Unit 3 Pathophysiology - Chapter 37 Alterations of Pulmonary Fx in children Flashcards
Airways of infants and children
narrower than adults
* more prone to obstruction
Alveoli development
Infants and young children continue to form new alveoli for several years after birth
Surfactant produciton
- important marker for developmental maturity of fetal lungs
- secreted into airways by 30 weeks gestation
Chest wall development
- this immature structure is soft and compliant (lung’s ability to stretch and expand) l/t inefficient mechanisms of breathing
Immune mechanisms for youth
not fully developed at birth, young infants more susceptible to infection
Hypoxia and newborns
blunted ventilatory response compared to older children and adults; increasing risk for apnea and hypoxemia
Importance of physical exams
assess location + nature of upper airway obstruction and stridor
Upper airway infections
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
Viral croup
- 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
Acute epiglottis
- vaccine for H. influenzae (rarely happens)
- usually caused by vaccine failure or other bacterial organism, such as group A streptococci
Tonsillar infections
- can be severe enough to cause upper airway obstruction
- can be treated with antibiotics and corticosteroids
- can l/t tonsillar abcess
Aspiration of foreign body
- 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
Angioedema
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
Chronic upper airway obstruction (UAO)
- 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
Causes of stridor?
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
Obstructive sleep apnea syndrome
- 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
Surfactant deficiency disorder (respiratory distress syndrome [RDS] of the newborn)
- 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
bronchopulmonary dysplasia (BPD)
- 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
Bronchiolitis
- 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
Childhood pneumonia
- 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)
Aspiration pneumonia
- 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
Bronchiolitis obliterans
- 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
Asthma
- 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
Acute respiratory distress syndrome
- 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
Cystic fibrosis
- 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
Sudden infant death syndrome
- 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
