Strong Cough Research Articles

Computational Modeling of Cough Droplet Behavior in the Human Upper Respiratory Airway

Abstract This study investigated the interaction of cough droplets with airflow in a realistic human airway. The ultimate aim was to understand the behavior of cough droplets inside the airway and to assess the potential of droplets to be retained in the airway or transmitted to the lungs. A computational fluid dynamics (CFD) model, based on the Euler–Lagrangian framework, was employed to predict the two-phase, droplet-laden transient cough flow in a realistic three-dimensional (3D) human airway. The airway geometry was reconstructed from patient computed tomography (CT) scan dataset. The discrete phase model was used to track the motion of the droplets in the air flow. Two distinct cough profiles—a strong cough and a weak cough—acquired experimentally from human subjects, were used as input to simulate normal and disordered cough functions. The effects of cough strength and droplet size on droplet retention and aspiration in the airway were investigated. It was found that droplet retention was significantly higher for a weak cough compared to a strong cough. For a weak cough, the highest droplet retention percentage exceeded 60%, while for a strong cough, it was less than 20%. Larger sized droplets were more likely to be aspirated into the lungs, especially under weak cough conditions. In the case of weak cough, more than 5% of the 200 μm sized droplets were aspirated into the lungs, whereas for strong cough, aspiration was less than 2%.

Incidence, Risk Factors, and Long-Term Outcomes for Extubation Failure in ICU in Patients With Obesity: A Retrospective Analysis of a Multicenter Prospective Observational Study

BackgroundNo large observational study has compared the incidence and risk factors for extubation failure within 48 hours and during intensive care unit (ICU) stay in the same cohort of unselected critically ill patients with and without obesity. Research questionWhich are the incidence and risk factors of extubation failure in patients with and without obesity? Study design and methodsIn this prospective multicenter observational FREE-REA study in 26 intensive care units, the primary objective was to compare the incidence of extubation failure within 48 hours in patients with and without obesity. Secondary objectives were to describe and to identify the independent specific risk factors for extubation failure using first a logistic regression model and second a decision tree analysis. ResultsOf 1,370 extubation procedures analyzed, 288 (21%) were performed in patients with obesity and 1082 (79%) in patients without obesity. The incidence of extubation failure within 48 hours among patients with or without presence of obesity was 23/288 (8.0%) versus 118/1082 (11%) respectively; unadjusted odds ratio (OR) 0.71 95% confidence interval (CI, 0.45-1.13), P=0.15); alongside patients with obesity receiving significantly more noninvasive ventilation (87/288, 30% versus 233/1082, 22%, P=0.002) and physiotherapy (165/288, 57% versus 527/1082, 49%, P=0.02) than patients without obesity. Risk factors for extubation failure also differed according to obesity status: female gender [adjusted (a)OR 4.88 95%CI(1.61-13.9), P=0.002] and agitation before extubation [aOR 6.39 95%CI (1.91-19.8), P=0.001] in patients with obesity; absence of strong cough before extubation [aOR 2.38 95%CI (1.53-3.84), P=0.0002] and duration of invasive mechanical ventilation before extubation [aOR 1.03 per day 95%CI (1.01-1.06), P=0.01] in patients without obesity. The decision tree analysis found similar risk factors. InterpretationOur findings indicate that anticipation and application of preventive measures for patients with obesity before and after extubation led to similar rate of extubation failure among patients with and without obesity. Clinical trial registrationNCT XXX

Independent Risk Factors of Failed Extubation among Adult Critically Ill Patients: A Prospective Observational Study from Saudi Arabia.

Mechanical ventilation provides essential support for critically ill patients in several diagnoses; however, extubation failure can affect patient outcomes. From Saudi Arabia, no study has assessed the factors associated with extubation failure in adults. This prospective observational study was conducted in the intensive care unit of a tertiary care hospital in Riyadh, Saudi Arabia. Adult patients who had been mechanically ventilated via the endotracheal tube for a minimum of 24 hours and then extubated according to the weaning protocol were included. Failed extubation was defined as reintubation within 48 hours of extubation. A total of 505 patients were included, of which 72 patients had failed extubation (14.3%, 95% CI: 11.4%-17.7%). Compared with the failed extubation group, the successfully extubated group had significantly shorter duration of mechanical ventilation (mean difference: -2.6 days, 95% CI: -4.3 to -1; P = 0.001), a slower respiratory rate at the time of extubation (mean difference: -2.3 breath/min, 95% CI: -3.8 to -1; P = 0.0005), higher pH (mean difference: 0.02, 95% CI: 0.001-0.04; P = 0.03), and more patients with strong cough (percent difference: 17.7%, 95% CI: 4.8%-30.5%; P = 0.02). Independent risk factors of failed extubation were age (aOR = 1.02; 95% CI: 1.002-1.03; P = 0.03), respiratory rate (aOR = 1.06, 95% CI: 1.01-1.1; P = 0.008), duration of mechanical ventilation (aOR = 1.08, 95% CI: 1.03 - 1.1; P < 0.001), and pH (aOR = 0.02, 95% CI: 0.0006-0.5; P = 0.02). Older age, longer duration of mechanical ventilation, faster respiratory rate, and lower pH were found to be independent risk factors that significantly increased the odds of extubation failure among adults.

Pulmonary artery thrombosis. Clinical aspects and the possibility of prognosis

BACKGROUND: Recently, there has been a growing interest to the pulmonary artery thrombosis due to the collected data on pathogenesis of this complication and the awareness about developing diagnostic and therapeutic strategy distinctive from those in pulmonary embolism.&#x0D; AIM: To estimate the pulmonary artery thrombosis clinical presentation, its electrocardiographic and echocardiographic signs and the possibility of applying venous thromboembolism risk assessment scores and diagnostic scoring systems in the cohort of deceased patients with verified pulmonary artery thrombosis.&#x0D; MATERIALS AND METHODS: A retrospective study based on the medical records analysis of two groups of deceased patients has been carried out. The first group included 80 patients with pulmonary artery thrombosis and the second one included 42 patients with pulmonary embolism. All the patients’ diagnoses were confirmed by the results of sectional and histological studies. 61 patient with COVID-19 and 19 non-COVID urgent patients with different pathologies were included in pulmonary artery thrombosis group. All 42 patients in pulmonary embolism group had verified venous thrombosis or heart chambers thrombi. Clinical presentation peculiarities, the electrocardiographic and echocardiographic reports as well as the possibility of application of Caprini, IMPROVE VTE, Padua, Wells and Geneva scoring systems were analyzed.&#x0D; RESULTS: None of the 80 pulmonary artery thrombosis patients had hemoptysis, unexpected dyspnoea, sudden strong cough, chest pain, or syncopea. Electrocardiographic changes indicative of right ventricular strain were found in 52.5% in the pulmonary artery thrombosis group and in 57.1% in the pulmonary embolism group. Inversion of T waves, complete and incomplete right bundle branch block were recorded in 14.6% and in 12.5%, in 36.3% and in 47.5% in the pulmonary artery thrombosis group and in the pulmonary embolism group, respectively, without statistical significance between two groups. Echocardiographic findings of right ventricular overload and/or dysfunction were present in 5 out of 10 patients with pulmonary artery thrombosis and in 5 out of 9 patients with pulmonary embolism. The correlation between Caprini, IMPROVE VTE and Padua scores and the incidence of pulmonary artery thrombosis was as strong as with the incidence of pulmonary embolism. On the contrary, Wells and Geneva clinical prediction scores failed to determine the probability of pulmonary artery thrombosis.&#x0D; CONCLUSIONS: Pulmonary artery thrombosis occurs without obvious clinical manifestations typical for pulmonary embolism. Electrocardiography and echocardiography reveal right ventricular overload in pulmonary artery thrombosis and in pulmonary embolism with equal frequency. Patients with high risk of pulmonary artery thrombosis can be identified by using the Caprini, IMPROVE VTE, Padua Prediction scores.

Laryngeal office-based procedures: A safe approach

PurposeLaryngeal surgeries using a flexible nasopharyngoscope equipped with an operative channel has gained popularity, with gradual increase in the variety of interventional office-based procedures, under local anesthesia. The purpose of this study is to analyze the tolerance of such procedures. Materials and methodsRetrospective cohort study. 337 cases were performed during 2 years. We collected the following data: type of pathology, type of procedure and modalities of anesthesia, adverse events. Results19 % of the visits were for the purpose of Biopsy, 65 % for an injection, and Trublue Laser was utilized in 12 % of the procedures. Regarding the pathologies, 27 % were vocal fold paralysis, 18 % leukoplakia or another suspicious lesion, 15 % recurrent respiratory papillomatosis, 13 % neuromuscular disorder, 9 % vocal fold scarring, 7 % vocal cord atrophy and 6 % had an inflammatory presentation. Side effects were documented in 26 visits (7.7 %) and were minor in almost all the encounters: they included strong reflexive cough, deep throat pain, discomfort, gag reflex, anxiety, vagal discomfort, malaise, hypersalivation, nose pain, labile hypertension. More severe side effects were very rare and included septal wound and epistaxis, erythematous rash, dyspnea, and transient dysarthria. 13 procedures were either aborted, or canceled at initial steps, due to inability of the patient to tolerate the procedure and were rescheduled for general anesthesia. 97 % of the cases were released home after 1 h of surveillance. ConclusionOffice-based flexible interventional laryngoscopy under local anesthesia is a safe and well-tolerated procedure, with abundance of various interventions feasible on ambulatory, office-based setup.

Physiotherapy Management for Complete Right Lung Collapse- is there role of mechanical insufflation and exsufflation? -A Case Report

We are reporting, a case of 52 year old male, with obstructive uropathy who underwent cystolithotripsy surgery associated with chronic kidney disease presented with respiratory distress, tachypnea and hypoxia on 3rd post-operative day. He was on maintenance hemodialysis. Examination revealed absent air-entry on right side, dull percussion note on right side and positive trail sign. Chest X-ray and HRCT showed complete collapse of right lung with ipsilateral shift of trachea with mediastinum. Conventional physiotherapy postural drainage, breathing exercises, active cycle of breathing technique, forced expiratory techniques, spirometry, nebulization given for a day, no improvement seen because patient had strong cough reflex but unable to expectorate; any effort to cough caused more distress and breathing difficulty. Mechanical insufflation-exsufflation, a therapy in which the device which inflates the lungs(Insufflation pressure start at 15-20 cmH2O and increase to give an inspiration to total lung capacity, last for 2 second) followed by an immediate and abrupt change to negative pressure (exsufflation pressure same as the insufflation, then increase up to 10–20cmH2O, held for 3-6 second), which produces rapid exhalation, simulates cough and thus moves secretions cephaladly. Thus device helps patient cough out effectively. Lung collapse resolved within 1 day, regular physiotherapy was given to prevent recurrent lung collapse until discharge, X-ray and auscultation findings and oxygen saturation improved. It concludes, successful utilization of chest physiotherapy and mechanical insufflators-exsufflators aids in the resolution of lung collapse in an urgent situation. KEYWORDS: Mechanical insufflator-exsufflator, Atelectasis, chronic kidney disease, cystolithotripsy

Therapeutic positioning to address neuromuscular scoliosis on an adolescent child with Aicardi syndrome: a case study

ABSTRACT Among persons with neuromuscular mobility limitations, therapeutic positioning has been implemented to improve body function, avoid secondary complications such as contractures and body shape distortions, and optimize body energy through restorative sleep. This case study describes the application of a 24-hour posture care management intervention for a preadolescent girl with Aicardi syndrome. The intervention was administered by adding therapeutic bed positioning to use of a custom molded wheelchair seating system. Over the 6-year intervention period overlapping with the subject’s adolescent years (age 11–17), marked improvement was observed in thoracic shape and symmetry. Moreover, the subject’s mother reported regular full-nights of uninterrupted sleep, relaxed muscle tone upon waking, a stronger cough with less audible congestion, more efficient swallowing and zero hospitalizations. The 24-hour posture care management intervention offers an alternative option for families and caregivers of persons with neuromuscular mobility impairments who wish to use a low-risk, noninvasive, locally available approach to improve body symmetry, increase hours of restorative sleep, and ease caregiving routines. Further research in 24-hour posture care management, including positioning for sleep and rest, should be explored in individuals with complex movement limiting disabilities who are at risk of developing neuromuscular scoliosis.

Primary site of constriction during the compression phase of cough in healthy young adults

Glottal closure has been considered as the primary constriction point during the compression phase (CP); however, vocal fold adduction alone cannot resist the high pressures, providing motivation to explore other mechanisms contributing to that resistance. The goal of this study was to identify site(s) and degree of constriction during the CP of cough of varying types in healthy young adults. Twenty-five healthy young participants participated in this study. The experimental protocol was comprised of: 1) baseline pulmonary function measures; 2) cough practice to establish weak, moderate and strong coughs; 3) voluntary and reflex cough assessments with fluoroscopy and airflow measures. We used a repeated measures ANOVA to identify whether there are differences in constriction ratio between cough types. There was a significant difference in constriction of varying cough types. Degree of constriction in all cough strengths showed that the glottis was the most constricted area, followed by the laryngeal vestibule, nasopharynx, hypopharynx, oropharynx, and cervical trachea, in order, but stronger cough resulted in more constriction in all areas compared to weaker cough. Degree of constriction in reflex cough showed a similar pattern though there was greater constriction in the oropharynx than the hypopharynx. Airflow measures in voluntary cough were consistent with previous findings. Differences in upper airway constriction during the compression phase of cough may be attributed to differences in motor control between reflex and voluntary cough, and the increased constriction seen during strong cough may reflect increased muscle recruitment during that task. In the future, we can use this knowledge to develop novel methods for cough rehabilitation.

Weak cough is associated with increased mortality in COPD patients with scheduled extubation: a two-year follow-up study

BackgroundCough strength is associated with short-term outcome in patients with scheduled extubation who successfully complete a spontaneous breathing trial (SBT). However, the long-term outcome is unclear.MethodsThis was a prospective observational study performed in a respiratory ICU of a teaching hospital. COPD patients who successfully completed a SBT were candidates. We enrolled the case who assessed the cough strength by cough peak flow (CPF) or semiquantitative cough strength score (SCSS, ranging from 0 = weak to 5 = strong). Patients were followed up to two years by phone every 3 months.ResultsA total of 215 patients were enrolled in current study. Among them, CPF and SCSS were measured in 214 and 208 cases, respectively. Strong cough was associated with a 16% decrease in the risk of two-year mortality (adjusted hazard ratio [HR] 0.84, 95%CI: 0.78–0.91) per 10 L/min increment of CPF. When it was tested by SCSS, decrease in the risk of two-year mortality per unit increment was 27% (adjusted HR 0.73, 95%CI: 0.62–0.86). Similar results were confirmed in the discharged patients. In all patients, the two-year mortality was 75%, 53%, and 38% in patients with CPF < 60, 60–90, and > 90 L/min; and 85%, 70%, and 40% in patients with SCSS of 0–1, 2–3, and 4–5, respectively. Similar trend was found among the discharged patients whether it was assessed by CPF or SCSS.ConclusionsIn COPD patients, weak cough is associated with increased two-year mortality after a scheduled extubation. It provides objective information to caregivers to improve decision-making process during hospitalization and after discharge.

Segmental Bronchoalveolar Lavage Provided a Favorable Clinical Course in a Case of Autoimmune Pulmonary Alveolar Proteinosis

A 49-year-old man was diagnosed with autoimmune pulmonary alveolar proteinosis. Chest computed tomography (CT) showed typical CT findings of pulmonary alveolar proteinosis: thickening of septa with ground-glass opacities in both lung fields. The diagnosis of autoimmune pulmonary alveolar proteinosis (PAP) was based on findings of bronchoalveolar lavage (BAL) fluid with milky appearance and elevated serum titer of anti-granulocyte-macrophage colony-stimulating factor antibody. We decided to perform segmental BAL via bronchoscopy. The surgery was performed under a general anesthesia since the patient had severe hypoxemia and strong cough reflex. Following 3 repeated courses of therapy, his respiratory condition and the ground-glass opacity in both lung fields improved remarkably, with no recurrence in 3 years. There are only a few published case reports in the world of the usefulness of segmental BAL under general anesthesia for PAP. We consider that segmental BAL is a useful therapeutic method for PAP in cases with severe hypoxemia, such as the present patient.

Подкожная эмфизема век как возможное осложнение эндоназальной эндоскопической дакриоцисториностомии

Periorbital subcutaneous emphysema, most often seen after trauma or stomatology procedures, is an unexpected and extremely rare condition after endonasal endoscopic dacryocystorhinostomy (EEDCR). It may be misdiagnosed as angioneurotic edema or eyelid phlegmon. The authors studied 2 011 cases of uncomplicated EEDCR and found 22 cases of periorbital edema with crepitation in the early post-op period. The analysis did not discover a significant dependence of complications on the technique of operations. In all cases subcutaneous emphysema has developed on the second-third day after successful EEDCR. Patients questioning showed that the reason of complication was sneezing or forced nose blowing. Subcutaneous eyelid emphysema after EEDCR is a rare complication and makes, according to our data, only 1 % of all operations. In most cases it regresses spontaneously but requires control of patients' visual functions. Patients should be recommended to avoid actions which can cause strong changes of pressure, such as strong cough, sneezing, and effort. Key words: endonasal dacryocystorhinostomy, emphysema, complication.

Predictive power of extubation failure diagnosed by cough strength: a systematic review and meta-analysis

BackgroundThe predictive power of extubation failure diagnosed by cough strength varies by study. Here we summarise the diagnostic power of extubation failure tested by cough strength.MethodsA comprehensive online search was performed to select potentially eligible studies that evaluated the predictive power of extubation failure tested by cough strength. A manual search was also performed to identify additional studies. Data were extracted to calculate the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) to evaluate the predictive power of extubation failure.ResultsA total of 34 studies involving 45 study arms were enrolled, and 7329 patients involving 8684 tests were analysed. In all, 23 study arms involving 3018 tests measured cough peak flow before extubation. The pooled extubation failure was 36.2% and 6.3% in patients with weak and strong cough assessed by cough peak flow, respectively. The pooled sensitivity, specificity, positive LR, negative LR, DOR, and AUC were 0.76 (95% confidence interval [CI]: 0.72–0.80), 0.75 (0.69–0.81), 2.89 (2.36–3.54), 0.37 (0.30–0.45), 8.91 (5.96–13.32), and 0.79 (0.75–0.82), respectively. Moreover, 22 study arms involving 5666 tests measured the semiquantitative cough strength score (SCSS) before extubation. The pooled extubation failure was 37.1% and 11.3%, respectively, in patients with weak and strong cough assessed by the SCSS. The pooled sensitivity, specificity, positive LR, negative LR, DOR, and AUC were 0.53 (95% CI: 0.41–0.64), 0.83 (0.74–0.89), 2.50 (1.93–3.25), 0.65 (0.56–0.76), 4.61 (3.03–7.01), and 0.74 (0.70–0.78), respectively.ConclusionsWeak cough is associated with increased extubation failure. Cough peak flow is superior to the SCSS for predicting extubation failure. However, both show moderate power for predicting extubation failure.

Could clinical nursing procedures lead to tracheal cuff pressure drop? A prospective observational study.

To evaluate the dynamic changes in tracheal cuff pressure before and after four clinical nursing procedures including sputum suction, oral care, atomisation inhalation, and turning over, and thus provide references for the adjustment time of cuff pressure in clinical practice. Cuff pressure must be kept within the range of 25-30cmH2 O to ensure effective ventilation and prevent aspiration, while maintaining tracheal bloodflowperfusion. A prospective observational study. The cuff pressure of 56 intubated patients was adjusted to 28-30cmH2 O. A cuff pressure monitor was used to continuously monitor cuff pressure changes before and after four clinical nursing procedures (sputum suction, oral care, atomisation inhalation, and turning over) and the cuff pressures at various time points were compared. The semi-quantitative cough strength score (SCSS) was used to evaluate cough strength during sputum suction and the effect of cough strength on cuff pressure during sputum suction. This study followed the STROBE checklist for cross-sectional studies. The cuff pressures during the four clinical nursing procedures of sputum suction, atomisation inhalation, turning over, and oral care, all temporarily increased (p<0.001) and decreased to varying degrees 20min later (p<0.001). Among them, the cuff pressure rose the highest under a state of moderate or strong coughing during sputum suction (78.38±12.13cmH2 O) and dropped the most at 20min after the procedure (21.71±4.80cmH2 O). The four clinical nursing procedures of sputum suction, atomisation inhalation, turning over, and oral care can all cause different degrees of cuff pressure drop. Thedecision on whether the cuff pressure needs to be corrected depends on the specific situation. During clinical practice, the cuff pressure can be individually corrected according to different clinical nursing procedures, which can increase the qualified rate of cuff pressure and reduce the workload of nurses.

The role of clinical signs and spirometry in the diagnosis of obstructive airway diseases: a systematic analysis adapted to general practice settings.

BackgroundIn general practice (GP), the diagnosis of obstructive airway diseases much relies on diagnostic questions, in view of the limited availability of lung function. We systematically assessed the relative importance of such questions for diagnosing asthma and chronic obstructive pulmonary disease (COPD), either without or with information from spirometry.MethodsWe used data obtained in a pulmonary practice to ensure the validity of diagnoses and assessments. Subjects with a diagnosis of COPD (n=260), or asthma (n=433), or other respiratory diseases (n=230), and subjects without respiratory diseases (n=364, controls) were included. The diagnostic questions comprised eight items, covering smoking history, self-attributed allergic rhinitis, dyspnea, cough, phlegm and wheeze. Optionally standard parameters of the flow-volume-curve were included. Decision trees for the diagnosis of COPD and asthma were constructed, moreover a probabilistic diagnostic network based on the results of path analyses describing the relationship between variables.ResultsIn the decision trees, age, sex, current smoking, wheezing, dyspnea upon mild exertion, self-attributed allergic rhinitis, phlegm, forced expiratory volume in one second (FEV1), and expiratory flow rates were relevant, depending on the diagnostic comparison, while cough, dyspnea upon strong exertion and ex-smoker status were not relevant. In contrast, the probabilistic network for the diagnosis of COPD and asthma versus controls incorporated all diagnostic questions, i.e., dyspnea upon mild or strong exertion, current smoking, ex-smoking, wheezing, cough and phlegm but from spirometry only FEV1. Depending on the individual pattern, the probability for COPD could raise from 25% to 81%, while the diagnostic gain for asthma was lower.ConclusionsThe study developed simple diagnostic algorithms for asthma and COPD that take into account the relative importance of clinical signs and history, as well as spirometric data if available. The diagnostic accuracy was especially high for COPD. These algorithms may be helpful as a starting point in the standardisation of diagnostic strategies in GP practices.Trial registrationThe study is registered under DRKS00013935 at German Clinical Trials Register (DRKS, Date of registration 01/03/2018).

Transmission of COVID-19 virus by cough-induced particles in an airliner cabin section

With airborne transmissions found as one of the major transmission routes of SARS-CoV-2, its transmission in airliner cabin environments drew special attention due to high number of imported cases and in-cabin transmissions. This study numerically investigated the transmission of COVID-19 by cough-induced particles in a cabin section of Boeing 737 model. One passenger was coughing in each case, while cough particles with measured size distributions were released during coughs and were tracked using the Lagrangian framework. Outcomes revealed that cough flow released by passengers could develop rapidly into a strong turbulent cough jet, breaking up the local airflow field. The released cough particles were largely dominated by the cough jet within 5 s, especially the first 1.5 s. Deposition of particles under 100 µm were relatively delayed when released from a window-seat location. Small particles (under 50 µm) released by a window-seat passenger were more likely to spread widely in the studied cabin section, which could lead to the highest exposure risks to nearby passengers. Also, due to ventilation design and seating arrangement, cough particles released by the middle-seat passenger were found easily trapped in his/her own local environment. Cough particles released from aisle-seat passengers had the least exposure risk to adjacent passengers.

Novel predictive factors for patient discomfort and severe cough during bronchoscopy: A prospective questionnaire analysis.

During bronchoscopy, discomfort is mainly caused by an unavoidable cough; however, there are no reports of any predictive factors for strong cough during bronchoscopy identified before the procedure. To clarify the factors underlying the discomfort status and predictive factors for strong cough during bronchoscopy, we prospectively evaluated patients who underwent bronchoscopy at Kyorin University Hospital between March 2018 and July 2019. Before and after bronchoscopy, the enrolled patients answered a questionnaire regarding the procedure. At the same time, bronchoscopists evaluated cough severity using a four-grade cough scale. We evaluated patient characteristics and predictive factors associated with bronchoscopy from the perspective of discomfort and strong cough. A total of 172 patients were ultimately enrolled in this study. On multivariate logistic regression analysis, comparison of the subjective data between the discomfort and comfort groups revealed that factors that were more common in the former group were younger age (OR = 0.96, p = 0.002), less experienced bronchoscopist (OR = 2.08, p = 0.047), and elevation of cough score per 1 point (OR = 1.69, p < 0.001). Furthermore, the predictive factors for strong cough prior to performing bronchoscopy were female sex (OR = 2.57, p = 0.009), EBUS-TBNA (OR = 2.95, p = 0.004), and prolonged examination time of more than 36 min (OR = 2.32, p = 0.022). Regarding patients' discomfort, younger age, less experienced bronchoscopist, and the elevation of cough score per 1 point were important factors for discomfort in bronchoscopy. On the other hand, female sex, EBUS-TBNA, and prolonged examination time were crucial factors for strong cough.

COUGH-INDUCED DIFFUSE BRONCHIAL HEMORRHAGE

SESSION TITLE: Medical Student/Resident Procedures Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Bleeding from the tracheobronchial tree is usually caused by neoplasms, bronchitis, bronchiectasis, mucosal infections, and/or iatrogenic mucosal erosions. We present a rare case of petechial tracheobronchial hemorrhage developing after a severe bout of cough. CASE PRESENTATION: An 81-year-old male with past medical history of Acquired immunodeficiency syndrome (AIDS), combined pulmonary fibrosis and emphysema, pulmonary hypertension, and chronic hypoxemia on supplemental oxygen (3 L/min), presented with gradually worsening dyspnea and non-productive cough over 6 months. Computed tomography (CT) scan of the chest showed a right upper lobe cavitary lesion for which further evaluation with diagnostic flexible fiberoptic bronchoscopy was planned. His home medications included low dose aspirin (81 mg) daily for the primary prevention of cardiovascular disease. He did not have any prior history of hemoptysis or coagulopathy. The patient received aerosolized topical anesthesia with nebulized lidocaine orally prior to bronchoscopy after which he developed a strong coughing fit. Patient was intubated with a laryngeal mask and flexible bronchoscopy was performed under monitored anesthesia care using Propofol. Inspection of the airways incidentally showed numerous mucosal petechiae with oozing of blood in the entire tracheobronchial tree distal to the vocal cords [Figure 1]. Patient was admitted due to worsening hypoxia and hemoptysis post procedure. He had mild hemoptysis for the next two days after which it resolved without any intervention. Broncho alveolar lavage cultures showed Mycobacterium avium intracellulare complex for which he was treated. DISCUSSION: We describe an unusual case of diffuse bronchial hemorrhage that, given the clinical course, developed due to severe coughing fit immediately prior to bronchoscopy. Only a few cases of cough induced diffuse bronchial hemorrhage, also called as the "hemorrhagic bronchial mucosa syndrome", have been previously reported [1-3]. The presence of mucosal petechiae with evidence of bleeding is a characteristic finding and usually improves with conservative management. It has been postulated that high intrathoracic pressures during coughing can increase intravascular pressure resulting in local vessel damage and bleeding [3]. Immunocompromised status due to AIDS, old age, use of aspirin, and pulmonary hypertension may have been additional risk factors predisposing to hemorrhage in this case. CONCLUSIONS: Diffuse bronchial hemorrhage or "hemorrhagic bronchial mucosa syndrome” is a rare complication that can occur during bronchoscopy due to severe coughing and measures to prevent coughing should be considered. Reference #1: Panjwani A. Hemorrhagic bronchial mucosa syndrome. The Egyptian Journal of Internal Medicine. 2015;27(4):151-153. Reference #2: Hira HS. Cough-induced Tracheobronchial Mucosal Bleeding. J Bronchology Interv Pulmonol. 2011;18(1):51-52. Reference #3: Milman N. Diffuse bleeding from the bronchial mucosa on flexible bronchoscopy in lung transplanted patients: 'the hemorrhagic bronchial mucosa syndrome'. Respiration. 2009;77(4):416-419. DISCLOSURES: No relevant relationships by Steven Shaw, source=Web Response No relevant relationships by Abhishek Singla, source=Web Response

DYNAMIC RESPONSE AND FIRST PASSAGE OF SMA TRACHEAL STENT IN COUGH PROCESS

The high-order nonlinear terms are applied to express the strain–stress curves of shape memory alloy (SMA) materials, and a new type of SMA model is proposed. Cough process is regarded as a strong stochastic process, and the mechanical model of an SMA tracheal stent in cough process is proposed where the large deformation caused by cough is considered. The system’s natural frequency is obtained, and its dynamic response is analyzed. The analysis and simulation results show that when the intensity of outside excitation increased 3.5 times (from 0.2 to 0.7), the system’s first-passage time was advanced by 19%, which means that the increase of the cough intensity will cause the loss of the stent; the large-amplitude vibration can be eliminated by selecting materials with appropriate parameters, which means the loss of tracheal stent can be avoided even in strong cough. This paper provides a new way to avoid the stent’s loss.

Bacterial and host determinants of cough aerosol culture positivity in patients with drug-resistant versus drug-susceptible tuberculosis.

A burgeoning epidemic of drug-resistant tuberculosis (TB) threatens to derail global control efforts. Although the mechanisms remain poorly clarified, drug-resistant strains are widely believed to be less infectious than drug-susceptible strains. Consequently, we hypothesized that lower proportions of patients with drug-resistant TB would have culturable Mycobacterium tuberculosis from respirable, cough-generated aerosols compared to patients with drug-susceptible TB, and that multiple factors, including mycobacterial genomic variation, would predict culturable cough aerosol production. We enumerated the colony forming units in aerosols (≤10 µm) from 452 patients with TB (227 with drug resistance), compared clinical characteristics, and performed mycobacterial whole-genome sequencing, dormancy phenotyping and drug-susceptibility analyses on M. tuberculosis from sputum. After considering treatment duration, we found that almost half of the patients with drug-resistant TB were cough aerosol culture-positive. Surprisingly, neither mycobacterial genomic variants, lineage, nor dormancy status predicted cough aerosol culture positivity. However, mycobacterial sputum bacillary load and clinical characteristics, including a lower symptom score and stronger cough, were strongly predictive, thereby supporting targeted transmission-limiting interventions. Effective treatment largely abrogated cough aerosol culture positivity; however, this was not always rapid. These data question current paradigms, inform public health strategies and suggest the need to redirect TB transmission-associated research efforts toward host-pathogen interactions.

Characteristics of incomplete endobronchial ultrasound-guided transbronchial needle aspiration cases.

BackgroundsThe number of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) cases is increasing due to its less-invasiveness and usefulness. However, there are several unresolved issues, including the existence of incomplete cases and complications. This study aimed to investigate the frequency and diagnostic management of incomplete EBUS-TBNA cases.MethodsBetween July 2009 and December 2017, 424 patients underwent EBUS-TBNA for the diagnosis of suspected malignancy. Among them, we retrospectively reviewed the frequency, characteristics and diagnostic managements of incomplete cases of EBUS-TBNA.ResultsEBUS-TBNA was not completed in 16 patients (3.8%), all of whom underwent EBUS-TBNA cases under conscious sedation. The factors for incompleteness of EBUS-TBNA under conscious sedation were divided into two groups: impossibility to perform EBUS-TBNA under conscious sedation (n=8) and impossibility to perform safe needle biopsy (n=8). The former factor consisted of strong coughing reflex and insufficient sedation (n=5), frequent desaturation during EBUS-TBNA (n=2), and allergy to lidocaine (n=1), while the latter factor consisted of anatomical reasons (n=4), abundant blood flow in the target lesion (n=3), and invisibility of the target lesion due to airway deformation (n=1). Eventually, 10 out of 16 cases were histologically diagnosed as having malignancy by a surgical approach (n=5) and EBUS-TBNA under general anesthesia (n=5).ConclusionsAlthough the number was small, we did note some incomplete cases of EBUS-TBNA under conscious sedation. In incomplete cases under conscious sedation, EBUS-TBNA under general anesthesia and other surgical approaches can be considered as additional options.