Acute inflammatory Upper Airways Dr. Omar Y. Ali
StridorIt is a harsh, high-pitched respiratory sound, which is usually inspiratory but it can be biphasic and is produced by turbulent airflow through partially obstructed airways at level of supraglottis, glottis,subglottis,or trachea. it is not a diagnosis but a sign of upper airway obstruction .
acute stridor often accompanies upper respiratory tract infection. chronic stridor usually occurs with congenital conditions.
Causes of acute stridor
Laryngotracheobronchitis ( croup) . Epiglottitis . Bacterial tracheitis . Foreig body Angioedema . Hypocalcemic tetany . Edema after endotracheal intubation .Causes of chronic stridor
Laryngomalacia Tracheomalacia Laryngeal stenosis Extrinsic compresion (vascular ring) Subglottic hemangiomalaryngomalacia
It is the most common cause of stridor in infants. It may be due to decrease muscular tone of the larynx and surrounding structures or to immature cartilaginous structures.Laryngomalacia normally started during first 2 weeks of life and resolves between 6 and 12 months of age. occasionally it can persist up to 24 months of age, and even longer in children with underlying conditions, especially those with neurological diseases (such as cerebral palsy).
Clinical manifestations
The primary sign of laryngomalacia is inspiratory stridor. The stridor is typically loudest when the infant is feeding or crying and decreases when the infant is relaxed or placed prone, or when the neck is flexed.Laryngomalacia is exacerbated with viral upper respiratory tract infections and gastroesophageal reflux.
diagnosis
Usualy clinical by history and examination. in severe or atypical cases, the patient should undergo flexible nasopharyngoscopy to assess the patency and dynamic movement (collapse) of the larynx and surrounding structures, and to exclude vocal cord abnormalities.Treatment
Oberve the infant during respiratory infections for any evidence of respiratory compromize. severe laryngomalacia resulting in hypoventilation, hypoxia, may benefit from a surgical procedure (supraglottoplasty) or, in extreme cases, a tracheostomy to bypass the upper airway.Viral croup ( ALTB )
Viral croup is the most common infectious cause of acute stridor in children . Most patients with croup are between ages of 3 mths and 5 yrs , with the peak around 1-2 yrs .Common pathogens include parainfluenza viruses ( 1,2 & 3 ) account for 75% of cases; others include influenza ( A&B ) , RSV & measles Virus. Mycoplasma pneumoniae has rarely been isolated from children with croup .
The term laryngotracheobronchitis refers to viral infection of the glottic and subglottic regions . Inflammation & partial obstruction of the upper airways result in a bark like or brassy cough& inspiratory stridor & may be associated with hoarseness & Resp. distress.
Unlike relatively rare conditions as epiglottitis & bacterial tracheitis , croup has : a more insidious onset over a few days . systemic toxicity & fever are considerably less . As in many respiratory conditions , symptoms are often worse at night . Small children are at higher risk because of the relative small size of their upper airways. . .
Symptomes of croup usualy preceded by coryzal manifestation and there may be family history of flu illness
Assessment & evaluation
Mild: well , active child . barking cough . stridor with agitation. minimal resp. distress .MODERATE : stridor at rest . some signs of increased Resp. distress . SEVERE : stridor at rest + expiratory component . marked Resp. distress. increased RR & HR agitation & pallor . as obstruction became very serious stridor became quieter . agitation turn to exhaustion .
Acute spasmodic croup
recurrent short lived episodes of croup without preceding coryzal prodrome that is seen in classical viral croup. children are afebrile & awake suddenly with acute stridor, barky cough, and respiratory distress during night . recurrence occurs on subsequent 2-3 nights . children with recurrent spasmodic croup often have a strong atopic or asthmatic family background .Radiographs
Croup is a clinical diagnosis and does not require a radiograph of the neck . It may show the typical subglottic narrowing or ( steeple sign ) on AP view , which may be present as a normal variation & may be absent in patient with croup . Should be considered in patient with atypical presentation . May be helpful to distinguish severe LTB & epiglottitis , but airway management should always take priority .complications:
Treatment
Majority of cases will have a mild illness that can be managed at home . Those with significant RD and stridor at rest will require treatment & reassessment . Those showed significant improvement following treatment may be considered for discharge home .Parents of children not requiring admission should receive clear instructions when to return : chest wall recession . tachypnoea . color changes . inability to feed . decreased level of consciousness .
Therapies may be effective
Simple measures : in all cases it is very important to keep the child calm . direct inspection of the throat can be dangerous and result in complete obstruction of the airway.Adrenaline ( epinephrine ) : nebulized adrenaline is very effective in severe croup . It work by decrease the laryngeal mucosal edema. A dose of 0.25-0.5 mL of 2.25% racemic epinephrine in 3 mL of normal saline can be used as often as every 20 min.
Racemic epinephrine was initially chosen over the more active and more readily available L -epinephrine to minimize anticipated cardiovascular side effects such as tachycardia and hypertension. Current evidence does not favor racemic epinephrine over L-epinephrine (5 mL of 1 : 1,000 solution) in terms of efficacy or safety.
The indications for the administration of nebulized epinephrine include: moderate to severe stridor at rest the possible need for intubation respiratory distress and hypoxia
Steroids : improve clinical parametrs . Decrease the admission rate . decrease duration of hospital stay . Decrease the need for repeated nebulized adrenaline in children with croup .
oral dexamethasone used a single dose of 0.6 mg/kg. Intramuscular dexamethasone and nebulized budesonide have an equivalent clinical effect. oral dosing of dexamethasone is as effective as intramuscular administration.
Antibiotics are not indicated in croup.
Nonprescription cough and cold medications should not be used in children younger than 4 yr of age.
Epiglottitis
potentially lethal condition characterized by an acute , fulminating course of high fever , sore throat , dyspnea & rapidly progressing respiratory obstruction . otherwise healthy child develops sore throat and fever within a matter of 4-6 hrs .Child appear toxic ,swallowing is difficult and saliva drooling . sitting upright and assume tripod position.Stridor is a late and suggest near complete airway obstruction. If no treatment provided complete obstruction of airway and death may occur .
barking cough typical of croup is rare .
Etiology:In the past, Haemophilus influenzae type b was the most commonly identified etiology of acute epiglottitis. Streptococcus pyogenes, Streptococcus pneumoniae, nontypeable H. influenzae, and Staphylococcus aureus, represent a larger portion of pediatric cases of epiglottitis in vaccinated children.
Diagnosis
laryngoscopy : Showed large( cherry red) , swollen epiglottis . It should be performed in a controlled environment as operating theatre or ICU . Lateral radiograph of upper airway : Showed the classical ( thumb sign ) .Red arrow points ( normal & swollen epiglottis) known as thumb sign or thumb print .
Initial management of suspected epiglottitisDo not : Examine the throat . Put the child flat . Order a lateral XR of the neck . Upset the child by trying to gain iv access or place an O2 mask .
Do : Call airway team . Stay with the child and parents . Allow the child to sit on knee of his mother . Measure O2 sat if possible . Give O2 therapy if absolutely needed and well tolerated .
Treatment
Immediate treatment with artificial airway placed in OT or ICU . All cases should receive oxygen unless the mask causes excessive agitation . Racemic epinephrine & corticosteroids are ineffective . Blood & epiglottic surface C&S and in selected cases after stabilization of airway.Chemoprophylaxis
Foreign body aspirationChildren are more prone to aspirate foreign material for several reasons: The lack of molar teeth in children decreases their ability to sufficiently chew food. The propensity of children to talk, laugh, and run while chewing. Child tend to put any objects in their mouth.
Most foreign body aspirations occur in children younger than 4 years. peak between the first and second years. even immobile infants may aspirate foreign bodies
Common aspirated FB:
Foods: peanuts/nuts (account for more than half of FBAs), popcorn, sunflower seeds,fish bones, gum, raw fruits. Nonfood items: crayons, toy parts, pins, pen tops, nails/screw, teeth,coins, ballons.In 58% of cases, FB lodge in Rt Main Bronchus.male ˃ female
Clinical presentation
1. Initial event: Violent paroxysms of coughing, choking, gagging, occur immediately when the foreign body is aspirated. 2. Asymptomatic interval: The foreign body becomes lodged,reflexes fatigue, and the immediate irritating symptoms subside. 3. Complications: fever,cough, hemoptysis, pneumonia, and atelectasis
when acute aspiration causes total or near-total occlusion of the airway, death or hypoxic brain damage will occur.
On examination
Major findings include abnormal airway sounds, such as wheezing, stridor, or assymetric breath sounds.Differential diagnosis
Asthma Bronchitis PneumoniaImaging
Chest CT scan may reveal the material in the airway,or focal overinflation not detected using plain radiography. Even if no foreign body is evident on any of the radiographic studies, a foreign body may still be present, and a bronchoscopy should be performed if the suspicion is high.Managing the chocking child
Does the child have an effective cough? (ie crying, talking, can take a breath between coughs, not cyanosed ) If yes, they should be closely observed and encouraged to cough. Physiotherpy or back blows should be avoided because carry the risk of dislodging the FB and worsening the obstruction.If the cough not effective, the next question is: 2. Is the child conscious? If the child is conscious, the rescuer may intervene with 5 back blows followed by 5 chest thrusts. abdominal thrusts may be used in older children.
If the child is not conscious, the child should have airway, breathing and circulation assessed and managed as per the basic life support guidelines, with assisted ventilation and chest compressions.