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Computer Methods in Biomechanics and... Sep 2023Exercise-induced laryngeal obstruction is a paradoxical laryngeal closure during inspiration at high-intensity exercise, with supraglottic closure being most common....
Exercise-induced laryngeal obstruction is a paradoxical laryngeal closure during inspiration at high-intensity exercise, with supraglottic closure being most common. This study develops a model based on the computational fluid dynamics to investigate airflow velocity and pressure and the air-induced loads on the supraglottis at various inspiratory flow rates. It is found that at high flow rates, positive wall pressure is formed in the hypopharynx localise towards its lower region, while posterior supraglottic wall pressures shift from positive to negative. These findings suggest that high inspiratory flow rates may increase supraglottic pressure differentials, ultimately contributing in the collapse.
Topics: Humans; Larynx; Airway Obstruction; Pulmonary Ventilation
PubMed: 36094796
DOI: 10.1080/10255842.2022.2121605 -
The Laryngoscope Oct 2023Obstructive upper airway pathologies are a great clinical challenge for the airway surgeon. Protection against acute obstruction is critical, but avoidance of...
BACKGROUND
Obstructive upper airway pathologies are a great clinical challenge for the airway surgeon. Protection against acute obstruction is critical, but avoidance of unnecessary tracheostomy must also be considered. Decision-making regarding airway, although supported by some objective findings, is largely guided by subjective experience and training. This investigation aims to study the relationship between clinical respiratory distress and objective measures of airway resistance in laryngeal cancer as determined by computational fluid dynamic (CFD) and morphometric analysis.
METHODS
Retrospective CT and clinical data were obtained for series of 20 cases, defined as newly diagnosed laryngeal cancer patients who required admission or urgent airway surgery, and 20 controls. Cases and controls were matched based on T-staging. Image segmentation and morphometric analysis were first performed. Computational models based on the lattice Boltzmann method were then created and used to quantify the continuous mass flow, rigid wall, and constant static pressure inlet boundary conditions.
RESULTS
The analysis demonstrated a significant relationship between airway resistance and acute obstruction (OR 1.018, 95% CI 1.001-1.045). Morphometric analysis similarly demonstrated a significant relationship when relating measurements based on the minimum cross-section, but not on length of stenosis. Morphometric measurements also showed significance in predicting CFD results, and their relationship demonstrated that airway pressures increase exponentially below 2.5 mm. Tumor subsite did not show a significant difference, although the glottic subgroup tended to have higher resistances.
CONCLUSION
Airway resistance analysis from CFD computation correlated with presence of acute distress requiring emergent management. Morphometric analysis showed a similar correlation, demonstrating a radiologic airway assessment technique on which future risk estimation could be performed.
LEVEL OF EVIDENCE
4 (case-control study) Laryngoscope, 133:2734-2741, 2023.
Topics: Humans; Airway Resistance; Laryngeal Neoplasms; Hydrodynamics; Case-Control Studies; Retrospective Studies; Lung; Dyspnea; Airway Obstruction; Respiratory Distress Syndrome; Computer Simulation
PubMed: 36951521
DOI: 10.1002/lary.30649 -
Facial Plastic Surgery : FPS Jun 2024Nasal obstruction is one of the main symptoms of different nasal pathologies. Many physiological and pathological conditions can produce nasal airflow impairment causing... (Review)
Review
Nasal obstruction is one of the main symptoms of different nasal pathologies. Many physiological and pathological conditions can produce nasal airflow impairment causing nasal obstruction and affecting patients' quality of life. There are different methods for the measurement of nasal obstruction, but in clinical practice the most common used are acoustic rhinometry, rhinomanometry, and peak nasal inspiratory flow. This review describes the fundamentals of acoustic rhinometry, its normal values, the different physiological and pathological conditions that can modify nasal patency, and the utility of this instrument for the measurement of nasal obstruction in clinical practice. Acoustic rhinometry is a simple test, so it is suitable for measurements in the pediatric population, i.e., for evaluating adenoid hypertrophy. Acoustic rhinometry normal values are available, unilaterally and bilaterally for pediatric and adult populations. Acoustic rhinometry has been demonstrated to be reproducible and even superior to rhinomanometry when measuring nasal modifications during challenges. It is possible to use acoustic rhinometry before and after nasal surgery. Measuring nasal cavities volume and cross-sectional area, acoustic rhinometry is particularly indicated in rhinosurgery, especially for the evaluation of spreader grafts. Brief considerations about the correlation between nasal symptoms, in particular the subjective sensation of nasal obstruction, and the acoustic rhinometry results as well as the correlation of acoustic rhinometry with other methods for the measurement of nasal obstruction are also reported. Objective and subjective evaluation of nasal obstruction gives different information that together optimizes the diagnosis and the treatment of rhinologic patients. Acoustic rhinometry alone or in combination of other instruments for the measurement of nasal obstruction or patency should be used regularly in every outpatient clinic that treats patients with nasal obstruction as there is an increasing need of evidence-based therapies.
Topics: Humans; Rhinometry, Acoustic; Nasal Obstruction; Rhinomanometry; Nasal Cavity
PubMed: 38016661
DOI: 10.1055/a-2218-7297 -
Pediatric Pulmonology Dec 2023Negative pressure pulmonary edema (NPPE) is a potentially life-threatening complication that develops rapidly following acute upper airway obstruction. The condition is... (Review)
Review
INTRODUCTION
Negative pressure pulmonary edema (NPPE) is a potentially life-threatening complication that develops rapidly following acute upper airway obstruction. The condition is rare, dramatic but resolves quickly. Prompt recognition and appropriate supportive treatment may prevent unnecessary investigations and iatrogenic complications.
METHODS
We describe a spectrum of etiologies and clinical manifestation of pediatric NPPE in our center and review of previous publications.
CONCLUSION
The etiology for the development of NPPE in children has shifted over the years. Although dramatic in presentation, this type of pulmonary edema often resolves quickly with minimal support.
Topics: Humans; Child; Pulmonary Edema; Research; Airway Obstruction
PubMed: 37737464
DOI: 10.1002/ppul.26700 -
Current Allergy and Asthma Reports Oct 2023Mechanical nasal obstruction (MNO) is a prevalent condition with a high impact on patient's quality-of-life (QoL) and socio-economic burden. The aim of this study was to... (Review)
Review
PURPOSE OF REVIEW
Mechanical nasal obstruction (MNO) is a prevalent condition with a high impact on patient's quality-of-life (QoL) and socio-economic burden. The aim of this study was to determine the usefulness of both subjective and objective criteria in the appropriate management of MNO, either alone or associated to upper airway inflammatory diseases such as allergic rhinitis (AR) or chronic rhinosinusitis with nasal polyps (CRSwNP).
RECENT FINDINGS
A long debate persists about the usefulness of subjective and objective methods for making decisions on the management of patients with nasal obstruction. Establishing standards and ranges of symptom scales and questionnaires is essential to measure the success of an intervention and its impact on QoL. To our knowledge this is the first real-life study to describe the management of MNO using both subjective and objective criteria in MNO isolated or associated to upper airway inflammatory diseases (AR or CRSwNP). Medical treatment (intranasal corticosteroids) has a minor but significant improvement in MNO subjective outcomes (NO, NOSE, and CQ7) with no changes in loss of smell and objective outcomes. After surgery, all MNO patients reported a significant improvement in both subjective and objective outcomes, this improvement being higher in CRSwNP. We concluded that in daily clinical practice, the therapeutic recommendation for MNO should be based on both subjective and objective outcomes, nasal corrective surgery being the treatment of choice in MNO, either isolated or associated to upper airway inflammatory diseases, AR or CRSwNP.
Topics: Humans; Nasal Obstruction; Quality of Life; Rhinitis; Nose; Rhinitis, Allergic; Nasal Polyps; Chronic Disease
PubMed: 37561310
DOI: 10.1007/s11882-023-01104-y -
Scientific Reports Jul 2023This exploratory observational study aimed to evaluate whether the blood levels of serotonin and enzymes involved in serotonin synthesis are associated with sleep... (Observational Study)
Observational Study
This exploratory observational study aimed to evaluate whether the blood levels of serotonin and enzymes involved in serotonin synthesis are associated with sleep breathing parameters. A total of 105 patients were included in this study, who were subjected to single-night polysomnography with simultaneous audio-video recordings. Peripheral blood samples were collected to estimate the serum levels of serotonin, tryptophan hydroxylase 1 (TPH1), and aromatic l-amino acid decarboxylase (AADC). Results showed a negative correlation between blood serotonin levels, and oxygen desaturation index (ODI) (p = 0.027), central apnea (p = 0.044) and obstructive apnea (OA) (p = 0.032) scores. Blood TPH1 levels were negatively correlated with average (p = 0.003) and minimal saturation (p = 0.035) and positively correlated with apnea-hypopnea index (p = 0.010), OA (p = 0.049), and hypopnea index (p = 0.007) scores. A tendency to sleep-disordered breathing seemed to co-occur with lower blood serotonin and higher TPH1 levels.Clinical Trial Registration : www.ClinicalTrials.gov , identifier NCT04214561.
Topics: Humans; Serotonin; Respiration; Sleep; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Airway Obstruction; Sleep Wake Disorders
PubMed: 37479853
DOI: 10.1038/s41598-023-38842-y -
Facial Plastic Surgery : FPS Jun 2024Several methods are available for evaluating nasal breathing and nasal airflow, as this evaluation may be made from several different perspectives.Physiologic methods... (Review)
Review
Several methods are available for evaluating nasal breathing and nasal airflow, as this evaluation may be made from several different perspectives.Physiologic methods for nasal airway evaluation directly measure nasal airflow or nasal airway resistance, while anatomical methods measure nasal airway dimensions. Subjective methods evaluate nasal breathing through several validated patient-reported scales assessing nasal breathing. Computational fluid dynamics evaluates nasal airflow through the analysis of several physics' variables of the nasal airway.Being familiar to these methods is of utmost importance for the nasal surgeon to be able to understand data provided by the different methods and to be able to choose the combination of evaluation methods that will provide the information most relevant to each clinical situation.
Topics: Humans; Respiration; Nasal Cavity; Airway Resistance; Nasal Obstruction; Rhinomanometry; Nose; Hydrodynamics
PubMed: 38331036
DOI: 10.1055/s-0044-1779043 -
Revue Medicale Suisse Oct 2023Inducible laryngeal obstruction (ILO) is a phenomenon of paradoxical upper airway closure during breathing causing respiratory distress and a noisy breathing. It most...
Inducible laryngeal obstruction (ILO) is a phenomenon of paradoxical upper airway closure during breathing causing respiratory distress and a noisy breathing. It most often appears during maximal exertion but can also be induced by inhalation of irritants, pharyngolaryngeal reflux or stressful situations. It can sometimes be confused with an acute asthma attack. The gold standard investigation is a videolaryngoscopy during ergometry which can confirm the diagnosis, allowing appropriate treatment. The aim of this article is to describe the pathophysiology of ILO and to discuss paraclinical examinations and treatment options.
Topics: Humans; Laryngoscopy; Laryngeal Diseases; Airway Obstruction; Asthma; Dyspnea
PubMed: 37791693
DOI: 10.53738/REVMED.2023.19.844.1791 -
Journal of Bronchology & Interventional... Jul 2024The prevalence of malignant central airway obstruction at diagnosis and its 5-year incidence are largely unknown, as are basic epidemiological data pertaining to this...
BACKGROUND
The prevalence of malignant central airway obstruction at diagnosis and its 5-year incidence are largely unknown, as are basic epidemiological data pertaining to this serious condition. To address these data limitations, we retrospectively collected data from the cohort of patients diagnosed with lung cancer at our institution in 2015 and followed cohort patients 5 years forward, until 2020.
METHODS
We reviewed index PET/CT or CT scans at the time of lung cancer diagnosis to identify the presence, subtype, and severity of malignant central airway obstruction as well as progression/development over the next 5 years.
RESULTS
The prevalence of malignant central airway obstruction affecting the airway lumen by 25% or greater was 17%, and its 5-year incidence of development was 8.2%. Notable associations from the multivariate analysis included a younger age and a stepwise increase in obstruction with increasing stage of disease. Squamous cell carcinoma and small-cell lung cancer were the 2 histologic subtypes with the strongest association with obstruction. The presence of malignant central airway obstruction either at time of diagnosis or on follow-up imaging was associated with significantly shortened survival (multivariate Cox proportional HR for MCAO=1.702, P<0.001).
CONCLUSION
This study provides the first systematic characterization of fundamental epidemiological data on malignant central airway obstructions at a tertiary cancer center in the United States. This data is important to inform research directions and funding efforts of this serious complication. It also serves as a baseline value against which to compare for future studies.
Topics: Humans; Lung Neoplasms; Airway Obstruction; Male; Female; Aged; Retrospective Studies; Middle Aged; Prevalence; Positron Emission Tomography Computed Tomography; Carcinoma, Squamous Cell; Small Cell Lung Carcinoma; Incidence; Tomography, X-Ray Computed; Aged, 80 and over
PubMed: 38881337
DOI: 10.1097/LBR.0000000000000970 -
BMJ Open Respiratory Research Mar 2024While heated tobacco products (HTPs) may affect pulmonary function, the evidence supporting the utility of screening for HTP use in clinical settings is insufficient. We... (Observational Study)
Observational Study
BACKGROUND
While heated tobacco products (HTPs) may affect pulmonary function, the evidence supporting the utility of screening for HTP use in clinical settings is insufficient. We examined the association between HTP use and airway obstruction after switching from cigarettes.
METHOD
The study subjects were patients aged ≥20 years undergoing surgery from December 2021 to September 2022 who completed spirometry and reported tobacco (cigarette and HTP) use status during the preoperative assessment. Airway obstruction was defined as forced expiratory volume in 1 s to forced vital capacity ratio below the lower limit of normal. Current tobacco use was defined as past-30-day use. Multivariable Poisson regression analysis was performed to examine the associations between HTP use and airway obstruction by adjusting for demographic characteristics, lifetime cigarette smoking (pack-year) and duration of smoking cessation.
RESULTS
Overall (N=2850, 55.4% women, mean age 62.4), 4.6% and 10.7% reported current HTP use and cigarette smoking, respectively. 16.8% had airway obstruction. Airway obstruction was more common among current HTP-only users (adjusted prevalence ratio (APR)=2.32), current cigarette-only smokers (APR=2.57) and current dual users (APR=2.82) than never-tobacco users. Among current tobacco users (N=398), the prevalence of airway obstruction was not significantly different between HTP-only users and cigarette-only smokers. Among former cigarette smokers (>30-day cigarette quitters) (N=1077), current HTP users had 1.42 times the increased prevalence of airway obstruction than never-HTP users after adjusting for cigarette pack-year; a stronger association was observed when the analysis was restricted to ≥5-year cigarette quitters (N=772) (APR=1.96, vs never HTP users).
CONCLUSION
Current HTP use was associated with airway obstruction among patients with cancer who had completely switched from cigarettes even after quitting smoking for a long period. Patients should be routinely screened for HTP use and advised to quit any tobacco.
Topics: Female; Humans; Male; Middle Aged; Airway Obstruction; Cigarette Smoking; Japan; Tobacco Products
PubMed: 38460973
DOI: 10.1136/bmjresp-2023-001793