Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clini...Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clinical study to systematically evaluate the feasibility, safety and efficacy of awake ETI using the lightwand alone in patients with difficult airways. Methods Seventy adult patients with difficult airways were enrolled in this study. After the desired sedation with fentanyl and midazolam, airway topical anesthesia was performed with 9 ml of 2% lidocaine, which were in order sprayed in three aliquots at 5 minutes intervals into the supraglottic （two doses） and laryngotracheal areas （one dose） using a combined unit of the lightwand and MADgic atomizer. After airway topical anesthesia, awake ETI was performed using a Lightwand. Subjective assessments by patients and operators using the visual analogue scores （VAS）, and objective assessments by an independent investigator using patients＇ tolerance and reaction scores, coughing severity, intubating conditions and cardiovascular variables were taken as the observed parameters. Results Of 210 airway sprays, 197 （93.8%） were successfully completed on the first attempt. The total time for airway spray was （14.6±1.5） minutes. During airway topical anesthesia, the average patients＇ tolerance scores were 1.7-2.3. After airway topical anesthesia, the mean VAS for discomfort levels that the patients reported was 6.5. Also airway topical anesthesia procedure was rated as acceptable and no discomfort by 94.3% of patients. The lightwand-guided awake ETI was successfully completed on first attempt within 29 seconds in all patients. During awake ETI, patients＇ reaction and coughing scores were 1.9 and 1.6, respectively. All patients exhibited excellent or acceptable intubating conditions. Cardiovascular monitoring revealed that changes of systolic blood pressure and heart rate at each stage of airway manipulations were less than 20% of baseli展开更多
Recent state-of-the-art computed tomography and improved three-dimensional(3-D) postprocessing techniques have revolutionized the capability of visualizing airway pathology,offering physicians an advanced view of path...Recent state-of-the-art computed tomography and improved three-dimensional(3-D) postprocessing techniques have revolutionized the capability of visualizing airway pathology,offering physicians an advanced view of pathology and allowing for appropriate management planning.This article is a comprehensive review of trachea and main bronchi imaging,with emphasis on the dynamic airway anatomy,and a discussion of a wide variety of diseases including,but not limited to,congenital large airway abnormalities,tracheobronchial stenoses,benign and malignant neoplasms and tracheobronchomalacia.The importance of multiplanar reconstruction,3-D reconstruction and incorporation of dynamic imaging for non-invasive evaluation of the large airways is stressed.展开更多
Extraintestinal manifestations occur commonly in inflammatory bowel diseases(IBD). Pulmonary manifestations(PM) of IBD may be divided in airway disorders, interstitial lung disorders, serositis, pulmonary vasculitis, ...Extraintestinal manifestations occur commonly in inflammatory bowel diseases(IBD). Pulmonary manifestations(PM) of IBD may be divided in airway disorders, interstitial lung disorders, serositis, pulmonary vasculitis, necrobiotic nodules, drug-induced lung disease, thromboembolic lung disease and enteropulmonary fistulas. Pulmonary involvement may often be asymptomatic and detected solely on the basis of abnormal screening tests. The common embryonic origin of the intestine and the lungs from the primitive foregut, the co-existence of mucosa associated lymphoid tissue in both organs, autoimmunity, smoking and bacterial translocation from the colon to the lungs may all be involved in the pathogenesis of PM in IBD. PM are mainly detected by pulmonary function tests and highresolution computed tomography. This review will focus on the involvement of the airways in the context of IBD, especially stenoses of the large airways, tracheo-bronchitis, bronchiectasis, bronchitis, mucoid impaction, bronchial granulomas, bronchiolitis, bronchiolitis obliterans syndrome and the co-existence of IBD with asthma, chronic obstructive pulmonary disease, sarcoidosis and a1-antitrypsin deficiency.展开更多
Background：High intracuffpressure can cause severe pharyngeal complications including sore throat or hoarseness after laryngeal mask airway （LMA） removal postoperatively.Though the application of minimum effective ...Background：High intracuffpressure can cause severe pharyngeal complications including sore throat or hoarseness after laryngeal mask airway （LMA） removal postoperatively.Though the application of minimum effective cuffinflating volume is suggested to maintain airway sealing and adequacy of ventilation for patients receiving general anesthesia with LMA at lower level of the intracuffpressure,it is currently not a standard care in most of the anesthetic departments.In this study,the minimum effective cuff inflating volume was determined for classic LMA Well LeadTM （Well Lead Medical Co.,Ltd.,China） and its impact on postoperative pharyngeal complications was also explored.Methods：Patients with American Society of Anesthesiologists physical status （Ⅰ-Ⅲ） undergoing the short-duration urological surgery were recruited in this trial.First,the minimum effective cuff inflating volume was determined for size 4 or 5 LMA Well LeadTM in the study 1.Immediately following placement and confirmation of ideal LMA position,the cuff was inflated with 5,7,10 ml of air and up to 30 ml at 5 ml increment.The intracuff pressure,oropharyngeal leak pressure （OLP）,and inspiratory peak airway pressure under positive pressure ventilation at the corresponding cuff volume as indicated above were recorded.Second,the enrolled patients were randomly allocated into minimum effective cuff inflating volume group （MC） and routine care （RC） group in the study 2.The minimum effective cuff inflating volume was applied and maintained in MC group,whereas the cuff volume was inflated with half of the maximum cuff inflating volume recommended by manufacturer in RC group throughout the surgical procedure and stay in postanesthesia care unit prior to LMA removal.The incidence of pharyngeal complications at 0,2,24,and 48 h after removal of LMA and other intra-operative adverse events were also documented.Results：The intracuffpressure varied with the cuff inflating volume in a positive linear correlation manner （Y =11.68X-42展开更多
It is generally accepted that environmental factors can significantly influence respiratory system. Cold is one of these factors. Understanding of the reaction of airways to cold air is very important tool leading to ...It is generally accepted that environmental factors can significantly influence respiratory system. Cold is one of these factors. Understanding of the reaction of airways to cold air is very important tool leading to improvement in management of cold induced rhinitis, cold induced asthma, exercise induced asthma, and exacerbation of chronic airway diseases induced by cold exposure. Despite the airways are protected against cold air by powerful heat and moisture exchanging counter current system within the nose, they are still at the risk of onset and development of cold induced symptoms mainly if this mechanism is insufficient, exposed person hyperventilates or is breathing subfreezing air. Some of the mechanisms involved in cold air induced reactions are understood quite well, but some of them are still discussed as they have not been satisfactorily explained, yet. Most discussed mechanisms by which cold air may induce respiratory symptoms include direct cooling and exsiccation of mucosal surface with subsequent hyper-tonicity of superficial fluid layer and interactions between the trigeminal and the vagus nerve at the central level. Molecular background for such a reaction may rely on the presence of thermo sensitive channels, mainly TRPM8, expressed on airway afferent nerves, which initiate response to cold air, giving a rise to autonomic responses like bronchoconstriction, cough, dyspnoea, chest tightness, mucus secretion and mucosal swelling. Identification of targets for cold action in the airway may help to identify potent antagonists which may prevent or reverse cold induced reactions sharing possibility for clinical application.展开更多
Purpose: This study was designed to study the effect of early use of the King Airway (KA) and impedance threshold device (ITD) in out-of-hospital cardiac arrest on ETCO2 as a surrogate measure of circulation, survival...Purpose: This study was designed to study the effect of early use of the King Airway (KA) and impedance threshold device (ITD) in out-of-hospital cardiac arrest on ETCO2 as a surrogate measure of circulation, survival, and cerebral performance category (CPC) scores. After analysis of the first 9 month active period the KA was relegated to rescue airway status. Methods: This was a prospective pre-post study design. Patients >18 years with out-of-hospital cardiac caused arrest were included. Three periods were compared. In the first “non active” period conventional AHA 30/2 compression/ventilation ratio CPR was done with bag mask ventilation (BMV). No ITD was used. After advanced airway placement the compression/ventilation ratio was 10/1. In the second period continuous compressions were done. Primary airway management was a KA with an ITD. After placement of the KA the compression/ventilation ratio was 10/1. In the third period CPR reverted to 30/2 ratio with a two hand seal BMV with ITD. CPR ratio was 10/1 post endotracheal intubation (ETI) or KA. The KA was only recommended for failed BMV and ETI. Results: Survival to hospital discharge was similar in all three study periods. In Period 2 there was a strong trend to CPC scores >2. The study group hypothesized that the KA interfered with cerebral blood flow. For that reason the KA was abandoned as a primary airway. Comparing Period 1 to Period 3 there was a trend to improved survival in the bystander witnessed shockable rhythm (Utstein) subgroup, particularly if a metronome was used. ETCO2 was significantly increased in Period 2 and trended up in Period 3 when compared to Period 1. Advanced airway intervention had a highly significant negative association with survival. Conclusion: The introduction of an ITD into our system did not result in a statistically significant improvement in survival. The study groups were somewhat dissimilar. ETCO2 trended up. When comparing Period 1 to Period 3, the bundle of care was associated with a trend towards increased survi展开更多
This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describe...This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describes the deposition of charged particles in the different generations of the tracheobronchial tree of the human lung. The upper airways are characterized by a certain wall structure called cartilaginous rings which modify the particle deposition when compared to an airway with a smooth wall. The problem is defined by solving Naver-Stokes equations in combination with a convective-diffusion equation and Gauss law for electrostatics. Three non- dimensional parameters describe the problem, the Peclet number Pe = 2ūa/D , the Reynolds number Re = ūa/v and an electrostatic parameter α=α2c0q2/(4ε0κT) . Here U is the mean velocity, a the pipe radius and D the diffusion coefficient due to Brownian motion given by D=κTCu/3πμd , where Cu is the Cunningham-factor Cu=1+λ/d(2.34+1.05exp(-0.39d/λ)) Here d is the particle diameter and λ the mean free path of the air molecules. Results are provided for generations G4-G16 of the human airways. The electrostatic parameter is varied to model different concentrations and charge numbers.展开更多
Menthol is frequently used in over the counter medications for common colds and coughs. It was formerly considered to be under the class of herbal medicine, but identification of menthol receptor (TRPM8) moved it from...Menthol is frequently used in over the counter medications for common colds and coughs. It was formerly considered to be under the class of herbal medicine, but identification of menthol receptor (TRPM8) moved it from the class of herbal medicine to the molecular pharmacology. It has been documented that menthol reduces dyspnoea and nasal obstruction via stimulation of nasal cold or flow receptors. It has also antitussive and antiirritative effect. Menthol can also induce adverse reactions such as airway irritation, dyspnoea, chest tightness and potentially respiratory failure, mainly in children. The mechanisms responsible for adverse reactions of menthol are not known completely. The adverse reactions of menthol could be due to its effects on TRPA1 channel, relevant to airway irritation. Higher concentrations of menthol stimulate TRPA1 channel causing airway irritation. It also increases mucus production and at the same time reduces cilliary activity leading to mucus stagnation. As the adverse effects were reported mainly at the night it is supposed that suppressed cough reflex during sleep potentiated by menthol induced cough suppression might be responsible for lack of airway mucus clearing and obliteration of small airways. Adverse effects could also be due to consequences of reflexes induced by the menthol action on trigeminal afferents, like apnoea or bronchoconstriction. Menthol is effective in relieving respiratory symptoms, but cough and cold medications should be used with caution. Recommendations are low concentrations of menthol used locally (intranasal) and not combined with camphor or cineole, as they may have additive effects and should be avoided in children under 2 years. Further data are necessary to completely elucidate potential risks of over the counter menthol medication in children but based on the meta analysis of documented case reports, menthol can be used safely if its contraindications for use are followed as with any other over the counter medications.展开更多
The toxicity of hydrogen sulfide(H2S) has been known for a long time, as it is prevalent in the atmosphere. However accumulative data suggest that H2 S is also endogenously produced in mammals, including man, and is t...The toxicity of hydrogen sulfide(H2S) has been known for a long time, as it is prevalent in the atmosphere. However accumulative data suggest that H2 S is also endogenously produced in mammals, including man, and is the third important gas signaling molecule, besides nitric oxide and carbon monoxide. H2 S can be produced via non enzymatic pathways, but is mainly synthesizedfrom L-cysteine by the enzymes cystathionine-γ-lyase, cystathionine-β-synthetase, cysteine amino transferase and 3-mercaptopyruvate sulfurtransferase(3MTS). The formation of H2 S from D-cysteine via the enzyme D-amino acid oxidase and 3MTS has also been described. Endogenous H2 S not only participates in the regulation of physiological functions of the respiratory system, but also seems to contribute to the pathophysiology of airway diseases such as chronic obstructive pulmonary disease, asthma and pulmonary fibrosis, as well as in inflammation, suggesting its possible use as a biomarker for these diseases. This review summarizes the different implications of hydrogen sulfide in the physiology of airways and the pathophysiology of airway diseases.展开更多
Asthma is a heterogeneous disease that involves a complex interplay of genetic and environmental factors, leading to＇chronicinflammation and airway remodeling. The major features that lead to clinical symptoms are in...Asthma is a heterogeneous disease that involves a complex interplay of genetic and environmental factors, leading to＇chronicinflammation and airway remodeling. The major features that lead to clinical symptoms are infiltration of inflammatory cells, epithelial shedding, mucous gland hyperplasia, increased airway smooth muscle mass and contraction,展开更多
We hypothesized that liquid menisci occlusions may form inside small airways, travel along the airway while losing mass and finally may disintegrate into bioaerosols. Spreading of the COVID-19 virus is strongly relate...We hypothesized that liquid menisci occlusions may form inside small airways, travel along the airway while losing mass and finally may disintegrate into bioaerosols. Spreading of the COVID-19 virus is strongly related to the number of such bioaerosols exhaled by “super-spreaders”. We show, employing numerical methods, that this number can be diminished by administering surfactants which lower the surface-tension of the mucus which covers the airways.展开更多
OBJECTIVE The objective of this study was to characterize the neurotransmitter systems that cause constriction of murine airways.METHODS Murine precision cut lung slices(PCLS)and trachea were prepared,placed into perf...OBJECTIVE The objective of this study was to characterize the neurotransmitter systems that cause constriction of murine airways.METHODS Murine precision cut lung slices(PCLS)and trachea were prepared,placed into perfusion chambers equipped with platinum electrodes and stimulated transmurally(1.0 ms,50 V,0.1-30 Hz).To measure PCLS constriction,changes in airway luminal area in response to electric field stimulation(EFS)were captured as video images quantified using Image J software.For trachea,changes in isometric tension were recorded using Grass force transducers.Frequency response curves were generated in the absence and the presence of the inhibitors magnesium,atropine and capsaicin and responses analyzed and compared using a student's t-test(P<0.05).RESULTS EFS caused airway constriction in a frequency-dependent manner that was best fit by a biphasic curve.Neuron-specific stimulation was verified by Mg^(2+) blockade.Maximum airway constriction to 30 Hz EFS in PCLS was(51.8±3.0)%while tracheal constriction averaged(551±80)mg.Interestingly,in PCLS the muscarinic receptor antagonist atropine(10μmol·L^(-1))blocked(99.5±7.2)%of EFS induced constriction at 1 Hz,but only blocked(23.3±3.8)%of EFS induced constriction at 30 Hz and eliminated the first phase but not the second phase of the biphasic EFS response.Treatment with capsaicin to deplete sensory neurotransmitters significantly increased EFS constriction supporting the presence of sensory neurotransmitter systems in airways.CONCLUSION These data are consistent with parasympathetic constriction of airways by acetylcholine at lower EFS frequencies while higher frequencies release sensory dilator neurotransmitters.These data provide evidence for multiple nerve types innervating airways which may provide novel targets for treatment of lung disease.展开更多
Terminals of the trigeminal afferents innervating nasal mucosa are called gate keepers, since these fibres detect substances entering the airways. Trigeminal excitation by irritants initiates airway defensive mechanis...Terminals of the trigeminal afferents innervating nasal mucosa are called gate keepers, since these fibres detect substances entering the airways. Trigeminal excitation by irritants initiates airway defensive mechanisms, and it is also attributed to the influence of lower airways resistance in a term of nasobronchial reflex. This phenomenon is frequently under debate, because some investigators were unable to confirm its existence. The aim of our study was to determine, whether pharmacological approach could be useful to reach high accuracy and better interpretation of the data obtained by Pennock’s method. Pennock’s method, which is frequently used to measure airway resistance in vivo (Raw) in fact measures total airway resistance, however, the data are usually interpreted in a terms of bronchomotor response. The upper airway component, which represents approximately 40% of Raw, is commonly not considered as being important in this method. 30 Dunkin Hartley guinea pigs were exposed to nasal stimuli (TRPA1 agonist—irritant allylisothiocyanate (10 mM, AITC), TRPM8 agonist with cooling potential menthol (10-3 M) and saline as a control). Raw was measured pre challenge as baseline, after nasal provocation and further, after nasal inhalation of histamine and methacholine (10-6 M) each. The data showed rise of Raw only after nasal AITC challenge, with further increased responsiveness to histamine and methacholine (5.3 vs 10.18 vs 11.26 vs 17.32 cmH2O.s-1, p 0.05). No significant changes were detected after saline, or menthol respectively. Data obtained in further experiment and its analysis showed that pre-treatment with nasal administration of 1% oxymetazoline but without salbutamol inhalation prevented the rise of Raw after nasal irritant challenges. Raw after nasal irritant challenges rises rather due to nasal response than due to narrowing of the lower airways.展开更多
A quantitative technique was conducted at Rosh Pinah Zinc mine, Namibia with its main purpose to determine airways resistance which is a function of the parameters;roughness of the airways and the friction factor. The...A quantitative technique was conducted at Rosh Pinah Zinc mine, Namibia with its main purpose to determine airways resistance which is a function of the parameters;roughness of the airways and the friction factor. The 32 branch points (<em>i.e.</em> a-ag) that stand for ventilation circuit have been selected. Data collected includes, length and width of airways, air velocity;air density, and roughness of the airways which were used to determine coefficient of frictions, friction factors and airway resistances. A ventilation model was developed. In order to improve the current ventilation model, airways resistance of the mine was determined and simulated in a modified model using VentSim<sup>TM</sup> software. An average total airways resistance of 0.32027 Ns<sup>2</sup>/m<sup>8</sup> has been achieved for Rosh Pinah mine. It should be pointed out that, as the mine advances its production faces deeper, this value would increases suddenly. Simulation revealed that as much as 34.4 m<sup>3</sup>/s of air can be received at the production faces, compared to the measured received amount of 19.3 m<sup>3</sup>/s. Therefore, volumetric efficiency of the mine was improved from 29.3% to 68.3%. It was also noticed that after importing the resistance values into the model together with other parameters, the model was greatly improved and no cause for concern.展开更多
Objective To observe effects of medication use on small airway function,airway inflammation and acute exacerbations in patients with clinically controlled asthma.Methods Forced expiratory flow over the middle half of ...Objective To observe effects of medication use on small airway function,airway inflammation and acute exacerbations in patients with clinically controlled asthma.Methods Forced expiratory flow over the middle half of the forced expiratory curve(FEF25%–75%),percentage of eosinophil,concentrations of eosinophil cationic protein(ECP)and interleukin(IL)-5 in induced sputum were assessed in patients with clinically controlled asthma who were given oral anti-inflammatory agents alone or in combination with inhaled therapy and inhaled therapy alone.Subsequently,acute exacerbations were compared between two groups during the 24-week follow-up period.Results FEF25%–75%in 43 patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy was significantly higher than that in 49 patients given inhaled therapy alone.Meanwhile,the percentage of eosinophils and levels of IL-5 and ECP in patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy were significantly lower than those in patients given inhaled therapy alone.Additionally,the patients with clinically controlled asthma given inhaled therapy were likely to have more acute exacerbation than the patients given oral anti-inflammatory agents alone or in combination with inhaled therapy during the 24-week follow-up period.Conclusion Systemic anti-inflammatory agents may have a greater effect on parameters reflecting small airway patency and reducing acute exacerbations,presumably secondary to reduction in airway inflammation.展开更多
文摘Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clinical study to systematically evaluate the feasibility, safety and efficacy of awake ETI using the lightwand alone in patients with difficult airways. Methods Seventy adult patients with difficult airways were enrolled in this study. After the desired sedation with fentanyl and midazolam, airway topical anesthesia was performed with 9 ml of 2% lidocaine, which were in order sprayed in three aliquots at 5 minutes intervals into the supraglottic （two doses） and laryngotracheal areas （one dose） using a combined unit of the lightwand and MADgic atomizer. After airway topical anesthesia, awake ETI was performed using a Lightwand. Subjective assessments by patients and operators using the visual analogue scores （VAS）, and objective assessments by an independent investigator using patients＇ tolerance and reaction scores, coughing severity, intubating conditions and cardiovascular variables were taken as the observed parameters. Results Of 210 airway sprays, 197 （93.8%） were successfully completed on the first attempt. The total time for airway spray was （14.6±1.5） minutes. During airway topical anesthesia, the average patients＇ tolerance scores were 1.7-2.3. After airway topical anesthesia, the mean VAS for discomfort levels that the patients reported was 6.5. Also airway topical anesthesia procedure was rated as acceptable and no discomfort by 94.3% of patients. The lightwand-guided awake ETI was successfully completed on first attempt within 29 seconds in all patients. During awake ETI, patients＇ reaction and coughing scores were 1.9 and 1.6, respectively. All patients exhibited excellent or acceptable intubating conditions. Cardiovascular monitoring revealed that changes of systolic blood pressure and heart rate at each stage of airway manipulations were less than 20% of baseli
文摘Recent state-of-the-art computed tomography and improved three-dimensional(3-D) postprocessing techniques have revolutionized the capability of visualizing airway pathology,offering physicians an advanced view of pathology and allowing for appropriate management planning.This article is a comprehensive review of trachea and main bronchi imaging,with emphasis on the dynamic airway anatomy,and a discussion of a wide variety of diseases including,but not limited to,congenital large airway abnormalities,tracheobronchial stenoses,benign and malignant neoplasms and tracheobronchomalacia.The importance of multiplanar reconstruction,3-D reconstruction and incorporation of dynamic imaging for non-invasive evaluation of the large airways is stressed.
文摘Extraintestinal manifestations occur commonly in inflammatory bowel diseases(IBD). Pulmonary manifestations(PM) of IBD may be divided in airway disorders, interstitial lung disorders, serositis, pulmonary vasculitis, necrobiotic nodules, drug-induced lung disease, thromboembolic lung disease and enteropulmonary fistulas. Pulmonary involvement may often be asymptomatic and detected solely on the basis of abnormal screening tests. The common embryonic origin of the intestine and the lungs from the primitive foregut, the co-existence of mucosa associated lymphoid tissue in both organs, autoimmunity, smoking and bacterial translocation from the colon to the lungs may all be involved in the pathogenesis of PM in IBD. PM are mainly detected by pulmonary function tests and highresolution computed tomography. This review will focus on the involvement of the airways in the context of IBD, especially stenoses of the large airways, tracheo-bronchitis, bronchiectasis, bronchitis, mucoid impaction, bronchial granulomas, bronchiolitis, bronchiolitis obliterans syndrome and the co-existence of IBD with asthma, chronic obstructive pulmonary disease, sarcoidosis and a1-antitrypsin deficiency.
基金This study was under financial support by the Youth Health Talents Project of Nanjing Municipal Health Bureau and Natural Science Foundation Committee of Jiangsu Province （No. BK2012532）.
文摘Background：High intracuffpressure can cause severe pharyngeal complications including sore throat or hoarseness after laryngeal mask airway （LMA） removal postoperatively.Though the application of minimum effective cuffinflating volume is suggested to maintain airway sealing and adequacy of ventilation for patients receiving general anesthesia with LMA at lower level of the intracuffpressure,it is currently not a standard care in most of the anesthetic departments.In this study,the minimum effective cuff inflating volume was determined for classic LMA Well LeadTM （Well Lead Medical Co.,Ltd.,China） and its impact on postoperative pharyngeal complications was also explored.Methods：Patients with American Society of Anesthesiologists physical status （Ⅰ-Ⅲ） undergoing the short-duration urological surgery were recruited in this trial.First,the minimum effective cuff inflating volume was determined for size 4 or 5 LMA Well LeadTM in the study 1.Immediately following placement and confirmation of ideal LMA position,the cuff was inflated with 5,7,10 ml of air and up to 30 ml at 5 ml increment.The intracuff pressure,oropharyngeal leak pressure （OLP）,and inspiratory peak airway pressure under positive pressure ventilation at the corresponding cuff volume as indicated above were recorded.Second,the enrolled patients were randomly allocated into minimum effective cuff inflating volume group （MC） and routine care （RC） group in the study 2.The minimum effective cuff inflating volume was applied and maintained in MC group,whereas the cuff volume was inflated with half of the maximum cuff inflating volume recommended by manufacturer in RC group throughout the surgical procedure and stay in postanesthesia care unit prior to LMA removal.The incidence of pharyngeal complications at 0,2,24,and 48 h after removal of LMA and other intra-operative adverse events were also documented.Results：The intracuffpressure varied with the cuff inflating volume in a positive linear correlation manner （Y =11.68X-42
文摘It is generally accepted that environmental factors can significantly influence respiratory system. Cold is one of these factors. Understanding of the reaction of airways to cold air is very important tool leading to improvement in management of cold induced rhinitis, cold induced asthma, exercise induced asthma, and exacerbation of chronic airway diseases induced by cold exposure. Despite the airways are protected against cold air by powerful heat and moisture exchanging counter current system within the nose, they are still at the risk of onset and development of cold induced symptoms mainly if this mechanism is insufficient, exposed person hyperventilates or is breathing subfreezing air. Some of the mechanisms involved in cold air induced reactions are understood quite well, but some of them are still discussed as they have not been satisfactorily explained, yet. Most discussed mechanisms by which cold air may induce respiratory symptoms include direct cooling and exsiccation of mucosal surface with subsequent hyper-tonicity of superficial fluid layer and interactions between the trigeminal and the vagus nerve at the central level. Molecular background for such a reaction may rely on the presence of thermo sensitive channels, mainly TRPM8, expressed on airway afferent nerves, which initiate response to cold air, giving a rise to autonomic responses like bronchoconstriction, cough, dyspnoea, chest tightness, mucus secretion and mucosal swelling. Identification of targets for cold action in the airway may help to identify potent antagonists which may prevent or reverse cold induced reactions sharing possibility for clinical application.
文摘Purpose: This study was designed to study the effect of early use of the King Airway (KA) and impedance threshold device (ITD) in out-of-hospital cardiac arrest on ETCO2 as a surrogate measure of circulation, survival, and cerebral performance category (CPC) scores. After analysis of the first 9 month active period the KA was relegated to rescue airway status. Methods: This was a prospective pre-post study design. Patients >18 years with out-of-hospital cardiac caused arrest were included. Three periods were compared. In the first “non active” period conventional AHA 30/2 compression/ventilation ratio CPR was done with bag mask ventilation (BMV). No ITD was used. After advanced airway placement the compression/ventilation ratio was 10/1. In the second period continuous compressions were done. Primary airway management was a KA with an ITD. After placement of the KA the compression/ventilation ratio was 10/1. In the third period CPR reverted to 30/2 ratio with a two hand seal BMV with ITD. CPR ratio was 10/1 post endotracheal intubation (ETI) or KA. The KA was only recommended for failed BMV and ETI. Results: Survival to hospital discharge was similar in all three study periods. In Period 2 there was a strong trend to CPC scores >2. The study group hypothesized that the KA interfered with cerebral blood flow. For that reason the KA was abandoned as a primary airway. Comparing Period 1 to Period 3 there was a trend to improved survival in the bystander witnessed shockable rhythm (Utstein) subgroup, particularly if a metronome was used. ETCO2 was significantly increased in Period 2 and trended up in Period 3 when compared to Period 1. Advanced airway intervention had a highly significant negative association with survival. Conclusion: The introduction of an ITD into our system did not result in a statistically significant improvement in survival. The study groups were somewhat dissimilar. ETCO2 trended up. When comparing Period 1 to Period 3, the bundle of care was associated with a trend towards increased survi
文摘This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describes the deposition of charged particles in the different generations of the tracheobronchial tree of the human lung. The upper airways are characterized by a certain wall structure called cartilaginous rings which modify the particle deposition when compared to an airway with a smooth wall. The problem is defined by solving Naver-Stokes equations in combination with a convective-diffusion equation and Gauss law for electrostatics. Three non- dimensional parameters describe the problem, the Peclet number Pe = 2ūa/D , the Reynolds number Re = ūa/v and an electrostatic parameter α=α2c0q2/(4ε0κT) . Here U is the mean velocity, a the pipe radius and D the diffusion coefficient due to Brownian motion given by D=κTCu/3πμd , where Cu is the Cunningham-factor Cu=1+λ/d(2.34+1.05exp(-0.39d/λ)) Here d is the particle diameter and λ the mean free path of the air molecules. Results are provided for generations G4-G16 of the human airways. The electrostatic parameter is varied to model different concentrations and charge numbers.
文摘Menthol is frequently used in over the counter medications for common colds and coughs. It was formerly considered to be under the class of herbal medicine, but identification of menthol receptor (TRPM8) moved it from the class of herbal medicine to the molecular pharmacology. It has been documented that menthol reduces dyspnoea and nasal obstruction via stimulation of nasal cold or flow receptors. It has also antitussive and antiirritative effect. Menthol can also induce adverse reactions such as airway irritation, dyspnoea, chest tightness and potentially respiratory failure, mainly in children. The mechanisms responsible for adverse reactions of menthol are not known completely. The adverse reactions of menthol could be due to its effects on TRPA1 channel, relevant to airway irritation. Higher concentrations of menthol stimulate TRPA1 channel causing airway irritation. It also increases mucus production and at the same time reduces cilliary activity leading to mucus stagnation. As the adverse effects were reported mainly at the night it is supposed that suppressed cough reflex during sleep potentiated by menthol induced cough suppression might be responsible for lack of airway mucus clearing and obliteration of small airways. Adverse effects could also be due to consequences of reflexes induced by the menthol action on trigeminal afferents, like apnoea or bronchoconstriction. Menthol is effective in relieving respiratory symptoms, but cough and cold medications should be used with caution. Recommendations are low concentrations of menthol used locally (intranasal) and not combined with camphor or cineole, as they may have additive effects and should be avoided in children under 2 years. Further data are necessary to completely elucidate potential risks of over the counter menthol medication in children but based on the meta analysis of documented case reports, menthol can be used safely if its contraindications for use are followed as with any other over the counter medications.
文摘The toxicity of hydrogen sulfide(H2S) has been known for a long time, as it is prevalent in the atmosphere. However accumulative data suggest that H2 S is also endogenously produced in mammals, including man, and is the third important gas signaling molecule, besides nitric oxide and carbon monoxide. H2 S can be produced via non enzymatic pathways, but is mainly synthesizedfrom L-cysteine by the enzymes cystathionine-γ-lyase, cystathionine-β-synthetase, cysteine amino transferase and 3-mercaptopyruvate sulfurtransferase(3MTS). The formation of H2 S from D-cysteine via the enzyme D-amino acid oxidase and 3MTS has also been described. Endogenous H2 S not only participates in the regulation of physiological functions of the respiratory system, but also seems to contribute to the pathophysiology of airway diseases such as chronic obstructive pulmonary disease, asthma and pulmonary fibrosis, as well as in inflammation, suggesting its possible use as a biomarker for these diseases. This review summarizes the different implications of hydrogen sulfide in the physiology of airways and the pathophysiology of airway diseases.
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 81170039）.
文摘Asthma is a heterogeneous disease that involves a complex interplay of genetic and environmental factors, leading to＇chronicinflammation and airway remodeling. The major features that lead to clinical symptoms are infiltration of inflammatory cells, epithelial shedding, mucous gland hyperplasia, increased airway smooth muscle mass and contraction,
文摘We hypothesized that liquid menisci occlusions may form inside small airways, travel along the airway while losing mass and finally may disintegrate into bioaerosols. Spreading of the COVID-19 virus is strongly related to the number of such bioaerosols exhaled by “super-spreaders”. We show, employing numerical methods, that this number can be diminished by administering surfactants which lower the surface-tension of the mucus which covers the airways.
文摘OBJECTIVE The objective of this study was to characterize the neurotransmitter systems that cause constriction of murine airways.METHODS Murine precision cut lung slices(PCLS)and trachea were prepared,placed into perfusion chambers equipped with platinum electrodes and stimulated transmurally(1.0 ms,50 V,0.1-30 Hz).To measure PCLS constriction,changes in airway luminal area in response to electric field stimulation(EFS)were captured as video images quantified using Image J software.For trachea,changes in isometric tension were recorded using Grass force transducers.Frequency response curves were generated in the absence and the presence of the inhibitors magnesium,atropine and capsaicin and responses analyzed and compared using a student's t-test(P<0.05).RESULTS EFS caused airway constriction in a frequency-dependent manner that was best fit by a biphasic curve.Neuron-specific stimulation was verified by Mg^(2+) blockade.Maximum airway constriction to 30 Hz EFS in PCLS was(51.8±3.0)%while tracheal constriction averaged(551±80)mg.Interestingly,in PCLS the muscarinic receptor antagonist atropine(10μmol·L^(-1))blocked(99.5±7.2)%of EFS induced constriction at 1 Hz,but only blocked(23.3±3.8)%of EFS induced constriction at 30 Hz and eliminated the first phase but not the second phase of the biphasic EFS response.Treatment with capsaicin to deplete sensory neurotransmitters significantly increased EFS constriction supporting the presence of sensory neurotransmitter systems in airways.CONCLUSION These data are consistent with parasympathetic constriction of airways by acetylcholine at lower EFS frequencies while higher frequencies release sensory dilator neurotransmitters.These data provide evidence for multiple nerve types innervating airways which may provide novel targets for treatment of lung disease.
文摘Terminals of the trigeminal afferents innervating nasal mucosa are called gate keepers, since these fibres detect substances entering the airways. Trigeminal excitation by irritants initiates airway defensive mechanisms, and it is also attributed to the influence of lower airways resistance in a term of nasobronchial reflex. This phenomenon is frequently under debate, because some investigators were unable to confirm its existence. The aim of our study was to determine, whether pharmacological approach could be useful to reach high accuracy and better interpretation of the data obtained by Pennock’s method. Pennock’s method, which is frequently used to measure airway resistance in vivo (Raw) in fact measures total airway resistance, however, the data are usually interpreted in a terms of bronchomotor response. The upper airway component, which represents approximately 40% of Raw, is commonly not considered as being important in this method. 30 Dunkin Hartley guinea pigs were exposed to nasal stimuli (TRPA1 agonist—irritant allylisothiocyanate (10 mM, AITC), TRPM8 agonist with cooling potential menthol (10-3 M) and saline as a control). Raw was measured pre challenge as baseline, after nasal provocation and further, after nasal inhalation of histamine and methacholine (10-6 M) each. The data showed rise of Raw only after nasal AITC challenge, with further increased responsiveness to histamine and methacholine (5.3 vs 10.18 vs 11.26 vs 17.32 cmH2O.s-1, p 0.05). No significant changes were detected after saline, or menthol respectively. Data obtained in further experiment and its analysis showed that pre-treatment with nasal administration of 1% oxymetazoline but without salbutamol inhalation prevented the rise of Raw after nasal irritant challenges. Raw after nasal irritant challenges rises rather due to nasal response than due to narrowing of the lower airways.
文摘A quantitative technique was conducted at Rosh Pinah Zinc mine, Namibia with its main purpose to determine airways resistance which is a function of the parameters;roughness of the airways and the friction factor. The 32 branch points (<em>i.e.</em> a-ag) that stand for ventilation circuit have been selected. Data collected includes, length and width of airways, air velocity;air density, and roughness of the airways which were used to determine coefficient of frictions, friction factors and airway resistances. A ventilation model was developed. In order to improve the current ventilation model, airways resistance of the mine was determined and simulated in a modified model using VentSim<sup>TM</sup> software. An average total airways resistance of 0.32027 Ns<sup>2</sup>/m<sup>8</sup> has been achieved for Rosh Pinah mine. It should be pointed out that, as the mine advances its production faces deeper, this value would increases suddenly. Simulation revealed that as much as 34.4 m<sup>3</sup>/s of air can be received at the production faces, compared to the measured received amount of 19.3 m<sup>3</sup>/s. Therefore, volumetric efficiency of the mine was improved from 29.3% to 68.3%. It was also noticed that after importing the resistance values into the model together with other parameters, the model was greatly improved and no cause for concern.
基金supported by the National Natural Science Foundation of China(No.81970024).
文摘Objective To observe effects of medication use on small airway function,airway inflammation and acute exacerbations in patients with clinically controlled asthma.Methods Forced expiratory flow over the middle half of the forced expiratory curve(FEF25%–75%),percentage of eosinophil,concentrations of eosinophil cationic protein(ECP)and interleukin(IL)-5 in induced sputum were assessed in patients with clinically controlled asthma who were given oral anti-inflammatory agents alone or in combination with inhaled therapy and inhaled therapy alone.Subsequently,acute exacerbations were compared between two groups during the 24-week follow-up period.Results FEF25%–75%in 43 patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy was significantly higher than that in 49 patients given inhaled therapy alone.Meanwhile,the percentage of eosinophils and levels of IL-5 and ECP in patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy were significantly lower than those in patients given inhaled therapy alone.Additionally,the patients with clinically controlled asthma given inhaled therapy were likely to have more acute exacerbation than the patients given oral anti-inflammatory agents alone or in combination with inhaled therapy during the 24-week follow-up period.Conclusion Systemic anti-inflammatory agents may have a greater effect on parameters reflecting small airway patency and reducing acute exacerbations,presumably secondary to reduction in airway inflammation.
