Respiratory and FB Flashcards
Bronchial Tree
left vs right
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
Alveoli
pneumocytes
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
Pleura
A double-layered serous membrane that lines the walls of the thoracic cavity and the surface of the lungs
Parietal pleura
Lines the inner surface of the thoracic cavity
Sensitive to pressure, pain, and temperature
Separated from the thoracic wall by the endothoracic fascia
Visceral pleura
Lines the outer surface of the lungs
Covers lung fissures
**Not sensitive to pain
Eupnea
Normal, relaxed, quiet breathing; 12-15 breaths/minute
Dyspnea
- Labored, gasping breathing; shortness of breath
Apnea
Temporary cessation of breathing
Respiratory arrest
Permanent cessation of breathing
Hyperpnea
Increased rate and depth of breathing in response to exercise, pain, or medical conditions
Hyperventilation
Increased pulmonary ventilation in excess of metabolic demand; frequently associated with anxiety
Expel CO2 quickly
Hypoventilation
Reduced pulmonary ventilation; leads to an increase in blood CO2 concentration
Tidal volume (TV)
Volume of air inhaled or exhaled with each breath under resting conditions
Residual volume (RV)
Volume of air left in lungs after forced exhalation
Expiratory reserve volume (ERV)
Volume of air that can be forcefully exhaled after normal tidal volume exhalation
Inspiratory reserve volume (IRV)
Volume of air that can be forcefully inhaled after normal tidal volume inhalation
Hypercapnia
Increased carbon dioxide in the blood
PCO₂ > 40 mm Hg
Foreign Body Aspiration (FBA)
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
Foreign bodies (FBs) aspirated vary based on age
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
Upper airway obstruction
Pathophysiology
More common in children due to anatomical narrowing of tracheobronchial tree
Large food or objects are visible in theoropharynx in most pediatric patients
Lower airway obstruction
patho
Ball-valve effect – partial obstruction
Allows air in withinspiration
Prevents air exiting uponexpiration
Results inhyperinflationof 1 or more lobes
foreign body aspiration
clin man
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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Foreign body
Dx
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
foreign body
Tx
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
