Background: Accurate determination of the optimal insertion depth of a pediatric endotracheal tube (ETT) is quite important. The aim of this study was to create an easily available formula that can be used to determin...Background: Accurate determination of the optimal insertion depth of a pediatric endotracheal tube (ETT) is quite important. The aim of this study was to create an easily available formula that can be used to determine the optimal insertion depth for a cuffed ETT even without depth marking with clear definitions of the upper and lower limits for the tip of ETT in the trachea in clinical practice. Methods: Eighty children under 12 years of age were enrolled. The depth marking of the cuffed ETT was placed at the vocal cords and both lungs were then auscultated using a stethoscope. The upper limit was radiographically defined as the position of the tip of the cuffed ETT being between the clavicles. The lower limit was defined as a distance of 5 mm above the carina. The relationship between the insertion depth and patient characteristics was analyzed to create a formula for optimal ETT insertion depth. Results: Sixty-nine ETTs were optimally placed in the trachea. There were good correlations between the optimal insertion depth of ETTs and patients characteristics (height (R = 0.92);BSA (R = 0.92);weight (R = 0.91);age (R = 0.88)). Using these patient characteristics, we created the following three formulas for calculation of the optimal insertion depth for pediatric cuffed ETTs: insertion depth (cm) = height (cm)/11 + 5.5, weight (kg)/3 + 9.5 or 11 + 3/4 × age (years). The rates of appropriate tube placement of both pediatric cuffed ETTs were 87.5% (Hi-Contour) and 85.0% (Microcuff). Conclusions: Our formula and graphs may be easy to determine the optimal insertion depth of cuffed ETT even without depth marking in clinical practice.展开更多
The number of patients with chronic kidney disease re-quiring renal replacement therapy has increased world-wide. The most common replacement therapy is hemo-dialysis （HD）. Vascular access （VA） has a key role for ...The number of patients with chronic kidney disease re-quiring renal replacement therapy has increased world-wide. The most common replacement therapy is hemo-dialysis （HD）. Vascular access （VA） has a key role for successful treatment. Despite the advances that have taken place in the feld of the HD procedure, few things have changed with regards to VA in recent years. Ar-teriovenous fstula （AVF）, polytetrafuoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common com-plications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunc-tion is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the frst choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the frst choice, fol-lowed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most importantissue for patients on HD and despite the technical im-provements, a number of problems and complications have to be resolved.展开更多
用0、50、100、150和200 m M Na Cl溶液处理不同秋眠等级紫花苜蓿标准品种Maverick、Archer和CUF101,观察形态特征和盐害级别,测定叶片净光合速率(Pn)、细胞间隙CO2浓度(Ci)和气孔导度(Gs),分析盐胁迫对不同秋眠等级紫花苜蓿光合特性的...用0、50、100、150和200 m M Na Cl溶液处理不同秋眠等级紫花苜蓿标准品种Maverick、Archer和CUF101,观察形态特征和盐害级别,测定叶片净光合速率(Pn)、细胞间隙CO2浓度(Ci)和气孔导度(Gs),分析盐胁迫对不同秋眠等级紫花苜蓿光合特性的影响.不同秋眠等级紫花苜蓿植株叶片盐害级别随品种和处理浓度不同而不同,但均随Na Cl浓度的增加和胁迫时间的延长而加大.在较低Na Cl浓度下Maverick、Archer和CUF101光合响应存在着预警阶段-恢复阶段-耗尽阶段,在高Na Cl浓度下,所有的供试品种光合响应直接进入耗尽阶段.展开更多
Background: Surveys of pediatric endotracheal tube (ETT) management previously reported that specialists in pediatric anesthesia and intensive care medicine preferred to use uncuffed ETTs for children younger than 8 t...Background: Surveys of pediatric endotracheal tube (ETT) management previously reported that specialists in pediatric anesthesia and intensive care medicine preferred to use uncuffed ETTs for children younger than 8 to 10 years of age. The aim of this study was to reveal the most recent attitudes and clinical practices of pediatric ETT management in Japan. Methods: The attitudes and clinical practices of pediatric ETT management were investigated using the data sheets of each institution and each patient. The data sheets contained information on patient characteristics and type of hospital, surgical procedures, devices used for intubation, and ETT information including types, size, depth, intracuff pressure (ICP), interval of ICP measurement, laryngeal packing, ETT exchange, airway complications, and reintubations. Results: The response rate of this survey was 66.7%. More than half of children older than 2 years of age were intubated with cuffed ETTs;83.5% of cuffed ETTs were used with the cuffs inflated, and ICP was measured in 80.7% of cuffed ETTs. More than half of ICP measurements were only taken at the time of intubation. Post-extubation stridor was rarely observed in cuffed (0.4%) or uncuffed ETTs (1.2%). The pediatric ETT management questionnaire revealed age-based size selection, differences in pressure of air leakage between cuffed (15 - 20 cmH2O) and uncuffed ETTs (20 - 30 cmH2O) of different sizes, the depthmarking method of insertion length. Continuous measurement of ICP was not common. Conclusion: This study revealed widespread use of cuffed ETTs in children older than 2 years of age, rarely occurrence of post-extubation stridor, inflation of cuffs, and practice of ICP measurement.展开更多
Background: Comparison of the tracheal tube depth over the same body height of men and women based upon intubation depth markings. Methods: Kashan University of Medical Sciences ethics committee approved the study and...Background: Comparison of the tracheal tube depth over the same body height of men and women based upon intubation depth markings. Methods: Kashan University of Medical Sciences ethics committee approved the study and written informed consent was taken for each patient. Patients undergoing surgery requiring general anesthesia with oro-tracheal intubation were included in a prospective observational study. After induction of general anesthesia, the endotracheal tube was secured at the point at which the cuff was just below the vocal cord on laryngoscopy. Results: In a statistical study of 682 intubated patients which consisted of 499 women and 183 men, 28 cases of laryngoscopic view grade III and IV were excluded from the study. The measurement markings on the ETT at the level of right corner of the mouth were 20.65 ± 0.13 and 18.52 ± 0.08 for men and women respectively (CI 95%). Patient’s height has a meaningful correlation with the measurement of the fixation point of the ETT. Pearson correlation coefficient between the securing point of the tube and height was 0.2 and 0.357 for men and women respectively. In most cases of men and women of the same height, Mann-Whitney U test rejected the hypothesis that the tube can be fixed in the particular point. Conclusions: In general, men are taller than women. Comparing the fixation depth of the tube, even when man and woman have the same body height, the endotracheal tube might be placed in a deeper level for men rather than women.展开更多
The mechanical behavior of advanced composites can be modeled mathematically through unknown variables and Shear Strain Thickness Functions(SSTFs). Such SSTFs can be of polynomial or non-polynomial nature and some par...The mechanical behavior of advanced composites can be modeled mathematically through unknown variables and Shear Strain Thickness Functions(SSTFs). Such SSTFs can be of polynomial or non-polynomial nature and some parameters of non-polynomial SSTFs can be optimized to get optimal results. In this paper, these parameters are called ‘‘r" and ‘‘s" and they are the argument of the trigonometric SSTFs introduced within the Carrera Unified Formulation(CUF). The Equivalent Single Layer(ESL) governing equations are obtained by employing the Principle of Virtual Displacement(PVD) and are solved using Navier method solution. Furthermore, trigonometric expansion with Murakami theory was implemented in order to reproduce the Zig-Zag effects which are important for multilayer structures. Several combinations of optimization parameters are evaluated and selected by different criteria of average error. Results of the present unified trigonometrical theory with CUF bases confirm that it is possible to improve the stress and displacement results through the thickness distribution of models with reduced unknown variables. Since the idea is to find a theory with reduced numbers of unknowns, the present method appears to be an appropriate technique to select a simple model. However these optimization parameters depend on the plate geometry and the order of expansion or unknown variables. So, the topic deserves further research.展开更多
文摘Background: Accurate determination of the optimal insertion depth of a pediatric endotracheal tube (ETT) is quite important. The aim of this study was to create an easily available formula that can be used to determine the optimal insertion depth for a cuffed ETT even without depth marking with clear definitions of the upper and lower limits for the tip of ETT in the trachea in clinical practice. Methods: Eighty children under 12 years of age were enrolled. The depth marking of the cuffed ETT was placed at the vocal cords and both lungs were then auscultated using a stethoscope. The upper limit was radiographically defined as the position of the tip of the cuffed ETT being between the clavicles. The lower limit was defined as a distance of 5 mm above the carina. The relationship between the insertion depth and patient characteristics was analyzed to create a formula for optimal ETT insertion depth. Results: Sixty-nine ETTs were optimally placed in the trachea. There were good correlations between the optimal insertion depth of ETTs and patients characteristics (height (R = 0.92);BSA (R = 0.92);weight (R = 0.91);age (R = 0.88)). Using these patient characteristics, we created the following three formulas for calculation of the optimal insertion depth for pediatric cuffed ETTs: insertion depth (cm) = height (cm)/11 + 5.5, weight (kg)/3 + 9.5 or 11 + 3/4 × age (years). The rates of appropriate tube placement of both pediatric cuffed ETTs were 87.5% (Hi-Contour) and 85.0% (Microcuff). Conclusions: Our formula and graphs may be easy to determine the optimal insertion depth of cuffed ETT even without depth marking in clinical practice.
文摘The number of patients with chronic kidney disease re-quiring renal replacement therapy has increased world-wide. The most common replacement therapy is hemo-dialysis （HD）. Vascular access （VA） has a key role for successful treatment. Despite the advances that have taken place in the feld of the HD procedure, few things have changed with regards to VA in recent years. Ar-teriovenous fstula （AVF）, polytetrafuoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common com-plications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunc-tion is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the frst choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the frst choice, fol-lowed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most importantissue for patients on HD and despite the technical im-provements, a number of problems and complications have to be resolved.
文摘用0、50、100、150和200 m M Na Cl溶液处理不同秋眠等级紫花苜蓿标准品种Maverick、Archer和CUF101,观察形态特征和盐害级别,测定叶片净光合速率(Pn)、细胞间隙CO2浓度(Ci)和气孔导度(Gs),分析盐胁迫对不同秋眠等级紫花苜蓿光合特性的影响.不同秋眠等级紫花苜蓿植株叶片盐害级别随品种和处理浓度不同而不同,但均随Na Cl浓度的增加和胁迫时间的延长而加大.在较低Na Cl浓度下Maverick、Archer和CUF101光合响应存在着预警阶段-恢复阶段-耗尽阶段,在高Na Cl浓度下,所有的供试品种光合响应直接进入耗尽阶段.
文摘Background: Surveys of pediatric endotracheal tube (ETT) management previously reported that specialists in pediatric anesthesia and intensive care medicine preferred to use uncuffed ETTs for children younger than 8 to 10 years of age. The aim of this study was to reveal the most recent attitudes and clinical practices of pediatric ETT management in Japan. Methods: The attitudes and clinical practices of pediatric ETT management were investigated using the data sheets of each institution and each patient. The data sheets contained information on patient characteristics and type of hospital, surgical procedures, devices used for intubation, and ETT information including types, size, depth, intracuff pressure (ICP), interval of ICP measurement, laryngeal packing, ETT exchange, airway complications, and reintubations. Results: The response rate of this survey was 66.7%. More than half of children older than 2 years of age were intubated with cuffed ETTs;83.5% of cuffed ETTs were used with the cuffs inflated, and ICP was measured in 80.7% of cuffed ETTs. More than half of ICP measurements were only taken at the time of intubation. Post-extubation stridor was rarely observed in cuffed (0.4%) or uncuffed ETTs (1.2%). The pediatric ETT management questionnaire revealed age-based size selection, differences in pressure of air leakage between cuffed (15 - 20 cmH2O) and uncuffed ETTs (20 - 30 cmH2O) of different sizes, the depthmarking method of insertion length. Continuous measurement of ICP was not common. Conclusion: This study revealed widespread use of cuffed ETTs in children older than 2 years of age, rarely occurrence of post-extubation stridor, inflation of cuffs, and practice of ICP measurement.
文摘Background: Comparison of the tracheal tube depth over the same body height of men and women based upon intubation depth markings. Methods: Kashan University of Medical Sciences ethics committee approved the study and written informed consent was taken for each patient. Patients undergoing surgery requiring general anesthesia with oro-tracheal intubation were included in a prospective observational study. After induction of general anesthesia, the endotracheal tube was secured at the point at which the cuff was just below the vocal cord on laryngoscopy. Results: In a statistical study of 682 intubated patients which consisted of 499 women and 183 men, 28 cases of laryngoscopic view grade III and IV were excluded from the study. The measurement markings on the ETT at the level of right corner of the mouth were 20.65 ± 0.13 and 18.52 ± 0.08 for men and women respectively (CI 95%). Patient’s height has a meaningful correlation with the measurement of the fixation point of the ETT. Pearson correlation coefficient between the securing point of the tube and height was 0.2 and 0.357 for men and women respectively. In most cases of men and women of the same height, Mann-Whitney U test rejected the hypothesis that the tube can be fixed in the particular point. Conclusions: In general, men are taller than women. Comparing the fixation depth of the tube, even when man and woman have the same body height, the endotracheal tube might be placed in a deeper level for men rather than women.
基金“Diseno y optimización de dispositivos de drenaje para pacientes con glaucoma mediante el uso de modelos computacionales de ojos"founded by Cienciactiva,CONCYTEC,under the contract number N°008-2016-FONDECYTfinancial support from the Peruvian Government
文摘The mechanical behavior of advanced composites can be modeled mathematically through unknown variables and Shear Strain Thickness Functions(SSTFs). Such SSTFs can be of polynomial or non-polynomial nature and some parameters of non-polynomial SSTFs can be optimized to get optimal results. In this paper, these parameters are called ‘‘r" and ‘‘s" and they are the argument of the trigonometric SSTFs introduced within the Carrera Unified Formulation(CUF). The Equivalent Single Layer(ESL) governing equations are obtained by employing the Principle of Virtual Displacement(PVD) and are solved using Navier method solution. Furthermore, trigonometric expansion with Murakami theory was implemented in order to reproduce the Zig-Zag effects which are important for multilayer structures. Several combinations of optimization parameters are evaluated and selected by different criteria of average error. Results of the present unified trigonometrical theory with CUF bases confirm that it is possible to improve the stress and displacement results through the thickness distribution of models with reduced unknown variables. Since the idea is to find a theory with reduced numbers of unknowns, the present method appears to be an appropriate technique to select a simple model. However these optimization parameters depend on the plate geometry and the order of expansion or unknown variables. So, the topic deserves further research.
