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Many parents spend the first few years of their child’s life closely monitoring their breathing—listening for new or unusual sounds. These sounds may include wheezing, congestion or rough breathing that can be difficult to decode.
"It's important for parents to realize that breathing noises mean different things and these sounds sometimes point to a serious health issue," says Jonathan Walsh, M.D., an expert in pediatric care for ears, nose and throat.
Decoding Noisy Breathing
Changes in breathing sounds can be scary for parents, yet noisy breathing is remarkably common among infants and toddlers.
"Children's airways are softer and narrower than adults', so they're more prone to make loud breathing noises," Walsh says. "But not all noisy breathing is equally concerning—and some of these sounds will resolve on their own over time."
Here's how the three distinct noises break down:
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Wheezing stems from the child's lungs (the lower airway). "To tell if the sound you're hearing is a wheeze or not, you have to listen to the lungs," Walsh says. "In general, a wheeze is a higher-pitched sound that happens on the exhale, though it can occasionally happen on the inhale."
The most common causes of wheezing are asthma, and reactive airway disease, a condition that can occur in children, and is often triggered by a viral infection. "Wheezing can also happen when a child has a virus or if they choke on something that makes its way to the lungs," explains Walsh.
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Less musical sounding than a wheeze, stridor is a high-pitched, turbulent sound that can happen when a child inhales or exhales. Stridor usually indicates an obstruction or narrowing in the upper airway, outside of the chest cavity. "Stridor in infants, particularly without any associated illness, should always be checked out by a physician," Walsh says.
A number of conditions can block or narrow the upper airway and cause stridor. The most common is a viral infection called croup. Other causes include swallowing a small object that gets lodged in the airway, upper respiratory infection, inflammation, cysts or masses, vocal cord problems, scarring, and conditions such as laryngomalacia (where soft tissues partially obstruct the airway) and certain congenital heart conditions.
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While stertor is less well-known than either wheezing or stridor, it's also a lot more common. "The sound that a congested child makes is stertor," Walsh says. "It's almost like a snoring sound that indicates congestion in the mouth and nose."
Stertor can happen with a common cold. It can also indicate adenoid enlargement from allergies or flu. In rare cases, stertor may result from a structural abnormality in the back of the nasal cavity.
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Figuring out the cause of noisy breathing isn't clear-cut. Parents and primary care providers may not be able to differentiate between wheezing, stridor and stertor in an infant or young child by exam alone. Diagnosing the problem often requires a thorough evaluation of the lungs and airway.
"Most of the time, noisy breathing is not dangerous and will resolve without treatment, Walsh says. "If noisy breathing doesn't quiet down after an illness has passed, or if it goes away and comes back, the child should be evaluated by a specialist."
The specialist may perform a variety of tests to determine the source of noisy breathing. A few of the most common:
- Laryngoscopy, an in-office procedure to examine the throat and upper airway
- Bronchoscopy, a procedure that requires anesthesia but provides a clearer view of the entire airway
- Chest X-ray, to check for signs of blockage
- Swallow study, to determine whether the airway is compressed or functioning normally
Medical Treatments for Children with Noisy Breathing
Treatment for noisy breathing depends on the underlying cause. A child who is sick and wheezing, for example, may be less concerning than a child who has wheezing that stems from both lungs without any noticeable illness.
Successful treatment often hinges on having a team of professionals, including an ear, nose, and throat specialist; a pulmonologist; a gastroenterologist; and sometimes a cardiologist. Doctors may take a "wait-and-see approach," while providing children with supportive care such as a nebulizer (a device that turns liquid medicine into a mist that can be inhaled) to help them breathe easier. Other cases call for immediate surgery.
"If your child is struggling to breathe or showing signs of labored breathing, such as bluish hue on the lips, skin or body or the chest collapsing inward, call 9-1-1 or take your child to the nearest emergency room," notes Walsh.
Questions your doctor will ask that will inform your child's treatment:
- When did you first notice the condition?
- Has your child been ill recently?
- Did your child put a foreign object in his mouth?
- Does your child have trouble swallowing?
- Is your child struggling to breathe?
Wheezing is the symptomatic manifestation of any disease process that causes airway obstruction. Wheezing is commonly experienced by people who have asthma but can also be present in individuals with airway foreign bodies, congestive heart failure, airway malignancy, or any lesion that causes narrowing of the airways. This activity reviews the evaluation and management of wheezing and highlights the role of the interprofessional team in educating patients about the condition.
Objectives:
Explain how to evaluate patients that present with audible wheezing.
Summarize how to counsel a patient with wheezing.
Outline treatment considerations for patients with wheezing.
Review the importance of effective care coordination among interprofessional team members to improve outcomes for patients affected by wheezing.
Wheezing is the symptomatic manifestation of any disease process that causes airway obstruction. Rene Laennec's development of the stethoscope in 1816 has enabled a better appreciation of wheeze at the bedside, in comparison to the previously established practice of ear-to-chest auscultation. Wheeze is a musical, high-pitched, adventitious sound generated anywhere from the larynx to the distal bronchioles during either expiration or inspiration. Modern-day computerized waveform analysis has allowed us to characterize wheeze with more precision and given us its definition as a sinusoidal waveform, typically between 100 Hz and 5000 Hz with a dominant frequency of at least 400 Hz, lasting at least 80 milliseconds. Wheeze may be audible without the aid of a stereoscope when the sound is loud, but in most cases, wheezes are auscultated with a stethoscope.
The presence of wheezing does not always mean that the patient has asthma, and a proper history and physical exam are required to make the diagnosis.[1][2][3][4]
Wheezing is commonly experienced by people who have asthma; although, it can be heard in people with foreign bodies, congestive heart failure, a malignancy of the airway, or any lesion that causes narrowing of the airways. During expiration, the presence of wheezing indicates that the individual’s peak expiratory flow rate is less than fifty percent compared to normal. The quality and duration of wheezing also depend on where in the airways the obstruction is located. In asthma, the wheezing is due to narrowing of the lower airways, whereas, with malignancies, the obstruction is usually in the upper, more proximal airways. In rare cases, wheezing may be heard both during inspiration and expiration. In severe asthma, no wheeze may be heard as the airflow will be so severely reduced, and chest auscultation will be silent. Since any process that reduces airway caliber generates wheeze, below are some of the many of the conditions that can cause wheeze:
Respiratory infections (croup, laryngitis, bronchiolitis)
Obstructive airway diseases (asthma)
chronic obstructive pulmonary disease (COPD)
Anaphylaxis
Pulmonary peribronchial edema (congestive heart failure)
Vocal cord dysfunction (paradoxical vocal fold motion [PVFM], vocal cord paralysis)
Postnasal drip
Airway compression: Intrinsic or extrinsic (squamous cell carcinomas, goiter)
Hyperdynamic airway collapse (tracheobronchomalacia)
Carcinoid tumors
Foreign body inhalation
Forced exhalation by normal individuals[5][6][7]
The reported prevalence of wheezing amongst young children between 2 to 3 years of age is 26% in the United States. The global prevalence is lower in the adolescent age range, approximately 12%. Global surveys reveal a similar prevalence in adults, with European and Australian surveys reporting the highest prevalence rates, up to 17%.[8]
Wheezes are thought to be the product of fluttering vibrations of narrowed airway walls, induced by a diminished airflow velocity. The characteristics of their sound include how loud they are (i.e., the amplitude), how long they last and how intense (i.e., high pitched) they sound. A physiologic trial done in the 1980s identified the determinants of the pitch of a sound generated within collapsible tubes. It was determined that the pitch of a wheeze is a reflection of the stiffness, thickness, and longitudinal tension of the airway's wall. Subsequent clinical studies have shown that the pitch and, more so, duration of wheeze are the only two characteristics that correlate well with the severity of airway obstruction. The degree of bronchial obstruction is also proportional to the number of airways that are producing wheeze. And so, the amplitude of auscultated wheeze has no bearing on the severity of airway obstruction. At the very severe end of airway obstruction, if there is very little to no airflow, then no wheeze will be heard despite severe airway obstruction.[9][10][11][12]
History should be targeted toward the various etiologies of wheezing listed above. For example, patients who have had head and neck cancer surgery and/or radiation may develop vocal cord paralysis. Additionally, a prior history of endotracheal intubation can alert one to the possibility of tracheal or subglottic stenosis.
Physical examination of the trachea and thorax will identify wheeze. Wheeze associated with asthma is most commonly heard during expiration; however, wheeze is neither sensitive nor specific for asthma, so the wheezes can certainly extend into inspiration also. Upper airway obstruction from tonsilar hypertrophy can be evaluated with an oral examination, and palpation of the neck could identify a goiter.[13]
When wheezing is heard, some workup is required because it is an abnormal sound. The first imaging test of choice in a patient with wheezing is a chest x-ray to look for a foreign body or a lesion in the central airway. In the non-acute setting, if asthma is suspected, the next step is to obtain baseline pulmonary function tests with bronchodilator administration. Following this, it may be necessary to perform an airway challenge test with a bronchoconstrictive agent such as methacholine. If the wheezing resolves with a bronchodilation agent, a tumor or mass as the cause is a much less likely consideration. If there is no resolution after a breathing treatment, and a tumor or mass is suspected, then a CT scan of the chest and bronchoscopy may be required if possible malignancy is suspected on CT.[7]
Treatment predominantly revolves around the suspected etiology of wheezing. The ubiquitous approach to ensuring Airway, Breathing, and Circulation (ABCs) are stable is the priority. Those with signs of impending respiratory failure may require either noninvasive positive pressure ventilation or invasive mechanical ventilation following endotracheal intubation. In cases of anaphylaxis, epinephrine would be required. Nebulized, short-acting beta2 agonists such as albuterol and nebulized short-acting muscarinic antagonists are often administered while further workup is performed.[7]
Other lung sounds that can be mistaken for or that overlap with wheezes are rhonchi and stridor. Rhonchi share similar characteristics to wheezes, with the main difference being a lower dominant frequency of fewer than 200 MHz. This lower frequency is described as a snoring-like sound. Stridor is a higher-pitched and higher amplitude sound due to turbulent airflow around a region of upper airway obstruction. It is typically an inspiratory sound that is far more pronounced when auscultated over the trachea than the thorax.[14]
Possible causes of wheezing include:
Allergies
Anaphylaxis
Asthma
Bronchiectasis
Bronchiolitis
Bronchitis
Chronic obstructive pulmonary disease (COPD)
Emphysema
Epiglottitis
Foreign object
Gastroesophageal reflux disease (GERD)
Heart failure
Lung cancer
Drugs (i.e., aspirin)
Obstructive sleep apnea
Pneumonia
Respiratory syncytial virus (RSV)
Respiratory tract infection
Smoking
Vocal cord dysfunction
Wheezing is a common sign encountered in clinical practice by the nurse, primary care provider, internist, cardiologist, and pulmonologist. Evaluation and treatment can be optimized with an interprofessional team. When wheezing is heard, some workup is required because it is an abnormal sound. The first imaging test of choice in a patient with wheezing is a chest x-ray to look for a foreign body or a lesion in the central airway. In the non-acute setting, if asthma is suspected, the next step is to obtain baseline pulmonary function tests with bronchodilator administration. Following this, it may be necessary to perform an airway challenge test with a bronchoconstrictive agent such as methacholine. If the wheezing resolves with a bronchodilation agent, a tumor or mass as the cause is a much less likely consideration. If there is no resolution after a breathing treatment, and a tumor or mass is suspected, then a CT scan of the chest and bronchoscopy may be required if possible malignancy is suspected on CT.
Review Questions
1.
Gracia-Tabuenca J, Seppä VP, Jauhiainen M, Kotaniemi-Syrjänen A, Malmström K, Pelkonen A, Mäkelä M, Viik J, Malmberg LP. Tidal breathing flow volume profiles during sleep in wheezing infants measured by impedance pneumography. J Appl Physiol (1985). 2019 May 01;126(5):1409-1418. [PubMed: 30763165]
2.Peçanha MB, Freitas RB, Moreira TR, Silva LS, Oliveira LL, Cardoso SA. Prevalence of vitamin D deficiency and its relationship with factors associated with recurrent wheezing. J Bras Pneumol. 2019 Feb 11;45(1):e20170431. [PMC free article: PMC6534403] [PubMed: 30758429]
3.Arrais M, Lulua O, Quifica F, Rosado-Pinto J, Gama JMR, Taborda-Barata L. Prevalence of asthma, allergic rhinitis and eczema in 6-7-year-old schoolchildren from Luanda, Angola. Allergol Immunopathol (Madr). 2019 Nov - Dec;47(6):523-534. [PubMed: 30745247]
4.Sabil A, Glos M, Günther A, Schöbel C, Veauthier C, Fietze I, Penzel T. Comparison of Apnea Detection Using Oronasal Thermal Airflow Sensor, Nasal Pressure Transducer, Respiratory Inductance Plethysmography and Tracheal Sound Sensor. J Clin Sleep Med. 2019 Feb 15;15(2):285-292. [PMC free article: PMC6374099] [PubMed: 30736876]
5.Zamani A, Khanjani N, Bagheri Hosseinabadi M, Ranjbar Homghavandi M, Miri R. The effect of chronic exposure to flour dust on pulmonary functions. Int J Occup Saf Ergon. 2021 Jun;27(2):497-503. [PubMed: 30760129]
6.Khoo SK, Read J, Franks K, Zhang G, Bizzintino J, Coleman L, McCrae C, Öberg L, Troy NM, Prastanti F, Everard J, Oo S, Borland ML, Maciewicz RA, Le Souëf PN, Laing IA, Bosco A. Upper Airway Cell Transcriptomics Identify a Major New Immunological Phenotype with Strong Clinical Correlates in Young Children with Acute Wheezing. J Immunol. 2019 Mar 15;202(6):1845-1858. [PubMed: 30745463]
7.Khawaja A, Kotloff R. A 31-Year-Old Man With Airflow Obstruction, Intrathoracic Adenopathy, and Pulmonary Nodules. Chest. 2019 Feb;155(2):e55-e59. [PubMed: 30732704]
8.Mikeš O, Vrbová M, Klánová J, Čupr P, Švancara J, Pikhart H. Early-life exposure to household chemicals and wheezing in children. Sci Total Environ. 2019 May 01;663:418-425. [PubMed: 30716632]
9.Kwong CG, Bacharier LB. Phenotypes of wheezing and asthma in preschool children. Curr Opin Allergy Clin Immunol. 2019 Apr;19(2):148-153. [PMC free article: PMC6395501] [PubMed: 30640211]
10.Laidlaw TM. Pathogenesis of NSAID-induced reactions in aspirin-exacerbated respiratory disease. World J Otorhinolaryngol Head Neck Surg. 2018 Sep;4(3):162-168. [PMC free article: PMC6251957] [PubMed: 30506046]
11.Lee YJ, Fujisawa T, Kim CK. Biomarkers for Recurrent Wheezing and Asthma in Preschool Children. Allergy Asthma Immunol Res. 2019 Jan;11(1):16-28. [PMC free article: PMC6267183] [PubMed: 30479074]
12.Ullmann N, Mirra V, Di Marco A, Pavone M, Porcaro F, Negro V, Onofri A, Cutrera R. Asthma: Differential Diagnosis and Comorbidities. Front Pediatr. 2018;6:276. [PMC free article: PMC6178921] [PubMed: 30338252]
13.Rocha BM, Filos D, Mendes L, Serbes G, Ulukaya S, Kahya YP, Jakovljevic N, Turukalo TL, Vogiatzis IM, Perantoni E, Kaimakamis E, Natsiavas P, Oliveira A, Jácome C, Marques A, Maglaveras N, Pedro Paiva R, Chouvarda I, de Carvalho P. An open access database for the evaluation of respiratory sound classification algorithms. Physiol Meas. 2019 Mar 22;40(3):035001. [PubMed: 30708353]
14.Sánchez T, Gozal D, Smith DL, Foncea C, Betancur C, Brockmann PE. Association between air pollution and sleep disordered breathing in children. Pediatr Pulmonol. 2019 May;54(5):544-550. [PubMed: 30719878]