Generally, an inspiratorystridors suggests airway obstruction above the glottis while an expiratory stridor is indicative of obstruction in the lower trachea. A biphasic stridor suggests a glottic or subglottic lesion. Laryngeal lesions often result in voice changes. A child with extrinsic airway obstruction usually hyperextends the neck. The airway should be established immediately in children with severe respiratory distress. Treatment of stridor should be directed at the underlying cause.
Several anatomical and physiological features of the respiratory system in infants (age <1 yr) and young children render them susceptible to airway obstruction. The upper and lower airways are small, prone to occlusion by secretions, and susceptible to oedema and swelling. As resistance to laminar airflow increases in inverse proportion to the fourth power of the radius (Poiseuille's law), a small decrease in the radius of the airway results in a marked increase in resistance to airflow and the work of breathing.The support components of the airway are less developed and more compliant than in the adult. The ribs are cartilaginous and perpendicular relative to the vertebral column, reducing the effect of the ‘bucket handle’ movement of the rib cage. In addition, the intercostal muscles and accessory muscles of ventilation are immature. As a result, children are more reliant on the diaphragm for inspiration. Increased respiratory effort causes subcostal and sternal recession, and the mechanical efficiency of the chest wall is reduced. Higher metabolic rate and increased oxygen demand mean children with airway compromise can deteriorate very quickly. Also, with a smaller functional residual capacity and fewer fatigue-resistant fibres in the diaphragm, there is little respiratory reserve at times of stress.1
There are many causes of stridor in children. However, certain causes are very common, and can be categorised according to the location/site of obstruction. They can also be classified as Acute or Chronic causes. Clinical manifestation, treatment and management will depend on the cause determined.
Affects the glottic (middle part of larynx that contains voice box) and subglottic regions bottom part of larynx).Most patients have an upper respiratory tract infection with some comination of rhinorrhea, pharyngitis, mild cough, and low grade fever for about 1-3 days prior to the development of upper airway obstruction. The child then develops the characteristic “barking
PREVIOUS URTI : Cough, low grade fever, coryza, rhinorrhea,pharyngitis for 1-3 days approx before developing barking cough, stridor.
****However, the steeple sign may be absent in patients with croup, may be present in patients w/out croup as a normal variant, and may rarely be present in patients with epiglottis. Hence, they don’t correlate well with disease severity.
Mild – Patient improves ---can send homeModerate - Patient doesn’t improve – Give nebulisedadrenalie ----No improvement----Intubate and ventilate.Severe - Patient doesn’t improve – Intubate and ventilate.
As with many other aspects of the pediatric airway, the epiglottis is significantly different in the child from in the adult. In the infant, the epiglottis is located more anteriorly and superiorly than in the adult, and it is at a greater angle with the trachea. It is also more omega shaped and floppy than the more rigid, U-shaped epiglottis in the adult.
Patients may present with (depending on location/degree of obstruction) :Respiratory distress, pneumonia, pulmonary edema, or wheezing. Tachypnea; nasal flaring; intercostal, subcostal, and suprasternal retractions; and differences in percussion between hemithoraces also are common findings.Fever and central cyanosis are less common. Only rarely do children with a positive history have an examination with completely normal findings.
Initial radiographic studies should include AP and lateral views of the soft tissues of the neck, PA CXRs obtained during inspiration and expiration, and lateral CXRs. The depiction of radiopaque foreign bodies is straightforward. Obtaining 2 views of the foreign body helps in determining its location and excludes the presence of superimposed multiple foreign bodies. Most foreign bodies are radiolucent; therefore, indirect radiologic findings must often be obtained.Radiolucent tracheal foreign bodies may show signs of an infraglottic opacity or of swelling from airway inflammation on PA and lateral neck radiographs.Plain radiographic results cannot exclude foreign body aspiration. If the clinical suspicion is high for foreign body aspiration, endoscopy should be performed for definitive diagnosis and treatment.Patients with bronchial foreign bodies may have normal findings on CXRs; however, the affected lung may show hyperaeration (obstructive emphysema) and shifting of the mediastinum away from the affected lung on expiratory CXRs because of the ball-valve effect of the tracheal foreign body (see the images below). In such cases, the patients can inspire air past the foreign body but have difficulty exhaling.
A schematic of the anatomy of the deep spaces of the neck, as illustrated in lateral and cross-sectional views. The fascial planes, defined by the color key, surround the potential spaces. The retropharyngeal space is bounded anteriorly by the buccal pharyngeal fascia, which invests the pharynx, trachea, esophagus, and thyroid. The retropharyngeal space is bounded posteriorly by the alar fascia and laterally by the carotid sheaths and parapharyngeal spaces. It extends from the base of the skull to the mediastinum at the level of the tracheal bifurcation. Note the danger space located between the alar fascia and the prevertebral fascia.
1) (ABCs of emergency care) in patients with retropharyngeal abscess. Allow patients to remain in a position of comfort, which is usually supine with their necks extended. Neck flexion or forcing a child to sit up can occlude the airway.
Conclusion : Summarise what is stridor and what symptoms to look for in the child….mention all the clinical features one by one and emphasize on the importance.
Stridor by Dr. Anna
Presented by : Anna
Stridor is : •Harsh vibration sound, •Different pitch (high, low) •Produced by turbulent airflow through a narrowed/obstructed airway (upper respiratory tract – nose, larynx, trachea). Stridor may occur during the following respiratory phases :Inspiratory phase = suggest airway obstruction above glottisExpiratory phase = suggest obstruction in lower tracheaBiphasic (both inspiratory & expiratory) = suggest glottic/subglotticlesion.
•An infant or child’s airway lumen is naturally narrower/smaller than adults. •Therefore, any minor reductions to this airway diameter (such as inflammation, mucosal edema,Stridor can occur at the following places: foreign object, collapsing epiglottis) can result in1. Nose & Mouth further narrowing or obstruction of the airway.2. Larynx (Epiglottis, Supraglottis, •Due to this narrowing, it causes an exponential Glottis,Subglottis) increase in airway resistance which makes it3. Trachea. significantly difficult for the child to breathe.
According to Site of Obstruction Nose and pharynx Choanal atresia Lingual thyroid or thyroglossal cyst ACUTE Macroglossia Micrognathia Hypertrophic tonsils/adenoids • Acute laryngo- Retropharyngeal or peritonsillar abscess Larynx tracheobronchitis (Croup) Laryngomalacia Laryngeal web, cyst or laryngocele Laryngotracheobronchitis (viral croup) • Acute epiglottitis Acute spasmodic laryngitis (spasmodic croup) Epiglottitis Vocal cord paralysis • Foreign body inhalation Laryngotracheal stenosis Intubation Foreign body • Retropharyngeal abscess Cystic hygroma Subglottic hemangioma Laryngeal papilloma Angioneurotic edema Laryngospasm (hypocalcemic tetany) Psychogenic stridor Trachea CHRONIC Tracheomalacia Bacterial tracheitis External compression Laryngomalacia
Viral croup accounts for over 95% of laryngotracheal infections. Occurs from 6 months – 6 years. (Peak incidence : 2nd year of life) Viruses : Parainfluenza (most common). : Respiratory Synctial Virus (RSV) : Influenza Mucosal inflammation and increased secretions affect the : : Larynx (glottic & subglottic regions), : Trachea : Bronchi. Potential danger because it causes critical narrowing in the child’s airways (trachea).
Previous upper respiratory tract infection prior to development of upper airway obstruction. Child develops “Barking” cough Hoarseness of voice Inspiratory stridor (when excited, at rest or both) Symptoms worsen at night and often recur with decreasing intensity for several days and resolve completely within a week. Agitation and crying greatly aggravate the symptoms and signs. PHYSICAL EXAMINATION : Agitated child Normal to moderately inflamed pharynx Slightly increased respiratory rate Suprasternal, infrasternal, intercostal retractions in very severe cases.
Croup is a clinical diagnosis and does not necessarily require aradiographof the neck.Radiographs of theneck can show thetypical subglotticnarrowing, orsteeple sign, ofcroup on theposteroanteriorview.
First --- Assess/Determine the severityClinical Assessment of Croup (Wagener) Severity :1) Mild - Stridor with excitement or at rest, with no respiratory distress.2) Moderate – Stridor at rest with intercostal, subcostal or sternal recession.3) Severe – Stridor at rest with marked recession, decreased air entry and altered level of consiousness. Pulse oximetry : Helpful but not essential Arterial blood gas : Not so helpful as blood parameters may remain normal to the late stage. Child may get distressed with the blood taking procedure!
Indications for hospital admission :o Moderate and severe viral croupo Toxic lookingo Age : < 6 monthso Poor oral intakeo Family lives a long distance from hospital/lacks realiable transportationo Lacks reliable caregiver at home
MILD MODERATE SEVERE (Outpatient) (Inpatient) (Inpatient) Dexamethasone Dexamethasone Nebulised Oral/Parenteral Oral/Parenteral adrenaline0.15 kg/single dose 0.3-0.6mg/kg single 0.5mg/kg 1:1000 may repeat at 12, and 24 hours. And/or Dexamethasone Prednisolone Oral/Parenteral 1-2 mg/kg/stat Nebulised 0.3-0.6mg/kg Budesonide Nebulised Or if vomitting : 2mg stat Budesonide Nebulised And 1 mg 12 hrly 2mg stat, 1 mg 12 Budesonide hrly 2mg single dose If no improvement : And only Nebulised adrenaline OXYGEN Intubate & Ventilate
Acute epiglottitis is a life-threatening emergency due to respiratory obstruction. Affects all children’s age group, but most common in 1- 6 years children. It is caused by H. influenzae type b. The introduction of universal Hib immunisation in many countries during infancy has led to a decrease of over 99% in the incidence of epiglottitis and other invasive H. influenzae type b infections. There is intense swelling of the epiglottis and surrounding tissues associated with septicaemia.
Often, an otherwise healthy child suddenlydevelops :- Sore throat- FeverWithin a few hours, patient appears :- Toxic,- Difficulty in swallowing- Labored breathing- Drooling usually present (as patient finds it painful to swallow).- Neck hyperextended to attempt to maintain airway.- Child may assume tripod position – sitting upright & leaning forward with chin up and mouth open while bracing on the arms.- Brief period of air hunger with restlessness may be followed by rapidly increasing cyanosis and coma.- Stridor – usually is a late finding and suggest that airways maybe almost completely blocked!
Laryngoscope- Performed immediately in a controlled environment (O.T. or ICU). Lateral radiographs of the upper airway (in cases where epiglottis is thought to be the cause, but not certain).- Classic radiograph will show the “Thumb” sign.- Proper positioning of the patient crucial to avoid misinterpretation. of the film. Attempts to lie the child down or examine the throat with a spatula must not be undertaken as they can precipitate total airway obstruction and death.
Once the diagnosis of epiglottis is suspected, urgent hospitalization is required (ICU or OT or Anaesthetic room with resuscitation facilities). Treatment should be started immediately with a team of senior anaesthetist, paediatrician and ENT surgeon. (compulsory for senior experienced staff to be present!) Intubate child under general anaesthesia. Urgent tracheostomy (very rare) if intubation impossible. Take blood samples for culture (Only after airway is secured!). Start patient on antibiotics immediately (e.g. cefuroximine) for 3-5 days as most patients might have concomitant bacteremia. Tracheal tube can be removed usually within 24 hours (Depending on patient’s progress). Most children recover fully within 2-3 days. MINUTES COUNT IN ACUTE EPIGLOTTIS!
Children age 1 to 3 are most like to swallow or breathe in a foreign object,such as a coin, marble, pencil eraser, buttons, beads, or other small items orfoods as they are always veryintrigued and interested in theirsurroudings.
Choking & Coughing (common) (is present in 95% of patients presenting with foreign body aspiration) Stridor is commonly present with upper airway or upper tracheal foreign bodies. - Indicates prompt intervention required! - Approximately 50% of children have inspiratory stridor or expiratory wheezing, with prolongation of the expiratory phase, and medium-to- coarse rhonchi. Patients may present with (depending on location/degree of obstruction) : 1) Larynx - Hoarseness / aphonia - Stridor 2) Trachea - Wheezing (can mimic asthma) 3) Bronchial - Cough - Unilateral wheezing - Decreased breath sounds
RADIOGRAPHY Neck - AP view of neck - Lateral view of soft tissues Chest - PA view (take both during inspiration & expiration) - Lateral view Some points to remember about radiography investigation : Obtaining 2 views of the foreign body helps to determining its location and excludes the presence of superimposed multiple foreign bodies. Most foreign bodies are radiolucent Radiolucent tracheal foreign bodies may show signs of an infraglottic opacity or of swelling from airway inflammation on PA and lateral neck radiographs.
BRONCHOSCOPY (FLEXIBLE) : If the clinical suspicion is high for foreign body aspiration, flexible bronchoscopy should be performed for definitive diagnosis and treatment.COMPUTER TOMOGRAPHY (CT SCAN) As a result of its greater contrast resolution In addition to providing plain radiographic findings, such as hyperlucency, atelectasis, and lobar consolidation, CT scans can depict the foreign body within the lumen of the tracheobronchial tree and the 3-dimensional position of the foreign body within the thorax.
1) Most cases of inhalation events are not witnessed, hence diagnosis usually depends on high index of suspicion.2) Bring child to hospital3) Immediately do a lateral neck X-ray, AP-Chest X-ray (but hard to detect at times).4) Endoscopy under general anaesthesia is usually the preferred choice of investigation as it also allows removal of the foreign body.5) Children with foreign body inhalation are usually comfortable despite some stridor and chest recession.6) Most interventions can be organised semi-urgently.7) However, immediate attention is required if the child decompensates.
Retropharyngeal abscesses are deep neck space infections thatcan pose an immediate life-threatening emergency, withpotential for airway compromise and other catastrophiccomplications
The retropharyngeal space can become infected in two ways : 1) Infection spreads from a contiguous area 2) Penetrating trauma (can directly inoculate the space) The "classic" retropharyngeal abscess observed in pediatric patients occurs when an upper respiratory tract infection (URTI) spreads to retropharyngeal lymph nodes, forming chains in the retropharyngeal space on either side of the superior constrictor muscle.
Common complaints : Sore throat Fever Neck pain Neck stiffness (torticollis) Jaw stiffness (trismus) Stridor Drooling of saliva Muffled voice Sensation of lump in the throat Breathing difficulties Sometimes an upper respiratory illness can precede symptoms by weeks.
1) Laboratory Studies (Non-specific)- WBC counts can be elevated- Culture and sensitivity test (Gram stain can help direct with empiric antibiotic treatment).2) Imaging Studies (Lateral plain X-ray)- May also demonstrate gas or a foreign body in the retropharyngeal space.- Perform the study during inspiration with the neck held in normal extension
Medical Care ABC - Determining airway stability remains a top priority. Allow patients to remain in a position of comfort, which is usually supine with their necks extended. Neck flexion or forcing a child to sit up can occlude the airway. Only experienced physician in airway management should attempt a definitive procedure. Remember that sedatives and paralytics can cause relaxation of airway muscles with subsequent complete occlusion! Start empiric antibiotic therapy without delay (After obtaining blood culture results) Broad- spectrum coverage is indicated. Clindamycin is first-line treatment. Because of the increasing frequency of resistant bacteria, treatment may be initiated alone or in combination with cefoxitin or a beta-lactamase–resistant penicillin, such as ticarcillin/clavulanate, piperacillin/tazobactam, or ampicillin/sulbactam. Patients with cellulitis can be treated with parenteral antibiotics alone. Closely observe these patients for development of an abscess. Some authors advocate the use of antibiotics alone for small abscesses. These patients need to be closely monitored for improvement.
SURGICAL INTERVENTION Needle aspiration of an abscess can be performed both to assist in diagnosis and to treat an abscess. This should only be performed by a qualified surgeon in the operating suite. Definitive airway management should be immediately available. A small retropharyngeal abscess can be aspirated with an 18-gauge needle by the intraoral route. Larger abscesses require incision and drainage using either an intraoral or transcervical approach or both, depending on the location of the carotid sheath in relationship to the abscess. Completely evacuate pus from the abscess. Obtain a specimen for Gram stain, culture, and sensitivity. Abscesses in the parapharyngeal space isolated lateral to the carotid sheath can be aspirated by an external approach. CT scanning or ultrasonography may be used to help guide the aspiration.
- Diphtheria is an infectious disease caused by the bacteriumCorynebacterium diphtheriae.- This disease primarily affects the mucous membranes of the respiratory tract (respiratory diphtheria), although it may also affect the skin (cutaneous diphtheria) and lining tissues in the ear, eye, and the genital areas.
The symptoms usually begin after a two- to five-day incubation period. Symptoms of respiratory diphtheria may include the following: sore throat, fever, malaise, hoarseness, difficulty swallowing, stridor difficulty breathing. With the progression of respiratory diphtheria, the infected individual may also develop an adherent gray membrane (pseudomembrane) forming over the lining tissues of the tonsils and/or nasopharynx. Individuals with severe disease may also develop neck swelling and enlarged neck lymph nodes, leading to a "bull-neck" appearance. Extension of the pseudomembrane (which consists of fibrin, bacteria, and inflammatory cells, no lipid) into the larynx and trachea can lead to obstruction of the airway with subsequent suffocation and death. (stridor and respiratory difficulty). The dissemination of diphtheria toxin can also lead to systemic disease, causing complications such as inflammation of the heart (myocarditis) and neurologic problems such as paralysis of the soft palate, vision problems, and muscle weakness.
LABARATORY TEST Confirmed by isolation of the bacterium Corynebacterium diphtheriae. Diagnostic tests to isolate the bacterium involve obtaining cultures from the nose and throat in any individual suspected of having diphtheria, as well as their close contacts. It is also important to determine whether or not the isolate is capable of producing diphtheria toxin, and this can be accomplished by testing in specialized laboratories.ECG To see if there are any signs of myocarditis development.
Diphtheria antitoxin - is the mainstay of therapy. It neutralizes circulating diphtheria toxin and reduces the progression of the disease. The effectiveness of diphtheria antitoxin is greatest if it is administered early in the course of the disease. Antibiotics - administered as soon as possible to patients with suspected diphtheria. Antibiotics help eradicate the bacteria, thereby stopping toxin production, and they also help to prevent transmission of diphtheria to close contacts. Penicillin and erythromycin are the recommended antibiotics. Asymptomatic carriers, as well as all close contacts potentially exposed to diphtheria, also require antibiotic treatment. Supportive measures - inserting a breathing tube (intubation), may be necessary if the patient cannot breathe on their own or if there is the potential for airway obstruction. Potential cardiac and neurologic complications also need to be closely followed and addressed in consultation with the proper specialist.
•Most common congenital laryngeal anomaly in children.•Most common cause of stridor (approximately 60% of cases)•Stridor characteristics : - Inspiratory- Low pitched-Exacerbated by any exertion, crying, feeding.-Stridor happens due to the collapse of supraglottic structures inwardsduring inspiration.•Symptoms usually appear within the first 2 weeks of life•They increase in severity up to 6 months (although gradual improvementcan begin at any time).•Laryngopharyngeal reflux is common.
FLEXIBLE LARYNGOSCOPE CHEST X-RAYS (when the breathing is moderate to severe) BARIUM CONTRAST X-RAY (dysphagia present) COMPLETE BRONCHOSCOPY (patients with moderate to severe obstruction – because 15- 60% of infants with laryngomalacia have synchronous airway anomalies).
EXPECTANT OBSERVATION (as most symptoms resolve spontaneously as the child and airway grows). SURGICAL INTERVENTION – Endoscopic Supraglottoplasty for patients with severe obstruction (Especially when there are other life-threatening events associated together e.g. cor pulmonale, cyanosis, failure to thrive).
ACUTE STRIDOR CROUP ACUTE EPIGLOTTITIS INHALED FOREIGN BODY RETRO-PHARYNGEAL DIPHTERIALaryngotracheobronchitis ABCESS•The most common cause •Acute onset •Common especially in • Common (under age 6 Insidious onsetof acute stridor •Is intensely painful children aged 1 to 2 years. years). Exudate spreads(Inspiratory) in children. Prevents the child from •Preceded by choking or • Present with high within 2-3 days and•Usually age 6 months to speaking or swallowing; coughing. fever and difficulty may form adherent2 years. •Saliva drools down the •Stridor (inspiratory) swallowing. membrane•Barking, chin happens depending on • Retropharyngeal•seal-like cough, low fever •Soft inspiratory stridor location of foreign object abscesses present Serious cause ofand worse at night. •High fever in an ill, toxic- and usually indicates with pain on stridor, but rare. looking child almost fully blocked swallowing and Stridor can occur. •Respiratory difficulty over airways. hyperextension of the hours neck. •Child sits immobile, • Peritonsillar upright, with an open abscess presents mouth to optimise the with trismus, difficulty airway. with swallowing and difficulty with speaking. • Stridor of low pitch can occur.
References :Paediatric Protocols for Malaysian Hospitals – 2nd EditionIllustrated Textbook of Paediatrics, - 3rd EditionNelson’s Textbook of Pediatrics – 19th Edition.