Dynamic Arterial Elastance as a Predictor of Supine-to-Prone Hypotension (SuProne Study): An Observational Study.

Background and Objectives: Supine-to-prone hypotension is caused by increased intrathoracic pressure and decreased venous return in the prone position. Dynamic arterial elastance (Eadyn) indicates fluid responsiveness and can be used to predict hypotension. This study aimed to investigate whether Eadyn can predict supine-to-prone hypotension. Materials and Methods: In this prospective, observational study, 47 patients who underwent elective spine surgery in the prone position were enrolled. Supine-to-prone hypotension is defined as a decrease in Mean Arterial Pressure (MAP) by more than 20% in the prone position compared to the supine position. Hemodynamic parameters, including systolic blood pressure (SAP), diastolic blood pressure, MAP, stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index, cardiac index, dP/dt, and hypotension prediction index (HPI), were collected in the supine and prone positions. Supine-to-prone hypotension was also assessed using two different definitions: MAPprone < 65 mmHg and SAPprone < 100 mmHg. Hemodynamic parameters were analyzed to determine the predictability of supine-to-prone hypotension. Results: Supine-to-prone hypotension occurred in 13 (27.7%) patients. Eadyn did not predict supine-to-prone hypotension [Area under the curve (AUC), 0.569; p = 0.440]. SAPsupine > 139 mmHg (AUC, 0.760; p = 0.003) and dP/dtsupine > 981 mmHg/s (AUC, 0.765; p = 0.002) predicted supine-to-prone hypotension. MAPsupine, SAPsupine, PPVsupine, and HPIsupine predicted MAPprone <65 mm Hg. MAPsupine, SAPsupine, SVVsupine, PPVsupine, and HPIsupine predicted SAPprone < 100 mm Hg. Conclusions: Dynamic arterial elastance did not predict supine-to-prone hypotension in patients undergoing spine surgery. Systolic arterial pressure > 139 mmHg and dP/dt > 981 mmHg/s in the supine position were predictors for supine-to-prone hypotension. When different definitions were employed (mean arterial pressure < 65 mmHg in the prone position or systolic arterial pressure < 100 mmHg in the prone position), low blood pressures in the supine position were related to supine-to-prone hypotension.

Association between body composition and chronic low back pain in Korean adults aged over 50 years: The Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2011.

Background The relationship between overweight or obesity and low back pain (LBP) has previously been investigated. Several recent studies have focused on the relationship between other indicators of obesity, particularly indicators of fat and the risk of LBP. However, the results of body composition and LBP have been inconsistent. Methods All data for the present retrospective, cross-sectional study was extracted from the Korea National Health and Nutrition Examination Survey (KNHANES) versions V-1 and 2 conducted in 2010 and 2011 by the Korean Centers for Disease Control and Prevention. In KNHANES V-1 (2010) and V-2 (2011), those over 50 years of age completed the surveys on LBP, body weight, and body composition assessed using dual-energy X-ray absorptiometry (DXA) were included. The multivariable logistic regression analysis was used to examine the relationship between the presence of chronic LBP and body composition adjusting for confounders. Results We analyzed 3,579 persons who completed the question. In the multivariable analyses adjusting for age and sex, none of the variables, including fat mass and fat-free mass, remained positively or negatively associated with LBP. Additionally, when depression, smoking, alcohol intake, physical activity, diabetes mellitus, and fat or lean tissue mass were included in the multivariable logistic model, no significant associations were found between all measures of fat mass, fat-free mass, and LBP Conclusion This study is contrary to previous studies that concluded that there is a correlation between obesity and fat mass and LBP. LBP is not associated with increased levels of obesity and fat mass.

Differences in preoperative gastric ultrasound findings in elderly compared to the mid-aged surgical patients: A retrospective observational study.

This study aimed to compare gastric ultrasound assessments between young and elderly patients, to determine whether the cross-section area (CSA) cutoff values for elderly and young patients should be different, and to suggest CSA cutoff values for elderly patients. This study evaluated the data of 120 patients who underwent elective surgery under general anesthesia between July 2019 and August 2020. Demographic and gastric ultrasound assessment data were retrieved. Patients were divided into the elderly group (n = 58, age: ≥65 years) and young group (n = 62, age: <65 years). The CSAs in the supine and right lateral decubitus positions (RLDP), semiquantitative 3-point Perlas grade (grades 0, 1, and 2), and gastric volume (GV) were determined. CSAs according to different Perlas grades were compared between the 2 groups. To compare normally and non-normally distributed continuous data, Student t test and the Mann-Whitney U test were used, respectively. Categorical data were compared using the chi-square test or Fisher exact test, as appropriate. The receiver operating characteristic (ROC) curves were built for the CSAs to predict pulmonary aspiration. The CSA cutoff values for predicting a high risk of pulmonary aspiration in both the groups were determined. Among patients with Perlas grade 0, the CSAsupine (P = .002) and CSARLDP (P = .002) were greater in the elderly group than in the young group. The specificity, positive predictive value, and accuracy of the CSA decreased when the CSA cutoff value for the young group was applied to the elderly group. The CSA cutoff values for the elderly group were: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2. The CSA of the empty stomach was greater in elderly patients than in young patients. We suggest that the following CSA cutoff values should be used for predicting pulmonary aspiration risk in elderly patients: CSAsupine, 6.92 cm2 and CSARLDP, 10.65 cm2.

Predicting the risk of inappropriate depth of endotracheal intubation in pediatric patients using machine learning approaches.

Endotracheal tube (ET) misplacement is common in pediatric patients, which can lead to the serious complication. It would be helpful if there is an easy-to-use tool to predict the optimal ET depth considering in each patient's characteristics. Therefore, we plan to develop a novel machine learning (ML) model to predict the appropriate ET depth in pediatric patients. This study retrospectively collected data from 1436 pediatric patients aged < 7 years who underwent chest x-ray examination in an intubated state. Patient data including age, sex, height weight, the internal diameter (ID) of the ET, and ET depth were collected from electronic medical records and chest x-ray. Among these, 1436 data were divided into training (70%, n = 1007) and testing (30%, n = 429) datasets. The training dataset was used to build the appropriate ET depth estimation model, while the test dataset was used to compare the model performance with the formula-based methods such as age-based method, height-based method and tube-ID method. The rate of inappropriate ET location was significantly lower in our ML model (17.9%) compared to formula-based methods (35.7%, 62.2%, and 46.6%). The relative risk [95% confidence interval, CI] of an inappropriate ET location compared to ML model in the age-based, height-based, and tube ID-based method were 1.99 [1.56-2.52], 3.47 [2.80-4.30], and 2.60 [2.07-3.26], respectively. In addition, compared to ML model, the relative risk of shallow intubation tended to be higher in the age-based method, whereas the risk of the deep or endobronchial intubation tended to be higher in the height-based and the tube ID-based method. The use of our ML model was able to predict optimal ET depth for pediatric patients only with basic patient information and reduce the risk of inappropriate ET placement. It will be helpful to clinicians unfamiliar with pediatric tracheal intubation to determine the appropriate ET depth.

Machine learning for prediction of postoperative nausea and vomiting in patients with intravenous patient-controlled analgesia.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a still highly relevant problem and is known to be a distressing side effect in patients. The aim of this study was to develop a machine learning model to predict PONV up to 24 h with fentanyl-based intravenous patient-controlled analgesia (IV-PCA). METHODS: From July 2019 and July 2020, data from 2,149 patients who received fentanyl-based IV-PCA for analgesia after non-cardiac surgery under general anesthesia were applied to develop predictive models. The rates of PONV at 1 day after surgery were measured according to patient characteristics as well as anesthetic, surgical, or PCA-related factors. All statistical analyses and computations were performed using the R software. RESULTS: A total of 2,149 patients were enrolled in this study, 337 of whom (15.7%) experienced PONV. After applying the machine-learning algorithm and Apfel model to the test dataset to predict PONV, we found that the area under the receiver operating characteristic curve using logistic regression was 0.576 (95% confidence interval [CI], 0.520-0.633), k-nearest neighbor was 0.597 (95% CI, 0.537-0.656), decision tree was 0.561 (95% CI, 0.498-0.625), random forest was 0.610 (95% CI, 0.552-0.668), gradient boosting machine was 0.580 (95% CI, 0.520-0.639), support vector machine was 0.649 (95% CI, 0.592-0.707), artificial neural network was 0.686 (95% CI, 0.630-0.742), and Apfel model was 0.643 (95% CI, 0.596-0.690). CONCLUSIONS: We developed and validated machine learning models for predicting PONV in the first 24 h. The machine learning model showed better performance than the Apfel model in predicting PONV.

Oxygen reserve index guided fraction of inspired oxygen titration to reduce hyperoxemia during laparoscopic gastrectomy: A randomized controlled trial.

BACKGROUND: The usefulness of the oxygen reserve index (ORi) in reducing hyperoxemia remains unclear. We designed this study to investigate whether fraction of inspired oxygen (FiO2) adjustment under a combination of ORi and peripheral oxygen saturation (SpO2) guidance can reduce intraoperative hyperoxemia compared to SpO2 alone. METHODS: In this prospective, double-blind, randomized controlled study, we allocated patients scheduled for laparoscopic gastrectomy to the SpO2 group (FiO2 adjusted to target SpO2 ≥ 98%) or the ORi-SpO2 group (FiO2 adjusted to target 0 < 0 ORi < .3 and SpO2 ≥ 98%). The ORi, SpO2, FiO2, arterial partial pressure of oxygen (PaO2), and incidence of severe hyperoxemia (PaO2 ≥ 200 mm Hg) were recorded before and 1, 2, and 3 hours after surgical incision. Data from 32 and 30 subjects in the SpO2 and ORi-SpO2 groups, respectively, were analyzed. RESULTS: PaO2 was higher in the SpO2 group (250.31 ± 57.39 mm Hg) than in the ORi-SpO2 group (170.07 ± 49.39 mm Hg) 1 hour after incision (P < .001). PaO2 was consistently higher in the SpO2 group than in the ORi-SpO2 group, over time (P = .045). The incidence of severe hyperoxemia was higher in the SpO2 group (84.4%) than in the ORi-SpO2 group (16.7%, P < .001) 1 hour after incision. Higher FiO2 was administered to the SpO2 group [52.5 (50-60)] than the ORi-SpO2 group [40 (35-50), P < .001] 1 hour after incision. SpO2 was not different between the 2 groups. CONCLUSION: The combination of ORi and SpO2 guided FiO2 adjustment reduced hyperoxemia compared to SpO2 alone during laparoscopic gastrectomy.

Application of the dynamic needle tip positioning method for ultrasound-guided arterial catheterization in elderly patients: A randomized controlled trial.

BACKGROUND: Arterial cannulation in elderly patients is difficult because of age-related morphological changes. Applying dynamic needle tip positioning (DNTP) that guides the catheter to position inside the vessel sufficiently may aid in successful cannulation. METHODS: This prospective study enrolled patients aged over 70 years, who were scheduled for elective surgery under general anaesthesia with arterial cannulation. The patients were randomly assigned to the DNTP (group D, n = 76) or the conventional short-axis view(group C, n = 75) group. The arterial depth, diameter, and arterial conditions(calcification, segmental stenosis, and tortuosity) were evaluated using ultrasound, before puncture. We recorded the first attempt success, cannulation time, the number of attempts, and cannulation-related complications. RESULTS: A total of 151 patients were enrolled in this study. The first attempt success rate in group D was significantly higher than that in group C (89% versus 72%; P = 0.0168). The median cannulation time per last attempt in group D versus group C was 25 versus 30 sec(P = 0.0001), and the overall cannulation time was 25 versus 35 sec(P = 0.0001), respectively. Arterial cannulation per last attempt and overall cannulation time were shorter in group D. The number of attempts was higher in group C (P = 0.0038). The occurrence rate of hematoma was significantly lower in group D (16% versus 47%, relative risk = 3.0, P = 0.0001). CONCLUSIONS: The DNTP method may improve the first attempt success rate of arterial cannulation and reduce complications in elderly patients over 70 years of age.

Effect of changes in cerebral oximeter values during cardiac surgery on the incidence of postoperative neurocognitive deficits (POND): A retrospective study based on propensity score-matched analysis.

OBJECTIVES: The occurrence of postoperative neurocognitive deficits(POND)after major cardiac surgery is associated with an increase in perioperative mortality and morbidity. Oxidative stress caused by oxygen can affect neuronal damage, which can lead to POND. Whether the intraoperative rSO2 value reflects oxidative stress and the associated incidence of POND is unknown. METHODS: Among 3482 patients undergoing cardiac surgery, 976 patients were allocated for this retrospective study. Of these, 230 patients (32.5%) were observed to have postoperative neurologic symptoms. After propensity score 1:2 ratio matching, a total of 690 patients were included in the analysis. Recorded data on the occurrence of POND from the postoperative period to predischarge were collected from the electronic records. RESULTS: The mean baseline rSO2 value was higher in the POND (-) group than in the POND (+) group. The mean overall minimum rSO2 value was lower in the POND (+) group (52.2 ± 8.3 vs 48.3 ± 10.5, P < 0.001). The mean overall maximum rSO2 values were not significantly different between the two groups (72.7 ± 8.3 vs 73.2 ± 9.2, P = 0.526). However, there was a greater increase in the overall maximum rSO2 values as compared with baseline in the POND (+) group (10.9 ± 8.2 vs 17.9 ± 10.2, P < 0.001). The degree of increase in the maximum rSO2 value was a risk factor affecting the occurrence of POND (adjusted odds ratio, 1.08; 95% confidence interval [CI], 1.04-1.11; P < 0.001). The areas under the receiver-operating characteristic curve for delta values of minimal and maximal compared with baseline values were 0.60 and 0.71, respectively. CONCLUSIONS: Increased cerebral oximeter levels during cardiac surgery may also be a risk factor for POND. This is considered to reflect the possibility of oxidative neuronal damage, and further studies are needed in the future.

Machine Learning Approaches to Predict Chronic Lower Back Pain in People Aged over 50 Years.

Background and Objectives: Chronic lower back pain (LBP) is a common clinical disorder. The early identification of patients who will develop chronic LBP would help develop preventive measures and treatment. We aimed to develop machine learning models that can accurately predict the risk of chronic LBP. Materials and Methods: Data from the Sixth Korea National Health and Nutrition Examination Survey conducted in 2014 and 2015 (KNHANES VI-2, 3) were screened for selecting patients with chronic LBP. LBP lasting >30 days in the past 3 months was defined as chronic LBP in the survey. The following classification models with machine learning algorithms were developed and validated to predict chronic LBP: logistic regression (LR), k-nearest neighbors (KNN), naïve Bayes (NB), decision tree (DT), random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), and artificial neural network (ANN). The performance of these models was compared with respect to the area under the receiver operating characteristic curve (AUROC). Results: A total of 6119 patients were analyzed in this study, of which 1394 had LBP. The feature selected data consisted of 13 variables. The LR, KNN, NB, DT, RF, GBM, SVM, and ANN models showed performances (in terms of AUROCs) of 0.656, 0.656, 0.712, 0.671, 0.699, 0.660, 0.707, and 0.716, respectively, with ten-fold cross-validation. Conclusions: In this study, the ANN model was identified as the best machine learning classification model for predicting the occurrence of chronic LBP. Therefore, machine learning could be effectively applied in the identification of populations at high risk of chronic LBP.

Gastric emptying of preoperative carbohydrate in elderly assessed using gastric ultrasonography: A randomized controlled study.

BACKGROUND: Preoperative carbohydrate loading enhances postoperative recovery and reduces patient discomfort. However, gastric emptying of liquids can be delayed in elderly populations. Therefore, this study aimed to evaluate the gastric emptying of 400 mL of a carbohydrate drink ingested 2 hours before surgery in elderly patients. METHODS: In this prospective, randomized controlled study, patients aged >65 years were allocated to either fast from midnight (nil per os [NPO] group, n = 29) or drink 400 mL of a carbohydrate drink 2 hours before surgery (carbohydrate group, n = 29). The gastric antrum was assessed using ultrasonography in the supine position, followed by the right lateral decubitus (RLD) position. The gastric antrum was graded as grade 0 (fluid not seen in both positions), grade 1 (fluid only seen in the RLD position), and grade 2 (fluid seen in both positions). The gastric antral cross-sectional area (CSA) and aspirated residual gastric volume were measured. RESULTS: In 58 patients, the incidence of grade 2 stomach was 13.8% in NPO group and 17.2% in carbohydrate group (P = .790). The gastric antral CSA in the supine position was larger in carbohydrate group than in NPO group (4.42 [3.72-5.18] cm2 vs 5.31 [4.35-6.92] cm2, P = .018). The gastric antral CSA in the RLD position was not different in NPO and carbohydrate groups (P = .120). There was no difference in gastric volume (2 [0-7.5] vs 3 [0-13.4], P = .331) in NPO group versus carbohydrate group. CONCLUSION: The incidence of grade 2 stomach was not different between NPO group and carbohydrate group in elderly patients.

Machine learning model for predicting the optimal depth of tracheal tube insertion in pediatric patients: A retrospective cohort study.

OBJECTIVE: To construct a prediction model for optimal tracheal tube depth in pediatric patients using machine learning. METHODS: Pediatric patients aged <7 years who received post-operative ventilation after undergoing surgery between January 2015 and December 2018 were investigated in this retrospective study. The optimal location of the tracheal tube was defined as the median of the distance between the upper margin of the first thoracic(T1) vertebral body and the lower margin of the third thoracic(T3) vertebral body. We applied four machine learning models: random forest, elastic net, support vector machine, and artificial neural network and compared their prediction accuracy to three formula-based methods, which were based on age, height, and tracheal tube internal diameter(ID). RESULTS: For each method, the percentage with optimal tracheal tube depth predictions in the test set was calculated as follows: 79.0 (95% confidence interval [CI], 73.5 to 83.6) for random forest, 77.4 (95% CI, 71.8 to 82.2; P = 0.719) for elastic net, 77.0 (95% CI, 71.4 to 81.8; P = 0.486) for support vector machine, 76.6 (95% CI, 71.0 to 81.5; P = 1.0) for artificial neural network, 66.9 (95% CI, 60.9 to 72.5; P < 0.001) for the age-based formula, 58.5 (95% CI, 52.3 to 64.4; P< 0.001) for the tube ID-based formula, and 44.4 (95% CI, 38.3 to 50.6; P < 0.001) for the height-based formula. CONCLUSIONS: In this study, the machine learning models predicted the optimal tracheal tube tip location for pediatric patients more accurately than the formula-based methods. Machine learning models using biometric variables may help clinicians make decisions regarding optimal tracheal tube depth in pediatric patients.

Text Mining Approaches to Analyze Public Sentiment Changes Regarding COVID-19 Vaccines on Social Media in Korea.

The COVID-19 pandemic has affected the entire world, resulting in a tremendous change to people's lifestyles. We investigated the Korean public response to COVID-19 vaccines on social media from 23 February 2021 to 22 March 2021. We collected tweets related to COVID-19 vaccines using the Korean words for "coronavirus" and "vaccines" as keywords. A topic analysis was performed to interpret and classify the tweets, and a sentiment analysis was conducted to analyze public emotions displayed within the retrieved tweets. Out of a total of 13,414 tweets, 3509 were analyzed after preprocessing. Eight topics were extracted using the Latent Dirichlet Allocation model, and the most frequently tweeted topic was vaccine hesitation, consisting of fear, flu, safety of vaccination, time course, and degree of symptoms. The sentiment analysis revealed a similar ratio of positive and negative tweets immediately before and after the commencement of vaccinations, but negative tweets were prominent after the increase in the number of confirmed COVID-19 cases. The public's anticipation, disappointment, and fear regarding vaccinations are considered to be reflected in the tweets. However, long-term trend analysis will be needed in the future.

Gastric Ultrasound Assessing Gastric Emptying of Preoperative Carbohydrate Drinks: A Randomized Controlled Noninferiority Study.

BACKGROUND: Tools for the evaluation of gastric emptying have evolved over time. The purpose of this study was to show that the risk of pulmonary aspiration is not increased with carbohydrate drink, by demonstrating that the gastric antral cross-sectional area (CSA) of the NO-NPO group is either equivalent to or less than that of the NPO (nil per os) group. METHODS: Sixty-four patients scheduled for elective laparoscopic benign gynecologic surgery were enrolled and randomly assigned to the NPO group (n = 32) or the NO-NPO group (n = 32). After having a regular meal until midnight before surgery, the NPO group fasted until surgery, while the NO-NPO group ingested 400 mL of a carbohydrate drink at midnight and freely up to 2 hours before anesthesia. The primary outcome was the gastric antral CSA by gastric ultrasound in right lateral decubitus position (RLDP). Noninferiority was defined as a mean difference of CSA <2.8 cm2. Secondary outcomes included CSA in supine position, gastric volume (GV), GV per weight (GV/kg), GV/kg >1.5 mL/kg, and Perlas grade. RESULTS: CSA in RLDP was not different between the NPO group (6.25 ± 3.79 cm2) and the NO-NPO group (6.21 ± 2.48 cm2; P = .959). The mean difference of CSA in RLDP (NO-NPO group - NPO group) was 0.04 (95% confidence interval [CI], -1.56 to 1.64), which was within the noninferiority margin of 2.8 cm2. CSA was not different between the 2 groups (4.17 ± 2.34 cm2 in NPO group versus 4.28 ± 1.23 cm2 in NO-NPO group; P = .828). GV in NPO group (70 ± 56 mL) was not different from NO-NPO group (66 ± 36 mL; mean difference, 3.66; 95% CI, -20 to 27; P = .756). GV/kg in the NPO group (1.25 ± 1.00 mL/kg) was not different from the NO-NPO group (1.17 ± 0.67 mL/kg; P = .694). The incidence of GV/kg > 1.5 mL/kg was not different between NPO (31.3%) and NO-NPO group (21.9%; P = .768). The median (interquartile range) of the Perlas grade was 1 (0-1) in NPO group and 0.5 (0-1) in NO-NPO group (P = .871). CONCLUSIONS: Preoperative carbohydrates ingested up to 2 hours before anesthesia do not delay gastric emptying compared to midnight fasting, as evaluated with gastric ultrasound.

Effects of prophylactic atropine on the time to tracheal intubation with the pre-administration of remifentanil.

BACKGROUND: Pre-administration of remifentanil in target-controlled propofol and remifentanil anaesthesia could prolong the time of onset of muscle relaxation owing to haemodynamic effects, thereby prolonging the time to tracheal intubation. Although the sympatholytic effects of remifentanil result in bradycardia and hypotension, these responses can be attenuated by the administration of atropine. Therefore, we investigated whether prophylactic administration of atropine could prevent the prolongation of the time to tracheal intubation. METHODS: Sixty-four patients were included in this study. They were randomised into Group A (atropine 0.5 mg, n = 32) and Group S (saline 0.9%, n = 32), immediately before the pre-administration of remifentanil. The primary outcome was the time to tracheal intubation and the secondary outcomes were rocuronium onset time, time to loss of consciousness (LOC), time to reach a value of 60 on the bispectral index (BIS) and haemodynamic variables. RESULTS: The median [Interquartile range] of the time to tracheal intubation was 240 [214, 288]s in Group S and 190 [176, 212]s in Group A(median difference: 50 s, 95% confidence interval: 27-80 s, P = .001). Rocuronium onset time was significantly decreased in Group A compared to that in Group S (129 [110, 156] vs 172 [154, 200], P = .001). The times to LOC and reach 60 on the BIS were not significantly different between the two groups. Cardiac output(CO) and heart rate were less decreased in Group A than in Group S (P = .02, P < .001, respectively). CONCLUSIONS: Prophylactic administration of atropine could compensate for the reduction in CO in cases pre-administered with remifentanil in target-controlled propofol and remifentanil anaesthesia. This in turn prevented the prolongation of rocuronium onset time and reduced the time to tracheal intubation.

Application of machine learning approaches for osteoporosis risk prediction in postmenopausal women.

Many predictive tools have been reported for assessing osteoporosis risk. The development and validation of osteoporosis risk prediction models were supported by machine learning. INTRODUCTION: Osteoporosis is a silent disease until it results in fragility fractures. However, early diagnosis of osteoporosis provides an opportunity to detect and prevent fractures. We aimed to develop machine learning approaches to achieve high predictive ability for osteoporosis risk that could help primary care providers identify which women are at increased risk of osteoporosis and should therefore undergo further testing with bone densitometry. METHODS: We included all postmenopausal Korean women from the Korea National Health and Nutrition Examination Surveys (KNHANES V-1, V-2) conducted in 2010 and 2011. Machine learning models using methods such as the k-nearest neighbors (KNN), decision tree (DT), random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), artificial neural networks (ANN), and logistic regression (LR) were developed to predict osteoporosis risk. We analyzed the effect of applying the machine learning algorithms to the raw data and featuring the selected data only where the statistically significant variables were included as model inputs. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) were used to evaluate performance among the seven models. RESULTS: A total of 1792 patients were included in this study, of which 613 had osteoporosis. The raw data consisted of 19 variables and achieved performances (in terms of AUROCs) of 0.712, 0.684, 0.727, 0.652, 0.724, 0.741, and 0.726 for KNN, DT, RF, GBM, SVM, ANN, and LR with fivefold cross-validation, respectively. The feature selected data consisted of nine variables and achieved performances (in terms of AUROCs) of 0.713, 0.685, 0.734, 0.728, 0.728, 0.743, and 0.727 for KNN, DT, RF, GBM, SVM, ANN, and LR with fivefold cross-validation, respectively. CONCLUSION: In this study, we developed and compared seven machine learning models to accurately predict osteoporosis risk. The ANN model performed best when compared to the other models, having the highest AUROC value. Applying the ANN model in the clinical environment could help primary care providers stratify osteoporosis patients and improve the prevention, detection, and early treatment of osteoporosis.

Evaluation of ultrasound-guided erector spinae plane block for postoperative management of video-assisted thoracoscopic surgery: a prospective, randomized, controlled clinical trial.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) is a commonly performed minimally invasive procedure that has led to lower levels of pain, as well as procedure-related mortality and morbidity. However, VATS requires analgesia that blocks both visceral and somatic nerve fibers for more effective pain control. This randomized controlled trial evaluated the effect of erector spinae plane block (ESPB) in the postoperative analgesia management of patients undergoing VATS. METHODS: We performed a prospective, randomized, single-center study between December 2018 and December 2019. Fifty-four patients were recruited to two equal groups (ESPB and control group). Following exclusion, 46 patients were included in the final analysis. Patients were randomly assigned to receive preoperative ultrasound-guided ESPB with either ropivacaine or saline. The primary outcome was the numeric rating scale (NRS) score, assessed 12 hours postoperatively. Secondary outcomes were the Riker Sedation-Agitation Scale (SAS) score for emergence agitation, postoperative cumulative opioid consumption, length of post-anesthesia care unit (PACU) stay, incidence of postoperative nausea and vomiting (PONV) and dizziness, and ESPB-related adverse events. RESULTS: The NRS in the ESPB group during the postoperative period immediately after PACU admission was significantly lower than that in the control group (5.96±1.68 and 7.59±1.18, respectively; P<0.001) and remained lower until 6 hours postoperatively (P=0.001 at 1 hour and P=0.005 at 6 hours). At 12 hours postoperatively, NRS scores were not significantly different between groups (P=0.12). The median [interquartile range (IQR)] of the postoperative rescue pethidine consumption in PACU was significantly lower [25 mg (25 mg)] in the ESPB group than that in the control group [50 mg (56.2 mg); P=0.006]. The median (IQR) of PACU residual time was significantly lower [25 min (10 min)] in the ESPB group than that in the control group [30 min (15 min); P=0.034]. The median (IQR) Riker SAS was also lower in the ESPB group [4 (1.0)] than that in the control group [5 (1.25); P<0.001] in PACU. CONCLUSIONS: A single preoperative injection of ESPB with ropivacaine may improve acute postoperative analgesia and emergence agitation in patients undergoing VATS.

Comparison of vasodilatory properties between desflurane and sevoflurane using perfusion index: a randomised controlled trial.

BACKGROUND: The perfusion index (PI), calculated from the photoplethysmographic waveform, reflects peripheral vasomotor tone. As such, the PI serves as a surrogate for quantitative measures of drug-induced vasoconstriction or vasodilation. This study aimed to compare the effect on the PI of desflurane and sevoflurane at equi-anaesthetic concentrations in patients undergoing single-agent inhalation anaesthesia, where equi-anaesthetic dose was based on the known minimum alveolar concentration of these agents. METHODS: We randomly allocated patients scheduled for arthroscopic knee surgery to receive either desflurane or sevoflurane general anaesthesia after target-controlled induction of anaesthesia with propofol. Anaesthesia was maintained at age-corrected minimum alveolar concentration 1.0, under neuromuscular block (rocuronium). The PI and haemodynamic data were recorded every minute for 35 min after induction of anaesthesia and after standardised nociceptive stimulation. The primary outcome was PI, compared between the groups over time (repeated-measures analysis of variance). Secondary outcomes included MAP and HR. RESULTS: Sixty-nine participants (mean [range] age: 42 yr [19-65 yr]; 49% females) were assigned to either desflurane (n=34) or sevoflurane (n=35). The PI remained higher under desflurane compared with sevoflurane, both before (mean difference [MD]: 3.3; 95% confidence intervals [CIs]: 2.0-4.7; P<0.001) and after tetanic stimulation (MD: 2.8; 95% CI: 2.0-3.7; P<0.001). Higher PI paralleled lower MAP in participants assigned to desflurane anaesthesia (P<0.001), both before (MD: 8 mm Hg; 95% CI: 4-12) and after nociceptive stimulation (MD: 14 mm Hg; 95% CI: 7-22). HR was similar throughout. CONCLUSIONS: These findings suggest that at equipotent doses, desflurane exerts more potent vasodilatory properties and lowers blood pressure by a magnitude potentially associated with harm. CLINICAL TRIAL REGISTRATION: NCT03570164.

Novel Method for S1 Transforaminal Epidural Steroid Injection.

BACKGROUND: S1 transforaminal epidural steroid injection (S1-TFESI) results in positive clinical outcomes for the treatment of pain associated with the S1 nerve root. S1-TFESI via the transforaminal approach is commonly performed under fluoroscopic guidance. Ultrasound guidance is an alternative to mitigate radiation exposure. However, performing spinal procedures under ultrasound guidance has some limitations in confirming the position of the needle tip and vascular uptake. New techniques are therefore needed to make ultrasound and fluoroscopy complementary. Our objective was to describe a novel technique for S1-TFESI and confirm its reproducibility. METHODS: Records of patients with S1 radiculopathy were reviewed retrospectively; those treated using the new S1-TFESI technique were selected. Initially, ultrasound was used to distinguish anatomy of the sacral foramen and guide initial placement of the needle entry point. Fluoroscopy was subsequently used to confirm needle tip position and vascular injection. The number of times the needle required reinsertion was recorded, and ultrasound and C-arm images were stored. RESULTS: Sixty-seven S1-TFESIs were performed in 56 patients. All injections exhibited epidural spread of contrast media, not only to the S1 nerve. The cephalad angle was 16.25 ± 6.75° (range, 5-27°), the oblique angle was 2.48 ± 2.62° (range, 0-7°), and the mean number of attempts was 1.24 ± 1.25. CONCLUSIONS: The new technique, involving the use of ultrasound to guide initial placement of the needle entry point, followed by confirmatory imaging and any needed adjustment with the use of fluoroscopy, can be a technique to complement the shortcomings of using ultrasound or fluoroscopy alone.

Comparison of single minimum dose administration of dexmedetomidine and midazolam for prevention of emergence delirium in children: a randomized controlled trial.

PURPOSE: Emergence delirium (ED) is common in children after sevoflurane anesthesia and should be prevented for patient safety. A prospective, double-blind, randomized, controlled study was performed to compare the efficacy of minimal dosage of midazolam versus dexmedetomidine to prevent ED in children undergoing tonsillectomy. METHODS: Seventy children aged 24 months to 12 years were allocated to receive midazolam (0.03 mg/kg) or dexmedetomidine (0.3 µg/kg) 5 min before the end of surgery. The incidence and severity of ED were assessed using a four-point scale and the pediatric anesthesia emergence delirium scale, respectively. The emergence time and postoperative pain scores were also evaluated. RESULTS: The incidence of ED was 31.3% in the midazolam group and 26.5% in the dexmedetomidine group (P = 0.668). The severity of ED was similar in both groups (9.6 ± 5.8 in the midazolam group, vs. 8.1 ± 5.9 in the dexmedetomidine group, P = 0.299). The emergence time was comparable in the two groups [11.0 (8.3-13.8) min in midazolam group vs. 12.0 (10.0-13.5) min in dexmedetomidine group (P = 0.218)]. Postoperative pain score was higher in the midazolam group [0 (0-1)] than in the dexmedetomidine group [0 (0-0)] (P = 0.011). CONCLUSION: Dexmedetomidine and midazolam at single minimum dosages had equal effectiveness to prevent ED in children without delaying emergence time, when administered at the end of surgery. With regards to postoperative analgesic efficacy, although dexmedetomidine showed statistically significant higher analgesic effect than midazolam, further clinical investigations are needed to validate our findings.

The impact of a pulmonary recruitment maneuver to reduce post-laparoscopic shoulder pain: A randomized controlled trial.

OBJECTIVE: A pulmonary recruitment maneuver (PRM) can effectively reduce post-laparoscopic shoulder pain (PLSP). However, a high-pressure PRM may cause pulmonary barotrauma. This study aimed to evaluate the efficacy and safety of a PRM using two different maximum inspiratory pressures (40 and 60cmH2O) for reducing PLSP. STUDY DESIGN: Patients undergoing gynecologic laparoscopy were randomly allocated to a control group (n=30), a 40 cmH2O PRM group (n=30), and a 60 cmH2O PRM group (n=30). In the control group, residual carbon dioxide was removed by passive exsufflation through the port site. In the two intervention groups, the PRM consisting of five manual pulmonary inflations was performed at the end of surgery with a maximum pressure of 40 cmH2O or 60 cmH2O, respectively. Shoulder pain and wound pain were recorded using a visual analogue scale at 24 and 48h postoperatively. RESULTS: Wound pain scores at 24 and 48h post-surgery were not different between the three groups. The PLSP scores in the two intervention groups were significantly lower than that seen in the control group at 24 and 48h postoperatively (P=0.006 and P<0.001, respectively). However, there were no statistically significant differences in the PLSP scores between the two intervention groups. CONCLUSION: A low-pressure PRM (40cmH2O) is as effective as a high-pressure PRM (60cmH2O) for removing residual gas from the peritoneal cavity. PRM using a maximal inspiratory pressure of 40cmH2O is safe and efficacious for the reduction of PLSP.