Unit 3 Pathophysiology - Chapter 37 Alterations of Pulmonary Fx in children

Question 1

Airways of infants and children

Answer 1

narrower than adults
* more prone to obstruction

Question 2

Alveoli development

Answer 2

Infants and young children continue to form new alveoli for several years after birth

Question 3

Surfactant produciton

Answer 3

• important marker for developmental maturity of fetal lungs
• secreted into airways by 30 weeks gestation

Question 4

Chest wall development

Answer 4

• this immature structure is soft and compliant (lung’s ability to stretch and expand) l/t inefficient mechanisms of breathing

Question 5

Immune mechanisms for youth

Answer 5

not fully developed at birth, young infants more susceptible to infection

Question 6

Hypoxia and newborns

Answer 6

blunted ventilatory response compared to older children and adults; increasing risk for apnea and hypoxemia

Question 7

Importance of physical exams

Answer 7

assess location + nature of upper airway obstruction and stridor

Question 8

Upper airway infections

Answer 8

pose serious threats b/c of inflammatory edema and airway obstruction

bacterial tracheitis
1) invasive exudative bacterial infection of the soft tissues of the trachea
2) airway edema + copious purulent secretions

sx:
* dyspnea and stridor (rapid, turbulent flow air through narrowed or partially obstructed segment of upper airway - pharynx, epiglottis, larynx, and trachea)

tx:
* airway control and IV antibiotics against staphylococcus aureus and streptococcal species

retropharyngeal abcess
* develop in retropharyngeal lymph nodes at back of pharynx, adjacent to vertebrare; d/t infection of pharynx, sinuses, adenoids (high up in throat, behind the nose), or nose [these lymph nodes receed by 4-5 years] “nasopharyngeal”
* penetrating local injury
* common organisms => aerobic (streoptococcus and staphylococcus) and anaerobic (bacteriodes and fusobacterium)

sx:
* odynophagia (painful swallowing)
* dysphagia (swallowing difficulty)
* fever
* cervical lymphadenopathy (abnormal enlargement in head and neck)
* nuchal rigidity (neck stiffness)
* stridor
* dyspnea
* snoring
* torticollis (baby’s neck muscles cause head to twist and tilt to one side)
* eventually l/t airway obstruction, septic shhock, rupture of abscess into airway causing pneumonia or asphyxia (suffocation), mediastinitis (inflammation of chest area between the lungs), carotid rupture, and suppurative thrombophlebitis of internal jugular veins (Lemierre syndrome)

• immediate antibiotic tx

peritonsillar infection
* infection of tonsils and pharynx spreads to soft tissues
* unilateral, located betweel tonsil and superior pharyngeal constrictor muscle

• Hot potato
• Trismus (jaws muscles tight and cannot open mouth)
• exudate
• drooling
• halitosis
• inability to be consoled or distracted

Question 9

Viral croup

Answer 9

• laryngotracheobronchitis
• common cause of acute upper respiraotry airway inflammation in children age 6 months to 5 years
• mainly d/t parainfluenza
• subglottic edema mild to severe

Question 10

Acute epiglottis

Answer 10

• vaccine for H. influenzae (rarely happens)
• usually caused by vaccine failure or other bacterial organism, such as group A streptococci

Question 11

Tonsillar infections

Answer 11

• can be severe enough to cause upper airway obstruction
• can be treated with antibiotics and corticosteroids
• can l/t tonsillar abcess

Question 12

Aspiration of foreign body

Answer 12

• accidental breathing in of fluid, tissue or other substance
• should be considered if sudden onset of stridor, coughing, wheezing, or hoarseness
• ages 1-3
• diagnosis usually delayed
• sx: asthma, broncitis, pneumonia w/ recognition of underlying cause

Question 13

Angioedema

Answer 13

mast cell-mediated allergy to certain foods
causing:
* edema of mucuos membrane
* or subcutaneous layers of the skin
* resulting in mucosal swelling and airway obstruction

Question 14

Chronic upper airway obstruction (UAO)

Answer 14

• stridor (higher pitched d/t obstructionwith tracheal or laryngeal obstruction — on inspiration)
• abnormal cry
• wheezing (high pitched noise during expiration)
• dyspnea

bonus - rhonchi: low pitched wheeze w/ rumbling, coarse sounds like a snore during inspiration or expiration

Question 15

Causes of stridor?

Answer 15

Laryngomalacia
* birth defect in a child’s voicebox (layrnx); soft tissues of larynx fall over airway of opening and partially block it
* can resolve overtime or surgery called supraglottoplasty (cutting folds of tissue to open supraglottic airway or upper larynx)

tracheomalacia
Tracheomalacia occurs when the cartilage in the windpipe, or trachea, has not developed properly or was damaged, so instead of being rigid, the walls of the trachea are floppy or flaccid. The cartilage cannot keep the windpipe open, making breathing difficult — especially when breathing out (exhaling). Sometimes, pressure on the trachea from nearby blood vessels causes the trachea to collapse.
* humifidied air, careful feedings, antibiotics for infections

subglottic stenosis
* narrowing of airway below the vocal cords (subglottis) and above the trachea (epiglottis - cover that blocks food)
* steroid injections or surgery (no standardized tx)

laryngeal atresias
* also known as congenital high airway obstruction syndrome (CHAOS), is a very rare congenital (present at birth) condition in which the larynx (voice box) does not form properly.
* fetal surgery (before birth) or emergency tracheostomy (@ 4 y/o able to do reconstructive surgery and voice therapy)

tracheal stenosis
* Tracheal stenosis refers to abnormal narrowing of the trachea that restricts your ability to breathe normally (or subglottic stenosis)
* tx: laser surgery to remove scar tissue, airway stenting, widening of trachea w/ ballon
* for children: trachea enlarged by cartilage from ear or rib to expand

vocal cord paralysis
* you cannot control the muscles that control the voice; nerve impulses disrupted; hard to speak and breathe
* voice therapy and surgery

vascular ring
* A vascular ring is a condition in which both the trachea and the esophagus are encircled by vascular structures or its remnants
* may need surgery

Question 16

Obstructive sleep apnea syndrome

Answer 16

• occurs in older children (usually) rather than infants

typical sx:
* airway narrowing
* snoring, gasping, restless sleep
* increased upper airway collapsibility

common causes
* adenotonsilllar hypertrophy (increaed growth)
* gastroesophageal reflux (GERD) - occurs when stomach acid repeatedly flows back into the tube connecting your mouth and stomach (esophagus)
* obesity
* craniofacial anomalies

Question 17

Surfactant deficiency disorder (respiratory distress syndrome [RDS] of the newborn)

Answer 17

• usually occurs in premature infants born before surfactant produciton and alveolocapillary development are complete
• atelectasis (Atelectasis happens when lung sacs (alveoli) can’t inflate properly, which means blood, tissues and organs may not get oxygen. It can be caused by pressure outside of your lung, a blockage, low airflow or scarring) and hypoventilation l/t
• shunting, hypoxemia, and hypercapnia

Question 18

bronchopulmonary dysplasia (BPD)

Answer 18

• chronic lung disease of infancy
• consequence of acute respiratory disease in premature infants needing o2 and positive pressure ventilatory support

contributing factors:
* structural immaturity, inflammation, and disordered lung repair process

Question 19

Bronchiolitis

Answer 19

• infants and toddlers
• winter and early spring
• viruses (mostly RSV or respiratory syncytial virus)
• l/t extensive edema, inflammation, damage to bronchiolar epithemlium w/ airway obstruction + wheezing
• monoclonal antibody against RSV or immunetherapy for high risk infants

Question 20

Childhood pneumonia

Answer 20

• infection and inflammation (terminal airways and alveoli
• d/t comunity-acquired viruses (most common)
• bacteria
• mycoplasma
• lobar pneumonia — usually bacterial
• S. aureus and group A streoptococci (specifically) – fulimant (sudden and violent) disease, such as liver /// including abscesses and empyema (pockets of pus collected inside a body cavity)

Question 21

Aspiration pneumonia

Answer 21

• lung inflammation d/t foreign substance
• aspiration of orpharyngeal bacteria (happens d/t loss of protective reflexes in neurologically impaired children or during induction of anesthesia

Question 22

Bronchiolitis obliterans

Answer 22

• fibrotic obstruction of respiratory bronchioles and alveolar ducts
• usually secondary to severe respiratory viral infection or graft-versus-host disease after allograft transplantation (tissue from one to another)
• RARE IN CHILDREN HAHA

Question 23

Asthma

Answer 23

• bronchial hyperreactivity + reversible airway obstruction
• allergen, or has episodes of acute respiratory symptoms (cough, wheeze, dyspnea) or intermittent/chronic subacute sx
• common chronic condition amongst children as a result of genetic susceptibilty and environment

What do environmental triggers cause?
* inflammatory cell infiltration – presence of lymphocytes, mast cells, eosinophils w/o other evidence of inflammatory process
* mucosal edema
* mucus plugging of airways
* epithelial damage w/ obstruction to airflow and long-term remodeling of airways

Question 24

Acute respiratory distress syndrome

Answer 24

• severe hypoxemia
• poor lung compliance
• atelectasis
• diffuse densities

triggered by directly:
* acute lung injury (pneumonia, aspiration, near drowning, smoke inhalation)
* systemic insult, such as sepsis or multiple trauma

• high level ventilatory support required and mortality significant

Question 25

Cystic fibrosis

Answer 25

• autosomal recessive disease
• caused by CFTCR gene mutation or CF transmembrane conductance regulator gene mutation
• Inside the lung, an ion channel known as CFTR provides a route for chloride ions to move out of cells, which helps clear harmful material from the airways. Mutations affecting this protein cause the mucus lining the airways to become very sticky, leading to a severe disease known as cystic fibrosis.
• Defective chloride secretion (nothing leaves cells) + excess sodium aborption cause production of thick, tenacous mucus, plugging of airways, chronic pulmonary infection, and bronchietasis (abnormal widening of bronchi) r/t airway epithelial chloride and sodium transport
• other manifestations — digestive and nutritional r/t pancreatic insufficiency

sx:
* sweat has higher content of chloride
* Chronic coughing (dry or coughing up mucus)
* Recurring chest colds.
* Wheezing or shortness of breath.
* Frequent sinus infections.
* Very salty-tasting skin

tx:
* ivacaftor and lumacaftor and a triple combination medicine (elexacaftor–tezacaftor–ivacaftor) —- CFTR potentiators

Question 26

Sudden infant death syndrome

Answer 26

• SIDS
• event occurs during nighttime sleep
• cause unknown (investigation done after the sudden death of infant younger than 1 y/o_
• Avoidable risk factors
• includes — maternal smoking, prone sleeping, using soft bedding surfaces, overheating of infant
• ENCOURAGE SUPINE SLEEP POSITION