Upper airway obstruction

Contents

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Background
History
Location of obstruction
Signs and symptoms
Causes of airway obstruction
Fixed vs variable obstruction
Investigation
Management



Upper airway includes
 Nose
 Nasopharynx

 Oropharynx
 Larynx

(supraglottis, subglottis)

 Trachea

(extrathoracic)

Jacobson S. Upper airway obstruction. Emerg Med Clin North Am. 1989;7:205-17.



Upper airway is the segment of the conducting
airways that extends between the nose (during
nasopharyngeal breathing) or the mouth (during
oropharyngeal breathing)and the main carina,
located at the distal end of the trachea.



Physiological points of narrowing are the
nostrils, the velopharyngeal valve (at the
passage between the nasopharynx and
oropharynx), and the glottis




Common etiologies of upper airway obstruction
in adults include infection, inflammatory
disorders, trauma, and extrinsic compression
related to pathology of adjacent structures.



Definitive management depends on the
underlying etiology and may include both
medical and surgical interventions


In the mid-sixteenth century, the first successful
tracheostomy was performed to relieve upper
airway obstruction caused by a pharyngeal
abscess.
 In the early nineteenth century, the procedure
was used to treat croup, and diphtheria.
 By the turn of the twentieth century, rigid
bronchoscopy was used to remove a foreign
body from the trachea.
 Ikeda introduced the flexible bronchoscope in
1967.




Malignancy become more prevalent with
increasing tobacco use and exposure to
modern environmental toxins.



Complications of endotracheal intubation
and tracheostomy have become well
recognized causes of benign upper airway
stenosis.




Improvement in pharmacologic agents to treat
infectious, inflammatory, and malignant
etiologies, as well as developments in radiation
oncology, have had significant effects on
management of upper airway obstruction.



Development of new endoscopic and imaging
techniques and introduction of interventional
pulmonology also have proved useful in the
management of upper airway obstruction.


Upper Airway
Obstruction
Noisy
Breathing
Noise during INSPIRATION

Noise during EXPIRATION

Difficulty breathing IN

Difficulty breathing OUT

Proximal to Thoracic Inlet

Distal to Thoracic Inlet

Nose, pharynx, larynx

Trachea, bronchi, peripheral
airways

Khosh MM, Lebovics RS. Upper airway obstruction. In: Parrillo JE, Dellinger RP, eds. Critical Care Medecine. St. Louis:

.

Mosby; 2001:808-25

Upper Airway
Obstruction
Difficulty breathing IN

Awake/Crying
IMPROVES

Awake/Crying
DETERIORATES

Nose / Pharynx

Larynx


.

Mosby; 2001:808-25

Where in the Airway is the
Obstruction
Snoring
Naso
pharynx
Larynx

Stridor

Wheeze

+

+

-

+

+

Small babies

Trachea &
bronchi
Small
airways

Severe
obstructn

+

+
+




The main symptoms of upper airway obstruction
are dyspnea and noisy breathing.



They are prominent during exercise and also
may be aggravated by a change in body
position.

Breathing is labored in the recumbent position
& may have a severely disrupted sleep pattern.
Quan L. Diagnosis and treatment of croup. Am Fam Physician. 92419;6:747-55.





It also causes sleep apnea syndrome,
which may resolve completely when the
obstruction is relieved.



Daytime somnolence may be a
prominent feature of upper airway
obstruction




In severely affected patients, cor pulmonale may
occur as a result of chronic hypoxemia and
hypercarbia.



Typically, significant anatomic obstruction
precedes overt symptoms. {for example, by the
time exertional dyspnea occurs, the airway
diameter is likely to be reduced to about 8 mm.}




Dyspnea at rest develops when the airway
diameter reaches 5 mm, coinciding with the
onset of stridor.



Sound recordings from the neck and chest have
shown that the sound signals from the asthmatic
wheeze and stridor are of similar frequency.

This explains why errors in diagnosis can be
made and an upper airway obstruction due to a
tumor or foreign body may be mistakenly treated


Neck flexion may change the intensity of
stridor, suggesting a thoracic outlet
obstruction.
 When the obstructing lesion is below the
thoracic inlet, both inspiratory and expiratory
stridor may be heard.
 Hoarseness may be a sign of a laryngeal
abnormality.
 Muffling of the voice without hoarseness
Quan L. Diagnosis and treatment a croup. Am Fam Physician. 92419;6:747-55.
may represent of supra-glottic process.




Noise decreases as the severity of the
obstruction increases so the complete
absence of the sound is not the
improvement in the symptoms but the
complete blockage of tract.




Signs of hypoxemia are also present
Anxiety
 Restlessness
 Tachycardia
 Pallor
 Cyanosis (late sign)





Causes of obstruction can lies at any level of
upper airway starting from nose till trachea.



Cause includes can be of an infectious origin
(bacterial, viral or fungal) or can be non
infectious origin (tumours or foreign bodies)

Khosh MM, Lebovics RS. Upper airway obstruction.In: Parrillo JE, Dellinger RP, eds. Critical Care Medecine. St. Louis:
Mosby; 2001:808-25.



Nose


“Blocked” nose (infants < 6 months)



Choanal atresia



Foreign body



Polyps



Allergy

Mosby; 2001:808-25.



Oropharynx
 Main

reason in this section of obstruction is
adenoidal hypertrophy

 Foreign

 Nasal

bodies

polyp

 Tumors
Mosby; 2001:808-25.



Larynx (supra glottis)
 Epiglotitis

(bacterial or viral )

 Laryngomalacia

 Congenital

 Vocal

disorders like laryngeal web or cysts

cords ( paralysis or papilloma)

Mosby; 2001:808-25.



Larynx ( sub glottis)
 Main

reason is this part is laryngo-tracheobronchitis (croup)
 Etiological

 Another

agent is mainly Para influenza virus b

reason is congenital sub glottic stenosis

 <6

months
 No history of infection
Mosby; 2001:808-25.

Croup scoring system of Westley et al1
Croup score
Symptoms

0

1

2

3

5

Stidor at rest

None

Audible with
stethoscope

Audible
without
stethoscope

–

–

Retractions

None

Mild

Moderate

Severe

–

Air entry

Normal

Decreased

Severely
decreased

–

–

Cyanosis

None

With
agitation

At rest

–

–

Level of
Normal
–
–
–
Altered
consciousness
Mosby; 2001:808-25.



Trachea
 Bacterial

 Foreign

tracheitis

body ingestion

 Retropharyngeal

abscess

Mosby; 2001:808-25.

Croup scoring system of Westley et al1
Croup score
Symptoms

0

1

2

3

5

Stidor at rest

None

Audible with
stethoscope

Audible
without
stethoscope

–

–

Retractions

None

Mild

Moderate

Severe

–

Air entry

Normal

Decreased

Severely
decreased

–

–

Cyanosis

None

With
agitation

At rest

–

–

Level of
consciousness

Normal

–

–

–

Altered

Angioedema


Angioedema is characterized by welldemarcated swelling of the face, lips, tongue,
and mucous membranes of the nose , mouth,
and throat.



When the larynx is involved, upper airway
obstruction may occur and is fatal in as many as
25 % of patients.



In most instances, the cause of angioedema is
unclear; prior exposure to common allergens,
such as drugs , chemical additives, and insect
bites should be suspected.
www.wikepedia.com/angioedema



They include reactions to histamine-releasing
drugs, such as narcotics and radiocontrast
materials, to aspirin and other nonsteroidal
antiinflammatory drugs, and to angiotensinconverting enzyme inhibitors.



Hereditary angioedema, a rare cause of upper
airway obstruction, is an autosomal-dominant
trait that occurs in all races.



Hereditary angioedema is characterized by
painless nonpitting edema of the face and upper
airway



The underlying mechanism is a deficiency in
production or function of C1 esterase inhibitor, a
serum protease inhibitor that regulates the
complement, fibrinolytic, and kinin pathways.



Swelling progresses over many hours and then
resolves spontaneously over 1 to 3 days.



Death may occur from laryngeal obstruction.



Emergency management includes securing the
airway, administration of corticosteroids, and
use of antihistamines and epinephrine.

Fixed obstruction


Fixed obstructions of the upper airway are those
whose cross-sectional area does not change in
response to trans-mural pressure differences
during inspiration or expiration.



A fixed obstruction may occur in either the intrathoracic or extra-thoracic airways.

Irrespective of the site of the obstruction, a fixed
lesion results in the flattening of the flow-volume
Steinert R, Lullwitz E. Failed intubation with case reports. HNO. 1987;35:439-42
loop.





Non-distensible narrowing of the upper airway
(fixed airway obstruction) occur in benign and
malignancy strictures.



Maximal inspiratory and expiratory flow-volume
loops with fixed obstruction show constant
flow, represented by a plateau during both
inspiration and expiration.







On the expiratory curve, the plateau effect is
seen in the effort-dependent portion of the
curve near TLC; very little change is noted in
the effort-independent portion near residual
volume.
Since the inspiratory curve is similar in
appearance, the ratio of FEF50% to FIF50% is
normal (close to 1).
The FIV1 and FEV1 are nearly the same in
fixed upper airway obstruction.




The flow-volume
loop demonstrates
a plateau of flow
during inspiration
and expiration, the
FEF50%/FIF50%
ratio is near 1.


Variable extra thoracic
obstruction
A variable obstruction is one that eliciting
varying degrees of obstruction during the
respiratory cycle.
 Vocal cord paralysis is a common cause of
variable extrathoracic obstruction.
 A variable extrathoracic airway obstruction
increases the turbulence of inspiratory flow, and
intraluminal pressure falls markedly below
atmospheric pressure. This leads to partial
collapse of an already narrowed airway and a
plateau in the inspiratory flow loop.








Expiratory flow is not significantly affected, since
the markedly positive pressure in the airway
tends to decrease the obstruction.
The ratio of FEF50% to FIF50% is high (usually
> 2).
Similarly, the FEV1 is > the FIV1.




. Flow-volume loop
shows inspiratory
obstruction.FEF50%/
FIF50% is very high,
and the inspiratory
curve is flattened.


Variable intra thoracic
obstruction






A variable obstruction in the intrathoracic
airways show predominant reduction in maximal
expiratory flow is associated with a relative
preservation of maximal inspiratory flow.
This association occurs because intrapleural
pressure becomes markedly positive during
forced expiration and causes dynamic
compression of the intrathoracic airways.
The obstruction caused by an intrathoracic
lesion is accentuated and a plateau in expiratory
flow occurs on the flow-volume loop.




During inspiration, intrapleural pressure is
markedly negative; therefore, the obstruction is
decreased.



The ratio of FEF50% to FIF50% is very low and
may approach 0.3.



The FEV1 is considerably < the FIV1.




Although the flow ratios are similar to those
seen in patients with COPD and chronic
asthma, these disorders often can be
distinguished by expiratory curve in patients with
COPD and asthma is primarily altered in the
effort-independent portion of the curve, leading
to a characteristic shape unlike the plateau
configuration of an upper airway obstruction




Superimposed flow
volume loops show a
plateau of expiratory
flow preceded by a peak
of flow at higher lung
volumes. The forced
inspiratory flow is
preserved in comparison
to expiratory flow, but it
is also reduced.



FEF50%/FIF50% is 0.4




Quick history and physical examination :most important diagnostic tool in diagnosis of
airway obstruction.

In cases of severe acute upper airway
obstruction (UAO) every single minute counts
and doctors don’t have enough time for
specific investigation before commencement
of treatment.
Goldberg J, Levy PS, Morkovin V, Goldberg JB. Mortality from traumatic injuries: a



casecontrol study using data from the national hospital discharge survey. Med Care. 1983;21:
692-704.



It is useful to separate patients with potential
UAO into those with severe symptoms and
impending respiratory failure and those with a
more indolent course and less severe
symptoms.

Airway resistance varies inversely with the
fourth power of the radius at the point of UAO,
and that small changes in the underlying
Goldberg J, Levy PS, may dramatically worsen respiratory
pathology Morkovin V, Goldberg JB. Mortality from traumatic injuries: a
692-704.
airflow.





Plain neck and chest radiographs
 Plain

neck and chest films may be useful as
screening tests by identifying tracheal deviation,
extrinsic compression, or radiopaque foreign
bodies.

 Lateral

neck radiographs are considered
insensitive and may result in unnecessary delay
in securing the airway
692-704.



Spirometry :- in gradual and mild cases of
obstruction not in acute cases.



CT scan :important investigation and in stable or in
unstable pts with secured airway.
 High-resolution CT of neck and chest can help
identify intrinsic and extrinsic tumors, vascular
structures, and foreign bodies


692-704.



Bronchoscopy : Rigid

or flexible bronchoscopy with direct
visualization is the most effective tool in
establishing diagnosis and frequently provides the
best way to correct UAO.
 Rigid bronchoscopy can be used in an
emergency department to secure the airway.
 Flexible bronchoscopy can be used to establish
the diagnosis as well deliver treatment including
laser therapy, electrocautery, electrosurgery,
balloon bronchoplasty, once the airway has been
Goldberg J, Levy PS,and theGoldberg JB. Mortality from traumatic injuries: a
secured Morkovin V, patient stabilized
692-704.



Establishing a secure and patent airway is the
most important goal in the resuscitation of a
patient with acute UAO.



Quick history and clinical examination can help
in determining the site of obstruction.

In the outpatient setting the most common
cause of UAO is obstruction of the larynx with a
foreign body



692-704.



Heimlich maneuver is
recommended for relief
of the airway obstruction
in adults and children
one to eight years of age



subdiaphragmatic
abdominal thrust can
force air from the lungs;
this may be sufficient to
create an artificial cough
and expel a foreign body
from the airway.

692-704.



Most important management is medical
management which tried are
Oropharyngeal airways
 Endotracheal intubation (transnasally or orally)
 Racemic epinephrine
 Corticosteroids
 Helium–oxygen mixture


692-704.



Surgical intervention which forms the most
important part of treatment in severe
emergency
 Fiberoptic

intubation
 Cricothyroidotomy
 Tracheostomy
 Laser/electrocautery/balloon dilation
 Airway stenting
692-704.

Algorithm for UAO

Goldberg J, Levy PS, Morkovin V, Goldberg JB. Mortality from traumatic injuries: a casecontrol study
using data from the national hospital discharge survey. Med Care. 1983;21: 692-704.

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