International Symposium on Lung Sounds. Synopsis of proceedings

Physicians' ability to recognize adventitious lung sounds

BACKGROUND

Lung auscultation is an important tool for diagnosing respiratory diseases. However, the ability of observers to recognize respiratory sounds varies considerably and depends on the sound. The present study aimed to assess the auscultatory skills of healthcare professionals and medical students.

METHODS

A total of 295 physicians (185 pediatricians, 69 pulmonologists, and 41 physicians of general/internal medicine and subspecialties), 55 residents, and 50 medical students participated in the survey. They listened to five audio-recorded respiratory sounds and described them in free-form answers.

RESULTS

The rates of correct answers were 55.2% for fine crackles, 74.5% for coarse crackles, 72.2% for wheezes, 18.75% for squawks, and 11.25% for pleural friction rub. The medical specialty was correlated with the correct answers and both pediatricians and physicians of general/internal medicine and subspecialties recognized fewer sounds compared with respiratory physicians (odds ratio [OR]: 0.37; confidence interval [CI]: 0.22-0.62; p < 0.001 and, OR: 0.47; CI: 0.22-0.99, p = 0.048, respectively). Years of experience were negatively correlated with the number of correct answers (OR: 0.73; CI:0.62-0.84; p = 0.001).

CONCLUSIONS

Gaps remain in both terminology and recognition of lung sounds among a wide population of Greek physicians. Less experienced physicians perform better on lung auscultation, indicating that continuing education with critical feedback should be offered.

Influence of observer preferences and auscultatory skill on the choice of terms to describe lung sounds: a survey of staff physicians, residents and medical students

Background

In contrast with the technical progress of the stethoscope, lung sound terminology has remained confused, weakening the usefulness of auscultation. We examined how observer preferences regarding terminology and auscultatory skill influenced the choice of terms used to describe lung sounds.

Methods

Thirty-one staff physicians (SP), 65 residents (R) and 47 medical students (MS) spontaneously described the audio recordings of 5 lung sounds classified acoustically as: (1) normal breath sound; (2) wheezes; (3) crackles; (4) stridor and (5) pleural friction rub. A rating was considered correct if a correct term or synonym was used to describe it (term use ascribed to preference). The use of any incorrect terms was ascribed to deficient auscultatory skill.

Results

Rates of correct sound identification were: (i) normal breath sound: SP=21.4%; R=11.6%; MS=17.1%; (ii) wheezes: SP=82.8%; R=85.2%; MS=86.4%; (iii) crackles: SP=63%; R=68.5%; MS=70.7%; (iv) stridor: SP=92.8%; R=90%; MS=72.1% and (v) pleural friction rub: SP=35.7%; R=6.2%; MS=3.2%. The 3 groups used 66 descriptive terms: 17 were ascribed to preferences regarding terminology, and 49 to deficient auscultatory skill. Three-group agreement on use of a term occurred on 107 occasions: 70 involved correct terms (65.4%) and 37 (34.6%) incorrect ones. Rate of use of recommended terms, rather than accepted synonyms, was 100% for the wheezes and the stridor, 55% for the normal breath sound, 22% for the crackles and 14% for the pleural friction rub.

Conclusions

The observers’ ability to describe lung sounds was high for the wheezes and the stridor, fair for the crackles and poor for the normal breath sound and the pleural friction rub. Lack of auscultatory skill largely surpassed observer preference as a factor determining the choice of terminology. Wide dissemination of educational programs on lung auscultation (eg, self-learning via computer-assisted learning tools) is urgently needed to promote use of standardised lung sound terminology.

Influence of language skills on the choice of terms used to describe lung sounds in a language other than English: a cross-sectional survey of staff physicians, residents and medical students

INTRODUCTION

The value of chest auscultation would be enhanced by the use of a standardised terminology. To that end, the recommended English terminology must be transferred to a language other than English (LOTE) without distortion.

OBJECTIVE

To examine the transfer to Hebrew-taken as a model of LOTE-of the recommended terminology in English.

DESIGN/SETTING

Cross-sectional study; university-based hospital.

PARTICIPANTS

143 caregivers, including 31 staff physicians, 65 residents and 47 medical students.

METHODS

Observers provided uninstructed descriptions in Hebrew and English of audio recordings of five common sounds, namely, normal breath sound (NBS), wheezes, crackles, stridor and pleural friction rub (PFR).

OUTCOMES

(a) Rates of correct/incorrect classification; (b) correspondence between Hebrew and recommended English terms; c) language and auscultation skills, assessed by crossing the responses in the two languages with each other and with the classification of the audio recordings validated by computer analysis.

RESULTS

Range (%) of correct rating was as follows: NBS=11.3-20, wheezes=79.7-87.2, crackles=58.6-69.8, stridor=67.4-96.3 and PFR=2.7-28.6. Of 60 Hebrew terms, 11 were correct, and 5 matched the recommended English terms. Many Hebrew terms were adaptations or transliterations of inadequate English terms. Of 687 evaluations, good dual-language and single-language skills were found in 586 (85.3%) and 41 (6%), respectively. However, in 325 (47.3%) evaluations, good language skills were associated with poor auscultation skills.

CONCLUSION

Poor auscultation skills surpassed poor language skills as a factor hampering the transfer to Hebrew (LOTE) of the recommended English terminology. Improved education in auscultation emerged as the main factor to promote the use of standardised lung sound terminology. Using our data, a strategy was devised to encourage the use of standardised terminology in non-native English-speaking countries.

Characteristics of Pulmonary Auscultation in Patients with 2019 Novel Coronavirus in China

BACKGROUND

Effective auscultations are often hard to implement in isolation wards. To date, little is known about the characteristics of pulmonary auscultation in novel coronavirus (COVID-19) pneumonia.

OBJECTIVES

The aim of this study was to explore the features and clinical significance of pulmonary auscultation in COVID-19 pneumonia using an electronic stethoscope in isolation wards.

METHODS

This cross-sectional, observational study was conducted among patients with laboratory-confirmed COVID-19 at Wuhan Red-Cross Hospital during the period from January 27, 2020, to February 12, 2020. Standard auscultation with an electronic stethoscope was performed and electronic recordings of breath sounds were analyzed.

RESULTS

Fifty-seven patients with average age of 60.6 years were enrolled. The most common symptoms were cough (73.7%) during auscultation. Most cases had bilateral lesions (96.4%) such as multiple ground-glass opacities (69.1%) and fibrous stripes (21.8%). High-quality auscultation recordings (98.8%) were obtained, and coarse breath sounds, wheezes, coarse crackles, fine crackles, and Velcro crackles were identified. Most cases had normal breath sounds in upper lungs, but the proportions of abnormal breath sounds increased in the basal fields where Velcro crackles were more commonly identified at the posterior chest. The presence of fine and coarse crackles detected 33/39 patients with ground-glass opacities (sensitivity 84.6% and specificity 12.5%) and 8/9 patients with consolidation (sensitivity 88.9% and specificity 15.2%), while the presence of Velcro crackles identified 16/39 patients with ground-glass opacities (sensitivity 41% and specificity 81.3%).

CONCLUSIONS

The abnormal breath sounds in COVID-19 pneumonia had some consistent distributive characteristics and to some extent correlated with the radiologic features. Such evidence suggests that electronic auscultation is useful to aid diagnosis and timely management of the disease. Further studies are indicated to validate the accuracy and potential clinical benefit of auscultation in detecting pulmonary abnormalities in COVID-19 infection.

A case of tracheal pleomorphic adenoma misdiagnosed as asthma

A 51-year-old woman had an incidental finding of a tracheal tumor during oesophagogastroduodenoscopy following the diagnosis of asthma for 2 months. A computed tomography scan revealed a 15-mm tumor in the subglottis. Endoscopic resection was performed safely, and pleomorphic adenoma was diagnosed histologically. The patient’s condition was satisfactory 30 months after the procedure. Tracheal pleomorphic adenoma is rare and may be misdiagnosed as asthma. If the tumor is large, surgery may be required; however, endoscopic polypectomy may be effective if the tumor is small. Therefore, early diagnosis of tracheal pleomorphic adenoma is important. At the first visit, the flow–volume curve suggested upper airway obstruction, which should have raised the suspicion of an upper airway obstruction. In patients with suspected asthma, early pulmonary function testing is needed to substantiate asthma diagnosis and prevent an alternative diagnosis being missed.

Smartphone Based Human Breath Analysis from Respiratory Sounds

Human breath analysis plays important role for diagnosis and management of pulmonary diseases to guarantee normal health. The critical task is to distinguish normal and abnormal lung sounds. This research work presents a scheme for breath analysis used to detect irregular patterns occurred in respiratory cycles due to respiratory diseases. After de-noising breath segments using wavelet de-noising method, intrinsic mode functions are extracted with complete ensemble empirical mode decomposition (CEEMD). Instantaneous frequency (IF) and instantaneous envelope are extracted to get robust features for classification. The study contains breath samples captured using smartphone under natural setting. The data set contains 255 breath cycles. For cycle classification, Bag-of-word was applied to group segments based features. The support vector machine (SVM) was applied on randomly partitioned data samples. Experiments resulted with performance accuracy of (75.21%±2) for asthmatic inspiratory cycles and (75.5%±3%) for complete Respiratory Sounds (RS) cycle with diagnostic odds ratio (DOR) of 20.61% and 13.S7% respectively.

Instantaneous frequency based index to characterize respiratory crackles

BACKGROUND

Crackle is a lung sound widely employed by health staff to identify respiratory diseases. The two-cycle duration (2CD) is a quantitative index pointed out by the American Thoracic Society and the European Respiratory Society to classify respiratory crackles as fine or coarse. However, this index, measured in the time domain, is highly affected by noise and filters of recording systems. Such factors hamper the analysis of data reported by different research groups. This work proposes a new index based on the instantaneous frequency of crackles estimated by means of discrete-time pseudo Wigner-Ville distribution.

METHOD

Comparisons between 2CD and the proposed index were carried out for simulated and actual crackles. Normal breathing sounds were added to simulated crackles; the resulting signals were then applied to a band-pass filter that mimics those belonging to lung sound acquisition systems. Thus, the impact of noise and filtering on these two indices was assessed for simulated crackles. Kruskal-Wallis and Dunn's tests as well as Gaussian mixture model (GMM) were applied to the two indices measured from 382 actual crackles belonging to open databases.

RESULTS

The proposed index is much less susceptible to waveform distortions due to noise and filtering when compared to the 2CD. Thus, the statistical analyses allow the identification of two classes of crackles from actual databases; the same does not occur when using 2CD.

CONCLUSIONS

The new proposed index has the potential to contribute for a better characterization of crackles generated by different respiratory diseases, assisting their diagnosis during clinical exams.

Detection of inspiratory recruitment of atelectasis by automated lung sound analysis as compared to four-dimensional computed tomography in a porcine lung injury model

Background

Cyclic recruitment and de-recruitment of atelectasis (c-R/D) is a contributor to ventilator-induced lung injury (VILI). Bedside detection of this dynamic process could improve ventilator management. This study investigated the potential of automated lung sound analysis to detect c-R/D as compared to four-dimensional computed tomography (4DCT).

Methods

In ten piglets (25 ± 2 kg), acoustic measurements from 34 thoracic piezoelectric sensors (Meditron ASA, Norway) were performed, time synchronized to 4DCT scans, at positive end-expiratory pressures of 0, 5, 10, and 15 cmH₂O during mechanical ventilation, before and after induction of c-R/D by surfactant washout. 4DCT was post-processed for within-breath variation in atelectatic volume (Δ atelectasis) as a measure of c-R/D. Sound waveforms were evaluated for: 1) dynamic crackle energy (dCE): filtered crackle sounds (600–700 Hz); 2) fast Fourier transform area (FFT area): spectral content above 500 Hz in frequency and above −70 dB in amplitude in proportion to the total amount of sound above −70 dB amplitude; and 3) dynamic spectral coherence (dSC): variation in acoustical homogeneity over time. Parameters were analyzed for global, nondependent, central, and dependent lung areas.

Results

In healthy lungs, negligible values of Δ atelectasis, dCE, and FFT area occurred. In lavage lung injury, the novel dCE parameter showed the best correlation to Δ atelectasis in dependent lung areas (R² = 0.88) where c-R/D took place. dCE was superior to FFT area analysis for each lung region examined. The analysis of dSC could predict the lung regions where c-R/D originated.

Conclusions

c-R/D is associated with the occurrence of fine crackle sounds as demonstrated by dCE analysis. Standardized computer-assisted analysis of dCE and dSC seems to be a promising method for depicting c-R/D.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1964-6) contains supplementary material, which is available to authorized users.

Wheezes, crackles and rhonchi: simplifying description of lung sounds increases the agreement on their classification: a study of 12 physicians' classification of lung sounds from video recordings

Background

The European Respiratory Society (ERS) lung sounds repository contains 20 audiovisual recordings of children and adults. The present study aimed at determining the interobserver variation in the classification of sounds into detailed and broader categories of crackles and wheezes.

Methods

Recordings from 10 children and 10 adults were classified into 10 predefined sounds by 12 observers, 6 paediatricians and 6 doctors for adult patients. Multirater kappa (Fleiss' κ) was calculated for each of the 10 adventitious sounds and for combined categories of sounds.

Results

The majority of observers agreed on the presence of at least one adventitious sound in 17 cases. Poor to fair agreement (κ<0.40) was usually found for the detailed descriptions of the adventitious sounds, whereas moderate to good agreement was reached for the combined categories of crackles (κ=0.62) and wheezes (κ=0.59). The paediatricians did not reach better agreement on the child cases than the family physicians and specialists in adult medicine.

Conclusions

Descriptions of auscultation findings in broader terms were more reliably shared between observers compared to more detailed descriptions.

Towards the standardisation of lung sound nomenclature

Auscultation of the lung remains an essential part of physical examination even though its limitations, particularly with regard to communicating subjective findings, are well recognised. The European Respiratory Society (ERS) Task Force on Respiratory Sounds was established to build a reference collection of audiovisual recordings of lung sounds that should aid in the standardisation of nomenclature. Five centres contributed recordings from paediatric and adult subjects. Based on pre-defined quality criteria, 20 of these recordings were selected to form the initial reference collection. All recordings were assessed by six observers and their agreement on classification, using currently recommended nomenclature, was noted for each case. Acoustical analysis was added as supplementary information. The audiovisual recordings and related data can be accessed online in the ERS e-learning resources. The Task Force also investigated the current nomenclature to describe lung sounds in 29 languages in 33 European countries. Recommendations for terminology in this report take into account the results from this survey.

Auscultation of the respiratory system

Auscultation of the lung is an important part of the respiratory examination and is helpful in diagnosing various respiratory disorders. Auscultation assesses airflow through the trachea-bronchial tree. It is important to distinguish normal respiratory sounds from abnormal ones for example crackles, wheezes, and pleural rub in order to make correct diagnosis. It is necessary to understand the underlying pathophysiology of various lung sounds generation for better understanding of disease processes. Bedside teaching should be strengthened in order to avoid erosion in this age old procedure in the era of technological explosion.

Validation of computerized wheeze detection in young infants during the first months of life

BACKGROUND

Several respiratory diseases are associated with specific respiratory sounds. In contrast to auscultation, computerized lung sound analysis is objective and can be performed continuously over an extended period. Moreover, audio recordings can be stored. Computerized lung sounds have rarely been assessed in neonates during the first year of life. This study was designed to determine and validate optimal cut-off values for computerized wheeze detection, based on the assessment by trained clinicians of stored records of lung sounds, in infants aged <1 year.

METHODS

Lung sounds in 120 sleeping infants, of median (interquartile range) postmenstrual age of 51 (44.5-67.5) weeks, were recorded on 144 test occasions by an automatic wheeze detection device (PulmoTrack®). The records were retrospectively evaluated by three trained clinicians blinded to the results. Optimal cut-off values for the automatically determined relative durations of inspiratory and expiratory wheezing were determined by receiver operating curve analysis, and sensitivity and specificity were calculated.

RESULTS

The optimal cut-off values for the automatically detected durations of inspiratory and expiratory wheezing were 2% and 3%, respectively. These cutoffs had a sensitivity and specificity of 85.7% and 80.7%, respectively, for inspiratory wheezing and 84.6% and 82.5%, respectively, for expiratory wheezing. Inter-observer reliability among the experts was moderate, with a Fleiss' Kappa (95% confidence interval) of 0.59 (0.57-0.62) for inspiratory and 0.54 (0.52 - 0.57) for expiratory wheezing.

CONCLUSION

Computerized wheeze detection is feasible during the first year of life. This method is more objective and can be more readily standardized than subjective auscultation, providing quantitative and noninvasive information about the extent of wheezing.

Wheeze

Wheeze is a continuous, musical, whistling-like abnormal breath sound that is usually heard in expiration. It is a common respiratory symptom and sign in children and adults; the 1958 British National Cohort study found the cumulative incidence of wheezing illness by age 33 to be 43% ( Strachan et al, 1996 ). This article considers wheeze only in adults.

Variation in family physicians' recording of auscultation abnormalities in patients with acute cough is not explained by case mix. A study from 12 European networks

BACKGROUND

Conflicting data on the diagnostic and prognostic value of auscultation abnormalities may be partly explained by inconsistent use of terminology.

OBJECTIVES

To describe general practitioners use of chest auscultation abnormality terms for patients presenting with acute cough across Europe, and to explore the influence of geographic location and case mix on use of these terms.

METHODS

Clinicians recorded whether 'diminished vesicular breathing', 'wheezes', 'crackles' and 'rhonchi' were present in an observational study of adults with acute cough in 13 networks in 12 European countries. We describe the use of these terms overall and by network, and used multilevel logistic regression to explore variation by network, controlling for patients' gender, age, comorbidities, smoking status and symptoms.

RESULTS

2345 patients were included. Wheeze was the auscultation abnormality most frequently recorded (20.6% overall) with wide variation by network (range: 8.3-30.8%). There was similar variation for other auscultation abnormalities. After controlling for patient characteristics, network was a significant predictor of auscultation abnormalities with odds ratios for location effects ranging from 0.37 to 4.46 for any recorded auscultation abnormality, and from 0.25 to 3.14 for rhonchi.

CONCLUSION

There is important variation in recording chest auscultation abnormalities by general practitioners across Europe, which cannot be explained by differences in patient characteristics. There is a need and opportunity for standardization in the detection and classification of lung sounds.

Lung sounds in bronchial asthma

Modern understanding of lung sounds started with a historical article by Forgacs. Since then, many studies have clarified the changes of lung sounds due to airway narrowing as well as the mechanism of genesis for these sounds. Studies using bronchoprovocation have shown that an increase of the frequency and/or intensity of lung sounds was a common finding of airway narrowing and correlated well with lung function. Bronchoprovocation studies have also disclosed that wheezing may not be as sensitive as changes in basic lung sounds in acute airway narrowing. A forced expiratory wheeze (FEW) may be an early sign of airway obstruction in patients with bronchial asthma. Studies of FEW showed that airway wall oscillation and vortex shedding in central airways are the most likely mechanisms of the generation of expiratory wheezes. Studies on the genesis of wheezes have disclosed that inspiratory and expiratory wheezes may have the same mechanism of generation as a flutter/flow limitation mechanism, either localized or generalized. In lung sound analysis, the narrower the airways are, the higher the frequency of breathing sounds is, and, if a patient has higher than normal breathing sounds, i.e., bronchial sounds, he or she may have airway narrowing or airway inflammation. It is sometimes difficult to detect subtle changes in lung sounds; therefore, we anticipate that automated analysis of lung sounds will be used to overcome these difficulties in the near future.

Wheezing after respiratory tract infection in athletes

Wheezing is a commonly encountered complaint by patients seen in sports medicine practice. Wheezes are a continuous musical sound heard best on expiration and can originate from one or more of several defined anatomical locations in the human airway. While common causes of wheezing include exercise-induced bronchoconstriction, postnasal drip, and asthma, wheezing also follows specific respiratory infections and can persist for months after the onset of symptoms. Abnormal lung physiology following pneumonia can persist for decades. These postinfectious pulmonary changes affect the ability of athletes to return to sports. In addition to history and physical examination, diagnosis may require pulmonary function testing and exercise challenge testing. The cornerstone to management is an accurate diagnosis and using lifestyle and pharmacologic intervention. Return to play should be gradual and allowed only after individuals demonstrate adequate pulmonary capacity to meet the demands of their sport. Providers also should be aware of governing body regulations regarding treatments and required therapeutic use exemptions.

Gurgling breath sounds may predict hospital-acquired pneumonia

OBJECTIVES

To determine whether gurgling sounds heard during speech or quiet breathing, with or without a stethoscope over the glottis, predict hospital-acquired pneumonia (HAP).

METHODS

All patients admitted to the respiratory or general medicine ward of a 350-bed community teaching hospital were eligible. Patients were examined each day, and those who had upper airway gurgling, heard with or without the stethoscope, during breathing or speech at any point during admission were noted. Assuming an overall incidence of HAP (>48 h after admission) of 5% to 10% and estimated incidence of 30% to 50% in patients with gurgle, 20 patients with gurgle and 60 patients without gurgle, matched on the same day and ward of admission, were included in the study. Demographic, physiologic, and outcome variables were compared using univariate and multivariate techniques to ascertain whether gurgling is independently associated with HAP, rate of transfer to ICU, and inhospital mortality.

RESULTS

Twenty patients with gurgle were compared with 60 patients without gurgle. Patients with gurgle were older (78.5 vs 65.2 y; P < .001), more likely to reside in nursing homes (75% vs 6%; P < .001), and were more likely to have dementia (70% vs 13%; P < .001). In multivariate analysis, dementia (odds ratio [OR] = 23.4; 95% CI, 4.2-131.9) and recent (within 24 h) treatment with opiates (OR = 14.7; 95% CI, 2.2-97.5) emerged as the only statistically significant independent predictors of gurgling. HAP occurred in 55% of patients with gurgle compared with 1.7% of patients without gurgle (P < .001), and 50% of patients with vs 3.3% of patients without gurgle required transfer to ICU (P < .001). After adjustment for age, Charlson score, dementia, opiate administration, and stroke, gurgling emerged as the sole independent predictor of HAP (OR = 140.1; 95% CI, 5.6-3,529.4) and ICU transfer (OR = 35.1; 95% CI, 4.1-303.7). Gurgling did not predict mortality; the Charlson comorbidity index was the only significant predictor of inhospital death.

CONCLUSIONS

Gurgling sounds heard during quiet breathing or speech are independently associated with HAP.

Terminologia da ausculta pulmonar utilizada em publicações médicas brasileiras, no período de janeiro de 1980 a dezembro de 2003

OBJETIVO: Avaliar a adequação de uso de termos semiológicos da ausculta pulmonar em publicações médicas brasileiras sobre doenças respiratórias, no período de janeiro de 1980 a dezembro de 2003. MÉTODOS: Realizou-se um estudo descritivo, analisando-se três revistas médicas: Jornal de Pneumologia, Jornal de Pediatria e Revista Médica Brasileira. Foram selecionados os artigos originais e relatos de casos sobre doenças respiratórias, de onde foram extraídos os termos semiológicos da ausculta pulmonar. Foi avaliada a adequação dos termos na descrição dos ruídos adventícios. RESULTADOS: Encontrou-se maior inadequação no uso dos termos de ruídos descontínuos, comparado com o uso dos termos de ruídos contínuos (87,7% versus 44%, p = 0,0000). Não houve diferença significativa entre relatos de pneumologistas e de outros especialistas quanto à inadequação no uso dos termos (56,5% versus 62,0%, p = 0,26). Também não observamos diferença significativa entre as regiões do país e os períodos antes e após a divulgação da nomenclatura internacional. CONCLUSÃO: O uso inadequado dos termos para descrever ruídos adventícios na ausculta pulmonar continua sendo um fenômeno freqüente e geral nas publicações médicas brasileiras.

Adenosine Bronchial Provocation With Computerized Wheeze Detection in Young Infants With Prolonged Cough

BACKGROUND

Chronic cough in babies is often associated with bronchial hyperreactivity (BHR). The objective documentation of BHR in babies is difficult, and acoustic methods have been described (provocative concentration of a substance causing wheeze) for conducting bronchial provocation tests (BPTs). We conducted a study to evaluate automatic computerized wheeze detection (CWD) in determining BHR in young infants with prolonged cough, and its correlation with the subsequent development of wheezing.

METHODS

Infants aged < 24 months with prolonged cough (ie, > 2 months) underwent acoustic BPTs with the response determined by CWD and auscultation by a physician. Telephone interviews with parents were conducted after 1 month and yearly for the next 3 years.

RESULTS

A total of 28 infants who were 4 to 24 months old with prolonged cough were included in the study. Twenty of these infants (71.4%) had BHR as determined by a positive acoustic BPT result. In 11 of these 20 tests, the CWD occurred earlier, and in 9 tests it occurred at the same step as auscultation by a physician. Rhonchi or whistles often preceded wheezes. Seventeen of the 20 patients with BHR completed 3 years of follow-up. Of these, 14 had recurrent episodes of wheezing and shortness of breath, and 3 were well. Six of the eight adenosine-negative patients completed 3 years of follow-up and had no symptoms of BHR.

CONCLUSIONS

Acoustic BPT is a technically feasible test for the detection of BHR in young infants. CWD provides an earlier detection of wheeze than stethoscope auscultation. In our group of infants, a positive acoustic BPT result had high correlation with symptoms compatible with BHR over the next 3 years.

Clinical, laboratory findings and microbiologic characterization of bronchiectasis in Thai patients

OBJECTIVE

The aim of the present study was to characterize the clinical features, underlying disease states, laboratory findings and microbiological characterization of bronchiectasis in Thai patients.

METHODOLOGY

For a 2-year period all consecutive patients diagnosed with bronchiectasis at Phramongkutklao Hospital, Bangkok, Thailand, were recruited. Data including history, physical examination, underlying disease and laboratory studies were carefully reviewed and recorded.

RESULTS

Fifty patients diagnosed with bronchiectasis were enrolled. Their mean age was 58 years. The most common background aetiology was tuberculosis. Six per cent of the patients were diagnosed as having diffuse panbronchiolitis. Normal chest radiographs were found in 10%. The common organisms isolated were Pseudomonas aeruginosa (20%), Haemophilus influenzae (14%), Klebsiella pneumoniae (14%) and Streptococcus pneumoniae (6%). Non-tuberculous mycobacteria which included Mycobacterium kansasii and Mycobacterium chelonae were found in 6%.

CONCLUSION

We report the characteristics of bronchiectasis in Thai patients. The most common identifiable aetiology was tuberculosis.

The relationship between normal lung sounds, age, and gender

Auscultation is one of the most important noninvasive and feasible methods for the detection of lung diseases. Systematic changes in breathing sounds with increasing age are of diagnostic importance. To investigate these changes, we recorded lung sounds taken from four locations in the posterior thorax of 162 subjects, together with airflow. The data were analyzed according to age, sex, and smoking habit. In order to describe the power spectrum of the lung sounds, we calculated mean and median frequency, frequency with the highest power, and a ratio (Q) of relative power of the two frequency bands of 330 to 600 Hz and 60 to 330 Hz. Linear regression analysis was used as a measurement of age-dependence of these variables. Significant differences in Q were found in men versus women (p < 0.05), but not in smokers versus nonsmokers. Within the groups, a small but significant correlation existed between Q and age (r(2) </= 0.1, p < 0.05). For both men and women, a slight increase of the relative power in the frequency band of 330 to 600 Hz was recorded with increasing age. However, on the basis of large individual variations, these small changes (DeltaQ approximately 5%, SD(Q) >/= +/- 5%) have no clinical significance and need not to be considered in the automatic detection of lung diseases by analyzing lung sounds.

Pulmonary auscultatory skills during training in internal medicine and family practice

We conducted a multicenter, cross-sectional assessment of pulmonary auscultatory skills among medical students and housestaff. Our study included 194 medical students, 18 pulmonary fellows, and 656 generalists-in-training from 17 internal medicine and 23 family practice programs in the Mid- Atlantic area of the United States. All participants listened to 10 pulmonary events recorded directly from patients, and answered by completing a multiple choice questionnaire. Proficiency scores were expressed as the percentage of respondents per year and type of training who correctly identified each event. In addition, we calculated a series of cumulative scores for sound recognition, disease identification, and basic knowledge of lung auscultation. Trainees' cumulative scores ranged from 0 to 85 for both internal medicine and family practice residents (median = 40). On average, internal medicine and family practice trainees recognized less than half of all respiratory events, with little improvement per year of training, and were not significantly better than medical students in their scores. Pulmonary fellows had the highest diagnostic and knowledge scores of all groups. These data indicate that there is very little difference in auscultatory proficiency between internal medicine and family practice trainees, and suggest the need for revisiting these time-honored skills during residency training.

Nomenclature used by health care professionals to describe breath sounds in asthma

We studied the spontaneous, uninstructed description by 40 health care professionals of breath sounds in asthmatic patients, and their use of lung sound terminology following current recommendations. Tape play-back auscultation of recorded tracheal and lung sounds was performed by ten observers in each group of residents, nurses, staff physicians and physiotherapists. They repeated the test after two weeks to three months. Individual descriptions were compared to computer-aided characterization of the breath sound recordings. We found significant differences in the preferred terms for description of adventitious lung sounds between the groups of health care professionals. There was considerable intraobserver variability, with less agreement when suggestions for a more complex characterization were followed. Our observations indicate the importance of teaching a standardized nomenclature for lung sounds to health care professionals, using only terms which are clearly informative of pulmonary disease.