Expiratory Noises Research Articles

Tracheal obstructive mastocytoma in a pony

SummaryA 15‐year‐old pony gelding was presented with a history of dyspnoea with inspiratory and expiratory noise for 1 week. An upper airway respiratory endoscopic examination revealed two tracheal masses, the largest one being located on the distal third of the neck, occupying almost all of the tracheal diameter. Surgical removal undertaken was in two steps under endoscopic guidance. First, scissors and Babcock forceps inserted through a tracheotomy incision were used to sever the masses. Then, a diode laser was used to cauterise the resection sites. Gross examination and histopathology confirmed a diagnosis of tracheal mastocytoma.

Pathology in Practice.

HistoryA 16-year-old 487.2-kg (1,071.8-lb) Quarter Horse gelding was presented to a veterinary medical teaching hospital because of a 4- to 5-month history of intermittent, unilateral (right-sided) nasal discharge and epistaxis that did not improve with antimicrobial treatment. Additionally, right facial crest swelling had been observed approximately 3 weeks prior to presentation. The referring veterinarian performed skull radiography, which revealed a large mass lesion in the horse's right nasal cavity.Clinical and Gross FindingsOn physical examination, there was mildly decreased airflow from the right nostril, mildly increased expiratory noise on tracheal auscultation, and a small firm nodule over the

Human forced expiratory noise. Origin, apparatus and possible diagnostic applications.

Forced expiratory (FE) noise is a powerful bioacoustic signal containing information on human lung biomechanics. FE noise is attributed to a broadband part and narrowband components—forced expiratory wheezes (FEWs). FE respiratory noise is composed by acoustic and hydrodynamic mechanisms. An origin of the most powerful mid-frequency FEWs (400–600 Hz) is associated with the 0th–3rd levels of bronchial tree in terms of Weibel [(2009). Swiss Med. Wkly. 139(27–28), 375–386], whereas high-frequency FEWs (above 600 Hz) are attributed to the 2nd–6th levels of bronchial tree. The laboratory prototype of the apparatus is developed, which includes the electret microphone sensor with stethoscope head, a laptop with external sound card, and specially developed software. An analysis of signals by the new method, including FE time in the range from 200 to 2000 Hz and band-pass durations and energies in the 200-Hz bands evaluation, is applied instead of FEWs direct measures. It is demonstrated experimentally that developed FE acoustic parameters correspond to basic indices of lung function evaluated by spirometry and body plethysmography and may be even more sensitive to some respiratory deviations. According to preliminary experimental results, the developed technique may be considered as a promising instrument for acoustic monitoring human lung function in extreme conditions, including diving and space flights. The developed technique eliminates the contact of the sensor with the human oral cavity, which is characteristic for spirometry and body plethysmography. It reduces the risk of respiratory cross-contamination, especially during outpatient and field examinations, and may be especially relevant in the context of the COVID-19 pandemic.

P2.15-09 Clinical Features and Prognosis of Primary Tracheal Cancer at Our Institution’s Experience

Primary tracheal cancer (PTC) is rare. Although histological components of the trachea are similar to that of the lung, the reason for its low incidence is still unknown. Because of its rarity, there are no standard treatment strategies. PTC is not clearly defined. We defined it as a primary malignant neoplasm arising from the sub vocal cord region to the bilateral main bronchi via the bifurcation. The clinical features and prognosis of patients with PTC from 1999 to 2018 at the Kanagawa Cardiovascular and Respiratory Center were analyzed. A total of nine cases, 4 males and 5 females with the median age of 62 years (range:29-81), were included in this study. The clinical symptoms were 3 patients with a cough, 2 with expiratory noise, 2 with hemoptysis, 1 with wheezing, and 1 PTC was detected on screening computed tomography. The tumors were located at upper trachea region in 4 cases, at the lower in 4 cases, and at main right bronchus in 1 case (upper tracheal region is defined as the sub vocal cord area to the lower end of the thyroid and lower tracheal region is defined as the lower end of thyroid to the bifurcation). The histopathological types were 5 (55.6%) adenoid cystic carcinomas (ACC), 2 (22.2%) mucoepidermoid carcinomas, and 2 (22.2%) squamous cell carcinomas. Five patients (55.6%) received radical surgeries and 2 patients (22.2%) who had distant metastasis received palliative surgeries. The remaining 2 (22.2%) patients received tracheal stenting. The postoperative adjuvant therapies included 2 cases with irradiation, and 1 case with chemotherapy. The 2 tracheal stenting cases received full dose irradiation therapy (including case with concurrent chemotherapy) and the 2 cases with palliative surgery also received adjuvant irradiation and chemotherapy, respectively. The overall survival rate was 55.6% at 5 years in all cases. The ACC group tended to have a better prognosis compared to that of the non-ACC group, having the 5-year survival rate was 80.0% vs 25.0%, respectively. In the ACC group, only 1 case (20.0%) died from ACC. The overall survival rate of the radical surgery group and the non-radical group was 60.0% vs 50.0% at 5 years, respectively. We found that PTC generally had a poor prognosis. Among the different types of PTC, ACC had a better prognosis than the other histopathological types. Complete resection achieved a better prognosis, especially in ACC.

Estimation of Short- and Long-Term Postural Effects Used for Lunar Gravity Simulation on Human Tracheal Forced Expiratory Noise Time

The short- and long-term postural effects on the forced expiratory tracheal noise time were studied in a sample of 12 subjects. In contrast to the spirometric parameters, the tracheal forced expiratory noise time does not respond to a short-term change in the body posture from sitting and standing positions to the lying position, as well as to 14-day-long orthostatic hypokinesia in a lying position with a body angle of +9.6°. However, significant multidirectional individual dynamics of the tracheal forced expiratory noise time was observed in all subjects during long-term orthostatic hypokinesia, whereas the spirometric parameters had a dominant growth response. It is assumed that the estimation of the forced expiratory tracheal noise time during long-term orthostatic hypokinesia in lunar gravity simulation may provide useful data in addition to spirometry when assessing the individual lung function dynamics. The dynamics of acoustic parameters, as well as spirometric parameters, during long-term postural effects can be considered as adaptive changes.

A Technique of Forced Expiratory Noise Time Evaluation Provides Distinguishing Human Pulmonary Ventilation Dynamics During Long-Term Head-Down and Head-Up Tilt Bed Rest Tests Simulating Micro and Lunar Gravity.

Estimating the effect of microgravity/hypogravity on pulmonary ventilation function remains topical. Recently developed acoustic techniques based on the evaluation of the forced expiratory noise time (FETa) were hypothesized to be a promising tool for this aim. The aim of the protocol is to study the effect of two different modalities of bed rest space simulations (microgravity and lunar gravity) on FETa and spirometric indices. The FETa in the frequency band of 200–2000 Hz, recorded above human trachea, was evaluated. The 21st-day exposure to 6 degree head-down tilt (HDT) bed rest, simulating microgravity, and 9.6 degree head-up tilt (HUT) bed rest with head-zero tilt (HZT) rest intervals (HUT + HZT), simulating lunar gravity, in statistically identical subgroups of five and six healthy male volunteers, was studied. In the course of HDT bed rest, a significant elongation of FETa was found in relation to background measurements in “sitting” position (p = 0.016). The effect corresponded to a significant decrease of basic spirometric indices (p < 0.02). Moreover, FETa provided reliable discrimination of HDT and HUT + HZT bed rest tests (p = 0.018), while spirometric indices did not (p > 0.05). Based on previously found correlations (Korenbaum and Pochekutova, 2008; Malaeva et al., 2017), a FETa elongation in response to HDT bed rest was attributed to an increase of aerodynamic resistance of the respiratory tract. The technique seems promising to monitor human pulmonary ventilation dynamics in long-term space missions; however, new studies are welcome to verify it in real spaceflight.

Correlation between Acoustic Characteristics of Forced Expiratory Tracheal Noises and Lung Function Parameters in Healthy Subjects and Patients with Obstructive Lung Diseases

The correlations between acoustic characteristics and lung function parameters measured by body plethysmography were revealed when analyzing the sample of 230 subjects consisting of subgroups of healthy subjects, subjects with risk factors, and patients with obstructive lung diseases. Multidirectional character of the correlations between acoustic characteristics of forced expiratory tracheal sounds and parameters measured by body plethysmography/spirometry was established in subgroups of healthy subjects, asthma patients with spirometrically confirmed and unconfirmed obstructive changes, and patients with chronic pulmonary disease.

Acoustic biomechanical relationships of human forced exhalation in bronchial obstruction

A statistically significant bidirectional influence of the incidence and degree of bronchial obstruction on the acoustic parameters of forced expiration and the spirometry/body plethysmography indicators of lung function has been revealed by means of nonparametric analysis of variance in a sample of 218 subjects. It has been shown that the acoustic band pass times and energies of forced expiratory tracheal noises coordinate with both tidal resistance and residual volume.

Gender-specific characteristics of forced expiratory tracheal noise duration in humans aged 17–25 years

In a sample of 77 men and 53 women aged 17–25 years, it has been shown that the duration of tracheal forced expiratory noises is significantly shorter in women. However, normalizing the duration of tracheal forced expiratory noises to height, body mass, and chest circumference eliminates this difference.

Forced expiratory tracheal noise time in young men in health and in bronchial obstruction

A group of 270 young men aged 16–25 years including healthy nonsmokers, healthy smokers, and bronchial asthma patients with and without spirometry-confirmed bronchial obstruction was tested. The forced expiratory noise time recorded on the trachea in a frequency band of 200–2000 Hz, the spirometry indices, and the anthropometric parameters were measured. It was shown that the forced expiratory tracheal noise time and its ratios to the squared chest circumference, to the body mass, and to the height reflected bronchial resistance and are promising indices for diagnosing bronchial obstruction.

Dynamics of the duration of tracheal forced expiratory noises during long-term isolation in the Mars-500 experiment

Dynamics of duration of tracheal forced expiratory noises in a group of volunteers was studied before, during and after 520-days confinement. The duration did not change in most volunteers. Two volunteers demonstrated significant changes of tracheal sounds duration and some spirometric parameters. Increase in duration of tracheal forced expiratory noises and decrease in spirometric parameters reveal ventilatory impairment of obstructive type. Analysis of duration of tracheal forced expiratory noises dynamics during prolonged confinement proves to be a sensitive technique to test ventilatory function changes.

Malignant peripheral nerve sheath tumour in the nasopharynx of a cow

This case describes the findings in a Swiss Braunvieh cow with a malignant peripheral nerve sheath tumour (MPNST) in the nasopharynx. The major clinical signs were mixed dyspnoea with inspiratory and expiratory noises. Radiographic views of the head revealed an irregular mass with soft-tissue density in the nasopharynx originating from the dorsal pharynx and occupying and restricting the pharyngeal cavity. Endoscopic examination showed a lobulated mass obstructing almost the entire lumen of the aboral nasal passages and nasopharynx. Postmortem examination revealed a lobulated mass in the choanae with a broad attachment to the dorsal pharynx and histologically a soft tissue sarcoma with tumour cells positive for the S-100 and p75NTR (neurotrophin receptor) proteins and negative for CNPase. Electron microscopic examination showed few structures that indicated that the tumour originated from Schwann cells.

The influence of the bronchodilatation test on the duration of forced expiratory tracheal noises in young men

The diagnostic efficiency of estimating the duration of forced expiratory noises under the conditions of bronchial obstruction has been shown. The objective of this study was to analyze the response of the forced expiratory noise duration to the bronchodilatation test with the β2-agonist in the age- and genderhomogenous group of healthy volunteers and bronchial asthma patients selected as a model of variable bronchial obstruction. Two hundred and sixty young men (16–25 years old) were examined. It was shown that the prevailing type of response in bronchial asthma patients with spirometry confirmed bronchial obstruction was shortened forced expiratory noises. Furthermore, the degree of the shortening considerably depended on the severity of the background bronchial obstruction. The absence of a statistically significant response of the forced expiratory noise duration dominated among healthy volunteers (nonsmokers as well as smokers) and bronchial asthma patients without a spirometry confirmed bronchial obstruction. However, the shortened response occurred much more frequently in bronchial asthma patients than in healthy volunteers. The high specificity (86%) of the response as shortened forced expiratory noises to the β2-agonist may be useful for diagnostics.

Diagnosis of hidden bronchial obstruction using computer‐assessed tracheal forced expiratory noise time

Increased forced expiratory time was first recognized as a marker of obstruction half a century ago. However, the reported diagnostic capabilities of both auscultated forced expiratory time (FET(as)) and spirometric forced expiratory time are contradictory. Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noise time (FET(a)) being the object-measured analogue of FET(as). The aim of this study was to analyse FET(a) diagnostic capabilities in patients with asthma based on the hypothesis that FET(a) could reveal hidden bronchial obstruction. A group of asthma patients involved 149 males aged 16-25 years. In this group, 71 subjects had spirometry features of bronchial obstruction, meanwhile, the remaining 78 had normal spirometry. A control group involved 77 healthy subjects. Spirometry and forced expiratory tracheal noise recording were sequentially measured for each participant. FET(a) values were estimated by means of a developed computer procedure, including bandpass filtration (200-2000 Hz), waveform envelope calculation with accumulation period of 0.01 s, automated measurement of FET(a) at 0.5% level from the peak amplitude. Specificity, sensitivity and area under Receiver Operating Characteristic curve of FET(a) and its ratios to squared chest circumference, height, weight were indistinguishable with baseline spirometry index FEV1 /forced vital capacity. Meanwhile, acoustic features of obstruction were revealed in 41%-49% of subgroup of patients with asthma but normal spirometry. FET(a) of tracheal noise and its ratio to anthropometric parameters seem to be sensitive and specific tests of hidden bronchial obstruction in young male asthma patients.

Влияние бронходилатационного теста на продолжительность трахеальных шумов форсированного выдоха у молодых мужчин

A diagnostic effect of evaluation of forced expiratory noises duration in revealing bronchial obstruction was shown previously. The objective is an analysis of response of forced expiratory noises duration to bronchodilatation test with beta2-agonist among homogeneous in age and gender group of healthy volunteers and bronchial asthma patients, which was treated as a model of variable bronchial obstruction, 260 young men (age of 16-25 years) were examined. It was shown that in bronchial asthma patients with spirometry confirmed bronchial obstruction dominated response of shortening forced expiratory noises duration. Furthermore the magnitude of shortening was significantly dependent on background bronchial obstruction severity. Absence of statistically significant response of forced expiratory noises duration dominated among healthy volunteers (nonsmokers as well as smokers) and bronchial asthma patients without spirometry confirmed bronchial obstruction. However shortening response was met significantly frequently in bronchial asthma patients relatively to healthy volunteers. High specificity (86%) of forced expiratory noises duration shortening response to beta2-agonist may be useful for diagnostics.

Computer Evaluation of Tracheal Forced Expiratory Noise Time for Bronchial Obstruction Diagnostics

Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noises time (FETa). The objective is to analyze FET a diagnostic capability in revealing bronchial obstruction. A group of patients with bronchial asthma (BA) involved 50 males (16-24 years). Selection criteria: (a) diminution of FEV 1/FVC (VC) relation; (b) bronchodilator response to salbutamol; (c) diurnal variability of PEF. A group of 52 healthy volunteers were recruited as the control one. Spirometry and forced expiratory tracheal noises recording were sequentially accomplished for each person. FETa values were estimated by means of developed semiautomated procedure, including bandpass filtration (200-2000 Hz), waveform envelope calculation with accumulation period of 0.01 sec, measurement of FET a at 0.5% level from the peak value of the waveform. The value of FET a was significantly larger in BA patients group than in control one. Based on ROC-analysis the cutoff point FET a > 1.86 s was chosen as a sign of bronchial obstruction. Areas under ROC - curves of FETa and baseline spirometric index FEV1/FVC (VC) did not differ significantly. The mean intrasubject variability of FETa constituted 8.3% in the control group. Thus FETa is a reasonably sensitive, specific and quite repeatable test of bronchial obstruction in young men.

Influence of modified gas mixtures on the acoustic parameters of human forced exhalation

It was earlier demonstrated that the duration of tracheal noises of forced exhalation (FE) looks to be promising to determine adverse changes in the lung function after a dive. This study dealt with the parameters of tracheal expiratory noises (FE) as dependent of the composition of breathing gas mixtures. In the first type of experiments, 25 volunteers aged from 22 to 60 years carried out forced exhalation under a normal pressure of air or of an oxygen-helium or oxygen-krypton mixture. In the second type of experiments, six volunteers from 25 to 46 years of age performed forced exhalation with air in an altitude chamber under a normal pressure (0.1 MPa); the same subjects performed FE under an elevated pressure (0.263 MPa) while breathing air or an oxygen-helium mixture. In the first type of experiments, the total duration of tracheal FE noises in the frequency range 200–2000 Hz and 200-Hz bands FE noises depended directly and linearly on the density of the gas mixture; this was not the case in the high-frequency band from 1400 to 2000 Hz. In the second type of experiments, the high-frequency durations and spectral energies of tracheal FE noises (1600–2000 Hz) depended inversely and significantly on the adiabatic gas compressibility. In a simulated dive to a depth of 16.3 m (0.263 MPa), individual changes in the total duration of tracheal FE noises exceeded the diagnostic threshold of deterioration of the lung function in divers that was determined earlier under normal pressure.

Nocturnal moaning and groaning—catathrenia or nocturnal vocalizations

Descriptions of nocturnal vocalizations, including catathrenia, are few. We undertook a study at our center on patients diagnosed with catathrenia, to evaluate the characteristic features of these events and their response to continuous positive airway pressure (CPAP) treatment. Retrospective study of patients with a diagnosis of catathrenia who had an overnight polysomnogram (PSG) and available synchronized audio video recordings (to confirm the presence of moaning and groaning), at our center between January 2007 and May 2010. Ten patients were included in the analysis. Three (30%) patients presented with the chief complaint of expiratory noises during sleep. The other moaning/groaning sounds were incidental findings noted by the sleep technologist and/or the sleep physician. The number of moaning/groaning events during PSG varied between 2 and 343 per patient with sound duration ranging from 0.4 to 21.4s. Moaning/groaning events during exhalation (1,026 episodes) were separated into typical catathrenia events (as per the International Classification of Sleep Disorders, 2nd edition [ICSD-2] definition) and atypical/nocturnal vocalization events (moaning/groaning events that did not meet the ICSD-2 criteria). Typical catathrenia events (5% or 52/1,026) were experienced by five of the ten patients and had mean exhalation duration of 14.97 ± 5.13s (range 5.8-24s) with a mean sound duration of 8.47 ± 5.97s (range 2-21.4s). The typical and atypical events occurred predominantly in NREM sleep. Six of the ten patients had associated sleep-disordered breathing and four underwent CPAP titration. All four patients had significantly fewer events of moaning/groaning (mean reduction was 75.8 ± 26.2%) with CPAP. New and unique features were identified in our series of patients diagnosed with catathrenia. Though all events had the characteristic moaning and groaning sound during exhalation, only a small percentage (5%) met the catathrenia definition as outlined in ICSD-2. Do we label the atypical events as part of the spectrum of nocturnal vocalizations or consider them as catathrenia by redefining the criteria? CPAP appeared to be a reasonable treatment option.

Regression simulation of the dependence of forced expiratory tracheal noises duration on human respiratory system biomechanical parameters

Background Estimating the duration of forced exhalation tracheal noises shows promise for recognizing bronchial obstruction. Objective Experimental simulation of an influence of biomechanical parameters on the duration of normal forced exhalation tracheal noises. Method and materials Thirty-two healthy non-smoking men aged 16–22 years were examined. The duration of noises, the parameters of computer spirometry, and the maximum static expiratory pressure are recorded. These data were analyzed by means of multiple linear regression simulation for logarithms of the elements of the proportionality relation obtained with the use of a one-component biomechanical model of forced exhalation and a linearized approximation of flow–volume curve. Results Dependence between duration of the forced expiratory noises recorded on human trachea and the product of forced volume capacity (in power of 1.05±0.27), maximum static expiratory pressure (in power of 0.46±0.23), equivalent expiratory resistance in the stage of functional expiratory stenosis (in power of 0.72±0.15) is established. Determination coefficient is 0.57. The duration of forced expiratory noises recorded on human trachea in healthy is an estimate of the equivalent expiratory resistance of human bronchial tree in the functional expiratory stenosis phase, whereas in patients with bronchial obstruction it is supposed to take into account an excess of noise generation time compared with the time predicted from normal individual value of this resistance.

Incorrect assembly of non‐return valve of an Oxylog ventilator

We wish to report a critical incident during use of a Draeger Oxylog ventilator. Transfer was arranged for a burns victim whose lungs were mechanically ventilated. In preparation for the transfer he was changed to a Draeger Oxylog ventilator (Draeger Medical Ltd, Hertfordshire, UK) and the end-tidal carbon dioxide continually analysed. The initial end-tidal carbon dioxide measurement was 5.1 kPa, but within minutes this value increased to 11.0 kPa in association with a raised inspired concentration of carbon dioxide (1.5 kPa). Arterial blood gas analysis confirmed an elevated Paco2 of 13 kPa. The patient was reconnected to the ICU ventilator and ventilated to normocapnia. There appeared to be adequate chest expansion and appropriate movements of the pressure gauge on the ventilator were observed, but no gas flow could be detected from the PEEP valve situated on the expiratory port and the characteristic expiratory noise was absent. The Oxylog ventilator was examined closely and the non-return valve unit was discovered to have been incorrectly assembled such that the dark red ‘mushroom’ part of the valve had been inserted the wrong way around (see Figure 3). The result was that the patient was being ventilated predominantly with rebreathed gases. The correct assembly is shown in Figure 4. It is likely that the patient would have suffered an adverse event during the transfer had this error not been recognised at the bedside before departure. This was avoided by use of continuous end-tidal carbon dioxide monitoring to confirm the adequacy of ventilation on the new ventilator, as recommended by a number of professional organisations [1, 2]. The main learning point from this incident is that it is essential to confirm that the patient is stable on the transfer trolley and with the equipment that will be used for the transfer before leaving the relative safety of the parent unit. Incorrect assembly of non-return valve of Oxylog ventilator. Correct assembly of valve. We would like to thank Drs Thomas and Kuppurao for their report and for the opportunity to reply. From the information given in the letter we were not able to establish the exact model of Oxylog ventilator referred to. Therefore, we can only assume from studying the patient valve shown in the attachment sent to us that the Oxylog ventilator mentioned is either an Oxylog 1 or an Oxylog 1000. Our assumption is further supported by the fact that no mention or information is given in the article of any alarms being generated. This strongly suggests that an Oxylog 1 ventilator was being used and our following comments relate to this model. The Oxylog 1 ventilator is an early model in the ‘Dräger Oxylog family’ of emergency ventilators. It was first introduced into service in the 1980s and provided settings for minute volume, frequency, ‘air mix/no air mix’ and an on/off switch. Our initial concern with the letter is prompted by the fact that no reference is made to the manufacturer's Instructions for Use or the pre-use checks recommended in these [1]. Incorrect assembly of the check valve ‘dark red mushroom’ within the patient valve suggests that the valve was not assembled correctly as illustrated to users in the Instructions for Use. These instructions also have clear diagrams and explanations for cleaning, disinfecting, re-assembly and testing of the device. We would not disagree with the principle of the main learning point in the letter but consider it should be expanded further. To help ensure patient stability with the equipment and prior to leaving the safety of the parent unit, users should perform pre-use checks as detailed in the Instructions for Use before connecting the ventilator to the patient. M. S. RedpathDraeger Medical UK Ltd Hemel Hempstead HP2 7BW, UK E-mail: [email protected]