Tube Size Research Articles

Morphometry of Human Trachea in Male and Female using Computerized Tomography- A Comparative Study

Background: The architecture of the trachea can help doctors choose the right size of the endotracheal tube for patients. Non-invasive procedures like cadaveric dissection (CD) and Computed Tomography (CT) scans can also be used in the investigation. Objective: to describe the morphometry of a normal human trachea on CT scans and compare it to data from other studies Methodology: The normal CT scan pictures of 110 patients (69 males and 41 females) were analyzed in this prospective investigation. A 64-slice CT scanner was used to do chest CT scans. DICOM, a program for digital imaging and communication in medicine, was used to collect the data. For each parameter, the research population's lowest and maximum values were established. The correlation between all research variables and height and weight was determined using Pearson's correlation method. Height and weight were used as predictors in a regression analysis of substantially correlated factors. Results: In males, the AP and transverse diameters were substantially linked with height. The diameter of the AP and the CSA were found to be substantially linked with weight. A-P diameter, cross-sectional area, and volume were shown to be poorly predicted by weight. Weak predictors of length and transverse diameter were found to be height. In females, there was no association between height or weight with any of the research parameters. It was discovered that neither body mass index (BMI) nor height (or weight) could predict the dependent variables. Conclusion: The data might be valuable in the setup and design of tracheostomy tubes and endotracheal tubes in the future. Keywords: Trachea, diameters, Cross-sectional area, Volume, Computerized tomography.

Image quality assessments of focal spot size on radiographic images in dogs

The aim of this prospective study was to investigate the effects of focal spot size of X-ray tube on sharpness of clinical radiographic images of dogs and cats. Radiographic images of 24 stifle joints, 15 carpi, 18 lumbar spines, 61 thoraxes, and 47 abdomens of 102 dogs and 4 cats were obtained in the present study, using 2 X-ray tubes with nominal focal spots of 2.0 mm and 0.6 mm, respectively. The sharpness of specific anatomical structures in all the images of 5 projections was assessed. The radiographic sharpness of various anatomical structures of lumbar spine and cortex of stifle with fine focal spot was increased significantly compared with broad focal spot images. In addition, the blurred motion was significantly higher in the fine focal spot images of thorax. In conclusion, our study suggests that a selective use of fine foci for imaging of lumbar spine or cortex of stifle enhanced radiographic sharpness.

The relationship between dimensions of the Eustachian tube and acquired attic cholesteatoma.

This study investigated the relationship between physical dimensions of the Eustachian tube and the emergence of primary attic cholesteatoma. A total of 31 patients with unilateral attic cholesteatoma were selected for radiological comparison. Standard point measurements as well as specific measurements were performed using imaging software. The length, narrowest diameter and bony segment volume, and pharyngeal orifice diameter of both sides of the Eustachian tube (attic cholesteatoma and healthy control ears) were measured and compared. Comparison of the values did not reveal any statistically significant difference between the attic cholesteatoma ears and the healthy control ears in terms of: Eustachian tube height, narrowest diameter, bony segment volume or pharyngeal orifice diameter. No statistically significant difference was found between the cholesteatoma ears and the healthy control ears in terms of the osseous Eustachian tube size. The findings indicate that the Eustachian tube bony segment dimensions and pharyngeal orifice diameter are not factors in attic cholesteatoma development.

Simplification and further optimization of spatial cable-truss structure without inner ring cables

PurposeIn order to optimize SCSWIRC, the simplification and further optimization method is proposed. SCSWIRC's optimization includes two levels. The first level refers to simplifying structural system from the perspective of components; the second level refers to optimizing components' sectional areas from the perspective of mechanics. The first level aims to remove redundant components, and the second level aims to reduce structural self-weight based on the first level. The purpose of the paper is to simplify SCSWIRC's structural system and optimize structural self-weight and reduce construction forming difficulty.Design/methodology/approachGrid-jumping layout and multi-objective optimization method is used to simplify and further optimize Spatial cable-truss structure without inner ring cables (SCSWIRC). Grid-jumping layout is used to simplify remove redundant components, and multi-objective optimization method is used to reduce structural self-weight. The detailed solving process is given based on grid-jumping layout and multi-objective optimization method.FindingsTake SCSWIRC with a span of 100m as an example to verify the feasibility and correctness of the simplification and further optimization method. The optimization results show that 12 redundant components are removed and the self-weight reduces by 3.128t from original scheme to grid-jumping layout scheme 1. The self-weight reduces from 36.007t to 28.231t and feasible coefficient decreases from 1.0 to 0.627 from grid-jumping layout scheme 1 to multi-objective optimization scheme. The simplification and further optimization can not only remove the redundant components and simplify structural system to reduce construction forming difficulty, but also optimize structural self-weight under considering structural stiffness to reduce project costs.Originality/valueThe proposed method firstly simplifies SCSWIRC and then optimizes the simplified SCSWIRC, which can solve the optimization problem from the perspective of components and mechanics. Meanwhile, the optimal section solving method can be used to obtain circular steel tube size with the optimal stiffness of the same areas. The proposed method successfully solves the problem of construction forming and project cost, which promotes the application of SCSWIRC in practical engineering.

Indications of oxygenation after thoracic operations depending on the method of selection of dual endobronchial tube used

Annotation. Pulmonary complications are a key problem in the postoperative period in patients with diseases of the thoracic cavity. They are characterized as the main factors of longer recovery and hospital mortality. The aim of the study was to compare the indicators of oxygenation of patients and the number of postoperative pulmonary complications after thoracic surgery, depending on the method used to select a dual endobronchial tube. The study was performed on 192 patients with diseases of the thoracic cavity (esophagus, lungs, mediastinum), operated on in the thoracoabdominal department of the Shalimov National Institute of Surgery and Tranplantology. A retrospective comparison group – 96 patients after thoracic surgery, which used the choice of DLT size according to the well-known method of Slinger “according to the patient's height”. The study group consisted of 96 patients after thoracic surgery, in which the choice of the size of the dual endobronchial tube was used according to the developed method (according to the formula that evaluates morphometric indicators of height, sex and diameter of the left main bronchus). EZR v 1.54 statistical software was used for statistical calculations. (graphical user interface for statistical software R version 4.0.3, R Foundation for Statistical Computing, Vienna, Austria). Pulmonary complications developed in 33 (34.4%) patients of the control group and in 13 (13.5%) patients of the study group, the difference was statistically significant, p=0.001. One-factor analysis revealed a link between the risk of complications and the indicators method, sex, PaCO2, PaO2. For the study group, the risk of complications is lower (p=0.001), BP=0.30 (95% CI 0.15-0.61) compared with the control group. The risk of complications for men is higher (p=0.048), BP=2.33 (95% CI 1.01–5.37) compared to women. An increase in the risk of complications with an increase in PaCO2 (p<0.001), BP=1.34 (95% CI 1.21-1.49) with an increase in the indicator by 1 unit, respectively. With increasing PaO2, the risk of complications decreases (p<0.001): BP=0.96 (95% CI 0.94-0.98) – with increasing 1 unit. Thus, the application of the proposed method in comparison with the traditional method reduces (p=0.001) the number of postoperative pulmonary complications by 2.5 times (from 34.4% to 13.5%).

SIMULATION STUDY ON THE TUBULAR MICROREACTOR FOR HYDROGEN PRODUCTION BY STEAM REFORMING OF METHANOL

In order to reduce the carbon emissions of fuel vehicles, hydrogen has received extensive attention as a new clean energy. In this paper, a packed-bed microreactor for hydrogen production from methanol steam is designed for use in hydrogen fuel cells. By considering the heating gas velocity in the heating tubes, the inlet temperature of the microreactor, the size and number of heating tubes, inlet pressure, pellet porosity and thermal conductivity, parameters such as methanol conversion rates and hydrogen concentration were evaluated. First, the rate at which the gas is heated has a great influence on the reaction results. Choosing a larger heating gas velocity leads to an increase in the temperature inside the microreactor, thereby increasing the CH3OH conversion, resulting in a higher H2 concentration at the outlet. Changing the inlet temperature of the microreactor affects the reaction speed, but has little effect on the H2 concentration at the outlet. By studying the radius and number of heating tubes, we selected three different sets of data to compare the conversion rate of reactants and the concentration of products, and finally determined the optimal parameters as R = 4 mm and N = 8. Second, the inlet pressure has little effect on the H2 concentration at the outlet, but has a significant effect on the reaction speed. Particle porosity has no effect on the reaction results. Finally, the larger the thermal conductivity, the higher the temperature in the microreactor, which is more conducive to the reaction.

Do tapered tracheostomy cuffs improve translaryngeal gas flow when compared to barrel cuffed fenestrated tubes: A laboratory study.

ObjectiveThe benefits of tracheostomy are well documented and include improved comfort and a reduction in sedative requirements that may facilitate more rapid ventilation weaning. A stable airway established with tracheostomy allows pulmonary toilet that may help in addressing aspiration. It is postulated that it may also increase translargyngeal airflow and allow phonation. We hypothesized that taper‐shaped cuffed tracheostomy tubes have less bulk upon cuff deflation, and on this basis, gas flow past the deflated tapered cuff is better than non‐tapered barrel cuffs and equal to gas flow in equivalent‐sized fenestrated versions.MethodsThis comparative bench study measured exhaled gas flow of Shiley™ Flexible taper‐cuffed tracheostomy and Fenestrated Shiley™ FEN tubes of equivalent sizes. Three sizes of Shiley™ tracheostomy tubes were used in printed 3D model tracheas, Jackson sizes 4, 6, and 10 (6.5, 7.5, and 10 mm ISO sizes). A standard ventilator provided tidal volumes to mechanical lungs. Because expiratory volume was the focus, the mechanical lungs exhaled through the model trachea and only the air exiting the model trachea, representing exhalation, was measured.ResultsAcross three sizes, the Shiley™ Flexible tracheostomy tube allowed significantly more translaryngeal airflow compared to the tracheostomy tube with fenestrations.ConclusionThis bench study showed significantly improved air flow past the cuff compared to fenestrated tubes. Improved airflow may help the phonation ability of patients. Clinical studies are required to elucidate use of this cuff design to allow phonation in patients with a tracheostomy.Level of evidence: NA.

Behavior of circular-steel-tube-confined square CFST short columns under axial compression

This paper proposes circular-steel-tube-confined square concrete-filled steel tube (CFST) to improve the mechanical property of the newly built and existing deficient square CFST. The external adding circular steel tube does not enter the beam-column connection area and mainly functions as lateral confinement to the inner square CFST. Twelve circular-steel-tube-confined square CFST short column specimens and twelve conventional square CFST short column specimens were designed and tested under axial compressive load. The main variables of the test include column type, steel ratio, outer circular steel tube size, and concrete strength. The overall failure modes, axial load-displacement curves, macroscopic deformation characteristics, and the inner and outer circular steel tube confinement were analyzed and compared systematically. The study revealed that the outer circular steel tube yielded horizontally in tensile strength and provided effective confinement to the inner square CFST. Therefore, the bearing capacity of the square stub column was improved significantly, and the brittle failure in the confined area was prevented. Due to the effective confinement by the outer circular steel tube, the stress state in the square steel tube was much more uniform. The column configuration led to an effective but uneven confinement in the outer circular steel tube, concentrating near the square steel tube corner. Based on the superposition method, a suitable design method is proposed to predict the compressive strength of circular-steel-tube-confined square CFST, and the theoretical predictions are in good agreement with the test results of this paper.

Abstract No.: ABS1770: Cuffed versus uncuffed endotracheal tubes in infants undergoing elective surgery in prone position:peritubal leak at standardised ventilator settings

Background & Aims:The purpose of this study was to compare peritubal leak in cuffed and uncuffed tubes in infants at standardised ventilatorsettings. Secondary objective was to see incidence of accidental extubation and postoperative respiratory complications such as stridor and sore throat.Methods:With ethics committee approval, a prospective,randomised,clinical study was conducted. Patients aged between birth to 1 year, American Society of Anesthesiologists ASA grade I,II and III, requiring general anaesthesia with orotracheal intubation in prone position during elective surgery were included and children with parents not giving consent,children with airway anomaly, laparoscopic surgery, and emergency surgery were excluded. Tracheal tube size was judged as adequate if the leak pressure was 20 cm H2O or less. Tube was exchanged to next larger size if the leak pressure was too high and tube size was exchanged to next smaller size, when cuff pressure exceeded 20 cm H2O.Results:60 infants were studied.In group 1 in which cuffed tube was used, there were no leaks,on the other hand, in group 2,17 out of 30 patients had peritubal leak and tube was exchanged to next larger size uncuffed tube, p value was <0.001. Moreover, the incidenceof accidental extubation, post extubation sore throat and stridor was more in uncuffed group, It was 2/6/6 in uncuffed group and 0/3/4 in cuffed group respectively. Tracheal tube exchange rate was also higher in uncuffed group.Conclusion:We found that in microcuff paediatric endotracheal tube, there is less peritubal leak; selection of cuffed tube with small internal diameter compared to uncuffed tubes implicates a higher chance for adequate fit of the tube at cricoid ring and due to this there is least chance of accidental extubation in the prone position.Peritubal leakGroup I (n=30)Group II (n=30)Total (n=60) No.%No.%No.%Absent30100.01343.34371.7Present00.01756.71728.3

Abstract No. : ABS0814: Comparison of lung ultrasound technique versus clinical method to evaluate the accuracy of positioning of left endobronchial double lumen tube in patients undergoing elective thoracic surgery- a prospective observational study

Background & Aims:Clinical methods like height and gender were found to be inaccurate in predicting the size of double-lumen tube (DLT).Tracheal ultrasonography (TUS) reliably predicts the size of DLT by measuring tracheal diameter. The aim wasto check theaccuracy of ultrasound over clinical methods.Methods:This study was conducted on 68 patients undergoing elective thoracic surgery requiring one-lung ventilation (OLV) withDLT. The subjects were divided into two groups depending on the prediction of size of DLT by either clinical (Group1) orultrasound method. (Group 2). The transducer was placed perpendicular to skin over cricoid cartilage to measure the transversediameter of the column of air in the cricoid cartilage which denoted the size of the DLT. The primary objective of the study was to assess the accuracy in prediction of size and placement of DLT through various parameters in both clinical andultrasound groups.Results:The accuracy of predicted DLT size between the Group U and Group C was found to be statistically significant (p=0.044). In Group 1, 56% of patients showed a mismatch between the predicted DLT size and the actual size required, while in Group 2, the mismatch was only 32.4%. The accuracy of placement of DLT in the first attempt suggested by adequate lung isolation was also significantly higher (p=0.028) in the ultrasound group compared to the clinical group.Conclusion:The size of DLT can be predicted by using clinical parameters but have low accuracy. In our study, the size of DLT was calculated by measuring tracheal diameter using TUS, which significantly improved the selection of appropriate DLT size, avoiding complications.Actual DLT usedGroup 1Group 2Z test No.%No.%Same as predicted1544.02367.6Z=-2.01, P=0.044*Higher that predicted823.5514.7Lower than predicted1132.5617.6Total34100.034100.0

A research of micro-pulse tube cryocooler with displacer phase shifter

• The phase relationships in the whole displacer PTC system were analyzed. • Three different sizes of a displacer type micro PTCs have been designed. • A 2D CFD model was constructed and used to characterize the displacer micro PTC. • A displacer provides a good phase shifting for a small-cooling-power micro PTC. • A cooling power of 1.5 W@80 K and a COP of 20.96% is obtained by the second micro PTC. Investigations of phase shifters and power recovery mechanisms are of sustainable interest for developing Stirling pulse tube cryocoolers (SPTC) with more compact design and higher efficiency. The warm displacer type SPTC has been demonstrated with a very promising theoretical efficiency benefiting from its strong phase shifting and work recovery functions. Extending this same phase shifting approach to miniature pulse tube refrigerators may provide advantages over the other alternatives, since inertance tubes are severely limited in their phase shifting capability when the associated acoustic power decreases below 20 W. A comprehensive investigation regarding the micro-pulse tube cryocooler with a displacer phase shifter is carried out in this work, including the design of the major components of the cryocooler, theoretical analysis regarding the phase relationship in the whole displacer type cryocooler system, and 2D simulation work addressing the performance of the cryocooler systems. In the optimum phase angle conditions of the 3 mm pulse tube size cryocooler, the mass flow rate leads the pressure wave by 28.8° at the regenerator warm end, and lags the pressure wave by 27.7° at the regenerator cold end. A cooling power of 1.5 W at 80 K and a COP (Coefficient of Performance) of 20.96% is obtained with an input power of 7.4 W.

Abstract No.: ABS2522: Comparison of Age-Based Versus Length-Based Method Using BroselowTape for Estimating Endotracheal Tube Size in Indian Children

Background & Aims:Using correct size ETT for paediatric intubation is important for effective ventilation.There is no single formula for estimating accurate size endotracheal tube (ETT) despite various studies. The aim of the present study wasto compare two different methods; age-based andlength-based (using Broselow tape) for estimating accurate sizeMethods:60 patients of either gender between 1”and6years age, undergoing elective surgery under general anaesthesia requiring endotracheal intubation with uncuffed endotracheal tube(ETT) were enroled in this study. ETT size was selected by senior anaesthesiologist as per their discretion. The ETT used was deemed to be a correct fit based on minimal air leak with peakinspiratory pressure 15cmof H2O, expired tidal volume>7 ml/kg, bilateral equal breath sounds, square wave capnograph, ETTpassing smoothly through the glottis and respiratory rate according to child’s age. The actual ETT used was compared with that predicted by age and length of the child (using Broselow tape).Results:Each method was tested for accuracy at predicting clinically accepted ETT size by subtracting ETT size used for each patient from size predicted by each method. Our study revealed that Broselow tape has overall correct predictability rate of 53.3% whereas age based formula has 46.6%. The ETT used was found to correlate with length (p=0.004, p<0.005 being significant).Conclusion:Length of child has good correlation with size of ETT to be used in Indian children. Broselow tape is an effective tool to predict ETT size and is a simple,accurate aid especially where age and weight are unknown.

Endotracheal Tube Size and Post-Operative Sore Throat in Women

Aim: To determine the proportion of women with postoperative sore throat an hour after elective surgery in women intubated with a size 6 endotracheal tube versus size 7 endotracheal tube. Study design: Randomized controlled trial Place and duration of study: Department of Anesthesiology, The Indus Hospital, Karachi from 22-09-2016 to 2109-2017. Methodology: Patients were divided two equal groups through randomization i.e. endotracheal tube size 6 versus endotracheal tube size 7. Prior to intubation the endotracheal tube is to be lubricated with normal saline. In group ETT 6, trachea intubated with a high volume low pressure endotracheal tube with internal diameter 6.0 and in group ETT 7 with a 7.0 diameter tube respectively. Immediately after intubation the endotracheal tube was verified by a five-point auscultation technique and the cuff inflated with room air until no air leakage could be heard. No humidifiers or moisture exchangers were used. Results: The mean age of ETT 6 and ETT 7 group was 34.36±9.46 and37.34±10.96 years respectively. The mean duration of surgery in ETT 6 and ETT 7 group was 117.70±30.57 and 125.17±55.0 minutes respectively. When both groups were postoperative sore throat was noted in 38 (59.4%) in ETT 6 group whereas 62 (96.9%) noted in ETT7 group (p=0.0001). Conclusion: Highly significant difference was found in postoperative sore throat between the group endotracheal tube size 6 in comparison to the group endotracheal tube size 7. Keywords: Endotracheal intubation, Sore throat, Hoarseness, Postoperative complications, Elective surgery

Performance of steel-reinforced square CFST stub columns loaded in axial compression: Experiments

A steel-reinforced concrete-filled steel tubular column is a type of concrete-filled steel tubular (CFST) column reinforced by embedded steel profile. The inner carbon steel tube reinforced square concrete-filled stainless steel tubular column (SR-CFSST) has not been systematically investigated. In this project, stub composite columns with various experimental parameters were tested as loaded in axial monotonic compression, considering the effects of the concrete strength, column size and wall thickness of the steel tubes. The mechanical behaviour of stub columns was analysed in terms of ultimate load-bearing capacity, strength index, ductility, and failure modes. The calculation methods in five codes, including GB 50936, DBJ/T 13–51, Eurocode 4, ANSI/AISC 360 and AIJ, which are widely used for ordinary CFST stub columns, were compared. Finally, a simplified calculation method for the SR-CFSST stub columns was proposed for predicting the ultimate bearing capacity. The predicted results agree well with test results and the simplified calculation method can be used to design SR-CFSST stub columns loaded monotonically in axial compression.

The Effects of Endotracheal Tube Size During Bronchoscopy in Simulated Models of Intubated Patients.

The aim is to use a simulation lung model to assess the possibility of performing bronchoscopy through endotracheal tubes (ETT) less than 8.0-mm while appropriately ventilating patients with normal and ARDS lungs in the setting of SARS-CoV-2. Five SHERIDAN® ETTs were used to ventilate SimMan® 3G under respiratory compliance levels representing normal and severe ARDS lungs. Baseline measurements of peak pressure, plateau pressure, and auto-positive end expiratory pressure (auto-PEEP) were recorded at four different inspiratory times (Ti). Three different-sized disposable bronchoscopes were inserted, and all measurements were repeated. Normal lung model: Slim bronchoscopes in 6.0-mm ETTs resulted in plateau pressures <30 cm H2 O, and increasing Ti to minimize peak pressure resulted in low auto-PEEP. Regular bronchoscopes in 7.0-mm ETTs had similar results. Large bronchoscopes in 7.5-mm ETTs generated plateau pressures ranging from 28 to 35 cm H2 O with modest auto-PEEP. Severe ARDS lung model: Slim bronchoscopes in 6.0-mm ETTs resulted in plateau pressures of 46 and an auto-PEEP of 5cm H2 O. Regular bronchoscopes in 7.0-mm ETTs generated similar results. Large bronchoscopes in 8.0-mm ETTs displayed plateau pressures of 44 and an auto-PEEP of 2cm H2 O. To mitigate risk of laryngeal injury, larger ETTs during bronchoscopy should be avoided. Our data show bronchoscopy with any ETT causes auto-PEEP and high plateau pressures, especially in lungs with poor compliance; however, ETT less than 7.5 mm can be used when considering several factors. Our data also suggest similar studies in patients with varying degrees of ARDS would be informative. NA Laryngoscope, 133:147-153, 2023.

Morphometric indicators for selection of dual endobronchial tube in thoracic anesthesiology

For the purpose of single-lung ventilation, various methods of lung isolation are used in the world, which is a prerequisite for many thoracic, cardiac and esophageal surgeries. Numerous studies have reported various methods for determining the optimal suitability between the diameter of the tube and the diameter of the left main bronchus for adequate ventilation and gas exchange during operations on the thoracic cavity. However, there is no consensus among anesthesiologists on the choice of tube size for effective lung ventilation and isolation. We have developed a new mathematical formula for determining the appropriate size of the left bilateral luminal endobronchial tube (LDT). The aim of the study was to determine the effectiveness of the developed standardized mathematical formula for determining the appropriate size of LDT for use in thoracic anesthesiology. The study was performed on 192 patients with diseases of the thoracic cavity (esophagus, lungs, mediastinum), operated on in the thoracoabdominal department of the Shalimov National Institute of Surgery and Tranplantology. A retrospective comparison group – 96 patients after thoracic surgery, which used the choice of LDT size according to the well-known Slinger method “according to the patient’s height”. The study group consisted of 96 patients after thoracic surgery, in which the choice of the size of the bifurcated endobronchial tube was used according to the developed method (according to the formula that evaluates morphometric indicators of height, sex and diameter of the left main bronchus). The application of the proposed method reduces (p = 0.001) the risk of pulmonary complications, HR = 0.39 (95 % CI 0.22-0.70) compared to traditional methods. The risk decreased 2.5 times.

Endotracheal Tube Size Is Associated With Mortality in Patients With Status Asthmaticus.

There is limited evidence on the clinical importance of the endotracheal tube (ETT) size selection in patients with status asthmaticus who require invasive mechanical ventilation. We set out to explore the clinical outcomes of different ETT internal diameter sizes in subjects mechanically ventilated with status asthmaticus. This was a retrospective study of intubated and non-intubated adults admitted for status asthmaticus between 2014-2021. We examined in-hospital mortality across subgroups with different ETT sizes, as well as non-intubated subjects, using logistic and generalized linear mixed-effects models. We adjusted for demographics, Charlson comorbidities, the first Sequential Organ Failure Assessment score, intubating personnel and setting, COVID-19, and the first PaCO2 . Finally, we calculated the post-estimation predictions of mortality. We enrolled subjects from 964 status asthmaticus admissions. The average age was 46.9 (SD 14.5) y; 63.5% of the encounters were women and 80.6% were Black. Approximately 72% of subjects (690) were not intubated. Twenty-eight percent (275) required endotracheal intubation, of which 3.3% (32) had a 7.0 mm or smaller ETT (ETT ≤ 7 group), 16.5% (159) a 7.5 mm ETT (ETT ≤ 7.5 group), and 8.6% (83) an 8.0 mm or larger ETT (ETT ≥ 8 group). The adjusted mortality was 26.7% (95% CI 13.2-40.2) for the ETT ≤ 7 group versus 14.3% ([(95% CI 6.9-21.7%], P = .04) for ETT ≤ 7.5 group and 11.0% ([95% CI 4.4-17.5], P = .02) for ETT ≥ 8 group, respectively. Intubated subjects with status asthmaticus had higher mortality than non-intubated subjects. Intubated subjects had incrementally higher observed mortality with smaller ETT sizes. Physiologic mechanisms can support this dose-response relationship.

Parallel Tubular Channel Angular Pressing (PTCAP) Processing of the Cu-20.7Zn-2Al Tube.

Commercial Al-brass tube was successfully processed by Parallel Tubular Channel Angular Pressing (PTCAP) in 2 passes under an imposed strain of 1.49 per pass. The effect of the number of PTCAP passes on the microstructure and the mechanical properties (hardness, tensile, and wear mass loss) of the Al-brass tubes was fully investigated. The average grain size of the as-received tube decreased to 1.28 μm after up to two passes of PTCAP with a mixture of ultrafine grain (UFG) and coarse grain (CG). The annealed tubes’ tensile strength and Vickers hardness increased by 237.65% and 175.6%, respectively, after two passes. In addition, a ductile fracture occurred with a clear necking. The fracture surface morphology indicated an apparent decrease in dimple size after PTCAP processing, combined with a decrease in ductility. Moreover, the wear mass loss decreased with increasing number of PTCAP passes due to the decrease in the grain size, and the increase of the hardness of the tubes was enhanced after PTCAP processing.

Prediction of endotracheal tube size in the pediatric age group by ultrasound: A systematic review and meta-analysis.

Anatomical differences in the airway in pediatric patients, compared to adults pose many challenges during endotracheal intubation, such as selecting the proper sized endotracheal tube (ETT) during intubation. Our primary objective was to assess how accurate is ultrasound (US) co-relation in comparison to standard age-based formulas in pediatric patients. Meta-analysis was registered in PROSPERO 2020, CRD42020220041. Online literature available in PubMed, Cochrane, and Embase, Goggle scholar was searched from year 2000 till November 30, 2020, using relevant Mesh terms, ('airway US' OR (('airway'/exp OR airway) AND ('US'/exp OR US))) AND ('endotracheal intubation'/exp OR 'endotracheal intubation') AND ('pediatric'/exp OR pediatric)" to Predict endotracheal tube size/placement in pediatric age (neonate till 18 years) by the US. Bibliographic cross-references of selected publications were further manually screened. The full texts of each article were studied, once the abstract was found appropriate independently by two reviewers. A total of 48 papers published between 2010 and 2020 were identified as relevant and read in detail. Average numbers of patients were 86 and total numbers of patients were 1978. Most of the studies included pediatric patients posted for elective surgeries under general anesthesia and excluded emergency procedures, known laryngeal or tracheal pathology, high-risk patients, recent upper respiratory tract infections or allergy to ultrasound gel. A total of 18 independent correlations were analyzed. Final combined r value calculated from all the included articles was 0.824 (95% CI 0.677, 0.908) with a P < 0.00001 {strong co-relation (r > 0.80)}. Q statistic of 756.484, and I2 statistics of 97.53% showed a large degree of heterogeneity in the effect size across the studies. Use of US for upper airway in pediatric patients is an effective modality and can effectively predict endotracheal tube size estimations in comparison to standard age-based or height-based formulae in the pediatric age group. US is a non-invasive, cost-effective, portable, and reproducible technique as compared to CT and MRI. It also takes less time with increasing expertise and experience.

Tracheostomy healing time after decannulation.

BackgroundProlonged healing of tracheostomy after decannulation has a negative impact on respiration, hygiene, cosmetics, and social life. Even so, evidence-based observations of tracheostoma healing time are lacking. Therefore, the aim of this study was to determine tracheostomy wound healing time after decannulation.MethodsIn this prospective observational cohort study, we included 30 subjects undergoing decannulation following prolonged mechanical ventilation via tracheostomy. Our primary endpoint was tracheostomy healing time defined as time from decannulation to airtight healing. To identify any factors related to healing time, we included information about patient demographics, comorbidities, tracheostomy method, tube size, and intubation time. All subjects were observed daily until their tracheostomy wound had healed.ResultsThe median tracheostomy healing time was 6.5 (1-22) days. The duration of tracheal cannulation was the only factor significantly correlated with prolonged healing (p=0.03). Four patients were subjected to recannulation shortly after decannulation due to hypercapnia, respiratory failure, secretion accumulation, or self-decannulation. All wounds achieved complete spontaneous airtight closure.ConclusionsDuration of spontaneous tracheostomy closure after decannulation was 1-22 days, and closure time correlated with duration of cannulation.