Central Line Research Articles

Motion of Submerged Body in a Frozen Channel with Compressed Porous Ice

The problem of submerged body motion in a frozen channel is considered. The fluid in the channel is assumed to be inviscid and incompressible. Fluid flow is the potential. The ice cover has non-uniform compression along the principal coordinates. The damping of hydroelastic waves generated by the motion of submerged body is modeled by taking into account porosity of ice. The submerged body is modeled as a dipole, the potential of which is determined using mirror images from the channel walls. The main problem of the submerged body motion at constant speed along the central line of the channel is considered. Two subproblems are addressed: comparison of damping effects of the porosity and viscosity of ice and investigation of effects of symmetrically variable ice thickness relative to the central line of the channel. It was found that the most important compressive stress is the stress in the direction of the motion of the submerged body. The speed of the body, which was subcritical for uncompressed ice, may become critical or supercritical. Compressive stresses perpendicular to the direction of motion do not qualitatively change the character of the ice response. These stresses, in combination with compressive stresses along the direction of motion, strengthen the effect of the latter, making the transition from subcritical to supercritical regime faster.

Characteristics of thalweg profile and cross-sectional geometry along alluvial river bends

ABSTRACT River bends have always drawn attention for their complicated hydraulic, geometric and migration nature. Laboratory as well as field experiments have been carried out to study the geometric behaviour of channel bends. This study aims to analyse the nature of the thalweg profile, longitudinal and transverse slope and distribution of depth in the cross-sectional geometry of both single and consecutive double bends of the channel. In the single bend, the thalweg approaches to the outer bank and becomes closest after the apex of the bend whereas in the successive bends of a double bend, the thalweg is closest before the apex of the bend. These results indicate that the thalweg of a bend depends on the previous consecutive bend. The longitudinal slopes vary periodically along the river bend creating the deepest pool before the apex of the bend. The centre line transverse slope varies periodically; however, the outer transverse slope with respect to the thalweg is maximum where the thalweg is closest to the outer bank. The thalweg and outer quarter line to centre line depth ratio is higher before the apex and reduces after the apex of the bend. The inner quarter line to centre line depth ratio varies periodically with a relatively smaller amplitude.

Automated estimation of thoracic rotation in chest X-ray radiographs: a deep learning approach for enhanced technical assessment.

This study aims to develop an automated approach for estimating the vertical rotation of the thorax, which can be used to assess the technical adequacy of chest X-ray radiographs (CXRs). Total 800 chest radiographs were used to train and establish segmentation networks for outlining the lungs and spine regions in chest X-ray images. By measuring the widths of the left and right lungs between the central line of segmented spine and the lateral sides of the segmented lungs, the quantification of thoracic vertical rotation was achieved. Additionally, a life-size, full body anthropomorphic phantom was employed to collect chest radiographic images under various specified rotation angles for assessing the accuracy of the proposed approach. The deep learning networks effectively segmented the anatomical structures of the lungs and spine. The proposed approach demonstrated a mean estimation error of less than 2° for thoracic rotation, surpassing existing techniques and indicating its superiority. The proposed approach offers a robust assessment of thoracic rotation and presents new possibilities for automated image quality control in chest X-ray examinations. This study presents a novel deep-learning-based approach for the automated estimation of vertical thoracic rotation in chest X-ray radiographs. The proposed method enables a quantitative assessment of the technical adequacy of CXR examinations and opens up new possibilities for automated screening and quality control of radiographs.

Catheters linked thrombosis in neonates: a single center observational study

BackgroundCentral venous catheters (CVCs) are the major risk factors for neonatal thrombosis that might negatively affect morbidity and mortality in neonates. The aim of the present work was to estimate the incidence of CVC-linked thrombosis, among neonates in the NICU of Alexandria University Maternity Hospital, Egypt, over 1year, and to determine its possible risk factors.MethodsThis observational cohort study involved 134 newborn infants born from July 2020 to July 2021with CVCs insertion during their hospital stay. Patients who had congenital anomalies, had thrombosis unrelated to the implantation of CVCs or died before 7 days of catheter placement were excluded from the analysis. The 134 neonates who met the study’s eligibility requirements had 142 CVCs inserted. Serial ultrasound and Doppler scans on site of venous insertion of catheters were performed.ResultsSeventeen patients with catheter’s thrombosis (12%) were found during the placement of 142 catheters or 1615 CVCs’ days, resulting in an overall rate of 10.5 thrombotic events per 1000 catheters’ days. We constructed a logistic regression model to identify risk factors behind CVC-linked thrombosis. In univariate analysis, femoral central venous lines (CVLs), catheter dwell-time, sepsis, packed red cells (PRBCs) transfusions and low platelet count were risk factors for CVC-linked thrombosis. Nevertheless, only PRBCs transfusion was significant in the multivariate analysis, with OR and 95% confidence level 5.768 (1.013–32.836).ConclusionMany factors should be considered in prediction of patients at risk of thrombosis including sepsis, femoral line insertion, low platelet count and PRBCs-transfusions. In our analysis, PRBCs-transfusion through peripheral intravenous lines (PIVs) was the strongest factor associated with CVC-linked thrombosis.

Clinical profile and risk factors associated with Elizabethkingia anophelis infection in neonates born in a tertiary care hospital-a case-control study and outbreak investigation.

The objective of this study was to determine the risk factors associated with Elizabethkingia anophelis infection in neonates admitted to a tertiary care neonatal intensive care unit (NICU). A case-control study was undertaken as part of the outbreak investigation for E. anophelis sepsis in a tertiary care NICU in South India. Thirty-eight neonates with E. anophelis bloodstream infection (BSI) between January 2021 and February 2022 were enrolled as cases, and 38 neonates symptomatic with other BSIs, were selected as controls, and risk factors analysed. The 38 cases were relatively stable neonates, likely to be admitted to level 1 and level 2 NICU, unlike the controls, who were sicker and required level 3 NICU care. Only a third of neonates with Elizabethkingia sepsis had traditional risk factors like central lines, need for respiratory support or perinatal risk factors. Multiple logistic regression analysis revealed that neonates with E. anophelis infection were more likely to be stable and on only enteral feeds, cared in level 1 or 2 of the NICU. This observation, combined with isolation of Elizabethkingia meningosepticum from breast pumps earlier, led us to autoclave the feeding vessels and milk containers along with provision of hot water for cleaning breast pumps, and adoption of general infection control measures, after which incident cases declined. Sanger sequencing of 10 representative isolates obtained from the neonates showed 100% sequence identity to E. anophelis. Infection due to E. anophelis affects relatively stable neonates without traditional risk factors for sepsis. Adherence to asepsis routines and housekeeping protocols helps to prevent the spread of infection.

Extraction of Crop Row Navigation Lines for Soybean Seedlings Based on Calculation of Average Pixel Point Coordinates

The extraction of navigation lines is a crucial aspect in the field autopilot system for intelligent agricultural equipment. Given that soybean seedlings are small, and straw can be found in certain Northeast China soybean fields, accurately obtaining feature points and extracting navigation lines during the soybean seedling stage poses numerous challenges. To solve the above problems, this paper proposes a method of extracting navigation lines based on the average coordinate feature points of pixel points in the bean seedling belt according to the calculation of the average coordinate. In this study, the soybean seedling was chosen as the research subject, and the Hue, Saturation, Value (HSV) colour model was employed in conjunction with the maximum interclass variance (OTSU) method for RGB image segmentation. To extract soybean seedling bands, a novel approach of framing binarised image contours by drawing external rectangles and calculating average coordinates of white pixel points as feature points was proposed. The feature points were normalised, and then the improved adaptive DBSCAN clustering method was used to cluster the feature points. The least squares method was used to fit the centre line of the crops and the navigation line, and the results showed that the average distance deviation and the average angle deviation of the proposed algorithm were 7.38 and 0.32. The fitted navigation line achieved an accuracy of 96.77%, meeting the requirements for extracting navigation lines in intelligent agricultural machinery equipment for soybean inter-row cultivation. This provides a theoretical foundation for realising automatic driving of intelligent agricultural machinery in the field.

Use of different designed needle-free connectors: a snapshot of central venous catheter intraluminal blood occlusion and central line–associated bloodstream infection in hospitals

Use of different designed needle-free connectors: a snapshot of central venous catheter intraluminal blood occlusion and central line–associated bloodstream infection in hospitals

Implementing a Compliance Monitoring Process to Promote Chlorhexidine Gluconate Bathing and Hand Hygiene: An Initiative to Decrease Central Line–Associated Bloodstream Infections

Background Chlorhexidine gluconate (CHG) bathing has proven to reduce central line–associated bloodstream infections (CLABSI) in hospitalized patients. The aim of this study is to evaluate whether the implementation of a compliance monitoring process for CHG bathing and strict hand hygiene as part of the traditional CLABSI prevention bundle will reduce the overall hospital CLABSI standardized infection ratio (SIR). Methods A quasi-experimental study was conducted in intensive care and non-intensive care inpatient hospital units in an urban 361-bed teaching hospital in Western Pennsylvania. The pre-intervention period consisted of January–August 2021, the intervention period consisted of September–November 2021, and the post-intervention and sustainability period consisted of December 2021–June 2022. A compliance monitoring process for the initiation of a daily bath using a 4% CHG solution and strict hand hygiene surveillance was implemented as part of the standard CLABSI prevention bundle (which includes standardized insertion checklists and processes, daily necessity assessment, dressing change and integrity standards, five moments hand hygiene standards, CHG disk [Biopatch], end caps [Curos], and care of tubing). Outcomes A statistically significant increase in hand hygiene (p=<0.001) and in CHG bathing compliance (p=0.014) helped reduce the overall hospital CLABSI SIR from 1.45 to 0.82, standing for an overall 43.4% decrease. Cost reduction was statistically significant (p=0.011) and was an estimated $1.4 million dollars in savings for the hospital. Next Steps Incorporate the compliance monitoring component for CHG bathing and hand hygiene as part of the best strategy for CLABSI bundle prevention within the healthcare system.

Influence of ground motion parameters on seismic response of a large-longitudinal-slope and small-radius curved girder bridge.

The mechanical performance of curved bridges under the action of an earthquake is complex. To obtain the influence of seismic parameters on the seismic response of curved girder bridges, this paper relies on a large slope small-radius curved steel box girder bridge (LSCGB) and selects seismic wave incidence angle, vertical component of ground motion, and site category as seismic parameters to carry out nonlinear time history analysis. Based on the analysis results of the case bridge, it is shown that the torsional vibration of the first 10 modes of LSCGB is significant, the modes are dispersed, and the contribution of high-order modes of vibration cannot be ignored. The most unfavorable seismic wave incidence angle is in the direction of 45°∼60° counterclockwise Angle from the central connection line of Pier No. 1 and Pier No. 4 of the bridge. The seismic response of the curved bridge components increases with the vertical seismic intensity, and the influence on displacement responses is more significant. The basic vibration period of curved girder bridges built on soft soil sites is extended by approximately 18.23%, and the seismic response of key components increases with the softening of the site soil. Therefore, when analyzing the seismic response of LSCGBs, the influence of vertical component of ground motion and site category should not be ignored.

Clinical Profile of Febrile Neutropenia in Children with Malignancies in a Tertiary Care Hospital: A Prospective Observational Study

Abstract Introduction: Febrile neutropenia is a dreadful complication associated with malignancies. Knowledge of locally prevalent pathogens and their resistance pattern is of paramount importance in guiding antimicrobial therapy. Aims/Objectives: The aim of the study was to identify the common infectious agent, antibiotic susceptibility of culture positive patients, and outcome Methods: We conducted a single-center prospective observational study. Forty-three children with febrile neutropenia episodes admitted in KKCTH, Chennai, were included in the study. The duration of the study was 1 year. Relevant patient and disease specific details were obtained, results were analyzed, and conclusions were drawn. Results: There were 90 episodes of febrile neutropenia. Overall culture positivity was identified in 37 cases (41.11%). Bacteremia (23.3%) was the most common cause of microbiologically documented infection. Gram-positive organisms (60%) were more commonly documented. Among the gram-positive organisms, coagulase-negative Staphylococcus aureus was the predominant isolate followed by Streptococcus. Central line–associated bloodstream infections were documented in 13.33%. Chemo-port removal was done in four children. Three had invasive fungal disease. The majority of the gram-negative isolates were resistant strains. Morbidity was significantly more in gram-negative infections. Overall outcome was good though three children succumbed to sepsis. Conclusion: A vigilant management of illness is essential. Chemo-port carries risk of severe infection. Protocol-based management of catheter-related bloodstream infection (CRBSI) can limit the number of chemo-port removal. Though gram-positive organisms are in the rise, gram-negative organisms are still responsible for significant morbidity. Early initiation of broad-spectrum empirical antibiotics with optimal gram-positive coverage is crucial. Children with suspected fungal infections should be aggressively evaluated and treated. An organized approach is the key in successful management.

Cumulative Analysis of Device-associated Hospital-acquired Infection Quality Indicators in a Teaching Hospital in Telangana

Background and Aims: In the realm of healthcare, device-associated hospital-acquired infections (DA-HAIs) pose significant challenges. These infections occur due to invasive medical devices and can lead to serious complications for patients. This study intends to assess the trends in device-associated infections over time in order to improve patient safety and quality through measurements and improvements in device-associated infections. Methods: The Department of Microbiology conducted a routine surveillance using a specific infection surveillance proforma for various healthcare-associated infections, including ventilator-associated events (VAEs), central line–associated bloodstream infections (CLABSI) and catheter-associated urinary tract infections (CAUTI). The data were examined at the end of each month, and the infection rate was determined using CDC guidelines. Results: The overall rate of HAI was found to be 1.69 HAI cases per 1,000 patient days. The cumulative DAI rates for the years 2021 and 2022 were CAUTI 6.14/1,000 urinary catheter days, CLABSI 4.5/1,000 central line catheter days and VAE 16.3/1,000 ventilator days. Discussion: It was observed that the CAUTI and CLABSI rates in our institution were comparable to or slightly higher than the national standard benchmark and INICC report and were significantly higher compared to the CDC/NHSN benchmark. The VAE rate was comparable to INICC report but was significantly higher compared to the NSB and the CDC/NHSN reports. Conclusion: Individual hospitals should make efforts to generate and evaluate their DAI trends and overall HAI rates and implement and improve their infection control programme to collectively achieve the target in our country in bringing down HAIs.

A Single-Center Review of Clinical Outcomes After Transcatheter Relief of Superior Vena Cava Stenosis in a Pediatric and Young Adult Population

BackgroundThe suspected etiology of superior vena cava (SVC) obstruction is predominantly iatrogenic. Transcatheter interventions relieve stenosis with good long-term results, although there is a paucity of published data in pediatrics. We aim to describe patient characteristics and clinical outcomes after transcatheter SVC intervention at a single-center pediatric quaternary care center. MethodsSingle-center, retrospective study of all pediatric and young adult patients who underwent transcatheter SVC intervention from December 2006 to January 2020. SVC gradients and changes in vessel diameter were compared using paired-sample t-tests. Balloon and stent cohorts were compared using the Wilcoxon rank sum test or Fisher exact χ2 test. Reintervention was compared between balloon and stent cohorts using the McNemar test to determine if initial procedural type was associated with reintervention. Time to reintervention was compared between balloon vs stent cohorts using Kaplan-Meier survival analysis with a log-rank test. ResultsA total of 42 patients (median age, 1.5 years; IQR, 0.31-15; 64.2% male) underwent 81 procedures with 1 minor complication and no mortality attributed to the procedure. Most (71.4%) patients were asymptomatic. Affected patient subgroups include those with a history of central venous line (92.9%), congenital heart disease (76.2%), postorthotopic heart transplant (42.9%), post-ECMO (31.0%), and history of surgical baffling or SVC surgery (9.5%). Those who underwent initial balloon angioplasty were significantly younger and smaller than those with an initial stent. Significantly lower pressure gradients and larger SVC dimensions were achieved after stenting. The majority of patients (54.8%) resolved after initial balloon angioplasty and reintervention rates were similar between initial balloon angioplasty and stent, although reintervention trended toward being earlier after the balloon. ConclusionsTranscatheter SVC intervention in pediatrics is acutely effective and safe in relieving SVC obstruction in all subgroups. Reintervention rates are similar between balloon and stenting, with balloon tending to be earlier, with the majority resolving after initial intervention. Further research is necessary to investigate the most effective transcatheter intervention for each patient subgroup.

Widely tunable and narrow-linewidth hybrid-integrated diode laser at 637 nm.

We present hybrid-integrated extended cavity diode lasers tunable around 637 nm, with a gain-wide spectral coverage of 8 nm. This tuning range addresses the zero-phonon line of nitrogen-vacancy centers and includes the wavelength of HeNe lasers (633 nm). Best performance shows wide mode-hop free tuning up to 97 GHz and a narrow intrinsic linewidth down to 10 kHz. Also, the maximum output power is 2.5 mW in a single-mode fiber, corresponding to an on-chip power of 4.0 mW. Full integration and packaging in standard housing with fiber pigtails provide high intrinsic stability and enable integration into complex optical systems.

Reducing Central Line-Associated Bloodstream Infections With a Multipronged Nurse-Driven Approach.

Despite implementation of central catheter bundles, central line [catheter]-associated bloodstream infections (CLABSIs) remain a preventable hospital-acquired infection. A new population of patients with pulmonary artery catheters was introduced to the cardiac progressive care unit, increasing central catheter days, device use, and CLABSI rate. A quality improvement project was conducted. Nursing staff implemented a standardized central catheter rounding process 3 days a week to critically assess all central catheter dressings, deter-mine the necessity of each central catheter, and educate patients on the importance of keeping central catheter dressings clean, dry, and intact. Data were collected during central catheter rounds for each patient, entered in an electronic survey tool via mobile devices, and analyzed. From July 2019 through June 2022, a total of 2692 rounds were conducted for 707 individual patients with 3064 central catheters. Main interventions were dressing management, monitoring insertion site bleeding that extended beyond edges of the chlorhexidine gluconate pad, treating patients' allergies to products, and maintaining sustainability within the unit. Central catheter rounds decreased the CLABSI rate from 1.86 to 0.0 despite the continued increase in central catheter days. Central catheter dressing assessment, intervention, and education help reduce CLABSIs. Central catheter rounds are an important adjunct to the CLABSI bundle. A central catheter dressing management algorithm helps nurses decide when to change a dressing and which type of dressing to use.

A mechanical analogue of electromagnetic induction for waves in a chiral elastic structure

Classical Faraday’s law on electromagnetic induction states that a change of magnetic field through a coil wire induces a current in the wire. A mechanical analogue of the Lorentz force, induced by a magnetic field on an electric charge, is the gyroscopic force. Here, we demonstrate a mechanical analogy with a chiral elastic waveguide subjected to gyroscopic forcing. We study waves in an infinite mass-spring ‘gyrocore helix’, which consists of a helix and a central line (gyroscopic elastic core). The helicoidal geometric chirality is considered in conjunction with a physical chirality, induced by gyroscopic forces. It is shown that the interplay between these two chiral inputs leads to the breaking of symmetry of the associated dispersion diagram, resulting in a unidirectional waveform with the direction of propagation being tunable through the gyricity.

A fully automatic curve localization method for extracted spine

The automation of scoliosis positioning presents a challenging and often understated task, yet it holds fundamental significance for the automated analysis of spinal morphological anomalies. This paper introduces a novel spinal curve localization model for precisely differentiating the spinal curves and identifying their concave centers. The proposed model contains three components: i) custom spine central line model, to define the spine central line as a combination of several secant line sequences with different polarities; ii) custom curve model, to classify each spinal curve into one of 11 curves types and deduce each its concave centers by several custom formulas; and iii) adapted distance transform and quadratic line fitting algorithm coupled with custom secant line segment searching strategy (DTQL-LS), to search all line segments in the spine and group consecutive line segments with identical polarity into line sequence. Experimental results show that its positioning success rate is close to 99%. Furthermore, it exhibits significant time efficiency, with the average time to process a single image being less than 30 milliseconds. Moreover, even if some image boundaries are blurred, the center of the curve can still be accurately located.

Geometrical Optimization of Closed-End Cylindrical Air Filter Using CFD Simulation

This research aims to evaluate the effect of porous filter configuration on flow characteristics within filter using CFD simulation. This simulation model was chosen for comprehensive analysis that considers different variables affecting the filter performances. Dynamics of the flow and pressure drop under different flow conditions and filter geometry were studied. The Euler-Lagrangian approach was used to model multiphase flow, and the standard K-ε model was used for turbulence characterisation. Particle size distribution was characterized using Rosin-Rammler distribution. The initial status of these properties was obtained by previous experimental references and their evolution over time was simulated at the cell level of the model using User-Defined Functions (UDF). The main conclusions of the study are: i) The pressure drop increased with flow rate and thickness of the filter but decreased with increasing filter length and diameter. ii) There is no significant change in velocity ratio with the distance from the filter inlet at the filter centre line except the first 5% from the inlet and last 5% close to the end. iii) it was identified that higher radial velocity ratios imply a less particle deposition within the filter media. The results also shows that the particle loading on 290 mm filter is 50% - 60% lower than the other filters but evenly distributed across the filter. However, the pressure drop decreased with the filter length. 55mm filter that has the highest radial velocity ratio performs poorly in particle trapping.

Decoupling stiffness and peak moment via hierarchical snapping structures designed with machine learning

This work presents the hierarchical tape spring that uses vein topologies to enable novel structural properties that are essential for architected materials with snapping and phase transition capabilities. Such novel structural properties include bending-sense-independent snap-through with energy dissipation, and the decoupling of initial bending stiffness from peak moment. By leveraging an FEA-generated dataset of mechanical performance metrics, we employed a data-driven design approach from literature involving the use of a quadratic regression machine learning model to predict the mechanical behavior of various hierarchical tape springs. The machine learning model was then used as an objective function in a genetic algorithm that searched for hierarchical tape spring designs with user-specified combinations of peak moment and bending stiffness. Designs discovered with the genetic algorithm were validated with FEA, the results of which revealed that the decoupling of bending stiffness and peak moment was made possible by moving transverse veins along the length of hierarchical tape springs with longitudinal veins. If the transverse veins were close to the center line, the tape generally had a higher peak moment, if there were multiple transverse veins near the center line, the hierarchical tape would have a lower bending stiffness with a comparable peak moment. Finally, to prove that the hierarchical tape springs could be fabricated and tested, three designs were chosen and fabricated with a custom vacuum forming rig and tested via four-point bending. Experimental trends were similar to those observed from finite element results.

Con: Central Lines Should Be the Preferred Method of Vasopressor Administration

Con: Central Lines Should Be the Preferred Method of Vasopressor Administration

Prehospital transfusion of labile blood product using intraosseous perfusion with multi-lumen extender: Why not?

French prehospital military medical teams are provided with labile blood products to effectively address hemorrhagic shock. In combat environment, standard good medical practice may limit efficacy of therapeutic goals regarding damage control resuscitation. We present here a case report describing the management of a soldier heavily wounded during a helicopter forward medical evacuation in Sahel region. We report the challenge encountered by medical team using only a humeral intraosseous route available due to severity of lesions and challenging environment. In this configuration, multi-lumen extender enabled transfusion of two units of packed red blood cells and two units of plasma, and analgesia while limiting manipulation and dislodgment of the fragile intraosseous route. This situation, outside of usual good medical practice, raises issues of hemolysis, physicochemical compability of drugs and blood products, and consequences on flow rate reduction. With this case, we emphasize the benefit of multi-lumen extender associated with intraosseous route for early management of heavy casualties in harsh prehospital environment. Literature suggests that hemolysis and physicochemical compability should remain limited. The main issue of this setting consists of flow reduction and can be addressed by prioritizing humeral route, and using counter pressure cuffs, until a second peripheral or central line is available and management can resume without the need for multi-lumen extender.