Stridor
Encyclopedia
Stridor is a high pitched wheezing sound resulting from turbulent air flow in the upper airway. Stridor is a physical sign which is produced by narrow or obstructed airway path. It can be inspiratory, expiratory or biphasic . Inspiratory stridor is common. It can be indicative of serious airway
obstruction from severe conditions such as epiglottitis
, a foreign body lodged in the airway, or a laryngeal tumor. Stridor is indicative of a potential medical emergency
and should always command attention. Wherever possible, attempts should be made to immediately establish the cause of the stridor (e.g., foreign body, vocal cord edema
, tracheal compression by tumor, functional laryngeal dyskinesia, etc.) That examination requires visualization of the airway by a team of medical experts equipped to control the airway.
A reduction in oxygen saturation is considered a late sign of airway obstruction, particularly in a child with healthy lungs and normal gas exchange.
or tracheostomy is immediately necessary. Some patients will need immediate tracheal intubation. If intubation can be delayed for a period, a number of other potential options can be considered, depending on the severity of the situation and other clinical details. These include:
Chest and neck x-rays, bronchoscopy
, CT-scans, and/or MRIs may reveal structural pathology.
Flexible fiberoptic bronchoscopy
can also be very helpful, especially in assessing vocal cord function or in looking for signs of compression or infection.
Airway
The pulmonary airway comprises those parts of the respiratory system through which air flows, conceptually beginning at the nose and mouth, and terminating in the alveoli...
obstruction from severe conditions such as epiglottitis
Epiglottitis
Epiglottitis is an inflammation of the epiglottis - the flap that sits at the base of the tongue, which keeps food from going into the trachea . Due to its place in the airway, swelling of this structure can interfere with breathing and constitutes a medical emergency...
, a foreign body lodged in the airway, or a laryngeal tumor. Stridor is indicative of a potential medical emergency
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
and should always command attention. Wherever possible, attempts should be made to immediately establish the cause of the stridor (e.g., foreign body, vocal cord edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
, tracheal compression by tumor, functional laryngeal dyskinesia, etc.) That examination requires visualization of the airway by a team of medical experts equipped to control the airway.
A reduction in oxygen saturation is considered a late sign of airway obstruction, particularly in a child with healthy lungs and normal gas exchange.
Treatments
The first issue of clinical concern in the setting of stridor is whether or not tracheal intubationTracheal intubation
Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...
or tracheostomy is immediately necessary. Some patients will need immediate tracheal intubation. If intubation can be delayed for a period, a number of other potential options can be considered, depending on the severity of the situation and other clinical details. These include:
- Expectant management with full monitoring, oxygen by face mask, and positioning the head of the bed for optimum conditions (e.g., 45 - 90 degrees).
- Use of nebulizedNebulizerIn medicine, a nebulizer is a device used to administer medication in the form of a mist inhaled into the lungs....
racemicRacemicIn chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...
epinephrineEpinephrineEpinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
(0.5 to 0.75 ml of 2.25% racemic epinephrine added to 2.5 to 3 ml of normal saline) in cases where airway edema may be the cause of the stridor. (Nebulized cocaineCocaineCocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
in a dose not exceeding 3 mg/kg may also be used, but not together with racemic adrenaline [because of the risk of ventricular arrhythmias].) - Use of dexamethasoneDexamethasoneDexamethasone is a potent synthetic member of the glucocorticoid class of steroid drugs. It acts as an anti-inflammatory and immunosuppressant...
(Decadron) 4–8 mg IV q 8 - 12 h in cases where airway edema may be the cause of the stridor; note that some time (in the range of hours) may be needed for dexamethasone to work fully. - Use of inhaled HelioxHelioxHeliox is a breathing gas composed of a mixture of helium and oxygen .Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of...
(70% heliumHeliumHelium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
, 30% oxygenOxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
); the effect is almost instantaneous. Helium, being a less dense gas than nitrogen, reduces turbulent flow through the airways. Always ensure an open airway.
Causes
Stridor may occur as a result of:- Foreign bodies (e.g., aspiratedPulmonary aspirationPulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...
peanutPeanutThe peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...
, aspirated food bolus). - Tumor (e.g., laryngeal papillomatosis, squamous cell carcinomaSquamous cell carcinomaSquamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...
of larynx, trachea or esophagus). - Infections (e.g., epiglottitisEpiglottitisEpiglottitis is an inflammation of the epiglottis - the flap that sits at the base of the tongue, which keeps food from going into the trachea . Due to its place in the airway, swelling of this structure can interfere with breathing and constitutes a medical emergency...
, retropharyngeal abscessRetropharyngeal abscessMost commonly seen in infants and young children, retropharyngeal abscess is an abscess located in the tissues in the back of the throat behind the posterior pharyngeal wall . Because RPA's typically occur in deep tissue, they are difficult to diagnose by physical examination alone...
, croupCroupCroup is a respiratory condition that is usually triggered by an acute viral infection of the upper airway. The infection leads to swelling inside the throat, which interferes with normal breathing and produces the classical symptoms of a "barking" cough, stridor, and hoarseness...
). - Subglottic stenosisStenosisA stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....
(e.g., following prolonged intubation or congenital). - Airway edema (e.g., following instrumentation of the airway, tracheal intubationTracheal intubationTracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...
, drug side effect, allergic reaction). - Subglottic hemangiomaHemangiomaA hemangioma of infancy is a benign self-involuting tumor of endothelial cells, the cells that line blood vessels. It usually appears during the first weeks of life and sometimes resolves by age 10. In more severe case hemangioma may have permanency, if not treated by a physician...
(rare). - Vascular rings compressing the trachea.
- Many thyroiditis such as Riedel's thyroiditisRiedel's thyroiditisRiedel's thyroiditis, also called Riedel's struma is a chronic form of thyroiditis.It is believed to be a form of autoimmune thyroiditis.-Pathophysiology:...
. - Vocal cord palsy.
- TracheomalaciaTracheomalaciaTracheomalacia is a condition characterized by flaccidity of the tracheal support cartilage which leads to tracheal collapse especially when increased airflow is demanded....
or Tracheobronchomalacia (e.g., collapsed trachea). - Congenital anomalies of the airway are present in 87% of all cases of stridor in infants and children.
- Patients with enlarged oral and laryngeal anatomy have a close correlation to parents who tested positive for cannabis during pregnancy.
- VasculitisVasculitisVasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...
.
Diagnosis
Stridor is usually diagnosed on the basis of history and physical examination, with a view to revealing the underlying problem or condition.Chest and neck x-rays, bronchoscopy
Bronchoscopy
Bronchoscopy is a technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for...
, CT-scans, and/or MRIs may reveal structural pathology.
Flexible fiberoptic bronchoscopy
Bronchoscopy
Bronchoscopy is a technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for...
can also be very helpful, especially in assessing vocal cord function or in looking for signs of compression or infection.