Respiratory Flashcards
What embryologic structure forms the respiratory tract?
Endoderm (foregut)
Ventral esophagus–> Lungs
Mesodermal mesenchyme–> branching
When does airway branching complete?
12-14 weeks
What part of the central great vessels forms the pulmonary vasculature?
Sixth aortic arch branches
Pulmonary arteries supply the intrapulmonary structures
What structures does the bronchial artery system supply?
Conducting airways
Visceral pleura
Connective tissue
Pulmonary arteries
Where are the preacinar arteries and how do they develop?
When is their development complete?
Next to the terminal bronchioles (non-respiratory)
Angiogenesis
16 weeks
Where are the intra-acinar arteries and how do they develop?
Next to the respiratory bronchioles and alveolar ducts, within alveolar walls
Vasculogenesis
Develop until 8-10 years
How does fetal vessel wall thickness change throughout gestation?
Fetal vessel wall thickness is increased compared to an adult
During the second half of gestation, wall thickness and vessel diameter remain proportional
What small pulmonary artery development occurs in the fetus?
Small pulmonary arteries:
- Move along airways toward alveoli
- Have an encircling medial smooth muscle cell layer->
- layer later changes to incomplete muscularization in a spiral or helix->
- smooth muscle layer disappears (non muscularized vessels)
- -> vascular smooth muscle cells through preacinar arteries
What changes occur in the small pulmonary arteries in the near-term infant?
Half bronchiolar vessels are muscularized or partially muscularized
Vessels NEXT to alveoli are NON muscularized
How do small pulmonary arteries change in 4-6 week infants?
Medial smooth muscle layer involutes
Muscular wall thickness decreases
During what phase do bronchioles and alveoli increase?
Alveolar phase
When do alveoli develop?
Late gestation–> 3-8 years
How many alveoli does the term infant have?
50-150 million alveoli
How many alveoli does the adult have?
200-600 million
What factors delay alveolization?
Antenatal steroids
Supplemental oxygen
Nutritional deficiencies
Mechanical ventilation
What are the embryonic stages of lung development?
Embryonic pseudoglingular canalicular saccular alveolar
When does embryonic lung development occur?
0-5 weeks
What two key structures develop during the embryonic phase of lung development?
Trachea
bronchi
What pulmonary anomalies develop during the embryonic phase of lung development?
Laryngeal cleft
Tracheal stenosis
Tracheoesophageal fistula
When does the pseudo glandular phase of lung development occur?
5 to 15 weeks
What key structures develop during the pseudoglanular phase of lung development?
Non-respiratory bronchioles
What airway anomalies occur during the pseudo-glandular phase of lung development?
Branching abnormalities Bronchogenic cysts Congenital diaphragmatic hernia ongenital lobar emphysema Cystic adenomatoid malformation
When do the lungs begin to develop amniotic fluid?
During the pseudo-glandular phase
When does the canalicular phase of lung development occur?
15-25 weeks
What structures develop during the canalicular phase?
Respiratory bronchioles
What lung anomaly occurs during canalicular development?
Pulmonary hypoplasia
When during lung development do pneumocytes begin to differentiate from type 2 to type 1?
Canalicular phase, 15-25 weeks
When does the saccular phase of lung developing occur?
25-35 weeks
What structures develop during the saccular phase of lung development?
Alveolar ducts
What lung anomaly occurs during the saccular phase of lung development?
Pulmonary hypoplasia
When does the alveolar phase of lung development occur?
36+ weeks
What structures develop during the alveolar phase of lung development?
Alveoli
What does Each Pulmonary part Comes Through Age represent?
Stages of lung development Embryonic Pseudo-glandular Canalicular Terminal sac (Saccular) Alveolar
Describe type 1 pneumocytes
Fried egg Tight junctions 90% surface area Smaller number Gas exchange Formed from type 2 pneumocytes
Describe type 2 pneumocytes
Cuboid 10% of surface area Greater number Surfactant metabolism and secretion Form type 1 cells
Fetal lung fluid production prior to term is equivalent to
Functional residual capacity
20 to 30 ml/kg
At term fetal fluid production decreases to
4-5 ml/kg/hour
Chloride being _______ transported into airspaces _______ volume of fetal lung fluid
Actively
Increases
Sodium secretion into air spaces
Causes of reabsorption of fetal lung fluid
Prenatal factors that contribute to fetal fluid reabsorption (35%) are
Increased sodium secretion
Decreased chloride secretion
Increased lymphatic noncotic pressure
Low fetal alveolar protein
Fetal lung fluid is cleared during labor by
Mechanical compression (fetal lung compression) Catecholamine surge (increased Na transport) Higher cortisol and thyroid hormone concentrations (increased Na transport)
Fetal lung fluid is cleared postnatally by
Lung distention
Pulmonary lymphatic absorption by increased oncotic pressure/low fetal alveolar protein
Increased intrathoracic pressure from crying pushes fluid to capillaries and lymphatics
How is oxygenation index calculated?
FiO2 x MAP/ PaO2
How is oxygen content calculated?
(1.34xHgB)x(HgB) x O2 sat) + (0.003(paO2))
Alveolar-arterial gradient is calculated by:
PaCO2/R - paO2
R= 0.8
Surfactant consists primarily of what component?
Phosphatidylcholine-disaturated (50%)
What two surfactant proteins are in artificial surfactants?
SP-B, SP-C
Which surfactant protein is least clinically relevant?
SP-D
Which surfactant protein is most impacted by antenatal steroids?
SP-A
Chromosome 10 encodes SP___ and ____
A and D
SP-B is encoded on chromosome ____
2
SP-C is encoded on chromosome ____
8
Chronic interstitial lung diseases is associated with deficiency of surfactant protein _____
SP-B
Surfactant is produced by
Type II pneumocytes
Surfactant proteins nice in T2 pneumocytes from ______ to ___________ to join SP-A to create tubular myelin to reduce surface tension
Multivesicular bodies to
Lamellar bodies
Remaining surfactant in the alveolar surface are recycled through _________ to the _______ cell.
Remaining remnants are cleared by _______
Endocytosis
Type II pneumocytes
Macrophages
Lung maturity can be increased by
Inflammation, relative hypoxia, poor growth:
Hypertension/PIH, CV disease, infarction, IUGR, PROM, incompetent cervix, hemoglobinopathies, chorioamnionitis
Substances that showed lung maturity:
cAMP, growth factors, sex hormones (prolactin, estrogen), thyroid hormones, steroids, methylxanthines, B-agonists
Components that promote surfactant secretion and fetal lung fluid are
Purines
Prostaglandins
Beta agonist
Lung distension and fetal breathing
The amniotic fluid component that does indicate fetal lung maturity is
Lecithin
The pattern of phosphatidylinositol in amniotic fluid during lung maturation is
Early rise around 28 weeks and decrease around 35 weeks
Sphingomyelin is or is not related to lung maturity?
It is not related to lung maturity
A lecithin / sphingomyelin ratio that is greater than ____ indicates lung maturity
2
The pattern of phosphatidylglycerol and amniotic fluid during lung maturation is
Increase after 34 to 35 weeks
Correlated with lung maturity, infants with RDS will not have phosphatidylchloride in amniotic fluid
A lecithin / sphingomyelin ratio of ____ indicates 100% risk for RDS
Less than 1
Independent of the lecithin/sphingomyelin ratio the lack of ______ or the presence of ____ increases the risk of RDS
Phosphatidylglycerol
Diabetes or Rh isoimmunization
The presence of lamellar bodies in amniotic fluid suggests
Mature lung tissue
Natural surfactants contain which surfactant proteins?
SP/A and SP/B
Laplace’s law
The smaller the alveolar radius the greater the pressure needed to maintain distention against surface tension
P = 2T / r
Vasodilators that contribute to decrease in pulmonary vascular resistance at delivery are
Nitric oxide
Endothelin-1
Compounds that contribute to delayed decrease in pulmonary vascular resistance are
Defective prostaglandin or nitric oxide synthesis
Indomethacin
Prostaglandin synthesis inhibitors aka aspirin
Inflammatory response molecules: leukotrienes, thromboxane, platelet activating factor
Neural input to the medulla results in vagal nerve mediated limited inspiratory duration via the ______ reflex
Hering breuer inflationary
The herringbrew deflation reflex causes
Increase in ventilatory rate related to abrupt deflation of the lungs
Think of pneumothorax or periodic breathing
Maintains infants FRC
A pronounced increase in diaphragmatic contraction during inflation describes the
Paradoxical reflex of head
Chemoreceptors for CO2 and pH changes are located on
Central, Ventrolateral medulla
Changes in tidal volume are sensed by mechanoreceptors located
In the airway smooth muscle
Chemoreceptors for O2 changes are located on
Peripheral chemoreceptors in the carotid bodies in aortic bodies.
Response to hypoxemia by preterm and term infants differs in that term infants will have ________ and preterm infants will have ______
Increased respiratory rate
Apnea
Suprasternal retractions indicate
Upper airway obstruction
Unilateral subcostal retractions indicate
Decreased movement of the opposite diaphragm
The neonatal lung functions as zone
III
Air trapping or alveolar distention causes lung function to shift to zone
I or II
Increased extravascular fluid causes the lungs to shift to zone
IV
Increased pulmonary vascular resistance, decreased blood flow
Alveolar pressure rank correlates with lung perfusion zones
In zone I alveolar pressure is most prominent
In zone 2 alveolar pressure is second most prominent
In zone 3 alveolar pressure is third most prominent
In lung perfusion zones 2, 3 and 4, the prominent perfusion pressure is due to
Pulmonary arterial pressure
Optimal alveolar ventilation perfusion ratio should be
Close to 1
Have you ever ventilation is calculated by
(Tidal volume - dead space volume) x respiratory rate
High PCO2s are associated with a ____ alveolar ventilation and _____ perfusion
Low
Normal
An anatomic shunt will give a VQ ratio of
0
VQ ratio in the setting of a dead space will create a ratio of _____
> 1 to infinity
A VQ ratio greater than 1 suggests a _____ PaO2 and a ____ PaCO2.
O2 and CO2 content are ______
High
Low
Normal
A VQ ratio consistent with dead space demonstrates _____ ventilation and _______ perfusion.
Normal
Decreased
The most significant effect from VQ mismatching will be on oxygenation or ventilation?
Oxygenation
Two normal lung anatomical shunts exist in the
Coronary things draining to the thespian veins to the left ventricle
Bronchial circulation draining to the pulmonary veins
To determine the percentage of an interpulmonary shunt use the calculation
02 content pulmonary capillary - 02 content systemic arterial /
02 content pulmonary capillary - 02 content mixed venous
To estimate interpulmonary shunt % you can also use the calculation for ______, which does not take into consideration oxygenation as an increase of FIO2
A-a gradient
Bronchodilation ________ anatomic dead space
Increases
Fowler’s method estimates
Anatomic dead space using volume and nitrogen concentration of expired air
Physiologic dead spaces always greater than / less than an atomic dead space
Greater than
Physiologic dead space can be estimated using the _____ equation
Bohr
Bohr equation measures _______ through the following calculation:
Physiologic dead space
TV x (arterial CO2 - expired CO2) / arterial CO2
Partial pressure of gases within the alveoli tend to shift between _____ and _____ with relatively constant levels of _____ and _____
Oxygen and nitrogen
CO2 and H2O
Airway resistance is proportional to changes in ______
and inversely proportional to changes in _______
Pressure
Flow
Respiratory system resistant is broken down by: Airway (\_\_\_%) Chest wall (\_\_\_\_%) Lung tissue (\_\_\_\_%)
55%
25%
20%
In the newborn 50% of the airway resistance is due to
Nasal passages
Increased airway resistance with laminar flow are due to
Increased airway length
Increased gas viscosity
Poiseuille’s law describes
Laminar airflow resistance
Laminar flow is calculated with the equation
Poiseuille’s law:
Change in pressure x pi x radius^4 /
8 (length x viscosity)
Turbulent flow resistance ________ with increased airway length, ________ with increased radius, and _______ with increased gas density
Increases
Decreases
Increases
Turbulent flow resistance is calculated by
(length x density)/
Radius^5
Both turbulent and laminar flow resistance ______ with increased airway length and _______ with increasing radius.
Increase
Decrease
Laminar flow resistance is inversely proportional to _______ while turbulent flow resistance is proportional to _______
Viscosity
Density
Total and capacity equ
Vital capacity + residual volume
Or
Inspiratory capacity + functional residual capacity
Functional residual capacity is
Expiratory reserve volume
+
residual volume
Inspiratory capacity is
Inspiratory reserve volume
+
Title volume
Inspiratory capacity is approximately equal to
Functional residual capacity
Dead space is approximately equal to
1/3 Tidal volume
Infants with RDS have decreased ________ and increased _______
Lung volume capacities
Dead space
Compliance equals
Change in volume /
Change in pressure
Elastance equals
Change in pressure /
Change in volume
Hypoinflation lung disease such as atelectasis, RDS, and low volumes have findings of
Low FRC
Low compliance
Hyperinflation lung disease such as MAS, chronic lung disease
Low compliance
High FRC
Time constants for respiratory mechanics are dependent on
Resistance and compliance
The stiffer the long tissue, the lower the compliance, the ________ The time to for inspiration and the _______ The time for exhalation
Longer
Faster
One time constant is defined as
Time required for 63% of alveoli to discharge air volume
Compared to an adult neonatal lungs have decreased:
Tidal volume
Total capacity
Inspiratory capacity
Vital capacity
Pao2 measures the
Free 02 molecules dissolved in plasma in arterial blood
True or false: pao2 does include the amount of oxygen bound to hemoglobin.
False
Equation for oxygen content is
1.34 ml/g hgb x (hgb x o2 sat) + (0.003 * pao2)
Which parameter is most significantly impacted by changes in hemoglobin concentration?
Oxygen content
Oxygen saturation
Pao2
Oxygen content
Both high altitude and severe VQ mismatch have decreased
PAO2 and oxygen saturations
Pao2 and oxygen saturations in the setting of severe anemia are
Unchanged
Carbon monoxide poisoning causes PAO2, oxygen saturations, or both to be decreased?
Only oxygen saturations are decreased
Pao2 is unchanged
Increased a a gradients are associated with
VQ mismatch
Shunting
Oxygen delivery is determined by
Cardiac output * 02 content
Pacific principle
Oxygen consumption
Difference between oxygen delivered to tissues and oxygen returning from the tissues
Oxygen consumption is calculated by
CO x 1.34 ml/g hgb x hgb x (arterial o2 sat - venous o2 sat)
Increased oxygen consumption results in an increase in
Cardiac output
Five common sense areas in which oxygen is consumption is increased
Increased caloric intake Decreased body temperature Neonate versus adult Term versus preterm AGA versus SGA infant
Shift in barometric pressure and associated FIO2 requirements are calculated by
(pB1 - pH2O) x FiO2 = (pB2 - pH2O) x FiO2
The LEFT oxyhemoglobin dissociation curve happens with:
LOW
- acid
- paCO2
- 2,3 DPG
- temp
- P50
- adult hgb (more fetal hgb)
The left curve is the REST curve- higher O2 affinity wouldn’t work in high oxygen demand states
The RIGHT oxyhemoglobin dissociation curve happens with
RISING
- acid
- pCO2
- 2,3 DPG
- hydrogen
- temp
- p50
- Adult hgb
The right curve is the WORK curve- lower O2 affinity answers increased oxygen demand states
What inside catalyzes the conversion of CO2 to bicarbonate?
Carbonic anhydrase
70% of CO2 in the blood is transported as
Bicarbonate ions
Three forms of carbon dioxide in the body are
Dissolved CO2 (10%) Bicarbonate ion (70%) Carbamino compounds (20%)
How is CO2 solubility different than 02 and what is that advantage?
CO2 is 20 times more soluble in blood than oxygen
Increase solubility allows for easier transport and extraction with smaller changes in blood CO2 levels
Bohr effect:
Increased oxygen release at lower pH or higher PCO2 (think increased oxygen need while running)
Curve shifts right
O2 and CO2 exchange at tissue-blood interface
PaCO2 decreases as it’s carried to alveoli. Lower paCO2/increased O2
Curve shifts back to left
Haldane effect
High oxygen concentrations in the long facilitates carbon dioxide unloading into the alveoli
Bohr effect
High CO2 in the tissues facilitate 02 unloading
OR
Low CO2 in the lungs facilitates 02 loading
Henderson hasselbach equation
Hydrogen ions are adjusted by the kidneys and lungs to regulate pH by clearing CO2 or increasing bicarbonate
To calculate hydrogen concentration by the Henderson Hasselbach equation:
24 x PCO2 / HCO3
Carboxyhemoglobinemia is a result of
Excess carbon monoxide from tobacco smoke, fires, motor vehicle exhaust
In paradoxygen carry capacity results from carboxyhemoglobinemia due to
Carbon monoxide binding to hemoglobin at a higher affinity than oxygen and competing with oxygen for hemoglobin binding sites
Oxyhemoglobin curve shifts to the left causing decreased o2 delivery to the tissues
True or false: carbon monoxide can across the placenta and bind with you fetal hemoglobin
True
Treatment of carbon monoxide poisoning is
Providing 100% oxygen to displace carbon monoxide from hemoglobin
Excess nitrates, nitrites, exogenous nitric oxide, maternal prilocaine, aniline dyes, and hemoglobin M can cause
Methemoglobinemia
What enzyme if defective can cause methemoglobinemia
Cytochrome B5 reductase
How does methemoglobinemia alter iron and impact oxygen binding capacity of hemoglobin?
Changes iron from ferrous to ferric state
Decreases hemoglobin-oxygen binding abilities
Clinically methemoglobinemia will have
Desaturations with normal PaO2
Brown appearance of blood following exposure to oxygen
Mean airway pressure is calculated using
K (PIP - PEEP) X (ITIME/ITIME + ETIME) + PEEP
Mechanisms involved in high frequency ventilation include
Bulk convection Pendulluft Asymmetric velocity Taylor dispersion Molecular diffusion
Pendelluft effect is
Gas moving between alveoli due to different time constants
Think pendulum
Asymmetric velocity of high frequency ventilation is
Gas velocities varying during inspiration versus expiration
Think high inspiratory rates with passive, somewhat continuous exhalation
Parabolic movement of inspired gas in which the highest velocity moves within the middle is called
Taylor dispersion
Tall Taylor runs through the middle
Molecular diffusion
Transported gases across the alveoli taking advantage of a diffusion gradient
Indications for ECMO
Fi02 100%
PAO2 less than 40
A-a gradient greater than 600
OI greater than 40
Ekmo contraindications
Prematurity less than 34 weeks
Severe IVH
Significant coagulopathy
Irreversible pulmonary disease or neurologic abnormalities
Congenital anomalies or otherwise poor long-term outcome
Nitric oxide is formed from
L arginine and nitric oxide synthase
Nitric oxide relaxes vascular smooth muscle by
Guanylyl cyclase activation and increased cGMP
The inactive form of nitric oxide is
NO2/NO3 (oxidized)
How does nitric oxide selectively decrease pulmonary vascular resistance without causing hypotension?
Nitric oxide combined with hemoglobin becomes oxidized which is then an inactive form of nitric oxide
How does inhaled nitric oxide improve ventilation perfusion mismatch?
Inhale nitric oxide selectively dilates ventilated blood vessels as it is unable to reach those that are not ventilated, and therefore not perfused
In what clinical condition is inhaled nitric oxide contradicated?
Critical congenital heart disease with dependent right to left shunting
Potential adverse effect of inhaled naturic oxide therapy is
Methemoglobinemia
The most common microorganisms responsible for early congenital pneumonia are
GBS
E coli
Klebsiella
Listeria
The microorganisms must commonly responsible for late congenital pneumonia are
Staph aureus
Pseudomonas
Fungus
Chlamydia
Fever associated with congenital pneumonia is most commonly due to an infection with
Herpes or enterovirus
Vital sign changes associated with tension pneumothorax are
Decrease in blood pressure
Decrease in heart rate
Decrease in respiratory rate
Significant pneumothorax can be associated with these two comorbidities
Interventricular hemorrhage
SIADH
What is a Spinnaker sail sign?
X-ray finding with pneumomediastinum
Elevated, well visualized thymus and hyperlucency
Describe Wilson Mikity syndrome
Variant of BPD with minimal early disease progressing to significant BPD and slow recovery
What microorganism is associated with the increased risk of BPD?
Ureaplasma urealyticum
On x-ray stage 4 BPD has
Distortion of architecture, large cystic areas, interstitial fibrosis, atelectasis, hyperinflation
What is the mortality rate of severe chronic lung disease?
20-40%
Why are antibiotics given in the setting of meconium aspiration syndrome?
Meconium increases bacterial
Clinical findings are indistinguishable from congenital pneumonia
Sepsis may be a cause for aspiration
What cardiac findings are present in the setting of pulmonary hypertension?
Single or narrowly split loud S2
Possible ST changes due to subendocardial ischemia
What is the mechanism of action of sildenafil?
Phosphodiesterase 5 inhibitor
Inspiratory stridor is due to what type of airway obstruction?
Supraglottic
Nose, nasopharynx, oropharynx, hypopharynx
Differential includes Pierre-Robin, treacher-collins, macroglossia, Beckwith-Wiedeman syndrome, hypothyroidism, glycogen storage diseases, trisomy 21, choanal atresia, thyroglossal duct cyst
An obstruction with a fixed size during inspiration and expiration will cause what kind of stridor?
Biphasic
Due to laryngeal obstruction
Most common cause of biphasic strider is
Laryngomalacia
Expiratory stridor can be often due to
Tracheomalacia
Tracheal stenosis
External compression from vascular ring or mediastinal mass
The most concerning type of stridor is
Expiratory
Most common type of vascular ring is ______ due to a ______
Complete vascular ring
Double aortic arch (persistent right and left fourth branchial arches)
40%
An alternative cause of a complete vascular ring and second most common is
A rate aortic arch with ligamentum arteriosum/PDA
30%
Of the three causes of incomplete vascular rings, in order of most two least common are
Abberant right subclavian artery, 20%
Anomalous innominate artery, 10%
Abberant left pulmonary artery, rare
Choanal atresia was commonly occurs where and in what patient population?
Unilateral (2/3), right (2:1)
Females (2:1)
The syndrome most commonly associated with choanal atresia is
CHARGE C- coloboma H- heart disease A- choanal atresia R- mental deficiency G- genital hypoplasia E- ear anomalies
Most common location of vocal cord paralysis injury is
Unilateral, left (left recurrent laryngeal nerve)
Appropriate management of vocal cord paralysis includes
Imaging, x-ray and MRI, to determine side of pathology
Airway productive strategies: if bilateral, tracheostomy. If unilateral or mild may need observation in hopes of spontaneous resolution in 2-9 months
For persistent injury, arytenoidectomy or vocal cord lateralization techniques
Pathophysiology of tracheomalacia is
Collapse of cartilaginous rings supporting the trachea
Tracheomalacia presents with
Expiratory strider
Most common cause of congenital tracheal narrowing is
Tracheomalacia
Diagnosis of tracheomalacia is made with
Bronchoscopy
Treatment and outcome of tracheomalacia include
Supportive respiratory strategies including CPAP or tracheostomy
Resolution by 6 to 12 months of age
Pathophysiology of laryngeomalacia is
Epiglottis or arytenoid cartilage collapse with prolapse into the glottis
The most common cause of congenital stridor is
Laryngomalacia
Presentation and patient population associated with laryngomalacia is
Onset in the first month of life, male predominance (2:1)
Diagnosis of laryngeomalacia
Laryngoscopy
Treatment and expected outcome of laryngomalacia is
Conservative/supportive treatment
Spontaneous resolution by 2 years of age
Most congenital diaphragmatic hernias are on the _____ side
Left (85%)
Syndromes that maybe associated with a CDHR
Fryns syndrome Denys-Drash Cornelia-de-Lange Marfan Spondylocostal dysostosis Craniofrontonasal
Most common location of a CDH is
Left posterior lateral region, foramen of bochdalek, 90%
An infectious cause that has been associated with a right side CDH is
GBS infection
In CDH, herniation of the _____ and _____ often occur; prognosis is worse if _____ and _____ are also involved.
Intestine and spleen
Liver and stomach
Survival rate for infants with CDH is
60%
Diaphragmatic paralysis most commonly involves the
Right side, unilateral (9:1)
Right-sided diaphragmatic paralysis is most commonly associated with
Phrenic nerve injury due to birth trauma or cardiothoracic surgery
Physical exam in unilateral diaphragmatic paralysis will show
Affected side with decreased retractions,
Increased collapse during inspiration
Bilateral diaphragmatic paralysis can be due to
Furniture of injury due to birth trauma or cardiothoracic surgery
Neuromuscular disorder
Presentation of bilateral diaphragmatic paralysis is
Severe respiratory failure often requiring intubation
Outcome of unilateral versus bilateral diaphragmatic paralysis is
Spontaneous resolution by one year if unilateral, often fatal if bilateral
Pleural effusion due to congestive heart failure, hypoproteinemia, not immune hydrops, or iatrogenic has a _______ fluid
Transudative
Increased pH
Decreased WBC, protein, specific gravity, LDH
Pleural effusion due to inflammation or infection has a _______ fluid
Exudative
Decreased pH
Increased WBC, protein, specific gravity, LDH
Low glucose
Pathophysiology of chylothorax
Intrauterine thoracic duct obstruction
—>. Thoracic duct and plural space fistula
Laterality of a chylothorax is most often
Right side» left side»_space; bilateral
Fluid diagnosis of chylothorax shows
Xanthochromia
Lymphocytosis (70%)
Increased protein and triglycerides
Optimal feeding preference for patients with chylothorax is
Formula with medium chain triglycerides
Cartilaginous deficiency causing disruption of bronchopulmonary development and subsequent ball valve effect with over distention is called
Congenital lobar emphysema
Congenital lobar emphysema most commonly affects what patient population and what pulmonary location?
Males»_space;> females
Left upper lobe, 45%
Right middle lobe 30%
Right upper lobe 20%
What other anomaly can be associated with congenital lobar emphysema?
Congenital heart disease
What is the typical presentation of congenital lobar emphysema?
Respiratory distress in the first month of life
Gradual or rapid progression
Dimish breath sounds or wheezing
Maybe diagnosed on prenatal ultrasound, and can regress prior to birth
Chest x-ray shows opacification of affected lobe
A branching abnormality of the lung with communication to the tracheobronchial tree is a
Congenital cystic adenomatoid malformation
Perfusion and location of CCAMs are typically
Perfused by pulmonary circulation
Unilateral (80-90%)l
The most common type of CCAM is a type
Type 1, 50-70%
The most rare type of CCAM are type
Type zero and type four
Timing of defect of type 1 2 and 3 CCAM is
Type 1: 7-10 weeks
Type 2: 3 weeks
Type 3: 4 weeks
The CCAM most likely to cause a mass effect is a type
Type 3
Can also see compression with type 1 and type 4
CCAMs involving ciliated epithelium are
Type 0, type 1, type 2
Nonciliated epithelium are found in CCAMs type
Type 3 and 4
Mucus cells and cartilage are found only in CCAM type
Type 0 and 1
What is the typical progression of CCAMs during gestation?
Occur by the 10th week of gestation, many regress with peak size at 25 weeks gestation
Foresee cams that persist after birth, what is the difficult presentation?
50% asymptomatic at birth
Large lesions will cause respiratory distress after delivery
30% will present with recurrent pneumonia in childhood
What is the pre and postnatal management of CCAM?
Monitoring for hydrops, fetal surgery if indicated
Supportive care for respiratory distress
Complete resection
Which CCAM types have the best prognosis?
Type 1 and 4
Which CCAM types have the worst prognosis? And why?
Type 0 and 2, due to associated anomalies
Type 3 due to mass effect and associated pulmonary hypoplasia and hypertension
An airway cystic mass filled that is air filled or solid derived from the foregut is a
Bronchogenic cyst
Bronchogenic cysts tend to be located
Posterior to trachea
Can be intraparenchymal
May communicate with GI tract
Presentation of bronchogenic cysts
Most are asymptomatic until second decade of life, can present with coughing wheezing and recurrent pneumonia
Cysts that connect to the airway may enlarge rapidly after birth and cause respiratory distress
Why is surgical excision indicated for bronchogenic cysts even if asymptomatic?
Due to risk of complications including malignant changes
Congenital lymphangiectasia most commonly affects
Males, 2:1
Patients with noonan syndrome and trisomy 21
Congenital lymphangiectasia is caused by
Abnormal development or lymphatic obstruction that causes dilation of the lymphatic vessels in the lung
Clinical signs of congenital lymphangiectasia include
Respiratory distress after birth
Plural effusions
Hyperinflated lungs and diffuse granular densities on x-ray
Non-functional lung tissue that doesn’t communicate with the tracheobronchial tree and is perfused by systemic circulation is a
Bronchopulmonary sequestration
Most bronchopulmonary sequestrations are located
Intralobar, 75%
Lower lobes
Tend to occur more on left side
Are intralobar or extralobar sequestrations more likely to have associated anomalies?
Extralobar, 40 to 60%
A bronchopulmonary sequestration that presents in the neonatal period is more likely to be located in a _____ space.
Extralobar
Clinical course of bronchopulmonary sequestration is typically
Incidental finding during prenatal imaging
Mini regress in the prenatal period, some may develop hydrops
Extralobar type may present with respiratory distress in the neonatal.
Intralobar type may present with recurrent pneumonia in childhood
Additional anomalies that maybe associated with bronchopulmonary sequestration is
Congenital heart disease,
Congenital diaphragmatic hernia
Mechanism of action of acetazolamide is
Carbonic anhydrase inhibitor, proximal tubule
Mechanism of action of furosemide is
Blocks active chloride transport, ascending loop of Henle
Mechanism of action of spironolactone is
Aldosterone antagonist, collecting system
Mechanism of action of chlorothiazide is
Inhibition of sodium chloride reabsorption, distal tubule