System Based ApproachRespiratory Noises: How Useful are They Clinically?
Section snippets
Wheeze
Wheeze is a high-pitched, continuous musical noise, often associated with prolonged expiration. While predominantly heard in the expiratory phase, wheeze can occur throughout the respiratory cycle. Basic respiratory physiology tells us that wheeze emanates from the intrathoracic airways, and can be produced by pathology either in the large, central airways, or the small, peripheral airways. The intensity of the wheeze is a poor indicator of the severity of the obstruction. Indeed, if the
Prevalence of noisy breathing
Although wheeze is well studied, there are few observational studies of infants addressing the question of “how common are all forms of noisy breathing?” To answer this question Thornton and colleagues13 studied a birth cohort of almost 300 randomly chosen, normal-term infants in Cambridge, England. This cohort was followed longitudinally from birth to 6 months. Mothers were interviewed at home about any concerns they had regarding their infant's health. In addition, mothers were questioned in
What do parents understand by wheeze?
This question was addressed in a hospital-based observational study of older children.21 A total of 139 children (aged 4 months to 15 years, median 2.5 years) were assessed in the emergency department (ED) to measure the agreement between clinician and parent report on the noise. There was a less than 50% agreement between a clinician's finding wheeze and parents' report of wheeze. That is, in children presenting to ED with wheeze (or asthma), where the doctor finds wheeze, 39% of the parents
Validation of respiratory questionnaire to measure wheeze
A study from Brazil attempted to validate a questionnaire on wheeze in infancy.22 In this study of young children presenting to the ED with an acute respiratory illness, parents answered a questionnaire on wheezing (adapted from the International Study of Wheezing in Infants).22 A total of 209 infants aged 12 to 15 months were assessed. Fifty-six of these were reported to be currently wheezing and this was confirmed in 43. A further 153 parents reported “no current wheeze” and this absence of
Comparing the severity of parent-reported wheeze with clinician-confirmed wheeze
One observational study measured the lung function of children with “confirmed” (by clinicians) with “unconfirmed” (parent-reported) wheeze.23 This study was part of a large UK birth cohort (n = 1000) and describes a subgroup of 454 children followed to the age of 3 years. A total of 186 (41%) of these children had “parent-reported wheeze,” and in 130 (29%) the wheeze was “confirmed” by a clinician. Specific airway resistance (sRaw) was measured at the age of 3 by plethysmography. The major
Utility of videos as a “gold standard”
An observational study from the United Kingdom investigated the terminology used by parents to describe noisy breathing in infants younger than 18 months of age.7 The parents of approximately 100 infants with noisy breathing were interviewed. These infants were from three separate populations: hospital inpatients (n = 44), hospital outpatients (n = 19), and a community sample (n = 29). Almost half the parents used the term “wheeze” (or whistle/musical sound) to describe noisy breathing
Natural history/prognosis of noisy breathing
An important question is whether early respiratory noises predict subsequent wheeze. The study by Turner and colleagues28 described the natural history of the full range of these early respiratory noises. This observational study was part of a large Scottish birth cohort of approximately 2000 infants. A respiratory questionnaire (modified ISAAC questionnaire) was administered at the age of 2 and 5 years. The key findings were the following: children with a “whistle” at age 2 were more likely to
Do parents and children agree on symptoms of wheeze?
In an attempt to validate parent-reported exercise wheeze in older children (age 6 to 18 years), 97 children were assessed in summer camps in California.31 Both criterion validity and construct validity were assessed by comparing reported symptoms on exercise with measured lung function following an exercise provocation test. Parents completed a telephone survey of their child's symptoms with exercise. As expected, parents generally report fewer exercise-related symptoms of wheeze than their
Acoustic analysis
Adult studies have highlighted problems with both accuracy (validity) and reliability (or repeatability) of respiratory signs using a stethoscope.32, 33, 34 Given the increased difficulty of examining young, uncooperative children, the assumption is that errors will be substantially greater in pediatric practice. In an attempt to improve the utility of respiratory noises, computerized acoustic analysis has been evaluated. Most studies have been in adults and the published data in children are
Utility of tracheal sound recordings
Several groups have used tracheal sound recordings in children, particularly to explore this method as a more sensitive indicator of wheeze in bronchial provocation testing of very young children. Godfrey and colleagues36, 37 used nebulized AMP challenge in 80 preschool children and found detection of wheeze acoustically to be a more sensitive way of detecting airway obstruction than the stethoscope (PC wheeze), thus enabling the challenge to be ceased earlier (and safer). Pediatric studies
Use of video questionnaires to identify stridor
Video questionnaire has been used to identify upper airway abnormalities.42 A group of 43 preschoolers (range 3 to 58 months, median 17 months) with noisy breathing were studied via fiberoptic bronchoscopy. Thirty (70%) had wheeze as their main symptom, 19 were clinician confirmed, whereas the other 11 had only parent-reported wheeze. Parents were shown previously validated video clips of wheeze, stridor, and other airway noises. Ten of the 30 parents who initially reported wheeze identified
Summary
A number of conclusions can be drawn from the research evidence on noisy breathing (Box 1). It is clear that there are major problems with both the accurate (valid) and reliable (reproducible) identification of “respiratory noises.” This is particularly so when the noise is “parent reported,” and not confirmed by a clinician.
Clearly, clinicians must exercise great care when diagnosing specific types of noisy breathing to ensure it is not incorrectly labeled. An error in recognition will result
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Cited by (29)
Diagnostic clues for the identification of pediatric foreign body aspirations and consideration of novel imaging techniques
2023, American Journal of Otolaryngology - Head and Neck Medicine and SurgeryImpact of indoor air pollution in nursery and primary schools on childhood asthma
2020, Science of the Total EnvironmentCitation Excerpt :This study did not collect information on the history of other respiratory illnesses such as bronchitis or pneumonia which might also be linked to reduced FEV1, neither on viral respiratory infections which might be linked to wheezing instead of asthma. Although used as an outcome, parent-reported wheezing was not confirmed by a clinician in this study, thus it might have included some error as parents might describe any noisy breathing as “wheezing” (Mellis, 2009). This study did not also consider complete information about individual's atopy, as information about eczema, itchy rash or even parents' history of atopic disease were not collected.
Wheeze as an adverse event in pediatric vaccine and drug randomized controlled trials: A systematic review
2015, VaccineCitation Excerpt :Modern computer assisted techniques may also help assess wheeze and provide objectivity currently lacking in existing methods [27,28]. Conversely, an objective approach to wheeze assessment may require a simple algorithmic approach to lung sounds in children regardless of terminology [29,30]. Our results suggest that where resources permit, a three-stage assessment of wheeze that includes detection of acute respiratory illness by caregivers, confirmation of wheeze upon clinical examination by healthcare workers, and wheeze validation using specific tools or additional confirmation by another health worker optimizes sensitivity and specificity of wheezing illness as an adverse event in pediatric trials.
Clinical signs suggestive of pharyngeal dysphagia in preschool children with cerebral palsy
2015, Research in Developmental DisabilitiesCitation Excerpt :Conversely, parents reported a surprisingly high prevalence of signs such as wheezing, stridor, respiratory rate and effort, vomiting and snuffly nose, which were almost non-existent in the direct-assessments. This may be related again to the duration and method of direct-assessment (video rating in a single mealtime), but may also reflect lack of clarity for parents surrounding some terms (Mellis, 2009). A cough was more commonly noted by clinicians than parents.
Prevalence and clinical characteristics of wheezing in children in the first year of life, living in Cuiabá, Mato Grosso, Brazil
2014, Revista Paulista de PediatriaThe Management of Pre-School Wheeze
2011, Paediatric Respiratory ReviewsCitation Excerpt :Risk factors and outcomes for different respiratory sounds are also different when children are followed up to school age.19 In view of these difficulties clinicians should undertake a detailed clinical assessment of each child, which does not place undue weight on any one symptom.20 The prevalence of wheezing illness in pre-school children in the UK seems to be increasing.