ± 26.90%, sevoflurane: 149.80 ± 26.48 %). Most importantly, we were unable to find long-lasting consequences in mice that received long-interval sevoflurane exposures. Our study provides novel insights regarding the significance of the interval between multiple exposures, and also suggests that the neurotoxic effects of multiple anesthetic exposures may be reduced by simply increasing the interval between each exposure.

Is measurement of central venous pressure required to estimate systemic vascular resistance? A retrospective cohort study.

BACKGROUND: The clinical range of central venous pressure (CVP) (typically 5 to 15 mmHg) is much less than the range of mean arterial blood pressure (60 to 120 mmHg), suggesting that CVP may have little impact on estimation of systemic vascular resistance (SVR). The accuracy and feasibility of using an arbitrary CVP rather than actual CVP for the estimation of SVR during intraoperative period is not known. METHODS: Using vital records obtained from patients who underwent neurological and cardiac surgery, the present study retrospectively calculated SVR using fixed values of CVP (0, 5, 10, 15, and 20 mmHg) and randomly changing values of CVP (5 to 15 mmHg) and compared these calculated SVRs with actual SVR, calculated using actual CVP. Differences between actual SVR and SVRs based on fixed and random CVPs were quantified as root mean square error (RMSE) and mean absolute percentage error (MAPE). Bland-Altman analysis and four-quadrant plot analysis were performed. RESULTS: A total of 34 patients are included, including 18 who underwent neurosurgery and 16 who underwent cardiac surgery; 501,380 s (139.3 h) of data was analyzed. The SVR derived from a fixed CVP of 10 mmHg (SVRf10) showed the highest accuracy (RMSE: 115 and 104 [dynes/sec/cm- 5] and MAPE: 6.3 and 5.7% in neurological and cardiac surgery, respectively). The 95% limits of agreement between SVRf10 and actual SVR were - 208.5 (95% confidence interval [CI], - 306.3 to - 148.1) and 242.2 (95% CI, 181.8 to 340.0) dynes/sec/cm- 5 in neurosurgery and - 268.1 (95% CI, - 367.5 to - 207.7) and 163.2 (95% CI, 102.9 to 262.6) dynes/sec/cm- 5 in cardiac surgery. All the SVRs derived from the fixed CVPs (regardless of its absolute value) showed excellent trending ability (concordance rate > 0.99). CONCLUSIONS: SVR can be estimated from a fixed value of CVP without causing significant deviation or a loss of trending ability. However, caution is needed when using point estimates of SVR when the actual CVP is expected to be out of the typical clinical range. TRIAL REGISTRATION: This study was registered Clinical Research Information Service, a clinical trial registry in South Korea ( KCT0006187 ).

IKBKB siRNA-Encapsulated Poly (Lactic-co-Glycolic Acid) Nanoparticles Diminish Neuropathic Pain by Inhibiting Microglial Activation.

Activation of nuclear factor-kappa B (NF-κB) in microglia plays a decisive role in the progress of neuropathic pain, and the inhibitor of kappa B (IκB) is a protein that blocks the activation of NF-κB and is degraded by the inhibitor of NF-κB kinase subunit beta (IKBKB). The role of IKBKB is to break down IκB, which blocks the activity of NF-kB. Therefore, it prevents the activity of NK-kB. This study investigated whether neuropathic pain can be reduced in spinal nerve ligation (SNL) rats by reducing the activity of microglia by delivering IKBKB small interfering RNA (siRNA)-encapsulated poly (lactic-co-glycolic acid) (PLGA) nanoparticles. PLGA nanoparticles, as a carrier for the delivery of IKBKB genes silencer, were used because they have shown potential to enhance microglial targeting. SNL rats were injected with IKBKB siRNA-encapsulated PLGA nanoparticles intrathecally for behavioral tests on pain response. IKBKB siRNA was delivered for suppressing the expression of IKBKB. In rats injected with IKBKB siRNA-encapsulated PLGA nanoparticles, allodynia caused by mechanical stimulation was reduced, and the secretion of pro-inflammatory mediators due to NF-κB was reduced. Delivering IKBKB siRNA through PLGA nanoparticles can effectively control the inflammatory response and is worth studying as a treatment for neuropathic pain.

Comparison of PECS II and erector spinae plane block for postoperative analgesia following modified radical mastectomy: Bayesian network meta-analysis using a control group.

The present study compared the effects of pectoral nerve block II (PECS II) and erector spinae plane (ESP) block for postoperative analgesia in patients who underwent modified radical mastectomy by performing a network meta-analysis (NMA) using indirect comparison with systemic analgesia. Studies comparing the analgesic effects of PECS II and ESP block were searched on MEDLINE, PubMed, EMBASE and the Cochrane Library. The primary outcome of this study was cumulative opioid consumption for 24 h postoperatively. Pain score during this period was also assessed. NMA was performed to compare the postoperative analgesic effects of plane blocks and systemic analgesia. A search of databases identified 17 studies, with a total of 1069 patients, comparing the analgesic efficacies of PECS II block, ESP block, and systemic analgesia. Compared with systemic analgesia, mean difference of opioid consumption was - 10 mg (95% credible interval [CrI] - 15.0 to - 5.6 mg) with PECS II block and - 5.7 mg (95% CrI - 11.0 to - 0.7 mg) with ESP block. Relative to systemic analgesia, PECS II block showed lower pain scores over the first postoperative 24 h, whereas ESP block did not. PECS II block showed the highest surface under the cumulative ranking curves for both opioid consumption and pain score. Both PECS II and ESP blocks were shown to be more effective than systemic analgesia regarding postoperative analgesia following modified radical mastectomy, and between the two blocks, PECS II appeared to have favorable analgesic effects compared to ESP block.

Interval-dependent neurotoxicity after multiple ketamine injections in late postnatal mice.

PURPOSE: Measuring the neurotoxic effects of multiple anesthetic exposures during neurodevelopment is complex due to the numerous factors that can affect the outcome. While we recently discovered that the interval between multiple sevoflurane exposures can affect the level of neurotoxicity, the significance of interval for other anesthetic agents is unknown. Thus, we evaluated the significance of dosing interval in the neurotoxic effects of multiple ketamine injections in postnatal day (PND) 17 mice. METHODS: PND17 mice of both sexes were intraperitoneally injected with ketamine (35 mg/kg) three times at short (2 h) or long (24 h) intervals. Changes in synaptic transmission were measured in hippocampal pyramidal neurons 5 days after the last injection, and behavioral changes were assessed at the age of 8 weeks. Values are presented as mean ± SD. RESULTS: Whereas short-interval ketamine injections enhanced excitatory synaptic transmission, as evidenced by an increased frequency of miniature excitatory postsynaptic currents (mEPSCs; ketamine, 0.09 ± 0.07 Hz; control, 0.06 ± 0.03 Hz), long-interval ketamine injections did not; instead, they decreased the amplitude of miniature inhibitory postsynaptic currents (mIPSCs; ketamine, 47.72 ± 6.90 pA; control, 51.21 ± 7.65 pA,). However, only long-interval ketamine injections induced long-term changes in anxiety behavioral in the open-field test (decrease in center duration; ketamine, 400.1 ± 162.8 s; control, 613.3 ± 312.7 s). CONCLUSIONS: Multiple ketamine injections induce interval-dependent, long-lasting synaptic changes and behavioral impairments. Future studies should carefully consider the dosing interval as a significant factor when studying the neurotoxic effects of multiple anesthetic exposures.

Implementation of the Obturator Nerve Block into a Supra-Inguinal Fascia Iliaca Compartment Block Based Analgesia Protocol for Hip Arthroscopy: Retrospective Pre-Post Study.

Background and Objectives: The effect of supra-inguinal fascia iliaca compartment block (SI-FICB) in hip arthroscopy is not apparent. It is also controversial whether SI-FICB can block the obturator nerve, which may affect postoperative analgesia after hip arthroscopy. We compared analgesic effects before and after the implementation of obturator nerve block into SI-FICB for hip arthroscopy. Materials and Methods: We retrospectively reviewed medical records of 90 consecutive patients who underwent hip arthroscopy from January 2017 to August 2019. Since August 2018, the analgesic protocol was changed from SI-FICB to SI-FICB with obturator nerve block. According to the analgesic regimen, patients were categorized as group N (no blockade), group F (SI-FICB only), and group FO (SI-FICB with obturator nerve block). Primary outcome was the cumulative opioid consumption at 24 hours after surgery. Additionally, cumulative opioid consumption at 6 and 12 hours after surgery, pain score, additional analgesic requests, intraoperative opioid consumption and hemodynamic stability, and postoperative nausea and vomiting were assessed. Results: Among 87 patients, there were 47 patients in group N, 21 in group F, and 19 in group FO. The cumulative opioid (fentanyl) consumption at 24 hours after surgery was significantly lower in the group FO compared with the group N (N: 678.5 (444.0-890.0) µg; FO: 482.8 (305.8-635.0) µg; p = 0.014), whereas the group F did not show a significant difference (F: 636.0 (426.8-803.0) µg). Conclusion: Our findings suggest that implementing obturator nerve block into SI-FICB can reduce postoperative opioid consumption in hip arthroscopy.

Anesthetics and long-term survival after cancer surgery-total intravenous versus volatile anesthesia: a retrospective study.

BACKGROUND: Intravenous anesthesia has been reported to have a favorable effect on the prognosis of cancer patients. This study was performed to analyze data regarding the relation between anesthetics and the prognosis of cancer patients in our hospital. METHODS: The medical records of patients who underwent surgical resection for gastric, lung, liver, colon, and breast cancer between January 2006 and December 2009 were reviewed. Depending on the type of anesthetic, it was divided into total intravenous anesthesia (TIVA) or volatile inhaled anesthesia (VIA) group. The 5-year overall survival outcomes were analyzed by log-rank test. Cox proportional hazards modeling was used for sensitivity. RESULTS: The number of patients finally included in the comparison after propensity matching came to 729 in each group. The number of surviving patients at 5 years came to 660 (90.5%) in the TIVA and 673 (92.3%) in the VIA. The type of anesthetic did not affect the 5-year survival rate according to the log-rank test (P = 0.21). Variables associated with a significant increase in the hazard of death after multivariable analysis were male sex and metastasis at surgery. CONCLUSIONS: There were no differences in 5-year overall survival between two groups in the cancer surgery. TRIAL REGISTRATION: Trial registration: CRIS KCT0004101. Retrospectively registered 28 June 2019.

Interventional Removal of Knotted Pulmonary Artery Catheter: A Case Report.

A 60-year-old female patient underwent emergency cadaveric liver transplantation. During the insertion of the pulmonary artery catheter (PAC) through the left innominate vein, advancement of the catheter was not successful and a knot occurred. An interventional radiologist performed antegrade rigid wire insertion into the PAC and succeeded in loosening the knot in the vessel. We report the successful removal of a knot through intervention without additional invasive procedures in a hemodynamically unstable patient with a coagulopathy.

Comparison of topical ropivacaine with and without ketamine on post-surgical pain in children undergoing tonsillectomy: a randomized controlled double-blind study.

PURPOSE: Tonsillectomy in pediatric patients may cause severe postoperative pain. Topical local anesthetics are an easy and safe way to control post-tonsillectomy pain, but there is no benefit during the early postoperative stage. Topical ketamine shows a good effect on early stage postoperative pain. We compared the effect of topical ropivacaine with and without ketamine on post-tonsillectomy pain. METHODS: Patients aged 3-7 years undergoing tonsillectomy were selected to participate in the study. Our study was performed in a randomized, placebo-controlled, double-blind manner. Patients were randomly assigned to one of two groups using computer-generated random numbers. The researchers who assessed the pain score, the caregivers, and the patient were blinded to group assignment. One group received topical ropivacaine with saline (RS group) and the other group received topical ropivacaine with 20 mg ketamine (RK group) on the tonsillar bed. Pain scores using the modified Children's Hospital of Eastern Ontario Pain Scale (mCHEOPS) at 15 min and 30 min, and at 1, 2, 4, 8, 16 and 24 h were recorded. Rescue analgesic requirement and complications were also recorded. RESULTS: A total of 66 patients were randomly assigned to the RS group (n = 33) and the RK group (n = 33). The mCHEOPS scores were significantly lower in the RK group at 15 min (P = 0.046). The mCHEOPS scores of the two groups decreased with time, but there was no intergroup interaction. The RS group received more analgesics until 1 h after surgery and the RK group received more analgesics during 1-24 h after surgery. There were no differences in adverse outcomes. CONCLUSIONS: Topical ropivacaine with ketamine can reduce immediate postoperative pain and analgesic requirement better than ropivacaine alone.

Texture-preserving low dose CT image denoising using Pearson divergence.

Objective.The mean squared error (MSE), also known asL2loss, has been widely used as a loss function to optimize image denoising models due to its strong performance as a mean estimator of the Gaussian noise model. Recently, various low-dose computed tomography (LDCT) image denoising methods using deep learning combined with the MSE loss have been developed; however, this approach has been observed to suffer from the regression-to-the-mean problem, leading to over-smoothed edges and degradation of texture in the image.Approach.To overcome this issue, we propose a stochastic function in the loss function to improve the texture of the denoised CT images, rather than relying on complicated networks or feature space losses. The proposed loss function includes the MSE loss to learn the mean distribution and the Pearson divergence loss to learn feature textures. Specifically, the Pearson divergence loss is computed in an image space to measure the distance between two intensity measures of denoised low-dose and normal-dose CT images. The evaluation of the proposed model employs a novel approach of multi-metric quantitative analysis utilizing relative texture feature distance.Results.Our experimental results show that the proposed Pearson divergence loss leads to a significant improvement in texture compared to the conventional MSE loss and generative adversarial network (GAN), both qualitatively and quantitatively.Significance.Achieving consistent texture preservation in LDCT is a challenge in conventional GAN-type methods due to adversarial aspects aimed at minimizing noise while preserving texture. By incorporating the Pearson regularizer in the loss function, we can easily achieve a balance between two conflicting properties. Consistent high-quality CT images can significantly help clinicians in diagnoses and supporting researchers in the development of AI-diagnostic models.

Effect of local anesthetic volume (20 vs. 40 ml) on the analgesic efficacy of costoclavicular block in arthroscopic shoulder surgery: a randomized controlled trial.

BACKGROUND: Among the various diaphragm-sparing alternatives to interscalene block, costoclavicular block (CCB) demonstrated a low hemidiaphragmatic paresis (HDP) occurrence but an inconsistent analgesic effect in arthroscopic shoulder surgery. We hypothesized that a larger volume of local anesthetic for CCB could provide sufficient analgesia by achieving sufficient supraclavicular spreading. METHODS: Sixty patients scheduled for arthroscopic rotator cuff repair were randomly assigned to receive CCB using one of two volumes of local anesthetic (CCB20, 0.75% ropivacaine 20 ml; CCB40, 0.375% ropivacaine 40 ml). The primary outcome was the rate of complete analgesia (0 on the numeric rating scale of pain) at 1 h postoperatively. The secondary outcomes included a sonographic assessment of local anesthetic spread, diaphragmatic function, pulmonary function, postoperative opioid use, and other pain-related experiences within 24 h postoperatively. RESULTS: The rates of complete analgesia were not significantly different (23.3% [7/30] and 33.3% [10/30] in the CCB20 and CCB40 groups, respectively; risk difference 10%, 95% CI [-13, 32], P = 0.567). There were no significant differences in other pain-related outcomes. Among the clinical factors considered, the only factor significantly associated with postoperative pain was the sonographic observation of supraclavicular spreading. There were no significant differences in the incidence of HDP and the change in pulmonary function between the two groups. CONCLUSIONS: Using 40 ml of local anesthetic does not guarantee supraclavicular spread during CCB. Moreover, it does not result in a higher rate of complete analgesia compared to using 20 ml of local anesthetic in arthroscopic shoulder surgery.

Intraoperative changes in upper extremity perfusion index after thoracic paravertebral and intertransverse process block in patients undergoing lung resection surgery.

Background: Perfusion index (PI) has been used as a surrogate marker of sympathetic blockade. This study evaluated changes in PI of bilateral upper extremity after thoracic paravertebral block (PVB) and intertransverse process block (ITPB). Methods: This pilot study included three groups of patients undergoing elective unilateral pulmonary resection under general anesthesia with PVB (n=11) or ITPB (n=10), or urologic procedures with general anesthesia (control group, n=10). Blockades were performed using 10 mL aliquots of 0.5% ropivacaine administered at T3-4, T5-6, and T7-8 intercostal levels immediately after general anesthesia induction. The PI value of the operating side (PI-O) was divided by the contralateral side (PI-CL), and the relative change to baseline was assessed (relative PI-O/PI-CL), with a 50% increase considered meaningful. Results: In all cases within the PVB and ITPB groups, a significant increase in PI was observed following the blockades. The median (1Q, 3Q) intraoperative relative PI-O/PI-CL values were 0.9 (0.8, 1.4), 2.1 (1.4, 2.5), and 1.4 (0.9, 1.9) in the control, PVB, and ITPB groups (P=0.01), respectively. Pairwise comparison revealed a significant difference only between the control and PVB groups (adjusted P=0.01). While the relative PI-O/PI-CL value in the control group generally remained close to 1, occasional fluctuations exceeding 1.5 were noted. Conclusions: PVB induced a noticeable unilateral increase in upper extremity PI, whereas ITPB tended to result in an inconsistent and lesser degree of increase. Monitoring PI values can serve as an indicator of upper extremity sympathetic blockade, but consideration of potential confounders impacting these observations during surgery is essential. Further research is needed to validate these findings.

Mitochondrial dysfunction precedes hippocampal IL-1ß transcription and cognitive impairments after low-dose lipopolysaccharide injection in aged mice.

Acute cognitive impairments termed delirium often occur after inflammatory insults in elderly patients. While previous preclinical studies suggest mitochondria as a target for reducing neuroinflammation and cognitive impairments after LPS injection, fewer studies have evaluated the effects of a low-grade systemic inflammation in the aged brain. Thus, to identify the significance of mitochondrial dysfunction after a clinically relevant systemic inflammatory stimulus, we injected old-aged mice (18-20 months) with low-dose lipopolysaccharide (LPS, 0.04 mg/kg). LPS injection reduced mitochondrial respiration in the hippocampus 24 h after injection (respiratory control ratio [RCR], state3u/state4o; control = 2.82 ± 0.19, LPS = 2.57 ± 0.08). However, gene expression of the pro-inflammatory cytokine IL-1ß was increased (RT-PCR, control = 1.00 ± 0.30; LPS = 2.01 ± 0.67) at a more delayed time point, 48 h after LPS injection. Such changes were associated with cognitive impairments in the Barnes maze and fear chamber tests. Notably, young mice were unaffected by low-dose LPS, suggesting that mitochondrial dysfunction precedes neuroinflammation and cognitive decline in elderly patients following a low-grade systemic insult. Our findings highlight mitochondria as a potential therapeutic target for reducing delirium in elderly patients.

Apnea during moderate to deep sedation using continuous infusion of remimazolam compared to propofol and dexmedetomidine: A retrospective observational study.

Remimazolam's rapid onset and offset make it an innovative sedative for use during regional anesthesia. However, its respiratory safety profile is not well understood. We compared the continuous infusion of remimazolam with commonly used sedatives, propofol and dexmedetomidine, after regional anesthesia. In this retrospective study, the incidence of apnea (>10 seconds) was assessed in patients who underwent orthopedic surgery under regional anesthesia and received moderate to deep sedation using continuous infusion of remimazolam (group R: 0.1 mg/kg in 2 minutes followed by 0.5 mg/kg/hr). The incidence was compared with that of propofol (group P: 2-3 µg/mL target-controlled infusion) and dexmedetomidine (group D: 1 µg/kg in 10 minutes followed by 0.4-1 µg/kg/hr). Propensity score weighted multivariable logistic regression model was utilized to determine the effects of the sedative agents on the incidence of apnea. A total of 634 (191, 278, and 165 in group R, P, and D) cases were included in the final analysis. The incidence of apnea was 63.9%, 67.3%, and 48.5% in group R, P, and D, respectively. The adjusted odds ratios for apnea were 2.33 (95% CI, 1.50 to 3.61) and 2.50 (95% CI, 1.63 to 3.85) in group R and P, compared to group D. The incidence of apnea in patients receiving moderate to deep sedation using continuous infusion of remimazolam with dosage suggested in the current study was over 60%. Therefore, careful titration and respiratory monitoring is warranted.