NEO RESP Flashcards
what are the differentials for respiratory distress that is airway?
Choanal atresia
Tracheal stenosis
Laryngeal web
Vascular Ring
what are the differentials for respiratory distress that is thoracic?
Ribcage anomalies
(Jeune syndrome –
asphyxiating thoracic
dystrophy)
Air leak syndromes
Chylothorax
What are the differentials for respiratory distress that is of neuromuscular origin?
Neuromuscular
Spinal cord injury
Spinal muscular
atrophy
Phrenic nerve palsy
Myasthenia gravis
Muscular dystrophy
What are the differentials for respiratory distress that are nonspecific?
Other
Diaphragm eventration
Pain
Sepsis
Methemoglobinemia
Anemia
cyanotic with feeds,
with resolution during crying–> dx?
choanal atresia
what syndromes are associated with choanal atresia?
CHARGE association, Apert’s syndrome, DiGeorge syndrome, trisomy 18, Treacher Collins syndrome, and camptomelic dysplasia.
Approx 50% patients have other anomalies,
most commonly CHARGE syndrome
whats more common u/l or b/l choanal atresia?
u/l 2/3 and R>L
* Bilateral CA present early, more commonly
associated with other anomalies, unilateral
usually isolated
more choanal atresia in f vs m? or m>f?
F>M
what injury can you have that leads to respiratory distress with shoulder dystocia? waiters tip / erbs palsy
phrenic nerve palsy
Phrenic nerve injury – most commonly on right side after birth trauma
- Etiology – lateral neck
hyperextension at birth, affects
C3‐C5 - Approximately 75% have
associated injuries (brachial
plexus, Horner’s)
what does the cxr show with phrenic nerve palsy?
CXR with elevated hemidiaphragm with atelectasis
* Fluoroscopy diagnostic – paradoxical
movement of diaphragm – elevation with inspiration, descent with expiration
* Improvement over 2‐3 weeks, further over next few months
* If failure of improvement in respiratory status, may require diaphragm plication
what kind of nerve injury with breech with neck hyperextension?
spinal cord injury
brainstem injury what happens?
at or above c3?
Below C3?
Level of injury:
* Brain stem – can be fatal
* At or above C3 – phrenic nerve is also involved
* Below this level – Phrenic nerve is intact and diaphragm contracts vigorously to compensate for weak intercostal and abdominal muscles
- Vigorous use of diaphragmatic muscles in a hypotonic infant – rule out what?
- Vigorous use of diaphragmatic muscles in a hypotonic infant – rule out spinal cord injury
decreased risk for
development of pneumothorax?
Surfactant admin vs
Positive pressure ventilation
Frequent suctioning
Prematurity
incidence of ptx?
Risk factors?
when does a ptx usually resolve?
Pneumothorax
* Spontaneous pneumothorax in ~1‐2% of live births
* Risk factors include meconium aspiration, respiratory
distress syndrome, pulmonary hypoplasia
* Usually resolve in 1‐2 days
what is the sail sign, when do you see it?
Pneumomediastinum
* ‘sail sign’ – elevation of thymus from pericardial silhouette
heart sounds, pericardial rub, narrow pulse pressure - dx?
pneumopericardium
PIE - what causes it?
seen mostly in?
Is it diffuse? b/l?
Alveolar overdistension leading to rupture
* Primarily seen in premature ventilated patients
* Diffuse bilateral disease
* Localized – one or more lobes and mediastinal shift
You are passing by the bedside for a newborn infant on CPAP respiratory
distress and hear biphasic stridor as they are changing the mask.
Respiratory status worsens and stridor becomes louder. What is the most likely etiology?
Subglottic stenosis
inspiratory stridor due to what type of obstruction?
Inspiratory
Extrathoracic or upper airway obstruction
Large tongue, laryngomalacia, laryngeal cyst, congenital
tracheal stenosis (tracheal rings)
biphasic stridor due to what type of obstruction?
Biphasic
Glottic or subglottic
Subglottic stenosis, subglottic hemangioma
expiratory stridor due to what type of obstruction?
Expiratory
Intrathoracic airway obstruction
Arch anomalies, vascular rings, tracheomalacia of intrathoracic
segment of trachea
Most common cause of inspiratory stridor in a neonate?
Laryngomalacia
what are pulmonary causes of respiratory distress?
Acquired Pulmonary etiology
* Transient Tachypnea of the Newborn
* Pneumonia
* Pneumothorax
* Meconium aspiration syndrome
Congenital malformations of the lung
* Congenital Pulmonary airway malformation
* Congenital Pulmonary lymphangiectasia
* Congenital lobar emphysema
* Mediastinal tumors
what congenital anomalies happen during the embryonic phase?
TE fistula, pulm sequestration,
cong lobar emphysema
what congenital anomalies happen during the Pseudoglandular phase?
CDH, CPAM, bronch cyst,
bronchopulm sequestration
what congenital anomalies happen during the canicular phase?
RDS, alveolar capillary dysplasia, pulmonary hypoplasia
what congenital anomalies happen during the saccular phase?
RDS, BPD, pulmonary
hypoplasia
what congenital anomalies happen during the alveolar phase?
TTN, MAS, pneumonia, PPHN,
emphysema
A full‐term neonate is delivered by c‐section, and demonstrates tachypnea,
grunting, and hypoxemia necessitating NICU care. At birth, activation of which
intracellular channel aids in reabsorption of lung fluid?
Epithelial sodium channels
fetal lung fluid - how much is made towards end of gestation?
30‐50ml/kg fluid in fetal lamb lungs towards end of
gestation
- Fetal lung fluid encompasses 90‐95% total lung weight toward term, decreases few days prior to delivery
what ion does the pulmonary epithelium secrete into the alveoli? what ion follows?
- Pulmonary epithelium secretes chloride into alveoli
- Na follows Cl through paracellular pathways, maintaining lung fluid
labor onset what happens in lung with fluid?
Labor onset leads to increased circulating epinephrine,
stimulating epithelial sodium channels (ENaC)
Na moves into interstitium through Na/K channels with
chloride and water passively following
- Fluid then passes to pulmonary circulation primarily, lymphatics secondary
Fluid also exits via squeeze of thorax during vaginal birth
what are the risk factors for TTN?
C Section, maternal Diabetes, male sex, macrosomia, maternal asthma, delivery of preemie or late preterm
Incidence of TTN at 33-34 wga, 35 - 36 wga, and in term?
Incidence: 3.6‐5.7/1000 births
* 10% pts 33‐34wks
* 5% pts 35‐36wks
* 1% term infants
Symptoms within first 6 hours of delivery
* Tachypnea, grunting
Dx?
TTN
imaging in ttn shows?
Imaging
* Fluid in fissure
* Perihilar streaking
* Congestion
mx of ttn and when does it resolve?
Management
* Oxygen supplementation, positive pressure support
* Usually resolves by 48‐72 hours
Chylothorax - which is more common congenital or acquired? what syndromes are the congenital assoc with?
10% Primary/Congenital – Trisomy 21, Noonan’s, Turner
90% Secondary/Acquired –most commonly
associated with thoracic surgery,
other associations include venous
thrombosis leading to increased SVC
pressure
M> F
how many newborns with chylothorax are sx within 24 hrs and how many within 7 days?
50% within 24 hrs
75% within 7 days
how to dx chylothorax?
Fluid cell count >
1000 μL
Lymph >80%
TG >110 mg/dL
Pleural fluid: serum cholesterol < 1
how to mx chylothorax? when does it resolve?
Supportive, may take 4‐6 weeks for resolution, up to 80% will resolve
without surgery
- Fat free diet utilizing medium chain triglycerides (MCT) – absorbed by
portal venous system - Will need essential fatty acids if prolonged utilization of MCT
- If persistent, surgical options include pleurodesis, thoracic duct ligation,
pleuroperitoneal shunt
Dilation of lymphatics that
results in obstruction and fluid leakage - what is dx?
Congenital Pulmonary Lymphangiectasia (CPL)
what is secondary congenital pulmonary lymphangiectasia associated with?
Secondary CPL
Associated with cardiac defects – total anomalous pulmonary
venous return, hypoplastic left heart syndrome with restricted
atrial septum
what is primary congenital pulmonary lymphangiectasia associated with?
Associated with Noonan’s, Ehlers‐Danlos, Ullrich‐Turner,
Down’s syndrome
how does primary CPL happen?
Failure in development of lymphatics – starts to develop in 6th
week and lymphatic channels develop before 20 weeks
* Localized vs general lymphatic development defect
* Generalized tends to have less severe pulmonary
involvement
Respiratory failure, hypoxia at birth, often with chylothorax, hyperinflation seen in what dx? what are the differentials?
CPL
differentials:
On differential in a fetal patient with non‐immune hydrops and congenital chylothorax
congenital pna what bugs?
Early pna happens at what days? late pna at what days of life?
what bugs?
Congenital
– Herpes simplex, usually acquired during labor; disseminated HSV results in pneumonia in
approximately 33‐54%.
Early (1st 3‐7 days),– Group B streptococcus, E coli increasing
Late late (after 7 days of life)– RSV most common viral cause of late‐ onset pneumonia
systemic disease + pna what bugs?
Systemic Disease + Pneumonia – consider CMV, HSV, toxoplasma, disseminated candida (particularly
in preterm)
what is the pathophysiology of pna? both cellular and inflammatory
Cellular Injury
Alveolar surface impairment leading to
transudation of fluid (pulmonary edema), surfactant impairment
Inflammatory response
* Neutrophil recruitment
* Bacterial and inflammatory debris leading to airway obstruction
* Increases in pulmonary vascular resistance through vasoconstrictor and procoagulants
bacterial toxin exposure or Viral exposure – CMV and HSV infection
leads to lysis of pneumocytes,
further viral growth
lead to cellular injury and inflamm response
what is the cdc definition of pna?
Signs/Symptoms in infants <1year old:
Worsening Gas Exchange (Desats, increased vent settings)
+ 3 of the following:
* Temperature instability
* Leukopenia (≤4000 WBC/mm3 ) or leukocytosis (>15,000 WBC/mm3 ) and left shift (>10% band forms)
* New onset of purulent sputum or change in character of sputum , or increased respiratory secretions or increased suctioning requirements
* Apnea, tachypnea, nasal flaring with retraction of chest wall or nasal flaring with grunting
* Wheezing, rales, or rhonchi
* Cough
* Bradycardia (<100 beats/min) or tachycardia (>170 beats/min)
what will imaging show with pna?
Imaging:
With underlying pulmonary
or cardiac disease:
2 or more CXR with:
New and persistent or
Progressive and persistent
Infiltrate, consolidation,
cavitation or pneumatocele
*IF no underlying pulm or
CV disease, can diagnose
from 1 xray
You are called to a csection for a fetus with prenatal diagnosis of congenital lung malformation. Baby delivers via NSVD and is initially vigorous, crying, begins to quiet, and HR <100. Baby is then intubated and brought to NICU. Which is the most common type of congenital pulmonary airway malformation?
Type 1 – Macrocystic (cysts > 2cm)
Incidence
Rare, approximately 1/10000‐1/35000 live births
Types
* Congenital pulmonary airway malformation (CPAM) – 40%
* Bronchopulmonary sequestration (BPS) – 10%
* Congenital lobar emphysema (CLE)
* Bronchogenic cysts (BC)
Most common time for detection is a fetal
ultrasound – many asymptomatic in the neonatal
pulmonary sequestration happens in what phase of lung dev?
embryonic (pulm sequestration, TE fistula, congenital lobar emphysema)
cpam in what phase of lung dev?
pseudoglandular (cdh, cpam, bronchogenic cyst)
what is the pathophys of cpam?
Pathophysiology
Malformation during pseudoglandular stage
Macrocystic lesions (>5mm) better prognosis than microcystic (<5mm)
Most often found in lower lobes,
right = left
