Resonant Ionic, Covalent Bond, and Steric Characteristics Present in 1Σu+ States of Li2

The molecular bonding in the excited states of the alkali dimers involves the resonant ionic, covalent bond and steric interactions. We show here the case of the ¹Σ_u⁺ states of Li₂ by ab initio calculation. These interactions as functions of the internuclear distance lead to complex potential energy curves, providing an important application for high resolution laser spectroscopy. The spectroscopic constants for the 4 and 5 ¹Σ_u⁺ states are obtained for the first time.

Prediction of fluid responsiveness following liver compression in pediatric patients with single ventricle physiology

INTRODUCTION

The role of liver compression in predicting fluid responsiveness in children with a single ventricle has never been evaluated. The purpose of this study was to assess whether blood pressure changes during liver compression predict fluid responsiveness in children with single ventricle physiology.

METHODS

This prospective, interventional study included children aged 3 months to 5 years who underwent surgery for bidirectional cavopulmonary shunt or extracardiac Fontan operation. Before fluid loading, the right upper abdomen was compressed at 30 mmHg for 10 s, and changes in the blood pressure waves were recorded before administering 10 ml kg^-1 of crystalloid solution. Systolic arterial pressure, diastolic arterial pressure, central venous pressure, pleth variability index, respiratory variation in aortic blood flow peak velocity, and stroke volume were measured before and after fluid loading. A volume responder was defined as a patient with >15% increase in stroke volume index.

RESULTS

Thirty patients underwent bidirectional cavopulmonary shunt (15 responders and 15 non-responders), and 32 underwent Fontan surgery (17 responders and 15 non-responders). In children with bidirectional cavopulmonary shunt, Δsystolic arterial pressure > 8 mmHg (sensitivity 76.9% and specificity 93.3%), Δdiastolic arterial pressure > 7 mmHg (sensitivity 69.2% and specificity 93.3%), and Δmean arterial pressure > 7 mmHg (sensitivity 69.2% and specificity 100%) during liver compression predicted fluid responsiveness. The areas under the receiver operating characteristic curves of Δsystolic arterial pressure, Δdiastolic arterial pressure, and Δmean arterial pressure were 0.928, 0.859, and 0.874 (all p < .001). In children who underwent Fontan surgery, only Δsystolic arterial pressure > 16 mmHg was predictive of fluid responsiveness (sensitivity of 41.2% and specificity of 100%), with the areas under the receiver operating characteristic curves curve of 0.786 (p < .001). Pleth variability index and respiratory variation in aortic blood flow peak velocity had no predictive value for fluid responsiveness after both types of surgeries.

DISCUSSION

In BCPS patients, liver compression increases the inferior vena cava flow which directly leads to an increase in preload. On the other hand, blood flow from the liver drains directly into the pulmonary arteries in Fontan circulation. Because of this characteristics for preload determination, the clinical application of liver compression to monitor hemodynamic changes might be more useful in patients with bidirectional cavopulmonary shunt than those with Fontan circulation.

CONCLUSION

Increase in blood pressure induced by liver compression is predictive of fluid responsiveness in children with single ventricle physiology.

The effect of dexmedetomidine on neuroprotection in pediatric cardiac surgery patients: study protocol for a prospective randomized controlled trial

Background

Infants undergoing cardiac surgery under cardiopulmonary bypass are vulnerable to postoperative neurodevelopmental delays. Dexmedetomidine has been shown to have protective effects on the heart, kidneys, and brain in animals and adults undergoing cardiac surgery with cardiopulmonary bypass. We hypothesized that dexmedetomidine would have a neuroprotective effect on infants undergoing cardiopulmonary bypass and planned a prospective randomized controlled trial with postoperative neurodevelopment measurements.

Methods

This is a single-center, prospective, double-blinded, randomized controlled trial with 1:1 allocation. A cohort of 160 infants undergoing cardiac surgery with cardiopulmonary bypass will be enrolled. After induction, dexmedetomidine will be infused with a loading dose of 1 μg/kg and a maintenance dose of 0.5 μg/kg/h or the same amount of normal saline will be administered. Upon initiation of cardiopulmonary bypass, an additional dose of dexmedetomidine (0.01 μg/cardiopulmonary priming volume) will be mixed with the cardiopulmonary bypass circuit. The primary outcome will be the proportion of infants who score lower than 85 in any of the cognitive, language, or motor Bayley scales of infant development-III tests 1 year after the surgery. Other feasible outcome measures will include differences in plasma glial fibrillary acidic protein, troponin I, interleukin-6, urinary neutrophil gelatinase-associated lipocalin, and perioperative major adverse events. The results of the Bayley scales of infant development-III test from the study group and the control group will be compared using a chi-squared test under intention-to-treat analysis. A generalized estimating equation will be used to analyze repeated measurements over time.

Discussion

This study will enable us to assess whether the use of dexmedetomidine can alter the early neurodevelopmental outcome in infants undergoing cardiac surgery with cardiopulmonary bypass and also estimate effects of dexmedetomidine on other organs.

Trial registration

ClinicalTrials.gov NCT04484922. Registered on 24 July 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06217-9.

Anatomical changes of the ligamentum flavum and the epidural space after spinal surgery: a retrospective magnetic resonance imaging study

BACKGROUND

Anatomical changes of the ligamentum flavum (LF) and epidural space (ES) after spinal surgery may affect the loss-of-resistance during interlaminar epidural procedure and distribution of drug administered into the ES. This study aims to investigate clinically relevant anatomical changes of the LF and ES after spinal surgery.

METHODS

We reviewed pre- and post-operative lumbar magnetic resonance imaging (MRI) data from 34 patients who underwent spinal surgeries at two vertebral body levels. The presence and thickness of LF (midline, right, and left) and the cross-sectional area of the ES were checked at L2, L3, L4, L5, and S1 levels.

RESULTS

Intact LF was observed in only 4/34 (12%) and 9/27 (33%) patients at the upper and lower vertebral level of surgery, respectively. Intact LF was observed in 30/30 (100%), 28/33 (75%), and 2/4 (50%) patients, at two levels above, one level above, and one level below the segment level of surgery, respectively. Intact ES was observed in only 4/34 (12%) and 8/27(30%) patients at the upper and lower vertebral level of surgery, respectively. Intact ES was observed in 30/30 (100%), 29/33 (88%), and 3/4 (75%) patients, at two levels above, one level above, and one level below the segment level of surgery, respectively. The thickness of LF and the cross-sectional area of ES significantly decreased at the levels of spinal surgery.

CONCLUSIONS

For epidural anesthesia in patients who have previously undergone spinal surgery, it is reasonable to select a needle insertion site other than the level of spinal surgery.

Central venous catheter-related thrombosis in pediatric surgical patients: A prospective observational study

BACKGROUND

Perioperative central venous catheters are required but may be associated with various complications.

AIMS

The purpose of our study was to assess the incidence and perioperative risk factors for catheter-related internal jugular vein thrombosis in pediatric surgical patients.

METHODS

This prospective observational study included children under 6 years of age who were scheduled to undergo central venous catheterization of the right internal jugular vein under general anesthesia. A central venous catheter was inserted under real-time ultrasound guidance. An investigator examined for thrombosis using ultrasonography at predetermined time points. The primary aim was the incidence of catheter-related thrombosis from insertion until the 5th day postoperatively or the removal of the central venous catheter. The secondary aim was the determination of the risk factors for thrombosis.

RESULTS

Eighty patients completed the study. Internal jugular vein thrombi were found in 31 patients (38.8%, 95% CI 28.0-49.4). On multiple logistic regression analyses, the number of insertion attempts was the only influencing factor for catheter-related thrombosis (p < .001). More than two insertion attempts increased the risk of thrombosis (odds ratio 5.6; 95% CI 1.7 - 18.7, p = .004). Anesthesia time (p = .017; mean difference 166.4 min; 95% CI 55.7-277.1), intraoperative red blood cell transfusion (p = .001; median difference 21.1 ml kg^-1 ; 95% CI 6.6-34.4), and intensive care unit stay (p = .001; median difference 100.0 h; 95% CI 48-311) differed between patients with transient thrombosis and those with thrombosis lasting for more than 3 days.

CONCLUSION

Internal jugular vein thrombosis was frequently detected by ultrasound following central venous catheterization in pediatric surgical patients. Multiple insertion attempts may be associated with the incidence of thrombosis. The clinical relevance of thrombi detected via ultrasound surveillance has not been determined.

Comparison of the TOFscan and the TOF-Watch SX during pediatric neuromuscular function recovery: a prospective observational study

BACKGROUND

TOFscan is a three-dimensional acceleromyography neuromuscular monitoring device that does not require initial calibration before muscle relaxant injection. This study aimed to compare TOFscan with TOF-Watch SX, the currently widely accepted uni-dimensional acceleromyography, for use among the pediatric population. We aimed to assess the agreement between TOFscan with TOF-Watch SX in the pediatric population's neuromuscular recovery.

METHODS

A total of 35 children aged 6-12 years were enrolled. Prior to any muscle relaxant injection, TOFscan and TOF-Watch SX were applied at each opposite arm and monitoring began concurrently throughout neuromuscular recovery. Calibration was performed for TOF-Watch SX, and train-of-four values were recorded every 15 s. Agreement between the two devices was evaluated with Modified Bland-Altman analysis.

RESULTS

The bias between TOF-Watch SX and TOFscan were all within the 95% limits of agreement. The bias and standard deviation were smaller and the limit of agreement was narrower in the normalized group than in the non-normalized group [normalized bias -0.002 (95% CI, -0.013 to 0.010), standard deviation (SD) 0.111 vs non-normalized bias 0.010 (95% CI, -0.003 to 0.0236), SD 0.127].

CONCLUSIONS

TOFscan reliably demonstrated lack of bias and good concordance with TOF-Watch SX throughout the neuromuscular recovery, especially when normalized. Despite technical limitations, the two devices were unbiased along the path of spontaneous and pharmacological reversal in pediatric patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03775603. Registered on 13 March 2018.

Determining optimal positive end-expiratory pressure and tidal volume in children by intratidal compliance: a prospective observational study

BACKGROUND

Limited data exist regarding optimal intraoperative ventilation strategies for the paediatric population. This study aimed to determine the optimal combination of PEEP and tidal volume (V_T) based on intratidal compliance profiles in healthy young children undergoing general anaesthesia.

METHODS

During anaesthesia, infants (1 month-1 yr), toddlers (1-3 yr), and children (3-6 yr) were assigned serially to four ventilator settings: PEEP 8 cm H₂O/V_T 8 ml kg^-1 (PEEP8/V_T8), PEEP 10 cm H₂O/V_T 5 ml kg^-1 (PEEP10/V_T5), PEEP 10 cm H₂O/V_T 8 ml kg^-1 (PEEP10/V_T8), and PEEP 12 cm H₂O/V_T 5 ml kg^-1 (PEEP12/V_T5). The primary outcome was intratidal compliance profile, classified at each ventilator setting as horizontal (indicative of optimal alveolar ventilatory conditions), increasing, decreasing, or combinations of increasing/decreasing/horizontal compliance. Secondary outcomes were peak inspiratory, plateau, and driving pressures.

RESULTS

Intratidal compliance was measured in 15 infants, 13 toddlers, and 15 children (15/43 [35%] females). A horizontal compliance profile was most frequently observed with PEEP10/V_T5 (60.5%), compared with PEEP10/V_T8, PEEP8/V_T8, and PEEP12/V_T5 (23.3-34.9%; P<0.001). Decreasing compliance profiles were most frequent when V_T increased to 8 ml kg^-1, PEEP increased to 12 cm H₂O, or both. Plateau airway pressures were lower at PEEP8/V_T8 (16.9 cm H₂O [2.2]) and PEEP10/V_T5 (16.7 cm H₂O [1.7]), compared with PEEP10/V_T8 (19.5 cm H₂O [2.1]) and PEEP12/V_T5 (19.0 cm H₂O [2.0]; P<0.001). Driving pressure was lowest with PEEP10/V_T5 (4.6 cm H₂O), compared with other combinations (7.0 cm H₂O [2.0]-9.5 cm H₂O [2.1]; P<0.001).

CONCLUSIONS

V_T 5 ml kg^-1 combined with 10 cm H₂O PEEP may reduce atelectasis and overdistension, and minimise driving pressure in the majority of mechanically ventilated children <6 yr. The effect of these PEEP and V_T settings on postoperative pulmonary complications in children undergoing surgery requires further study.

CLINICAL TRIAL REGISTRATION

NCT04633720.

Optimal angle of needle insertion for spinal anesthesia in patients with spondylolisthesis: an ultrasonographic study

Background

Spondylolisthesis is a common degenerative spinal deformity. At the level of spondylolisthesis, the anatomy of the interlaminar space may differ from normal spine, in which case optimal angle of the needle insertion for spinal anesthesia may change. This study compared the optimal angle of needle insertion during spinal anesthesia in patients with and without lumbar spondylolisthesis using ultrasound.

Methods

We recruited 40 patients, 20 with and 20 without lumbar spondylolisthesis (group S and N, respectively). Ultrasonography was performed in the transverse midline and parasagittal oblique views at the spondylolisthesis level and the adjacent upper level. We measured the probe application angle with the longest interlaminar height of the ligamentum flavum-dura mater complex (LFD), depth from the skin to the LFD, depth from the skin to the anterior complex, and intrathecal space width. A positive angle represented a cephalad angulation.

Results

The optimal needle insertion angle in the transverse midline view at the spondylolisthesis level was (-) 2.7 ± 3.4° in group S and 0.8 ± 2.5° in group N (P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<$$\end{document}< 0.001). In the parasagittal oblique view, it was (-) 2.7 ± 4.5° in group S and 1.0 ± 3.2° in group N (P = 0.004). There were no between-group differences in the angles at the upper level, with all cephalad angles in both views. Other ultrasound image data were comparable between groups.

Conclusion

In patients with spondylolisthesis, caudad angulation of the spinal needle can aid successful spinal puncture at spondylolisthesis level, both in the midline and paramedian approaches.

Trial registration

www.ClinicalTrials.gov (NCT04426916); registered 11 June 2020.

Interventricular septal hematoma detected by transesophageal echocardiography after congenital heart surgery in an infant: a case report

Background

Interventricular septal hematoma is an extremely rare complication following congenital heart surgery. During cardiac surgery, interventricular septal hematomas can be detected only by intraoperative transesophageal echocardiography. Here, we report an interesting case of interventricular septal hematoma that was accidentally found in an infant following ventricular septal defect (VSD) closure.

Case presentation

Transesophageal echocardiography images were acquired from a 1-month-old boy after surgical repair of a large (6.5 mm) perimembranous outlet VSD with interventricular septal flattening. Surgical correction was performed with auto-pericardium and 7–0 Prolene sutures. The patient was successfully weaned from cardiopulmonary bypass, and transesophageal echocardiography showed no VSD leakage and good ventricular function. However, approximately 30 min later, two anechoic masses were found within the interventricular septum, which were suspected to be interventricular septal hematomas; the larger mass measured 1.51 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document}× 1.48 cm. The swollen interventricular septum showed decreased contractility and compressed both the right and left ventricles. However, there was no change in the size of hematomas or a significant hemodynamic instability for 30 min of observation. Therefore, expecting spontaneous resolution of the hematomas, the interventricular septum was not explored, and the patient was removed from cardiopulmonary bypass. On postoperative day 4, follow-up transthoracic echocardiography revealed thrombi filling the hematomas. The patient was discharged on postoperative day 15 and followed up with regular echocardiographic evaluations.

Conclusions

We describe a unique case of interventricular septal hematoma after VSD closure. Surgical manipulation of perimembranous VSD and injury of the septal perforating artery may contribute to the development of an interventricular septal hematoma. Moreover, conservative treatment and serial echocardiographic evaluation generally show gradual hematoma resolution in hemodynamically stable patients. Pediatric cardiac anesthesiologists should be aware of this rare complication after VSD repair.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-021-00552-4.

Exceeding ohmic scaling by more than one order of magnitude with a 3D ion concentration polarization system

We report an ion concentration polarization (CP) system that exceeds ohmic scaling, a barrier that has stood for more than four decades, by more than one order of magnitude. CP is used in many important applications, including the enrichment of trace analytes in microfluidic systems and water purification by electrodialysis. The mechanisms that control the current through these systems have been largely discovered, but the reduced currents and loss of efficiency imparted by the high resistance of the CP ion depleted zone have not been overcome. To obtain high currents, an ion permselective element with a microscale cross-section is interfaced with a macroscale reservoir. Confocal fluorescence microscopy and microparticle tracking velocimetry (μ-PTV) are used to characterize the depleted zone that emanates vertically from the CP inducing nanoporous gel into the macroscale reservoir. The shape and growth of the depleted zone and velocity in the surrounding bulk solution are consistent with natural convection being the driver of the depleted zone morphology and eliminating the high resistance created by the depleted zone in 1D and 2D systems. Once the resistance of the depleted zone is negated, the high currents are hypothesized to result from enhancement of counter-ion concentration in the nanoporous gel-filled microchannel. In contrast with conventional systems, the current increases monotonically and remains stable at a high quasi-steady level in the reported systems. These results may be used to increase the efficiency and performance of future devices that utilize CP, while the ability to collect purified water with this geometry is demonstrated.

Predicting hypotension during anesthesia: Variation in pulse oximetry plethysmography predicts propofol-induced hypotension in children

BACKGROUND

The development of hypotension on administration of intravenous propofol is common and independently associated with adverse outcomes. Identifying patients with a high risk for anesthesia-induced hypotension may help anesthesiologists prepare for such an event.

AIM

The authors hypothesized that propofol-induced hypotension is predictable by variables related to fluid responsiveness and investigated such variables to determine the factors which can predict hypotensive events.

METHODS

Patients 3-6 years of age who underwent general were included. Intravenous midazolam 0.1 mg kg^-1 was administered as premedication, and preoperative noninvasive blood pressure, heart rate, perfusion index, pleth variability index, and respiratory variation of pulse oximetry plethysmographic waveform were measured. Intravenous propofol 2.5 mg kg^-1 was given, and blood pressure was measured 5 times at 1-min intervals. Subjects with significant hypotension (mean blood pressure decrease ≥20%) were allocated to the hypotensive group; those without significant hypotension were allocated to the relatively normotensive group.

RESULTS

Of 77 patients, 50 (64.9%) developed significant hypotension. Patients in the hypotensive group exhibited significantly higher respiratory variation of pulse oximetry plethysmographic waveform (mean difference 11 [3.3] [95% confidence interval 4.9-18.1]; p = .001) and higher pleth variability index (mean difference 7.1 [2.8] [95% confidence interval 1.6-12.6]; p = .013) than the normotensive group. The areas under the receiver operating characteristic curve for respiratory variation of pulse oximetry plethysmographic waveform and pleth variability index were 0.722 and 0.649, respectively.

CONCLUSION

High preoperative respiratory variation of pulse oximetry plethysmographic waveform and pleth variability index were both independently associated with propofol-induced hypotension in children.

Ultrasound-guided insertion of peripherally inserted central catheter after anesthetic induction in children undergoing surgery for moyamoya disease - Thirty cases report

Background

Pediatric patients with moyamoya disease are vulnerable to ischemic attacks following physical or emotional stress, such as those experienced during blood sampling. A central venous catheter might be beneficial for blood sampling, and a peripherally inserted central catheter (PICC) is a considerable option for central venous access. However, PICC insertion during anesthetic management is relatively rare.

Case

Thirty cases of ultrasound-guided PICC insertion were performed in children undergoing surgery for moyamoya disease after anesthetic induction. Positioning was successful in 22 cases, and 5 were malpositioned. In three cases, the peripheral insertion failed. Adjustment of the insertion depth was performed in nine cases. No complications related to catheterization were observed during the procedure or the catheter indwelling period.

Conclusions

We report the successful use of PICC in children undergoing surgery for moyamoya disease with a considerable success rate and low incidence of malpositioning or complications.

Effects of tip-manipulated stylet angle on intubation using the GlideScope® videolaryngoscope in children: A prospective randomized controlled trial

BACKGROUND

An optimal endotracheal tube curve can be a key factor in successful intubation using the GlideScope videolaryngoscope.

AIMS

This study aimed to evaluate the effects of tube tip-modified stylet curve on the intubation time in children.

METHODS

Children aged 1-5 years were randomly assigned to either the standard curve (group S, n = 60) or tip-modified curve (group T, n = 60) groups. In group S, the endotracheal tube curve was similar to that in the GlideScope. In group T, a point approximately 1.5 cm from the tube tip was additionally angled to the left by 15°-20°. The primary outcome was the total intubation time, and the secondary outcomes were incidence of successful intubation in the first attempt, number of additional manipulations of the stylet curve, and visual analog scale (VAS) score for the easiness of intubation.

RESULTS

The mean total intubation time was significantly longer in group S than that in group T (13.9 [10.8] vs. 9.0 [3.4] sec, mean difference, 4.9 s; 95% confidence interval [CI], 2.0-7.8; p = .001). All patients in group T were successfully intubated in the first attempt, whereas those in group S were not (100% vs. 93.3%, relative risk [RR], 0.11; 95% CI, 0.01-2.02; p = .1376). Three patients in group S could be intubated after modifying the ETT curve similar to that in group T. Operators reported that tracheal intubation was easier in group T than in group S (median [interquartile range] for VAS; 1 [1-2] vs. 2 [1-3]; p < .001).

CONCLUSIONS

Having additional angle of the endotracheal tube tip to the left could be a useful technique to facilitate directing and advancing endotracheal tube into the vocal cords.

Comparative effectiveness of pharmacological interventions to prevent postoperative delirium: a network meta-analysis

Many pharmacologic agents were investigated for the effect to prevent delirium. We aimed to comprehensively compare the effect of the pharmacological interventions to prevent postoperative delirium. A Bayesian network meta-analysis of randomized trials was performed using random effects model. PubMed, the Cochrane Central Register of Controlled Trials, and Embase were searched on 20 January 2021. Randomized trials comparing the effect of a drug to prevent postoperative delirium with another drug or placebo in adult patients undergoing any kind of surgery were included. Primary outcome was the postoperative incidence of delirium. Eighty-six trials with 26,992 participants were included. Dexmedetomidine, haloperidol, and atypical antipsychotics significantly decreased the incidence of delirium than placebo [dexmedetomidine: odds ratio 0.51, 95% credible interval (CrI) 0.40-0.66, moderate quality of evidence (QOE); haloperidol: odds ratio 0.59, 95% CrI 0.37-0.95, moderate QOE; atypical antipsychotics: odds ratio 0.27, 95% CrI 0.14-0.51, moderate QOE]. Dexmedetomidine and atypical antipsychotics had the highest-ranking probabilities to be the best. However, significant heterogeneity regarding diagnostic time window as well as small study effects precludes firm conclusion.

Prediction of gastric fluid volume by ultrasonography in infants undergoing general anaesthesia

BACKGROUND

Point-of-care ultrasonography can estimate gastric contents and volume to assess the risk of pulmonary aspiration; however, its use in infants has not been well validated. We aimed to develop a predictive model for estimating gastric fluid volume using ultrasonography in infants.

METHODS

This prospective observational study enrolled 200 infants (≤12 months) undergoing general anaesthesia. After anaesthetic induction, while preserving spontaneous respiration, we measured gastric antral cross-sectional area using ultrasonography in both the supine and right lateral decubitus positions. We then suctioned the gastric content and measured its volume. The primary outcome was development of a gastric fluid volume prediction model with multiple regression analysis. Agreement between the predicted volume and the suctioned volume was evaluated using a Bland-Altman plot.

RESULTS

Overall, 192 infants were included in the final analysis. Pearson correlation analysis showed that the gastric antral cross-sectional area in the supine (P<0.001; correlation coefficient: 0.667) and right lateral decubitus (P<0.001; correlation coefficient: 0.845) positions and qualitative antral grade (P<0.001; correlation coefficient: 0.581) correlated with suctioned volume. We developed a predictive model: predicted volume (ml)=-3.7+6.5 × (right lateral decubitus cross-sectional area [cm²])-3.9 (supine cross-sectional area [cm²])+1.7 × grade (P<0.01). When comparing the predicted volume and suctioned volume, the mean bias was 0.01 ml kg^-1 and the limit of agreement was -0.58 to 0.62 ml kg^-1.

CONCLUSIONS

Gastric fluid volume can be estimated using a predictive model based on ultrasonography data in infants.

CLINICAL TRIAL REGISTRATION

NCT03155776.

Automated, multiparametric monitoring of respiratory biomarkers and vital signs in clinical and home settings for COVID-19 patients

Capabilities in continuous monitoring of key physiological parameters of disease have never been more important than in the context of the global COVID-19 pandemic. Soft, skin-mounted electronics that incorporate high-bandwidth, miniaturized motion sensors enable digital, wireless measurements of mechanoacoustic (MA) signatures of both core vital signs (heart rate, respiratory rate, and temperature) and underexplored biomarkers (coughing count) with high fidelity and immunity to ambient noises. This paper summarizes an effort that integrates such MA sensors with a cloud data infrastructure and a set of analytics approaches based on digital filtering and convolutional neural networks for monitoring of COVID-19 infections in sick and healthy individuals in the hospital and the home. Unique features are in quantitative measurements of coughing and other vocal events, as indicators of both disease and infectiousness. Systematic imaging studies demonstrate correlations between the time and intensity of coughing, speaking, and laughing and the total droplet production, as an approximate indicator of the probability for disease spread. The sensors, deployed on COVID-19 patients along with healthy controls in both inpatient and home settings, record coughing frequency and intensity continuously, along with a collection of other biometrics. The results indicate a decaying trend of coughing frequency and intensity through the course of disease recovery, but with wide variations across patient populations. The methodology creates opportunities to study patterns in biometrics across individuals and among different demographic groups.

Differential cardiopulmonary monitoring system for artifact-canceled physiological tracking of athletes, workers, and COVID-19 patients

Soft, skin-integrated electronic sensors can provide continuous measurements of diverse physiological parameters, with broad relevance to the future of human health care. Motion artifacts can, however, corrupt the recorded signals, particularly those associated with mechanical signatures of cardiopulmonary processes. Design strategies introduced here address this limitation through differential operation of a matched, time-synchronized pair of high-bandwidth accelerometers located on parts of the anatomy that exhibit strong spatial gradients in motion characteristics. When mounted at a location that spans the suprasternal notch and the sternal manubrium, these dual-sensing devices allow measurements of heart rate and sounds, respiratory activities, body temperature, body orientation, and activity level, along with swallowing, coughing, talking, and related processes, without sensitivity to ambient conditions during routine daily activities, vigorous exercises, intense manual labor, and even swimming. Deployments on patients with COVID-19 allow clinical-grade ambulatory monitoring of the key symptoms of the disease even during rehabilitation protocols.

Ultrasound-guided arterial catheterization

Ultrasonography facilitates arterial catheterization compared to traditional palpation techniques, especially in small arteries. For successful catheterization without complications, practitioners should be familiar with the anatomic characteristics of the artery and ultrasound-guided techniques. There are two approaches for ultrasound-guided arterial catheterization: the short-axis view out-of-plane approach and the long-axis view in-plane approach. There are several modified techniques and tips to facilitate ultrasound-guided arterial catheterization. This review deals with the anatomy relevant to arterial catheterization, several methods to improve success rates, and decrease complications associated with arterial catheterization.

Severity and Duration of Acute Kidney Injury and Chronic Kidney Disease after Cardiac Surgery

We aimed to evaluate whether the duration and stage of acute kidney injury (AKI) are associated with the occurrence of chronic kidney disease (CKD) in patients undergoing cardiac or thoracic aortic surgery. A total of 2009 cases were reviewed. The patients with postoperative AKI stage 1 and higher stage were divided into transient (serum creatinine elevation ≤48 h) or persistent (>48 h) AKI, respectively. Estimated glomerular filtration rate (eGFR) values during three years after surgery were collected. Occurrence of new-onset CKD stage 3 or higher or all-cause mortality was determined as the primary outcome. Multivariable Cox regression and Kaplan-Meier survival analysis were performed. The Median follow-up of renal function after surgery was 32 months. The cumulative incidences of our primary outcome at one, two, and three years after surgery were 19.8, 23.7, and 26.1%. There was a graded significant association of AKI with new-onset CKD during three years after surgery, except for transient stage 1 AKI (persistent stage 1: HR 3.11, 95% CI 2.62-4.91; transient higher stage: HR 4.07, 95% CI 2.98-6.11; persistent higher stage: HR 13.36, 95% CI 8.22-18.72). There was a significant difference in survival between transient and persistent AKI at the same stage. During three years after cardiac surgery, there was a significant and graded association between AKI stages and the development of new-onset CKD, except for transient stage 1 AKI. This association was stronger when AKI lasted more than 48 h at the same stage. Both duration and severity of AKI provide prognostic value to predict the development of CKD.

Structure and arrangement of perforated plates for uniform flow distribution in an electrostatic precipitator

A wide-angle diffuser installed at the entrance of an electrostatic precipitator (ESP) causes a non-uniform flow distribution due to the boundary layer separation. Because a non-uniform flow pattern decreases the particulate matter control efficiency of an ESP, it is important to maintain a uniform flow distribution. The objective of this study is therefore to understand flow distribution with the conditions of perforated plates placed in the diffuser and then to design an ESP to obtain uniform flow. Discharge coefficients were determined varying the porosity, thickness, and number of holes of the perforated plate inside the lab-scale duct system. The test results suggest that the perforated plate with a porosity of 50%, a thickness of 5 mm, and 0.104 hole/m² perforated plate is most acceptable. This perforated plate was placed in the diffuser of the lab-scale ESP system. Velocity profiles in the body of the ESP were obtained depending on the number and arrangement of perforated plates in the diffuser. One perforated plate placed in the diffuser did not improve the flow distribution. Although more uniform flow distribution was found with two perforated plates, stalled flow regions still existed at the top and bottom of the ESP body. When three perforated plates were placed in the diffuser, the 2nd and 3rd perforated plates were important to obtain uniform flow distribution. When the 2nd and 3rd perforated plates were placed at the inlet side and outlet of the diffuser, respectively, the most uniform flow distribution was obtained in the body of the ESP.Implications: In order to determine the optimal perforated plate for Electrostatic Precipitator (ESP), we investigated the discharge coefficient depending on the structure of the perforated plate in a square duct. We measured the velocity distribution in a laboratory ESP with perforated plates and found the effect of the number and arrangement of perforated plates on the flow distribution in the collection region. Based on the test results, we found the configuration of perforated plates for uniform flow distribution in the body of the ESP.

Comparative study of verbal rating scale and numerical rating scale to assess postoperative pain intensity in the post anesthesia care unit: A prospective observational cohort study

ABSTRACT

Postsurgical patients usually have difficulty in answering the self-report pain scales due to the residual effects of anesthetic or sedative agents in the post-anesthesia care unit (PACU). A comparative analysis of pain assessment tools used in the PACU is lacking.In this prospective observational study, we compared the intensity of pain using the 11-point numeric rating scale (NRS) and the 4-category verbal rating scale (VRS) thrice, 5 minutes after PACU admission, 20 minutes after the first assessment, and just before discharge from the PACU in 200 patients undergone surgery. Spearman rank correlation analysis was used to investigate the correlation between 2 scales, and the weighted kappa (κ) coefficient was performed to evaluate inter-scale reliability. Response rates of the 2 scales were also compared.VRS and NRS were highly correlated during all 3 comparisons (r = 0.767, 0.714, and 0.653, respectively; P < .0001). Each category of VRS showed a statistically significant difference in pain intensity measured by NRS during all 3 assessments. Inter-scale reliability had a fair strength of agreement for all 3 measurements (weighted κ = 0.519, 95% CI: 0.421-0.618; weighted κ = 0.511, 95% C.I: 0.409-0.613; weighted κ = 0.452, 95% C.I: 0.352-0.551, respectively). VRS showed a higher response rate for PACU patients compared to NRS in all 3 measurements (96% vs 77.5%, 99% vs 81.5%, and 96.5% vs 86.5%, respectively; P < .0001).In the PACU, VRS is a reasonable and practical pain intensity measurement tool for postsurgical patients, considering the high correlation between VRS and NRS, and a higher response rate.