Acute Stridor By Yehia Abo Arida Ward 7

Stridor  It is a harsh, high-pitched respiratory sound, which isusually inspiratory but it can be biphasic and is produced by turbulent airflow; it is not a diagnosis but a sign of upper airway obstruction.

Causes of acute stridor  Laryngotracheobronchitis ( croup).  Epiglottitis.  Bacterial tracheitis.  Foreig body  Angioedema.  Hypocalcemic tetany.  Edema after endotracheal intubation.

Assessment of severity of stridor  Timing : –The prominent phase of respiratory noise should be inspiratory – Expiratory stridor more severe, or intrathoracic obstruction.  Work of breathing : –Increased RR. –Sternal ( supra – sub ) recession. –Sternal ( supra – sub ) recession.  How effective is the breathing : –Chest expansion. –Breath sounds for air entery.  Is there adequate oxygenation : –Is HR increased. –Pallor, cyanosis. –O2 saturation. –Activity level.   

Worrying signs in children with stridor  High fever or signs of toxicity  Rapid onset.  Drooling & dysphagia.  Muffled voice & quiet stridor.  Angioedema.  Age less than 4 mths.  Skin cavernous hemangioma.  Previous ventilation as a neonate.

Croup Is derived from an old scottish word, roup, which means to cry out in a hoarse voice. Is derived from an old scottish word, roup, which means to cry out in a hoarse voice.

Viral croup ( ALTB )  Viral croup is the most common 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 V.  Mycoplasma pneumoniae has rarely been isolated from children with croup. 

 The term laryngotracheobronchitis refers to viral infection of the glottic and subglottic regions. Some clinicians use the term laryngotracheitis for the most common & most typical form of croup and reserve the term LTB for more severe form.  Inflammation & partial obstruction of the upper airways result in a barkelike or brassy cough& inspiratory stridor & may be associated with hoarseness & RD.  Small children are at higher risk because of the relative small size of their upper airways...

 Unlike relatively rare conditions as epiglottitis & bacterial tracheitis, croup has : – a more insidious onset over a few days. –systemic toxicity & fever are considerably less. –have typical barking cough, often associated with hoarse voice, stridor & low grade fever.  As in many respiratory conditions, symptoms are often worse at night.

Assessment & evaluation  Mild: –well, active child. –barking cough. –stridor with agitation –minimal sings of increased WOB.

 MODERATE : –stridor at rest. –some signs of increased WOB.  SEVERE : –stridor at rest + expiratory component. –marked increased WOB. –increased RR & HR –agitation & pallor. –as AW obstruction became very serious stridor became quieter. –agitation turn to exhaustion.

Acute spasmodic croup  Some children develop 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 during night.  recurrence occurs on subsequent 2-3 nights.  it occurs in children of the same age group, during same season & sometimes same virus can isolated.  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 or in epiglottitis & 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.

 Steeple sign (croup \ normal \ epiglottitis ) due to subglottic narrowing.

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.

 There should be a low threshold for admission in : –children under age of 12 mths. –all children with marked RD. –those with oxygen requirement on presentation. –those with parents remain anxious about discharge.

 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 and parents calm. –direct inspection of the throat can be dangerous and result in complete obstruction of the airway. –neck x ray is no longer useful and carry the risk of further upset and deterioration.

 Humidification : –steam inhalation for croup is widely used but of little proven benefits. –the percieved benefits ( placebo effect ) may be due to presence in a warm calming environment. – a steamy bathroom with hot water tap running and plug opened is accepted, but use of kettle and boilers should discouraged, because it carry the risk of scalding.

 Adrenaline ( epinephrine ) : –nebulized adrenaline is very effective in severe croup. –duration of action between 20 minutes and 3 hours. –it is used in most cases when intubation is considered. –weaning effect of adrenaline result in return to pretreatment baseline rather than a true rebound. –for children with severe croup, the period of improvement on adrenaline is long enough to allow the steroid to start working.

 Steroids : –Corticosteroids improve clinical parametrs. –Decrease the admission rate. – decrease duration of hospital stay. –Decrease the need for repeated nebulized adrenaline in children with croup. – nebulized budesonide or oral dexamethazone showed equal effect in treating children with croup. – approximately 1-5 % of croup cases require ETT before introduction of steroid therapy.

 Intubation : – a small numbers of children will still require ET for severe croup. –The decision to intubate should be based on worsening airway obstruction, signs of exhaustion or impending respiratory failure. –Children with epiglottitis and bacterial tracheitis require specialist care, with input from senior ENT & anethetic stuff. –IV antibiotics & intubation are often required. – steroid & adrenaline have minimal effect on these condition.

Mild croup  Reassurance.  May worse by night ( advice to return ).  Dexamethazone PO ( mg\kg \ dose).

Moderate croup  Cardio respiratory monitor  Dexamethazone PO&\or nebulized budesonide (pulmicort) 2 mg stat.  Reassess in 2 hours –If improved discharge. –If no improvement :  Consider nebulized adrenaline 1: 1000 –2.5 ml for those younger than 1 year. – ml for older than 1 year. –If improved -----observe for 4 hrs & discharge.

Severe croup  Cardio respiratory monitor.  Oxygen to maintain O2 sat ( 92% or more ).  Nebulized adrenaline ( 1\1000) Q 1-4 hrs.  IV dexamethazone ( mg\kg\dose ). Or  Nebulized budesonide ( pulmicort ) 2mg.  IF no improvement consider BGA, ICU.  Intubation & ventillation may be required.

Bacterial traheitis  Bacterial infection of upper airway, does not involve the epiglottis but, like epiglottitis and croup, is capable of causing life-threatening airway obstruction.  Staph aureus is the most commonly isolated organism.  Most patients were below 3 yrs, but in recent case series the mean age has been between 5-7 yrs.  I t may be considered as bacterial complication of disease, rather than a primary bacterial illness.

Clinical manifestations  Typically child has a brassy cough, apparently as a part of LTB.  High fever and toxicity with RD immediately or after few days of apparent improvement.  Patient can lie flat, does not drool, and does not have dysphagia associated with epiglottitis.  the usual treatment for croup is ineffective, intubation or tracheostomy may be necessary.  The major pathologic feature is mucosal swelling at level of ciricoid cartilage, complicated by copious thick purulent secretions sometimes causing pseudomembrane.

Diagnosis  Diagnosis is based on evidence of bacterial upper airway disease (high fever – purulent airway secretions & absent classic finding of epiglottitis ).  XR not needed, but may show classic findings (pseudomembrane detachment in the trachea ).  Purulent material is noted below the cords during ET intubation.

 Black arrow points tracheal pseudomemerane (bacterial tracheitis \ diphtheria )

Treatment  Antimicrobial therapy, which usually includes antistaph agents, should be instituted in any patient whose course suggest bacterial traheitis.  When diagnosed by direct laryngoscopy, or suspected on clinical background, an artificial airway should be strongly considered.  Supplemental oxygen may be necessary.

Complications  CXR showed : –Patchy infiltrates & show focal densities. –Subglottic narrowing.  Cardio respiratory arrest can occur if airway management is not optimal.  Toxic shock syndrome has been associated with staph tracheitis.

Prognosis  oxygen therapy continued. For most of patients is excellent.  Patient become afebrile within 2-3 days of institution of antimicrobial therapy, but prolonged hospitalization may be necessary.  After extubation the patient should be observed carefully while antibiotics and O2 continued.

Epiglottitis  Dramatic potentially lethal condition characterized by an acute, potentially fulminating course of high fever, sore throat, dyspnea & rapidly progressing respiratory obstruction.  Degree of RD at presentation is variable.  Often the otherwise healthy child develops sore throat and fever within a matter of 4-6 hrs.Child appear toxic,swallowing is difficult and saliva drooling.  He sitting upright and assume tripod position( leaning forward,chin up, bracing on the arm ).  A brief period of air hunger with restlessness may be followed by cyanosis and coma.  Stridor is a late and suggest near complete airway obstruction.  If no treatment provided complete obstruction of airway and death.  barking cough typical of croup is rare.

Diagnosis  laryngoscopy : –Showed large( cherry red), swollen epiglottis – Other supraglottic structures especially aryepiglottic fold, occasionally more involved. –It should be performed in a controlled environment as OR 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.

Intial management of suspected epiglottitis  Do 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 CSF should be collected after stabilization of airway.  Cefotriaxone, cefotaxime, or combination of ampicillin and salbactum should be given parenterally, pending C&S reports.  Antibiotics should be continued for 7-10 days.

Chemoprophylaxis  Not routine for household, child-care or nursery contacts of patient with invasive HIb infection, but observation & medical evaluation is mandatory when exposed child develop febrile illness.  Indication for rifampin prophylaxis : –Any contact less than 1y & incompletely immunized. –Any contacts less than 2 yrs of age who has not received the primary vaccination series. –An immunocompromised child in the household. –Dose : (20 mg \kg \d ) once, for 4 days, maximum dose is 600 mg \ day.

Prognosis  Length of hospitalization and mortality rate increase as infection spread to involve a greater portion of respiratory tract, except in epiglottitis in which local infection may prove to be fatal.  Causes of death in croup are : –Laryngeal obstruction. –Complications of tracheostomy. – rarely, fatal out-of-hospital arrest due to viral LTB have been reported.  Untreated epiglottitis has mortality rate of 6% but if treatment initiated the prognosis is excellent.  The outcome of LTB,and spasmodic croup is also excellent.