Neurotransmitter systems in mouse airways

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.

Qatar Airways Touches Down in Lisbon for the First Time

Qatar Airways’first ever passenger flight to Portugal landed at Lisbon Airport on 24June,2019,as the airline adds to its rapidly expanding European network.Operated by a Boeing787 Dreamliner aircraft,flight QR343 was greeted with a water cannon salute on arrival.Present on board the inaugural flight to Lisbon was the Portuguese Ambassador to Qatar,H.E Mr.Ricardo Pracana,and Qatar Airways Chief Commercial O fficer.

Role of hydrogen sulphide in airways

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.

Deposition of charged nano-particles in the human airways including effects from cartilaginous rings

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.

Qatar Airways Taking You more Personally

Qatar Airways is the national carrier of the Arabian Gulf State of Qatar. It has become one of the world's fastest growing airlines since the its re-launched in 1997 under the leadership of their Chief Executive Officer Mr. Akbar A1 Baker.……

Determination of Airways Resistance, Volumetric Efficiency and Development of Ventilation Model of Rosh Pinah Zinc Mine Namibia

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 (i.e. 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 VentSimTM software. An average total airways resistance of 0.32027 Ns2/m8 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 m3/s of air can be received at the production faces, compared to the measured received amount of 19.3 m3/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.

Qatar Airways Steps Up Frequency to Shanghai

Fourth Weekly Falight Added To China's Commercial Capital. Doha, QATAR - Qatar Airways has stepped up frequency on its highly-popular Doha - Shanghai route with the introduction of a fourth weekly scheduled flight. ……

Change in management of predicted difficult airways following introduction of video laryngoscopes

AIM To determine if video laryngoscopy(VL) has significantly impacted management of difficult airways by decreasing the rate of awake fiberoptic intubation(FOI). METHODS Anesthetic records of 3723 patients who underwent general anesthesia at Rush University Medical Center were reviewed over a 2-mo period prior to the introduction of VLs in 2009("pre-VL" group) and over the same 2-mo period after the introduction of VLs in 2012("postVL" group). Patient records with predicted difficult air-ways based on pre-operative airway examination were analyzed. The primary outcome was rate of awake FOI.RESULTS To control for possible factors that may influence the FOI rate, a logistic regression was performed with these factors included as covariates. The rate of awake FOI was 13.1% in pre-VL group compared to 9.0% in post-VL group. Although this decrease was not statistically significant individually(P = 0.1768), it showed a trend toward significance when covariates were accounted for(P = 0.0910). Several factors predicting a higherlikelihood of awake FOI were found to be statistically significant: Morbid obesity(larger BMI P = 0.0154, OR = 1.5 per 10 point BMI increase), male gender(P = 0.0026, OR = 3.0) and a higher el-Ganzouri airway score(P = 0.0007, OR = 1.5). Although VLs were seen to be used to intubate 51% of predicted difficult airways, the rate of awake FOI has not significantly changed.CONCLUSION Although VL may continue to grow in popularity, the most difficult airways are still managed using awake FOI.

Pharmacological basis for the medicinal use of Michelia champaca in gut, airways and cardiovascular disorders

Objective: To discover the mechanism behind ameliorative effects of Michelia champaca(M. champaca) in gastrointestinal, respiratory and cardiovascular disorders. Methods: Antispasmodic potential was evaluated by trying the M. champaca extract(aqueous:ethanolic) on rabbit aorta, trachea and jejunum in vitro. Isotonic and isometric transducers coupled with Power Lab data acquisition system was used to record the responses of isolated tissues. Results: M. champaca extract relaxed the spontaneous and high K^+(80 mmol/L)-induced contractions of isolated jejunum preparation of rabbit showing a Ca^(2+) channel blocking mechanism. Moreover, extract shifted calcium concentration response curves towards right like standard calcium channel blocker verapamil. In rabbit tracheal preparation, M. champaca relaxed both carbachol(1 μmol/L) and high K^+-induced contractions, likewise verapamil. In rabbit aorta preparation, M. champaca relaxed phenylephrine(1 μmol/L) and high K^+-induced contractions similar to verapamil. Conclusion: M. champaca possesses spasmolytic, airways relaxant and vasodilator actions mediated perhaps due to blocking of Ca^(2+) channels, hence validating its therapeutic usage in diarrhea, asthma and hypertension.

Multidetector computed tomography imaging of congenital anomalies of major airways:A pictorial essay

Congenital airway anomalies can be asymptomatic or may cause severe respiratory distress requiring immediate treatment.These anomalies can present early in life,or may be just incidental findings.It is important to recognize these entities to realize their clinical significance and to avoid false diagnosis.In this article, the various congenital airway anomalies and their imaging features by multidetector computed tomography (MDCT)are reviewed in order of occurrence during the embryological timeline.This pictorial essay reviews the various distinct congenital airway lesions and their MDCT manifestations.It also provides insight into the embryological basis of the congenital airway lesions encountered.

Fiberoptic Intubation through Adapter Removable Supraglottic Airways;Comparison of the Air-Q ILA^TM, LMA Classic Excel^TM, and LMA Unique^TM

Study Objective: We studied the overall efficacy of fiberoptic aided intubation using three different supraglottic airways (SGA) as intubation conduits with a standard endotracheal tube (ETT) to determine which, if any, is superior as an intubation conduit. Design: After induction of general anesthesia, subjects were randomized to one of three groups: Air-Q ILATM, LMA Classic ExcelTM, and LMA UniqueTM. Subjects were intubated with a fiberoptic aided technique with continuous ventilation with FiO2 = 1.0 through one of these SGAs. The primary endpoint was the overall efficacy of the intubation procedure. In addition, the following data were collected: demographic data, intubation times, grade of view of the larynx, and a visual analog scale (VAS) score of difficulty as determined by the primary anesthesiologist performing the procedure. Data were analyzed using a Kruskal-Wallis one-way analysis of variance and Post hoc analysis was done using Dunn’s Multiple Comparison Test. Results: 126 total subjects were studied. Intubation success rates were 100%, 87.8%, and 95% with the Air-Q ILATM, LMA Classic ExcelTM, and LMA UniqueTM respectively. There was no significant difference among the three different SGAs when comparing the times to place the SGA (T1), the true intubating time (T2), the time to remove the SGA (T3), or the total time (T4). Data were also stratified by the grade of view of the larynx;all grade I views, grade II views, and grade III views were grouped together regardless of the type of the SGA used. The grade I view of the larynx group had significantly faster true intubation times (T2 = 75.1 sec, p = 0.01) and significantly lower VAS scores (VAS = 1.9, P = TM provides the best view of the larynx and is the easiest one to use as an intubation conduit.

Simulation of Bleeding Airways in Cadavers: New Models for Experiential Learning

Background: Healthcare education models have recently shifted from the traditional reliance on the apprenticeship model, where trainees learn on real patients in actual clinical settings, to one based on simulation models. Education in airway management is a fundamental component of anesthetic training programs, and airway modification to simulate difficult airways increases the fidelity of airway management training. Objective: The study goal was to determine the feasibility of simulating difficult airways such as mandibular fracture and post-tonsillectomy bleed in cadaver models by surgical modification for the use in enhanced experiential learning of difficult airway management. Methods: Two cadaver heads were modified surgically to simulate a mandibular fracture and post-tonsillectomy bleed. Workshop facilitators conducted directed one-to-one learning and provided feedback to participants. A paper-based feedback was obtained from the participants on their confidence level, and the realism, attractiveness, beneficial levels, and difficulty levels of the simulation models used. Results: The modified cadavers were reliable in simulating difficult airways. The majority of participants (83.3% for fractured mandible and 87.1% for post-tonsillectomy bleed) reported an increase in confidence level for management of the difficult airway after the experience with the modified cadavers, and found both models realistic, attractive, and beneficial for difficult airway training. Conclusions: Surgical modifications of cadavers to simulate difficult airways such as fractured mandible and post-tonsillectomy bleed may be incorporated into advanced airway management courses to enhance experiential learning.

Should We Measure the FEV1 or the Specific Resistance of the Airways? An Evaluation in Patients with Either COPD, Chronic Dyspnea or Chronic Cough

Background: The purpose of this study was to evaluate the relative contribution of measuring the forced expiratory volume in one second (FEV1) or the specific resistance of the airways (sRaw) in adults referred for chronic obstructive pulmonary disease (COPD), chronic dyspnea or chronic cough. Methods: This was a prospective study of 321 subjects referred for lung function testing, in a setting of routine clinical management, for suspicion of COPD (or follow-up of known COPD), chronic dyspnea or chronic cough. The proportions of FEV1 values below the normal range and of sRaw values above the normal range were compared using a Chi-square exact test of Fisher. Results: In the COPD and chronic dyspnea groups, sRaw was as frequently abnormal as FEV1. In the chronic cough group, sRaw was increased in 56.5% of subjects, while FEV1 was decreased in solely 34.8% (p = 0.059). Conclusions: This study suggests that sRaw may be a better tool than FEV1 to detect bronchial obstruction in patients presenting with chronic cough.

Automatic Detection of Airways in CT Scans of Cystic Fibrosis Patients

This paper describes a prototype of an automatic system for the detection and evalua-tion of airways of Cystic Fibrosis (CF) patients from Computed Tomography (CT) Scans. The aim of the study is to present a prototype of an automatic system which could serve as a decision support for radiologists. The area percentages of airway in lung regions have been calculated in CT slices to represent Bronchiectasis stages of CF patients. The proposed automatic system has been tested on a dataset comprising of four CF patients belonging to different stages of Bronchiectasis.

Small airways in asthma:Pathophysiology,identification and management

Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Methods:A search in Medline was performed,using the keywords“small airways”,“asthma”,“oscillometry”,“nitrogen washout”and“imaging”.Our review was based on studies from adult asthmatic patients,although evidence from pediatric populations is also discussed.Results:In asthma,inflammation in small airways,increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease.Small airway dysfunction is a key component of asthma pathophysiology,leading to increased small airway resistance and airway closure,with subsequent ventilation inhomogeneities,hyperresponsiveness and airflow limitation.Classic tests of lung function,such as spirometry and body plethysmography are insensitive to detect small airway disease,providing only indirect measurements.As discussed in our review,both functional and imaging techniques that are more specific for small airways,such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma.Small airways disease is prevalent across all asthma disease stages and especially in severe disease,correlating with important clinical outcomes,such as asthma control and exacerbation frequency.Moreover,markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.Conclusions:Assessment of small airway disease provides unique information for asthma diagnosis and monitor-ing,with potential therapeutic implications.

Heparin-free veno-venous extracorporeal membrane oxygenation in non-trauma patients with difficult airways for surgery

To the Editor:For patients with critical tracheal stenosis in surgery,extracorporeal membrane oxygenation(ECMO)is probably the last,yet safest,choice to ensure definitive airway security.Systemic anticoagulation in the form of heparin is a typical choice.However,heparin is fraught with its own complications that include both bleeding in the patient and clotting within the circuitry.

Clinical assessment of awake endotracheal intubation using the lightwand technique alone in patients with difficult airways

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 baseline values. The postoperative follow-up showed that 95.7% of patients had no recall or slight memories of all airway instrumentation. The incidence of postoperative mild airway complications was 38.6%. Conclusion Alone use of the lightwand technique can achieve effective, safe and successful awake ETI in patients with difficult airways.

Inhibition of Bcl-6 Expression Ameliorates Asthmatic Characteristics in Mice

Objective The function of Bcl-6 in T follicular helper(Tfh)cell maturation is indispensable,and Tfh cells play a pivotal role in asthma.This study investigated the impact of Bcl-6 on asthmatic traits.Methods The microscopic pathological alterations,airway resistance(AR),and lung compliance(LC)were determined in asthmatic mice and Bcl-6 interference mice.The surface molecular markers of Tfh cells and the Bcl-6 mRNA and protein expression were determined by flow cytometry,RT-qPCR,and Western blotting,respectively.The relationships between the Tfh cell ratio and the IgE and IgG1 concentrations in peripheral blood mononuclear cells(PBMCs)and bronchoalveolar lavage fluid(BALF)were determined.Results Asthmatic inflammatory changes were observed in the lung tissue and were attenuated by Bcl-6 siRNA and dexamethasone(DXM).Asthmatic mice exhibited an increased AR and a decreased LC,while Bcl-6 siRNA or DXM mitigated these changes.The percentages of Tfh cells and eosinophils were significantly increased in the asthmatic mice,and they significantly decreased after Bcl-6 inhibition or DXM treatment.RT-qPCR and Western blotting analyses revealed that the Bcl-6 expression level in PBMCs was significantly higher in asthmatic mice,and it decreased following Bcl-6 inhibition or DXM treatment.The IgE expression in the serum and BALF and the B cell expression in PBMCs exhibited a similar trend.In asthmatic mice,the ratio of Tfh cells in the peripheral blood showed a strong positive correlation with the IgE levels in the serum and BALF,but not with the IgG1 levels.Conclusion The amelioration of airway inflammation and airway hyper-responsiveness is achieved through Bcl-6 suppression,which effectively hinders Tfh cell differentiation,ultimately resulting in a concurrent reduction in IgE production.

Current state and influencing factors in airbag management among emergency department nurses:A multicenter study

BACKGROUND The emergency department(ED)plays a critical role in establishing artificial airways and implementing mechanical ventilation.Managing airbags in the ED presents a prime opportunity to mitigate the risk of ventilator-associated pneumonia.Nonetheless,existing research has largely overlooked the understanding,beliefs,and practical dimensions of airway airbag management among ED nurses,with a predominant focus on intensive care unit nurses.AIM To investigate the current status of ED nurses'knowledge,beliefs,and practical behaviors in airway airbag management and their influencing factors.METHODS A survey was conducted from July 10th to August 10th,2023,using convenience sampling on 520 ED nurses from 15 tertiary hospitals and 5 sary hospitals in Shanghai.Pathway analysis was utilized to analyze the influencing factors.RESULTS The scores for ED nurses'airway airbag management knowledge were 60.26±23.00,belief was 88.65±13.36,and behavior was 75.10±19.84.The main influencing factors of airbag management knowledge included participation in specialized nurse or mechanical ventilation training,department,and work experience in the department.Influencing factors of airbag management belief comprised knowledge,department,and participation in specialized nurse or mechanical ventilation training.Primary influencing factors of airbag management behavior included knowledge,belief,department,participation in specialized nurse or mechanical ventilation training,and professional title.The belief in airbag management among ED nurses acted as a partial mediator between knowledge and behavior,with a total effect value of 0.513,and an indirect effect of 0.085,constituting 16.6%of the total effect.CONCLUSION ED nurses exhibit a positive attitude toward airbag management with relatively standardized practices,yet there remains room for improvement in their knowledge levels.Nursing managers should implement interventions tailored to the characteristics of ED nurses'airbag management knowledge,beliefs,and practices to enhance their airbag management proficiency.

Large isolated fibrous tumors in the upper esophagus: A case report

BACKGROUND Solitary fibrous tumors(SFT)are rare spindle cell tumors that are usually benign.A total of 10 cases of SFTs in the upper esophagus have ever been reported.Here,we report the anesthetic management of a patient with a large isolated fibrous tumor of the upper esophagus compressing the tracheal membrane.We also provide a literature review of the current research.CASE SUMMARY We report the case of a 49 year old male with“cough aggravation and wheezing after exercise”,who underwent esophagectomy for a large isolated fibrous tumor compressing the tracheal membrane in the upper esophagus.We advise the use of a single-lumen tube with a blocker in patients with difficult airways to reduce the incidence of airway injury and fibrinoscopy at all stages of the perioperative period to guide airway management.This case study is the first report of the anesthetic management of a large,isolated fibrous tumor compressing the tracheal membrane in the upper esophagus.CONCLUSION This rare case emphasizes the importance of perioperative management of anesthesia in patients with large isolated fibrous tumors of the upper esophagus that compress the tracheal membrane.The use of blocker reduce the incidence of airway injury and fibrinoscopy at the perioperative period to guide airway mana-gement.