Respiratory and FB

Question 1

Bronchial Tree

left vs right

Answer 1

Collective term that refers to the bronchi and all the subsequent branches
Begins at the bifurcation of the trachea at the carina (level of T4-T5)
Main bronchi
Left main bronchus is longer than the right
Right main bronchus is wider, shorter, and more vertical than the left
Most frequent pathway for aspirated foreign objects

Bronchi continue to branch until they form alveoli, the site of gas exchange

Trachea → carina → main bronchi → lobar bronchi → segmental bronchi → terminal bronchioles → respiratory bronchioles → alveolar duct → alveolar sac → alveoli

Question 2

Alveoli

pneumocytes

Answer 2

Type I: comprise 95% of total alveolar area and form the blood–air barrier

Type II: comprise 5% of total alveolar area and secrete surfactant

Question 3

Pleura

Answer 3

A double-layered serous membrane that lines the walls of the thoracic cavity and the surface of the lungs

Question 4

Parietal pleura

Answer 4

Lines the inner surface of the thoracic cavity
Sensitive to pressure, pain, and temperature
Separated from the thoracic wall by the endothoracic fascia

Question 5

Visceral pleura

Answer 5

Lines the outer surface of the lungs
Covers lung fissures
**Not sensitive to pain

Question 6

Eupnea

Answer 6

Normal, relaxed, quiet breathing; 12-15 breaths/minute

Question 7

Dyspnea

Answer 7

• Labored, gasping breathing; shortness of breath

Question 8

Apnea

Answer 8

Temporary cessation of breathing

Question 9

Respiratory arrest

Answer 9

Permanent cessation of breathing

Question 10

Hyperpnea

Answer 10

Increased rate and depth of breathing in response to exercise, pain, or medical conditions

Question 11

Hyperventilation

Answer 11

Increased pulmonary ventilation in excess of metabolic demand; frequently associated with anxiety

Expel CO2 quickly

Question 12

Hypoventilation

Answer 12

Reduced pulmonary ventilation; leads to an increase in blood CO2 concentration

Question 13

Tidal volume (TV)

Answer 13

Volume of air inhaled or exhaled with each breath under resting conditions

Question 14

Residual volume (RV)

Answer 14

Volume of air left in lungs after forced exhalation

Question 15

Expiratory reserve volume (ERV)

Answer 15

Volume of air that can be forcefully exhaled after normal tidal volume exhalation

Question 16

Inspiratory reserve volume (IRV)

Answer 16

Volume of air that can be forcefully inhaled after normal tidal volume inhalation

Question 17

Answer 17

Question 18

Hypercapnia

Answer 18

Increased carbon dioxide in the blood
PCO₂ > 40 mm Hg

Question 19

Foreign Body Aspiration (FBA)

Answer 19

Foreign body enters the airway with the potential to be life-threatening

Epidemiology
80% of cases occur inpatients < 15 years of age; 80% of pediatric cases < 3 years of age
Foreign bodies (FBs) aspirated vary based on age

Question 20

Foreign bodies (FBs) aspirated vary based on age

Answer 20

Food is the most common substance in infants and young children:
Nuts (35%–50%)
Seeds
Popcorn
Raw vegetables (carrots, celery)
Hot dogs
Small objects are more common in older children:
Jewelry (30%)
Coins (10%)
Toys
Button batteries
Adults:
Inorganic:
Nails or pins held in the mouth that are accidentally swallowed
Dental debris dislodged during dental procedure
Organic: miscellaneous food items

Question 21

Upper airway obstruction

Pathophysiology

Answer 21

More common in children due to anatomical narrowing of tracheobronchial tree
Large food or objects are visible in theoropharynx in most pediatric patients

Question 22

Lower airway obstruction

patho

Answer 22

Ball-valve effect – partial obstruction
Allows air in withinspiration
Prevents air exiting uponexpiration
Results inhyperinflationof 1 or more lobes

Question 23

foreign body aspiration

clin man

Answer 23

Variable: asymptomatic to sudden-onset coughing,cyanosis, respiratory distress

Initial choking spell followed by:
Symptom-free period – DO NOT misinterpreted as a sign of resolution
OR
Cough
Stridor(if lodged intrachea)
Wheezing(if lodged in bronchus)
Respiratory distress
Tachypneic
Hypoxia

Fever: late finding related topneumonia or abscess
Aspiration episode is not noticed (~50% of cases);complications due to delayed presentations include:
Tracheal laceration
Infection – pneumonia; lung abscess
Retained batteries → erosionof mucosal surfaces

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Question 24

Foreign body

Dx

Answer 24

X-rays - Lateralneckand chest radiographs
Initial tool for investigation in asymptomatic or stable, symptomatic patients
Onlyradiopaqueobjects (metal,bone) are visible
Normalx-rayDOES NOT rule out FB aspiration
Signs of FB invisible onX-ray
Mediastinal shift away from side of FB
Collapse (atelectasis) of single lobe
Hyperinflationof a segment of lung (air trapping)
Focalpneumonia
Bronchoscopy
Allows for retrieval of FB
CT scan
Used ifx-ray is negative, but patient is symptomatic

Question 25

foreign body

Tx

Answer 25

Airwayobstruction requires immediate action given the high risk forasphyxia
Life-threatening cases with complete blockage ofairway
Look inoropharynxand attempt to remove visible FB with finger sweep (blind finger sweep is not recommended)
Alternating back blows (5) and chest thrusts (5)for children < 1 year of age
Heimlich maneuver for children >1 and adults
Emergentcricothyroidotomymay be required if FB is lodged abovelarynxand patient is in respiratory arrest
Duringintubation, aspirated FB can be pushed further down intobronchito prevent completeairwayocclusion

Stable cases:
Objects that blockairwayor can lead to mucosal damage need prompt removal
Bronchoscopy(rigid preferred to flexible) is the method of choice when FB is past theoropharynx