RESPIRATORY Flashcards
Fanaroff 11th; chapters 62,63,64,65,66,67,68,69,70,38,37 (240 cards)
1
Q
most effective treatment for RDS in neonatology
A
antenatal corticosteroids and postnatal surfactant
2
Q
lung structural development “stages”
A
embryonic, pseudoglandular, canalicular, saccular and alveolar;
3
Q
embryonic period
A
lobar airway 37 days
segmental airway 42 days
subsegmental bronchi 48 days
mesenchyme
4
Q
pseudoglandular stage
A
5-18 weeks; airway branching is complete;
cuboidal cells filled with glycogen; major components of lungs are completed
5
Q
in what stage airway, arteries and veins have developed?
A
18 weeks, pseudoglandular stage
6
Q
canalicular stage
A
16-25 weeks; transformation of the previable lung to the potentially viable lung that can exchange gas
3 major events:
-appearance of acinus(berry-like clustering oof cells at the distal ends of respiratory brioncholes)
-epithelial differentiation (development of the air-blood barrier)
-start of the surfactant synthesis (recognizable type II cells)
7
Q
what is the first critical step for the development of the future gas exchange surface?
A
saccular branching (acinus: 6 branching generations of respiratory brioncholes, alveolar ducts, and alveoli)
8
Q
saccular stage
A
24 weeks to term; terminal sac is developing respiratory bronchiole (alveolar duct) to about 32 weeks(initiation of alveolarization)
type I pneumocytes: modulate gas exchange
type II pneumocytes: synthesis and secretion of surfactant
9
Q
when is the most rapid rate of accumulation of the alveoli?
A
32 weeks till first months after delivery
10
Q
factors that delay/interfere with alveolarization?
A
mechanical ventilation antenatal and postnatal glucocorticoids pro-inflammatory mediators chorioamninitis hyperoxia or hypoxia poor nutrition
11
Q
factors that stimulate alveolarization?
A
vit A(retinoids) and thyroxin
12
Q
stages of branching
A
airway branching, saccular branching, alveolarization
13
Q
number of distal structures
A
24 weeks: 65000
adult: 500 million
14
Q
fetal lung fluid
A
high chloride; bicarb and protein low;
15
Q
what can completely stop fetal lung fluid production?
A
epinephrine IV
16
Q
delay clearance of fetal lung fluid can cause what?
A
transient respiratory difficulties
17
Q
what causes secondary pulmonary hypoplasia?
A
restricted lung growth (mass, effusion, external compression)
renal agenesis (potter syndrome) and prolonged oligohydramnios
congenital diaphragmatic hernia
absence of fetal breathing
18
Q
pulmonary sequestrations
A
portion of the lungs that are in isolation from neighboring lung tissue and with no communication th the bronchial tree
19
Q
alveolar macrophages
A
immune cells; functions: immune surveillance, phagocytosis, antigen presentation, interaction with adaptive immune cells, surfactant homeostasis; fetus normally do NOT have macrophages; they populate in lungs with an onset of breathing; *chorioamnionitis can mature and stimulate macrophages prior the delivery
20
Q
surfactant composition
A
70-80% phospholipids (60% are saturated) , 8% protein, 10% neutral lipids
21
Q
what is measured for fetal lung maturity?
A
AF Phosphatidylglyceroid
22
Q
4 proteins in surfactant
A
SP-A (innate host defense protein); not used for RDS
SP-B (surface absorption of lipids and low surface tension on surface area compression); lack of SP-B lethal respiratory failure
SP-C only in type II cells; similar to SP-B
SP-D similar to SP-A; used in surfactant for ventilator mediated inflammation
23
Q
surfactant synthesis and secretion
A
type II cells;
synthesis: ?
secretion: stimulated by adenosine triphosphate mechanical stretch (distention or hyperinflation)
24
Q
what is primary cause of RDS?
A
surfactant deficiency
25
surfactant pool sizes
long delay between synthesis and secretion balanced by slow catabolism and clearance: this is favorable for surfactant treatment strategies
26
alveolar life cycle of surfactant
lamellar bodies "unravel" tubular myelin ...?
27
physiologic effects of surfactant in the preterm lung
```
alveolar stability (prevent from collapsing, and keep interstitial fluid from entering the alveolus, normalize size)
pressure-volume curves (increases maximal volume at max pressure, increase in lung volume increase gas exchange, stabilization of the lung on deflation
```
28
Lung maturation
surfactant appearance, induced lung maturation, glucocorticoids, intrauterine infections
defined by lack of RDS generally, present after 35 weeks of normal gestation
29
surfactant appearance test
L/S ration lecithin to sphingomyelin
30
fetal stress, fetal growth restriction or preeclampsia induce lung maturation
FALSE
31
fetal exposure to inflammation may have short time benefits of decreasing RDS
TRUE
32
corticosteroids and lung maturation
induce lung maturation by increasing the surface area for gas exchange; decrease pulmonary edema; induce surfactant synthesis; improve response to postnatal surfactant;
33
other use of maternal corticosteroids
PDA, IVH, NEC, increase kidney function and postnatal BP
34
clinical observations
respiratory rate, retractions, nasal flaring, grunting, cyanosis
35
work of breathing components
elastic and resistive
36
elastic component
work required to stretch the lungs and chest wall during a tidal inspiration
37
resistive component
work required to overcome friction caused by lung tissue movement and gas flow through the airways
38
respiratory rate
TV 6-7ml/kg; 40-60 bpm
39
retractions
substernal, subcostal, intercostal; caused by negative intrapleural pressure generated by the contraction of the diaphragm and other respiratory muscles and the mechanical properties of the lung and chest wall
suggest low lung compliance, obstruction or atelectatis
40
what increases retractions?
RDS (lung stiffness); airway obstruction, misplacement of ETT, pneumothorax, atelectasis
41
grunting definition
neonates attempt to close (adduct) their vocal cords during the initial phase of expiration, holding gas in the lungs and producing an elevated transpulmonary pressure in the absence of airflow. The elevated pressure and corresponding increased lung volume result in the enhancement of the ventilation-perfusion ratio (V̇/Q̇). During the last part of the expiratory phase, gas is expelled from the lungs against partially closed vocal cords, causing an audible grunt
compensatory mechanism to maintain FRC and maximize pO2 (partial pressure of oxygen)
42
central cyanosis
check tounge and oral mucosa; desaturated hemoglobin
43
assessing pulmonary function
pulse oximetry and blood gas
44
pressure of alveolar oxygen
PaO2
45
optimal gas exchange
appropriate matching of the alveolar gas with the mixed venous blood
46
mixed venous blood composition and volume include what?
arterial blood gas content, cardiac output, oxygen consumption, and carbon dioxide production
47
what does the quantity of oxygen bound to hemoglobin depends on?
PaO2 and oxygen dissociation curve
48
arterial oxygen content
CaO2; sum of hemoglobin bound and dissolved oxygen
49
indexes used to estimate the degree of oxygen derangement
1. arterial-alveolar oxygen tension ratio
2. alveolar-arterial oxygen tension gradient mmHg
3. oxygen ration mmHg
50
oxygenation index
OI
51
pulse oximetry
measures the amount of hemoglobin molecules that is bound with oxygen
52
ideal oxygen saturation
currently UNKNOWN; AAP guideline recommendation 90-95%
53
hyperoxia test
differentiate between primary lung disease and congenital heart disease with right-to-left shunting
54
hyperoxia-hyperventilation test
distinguish between structural congenital heart disease and PPHN (both have right to left shunting)
55
preductal
right hand
56
postductal
left hand/ or any foot
57
respiratory physiologic measurements
airflow (pneumotachometer), lung volume, pressure
58
functional residual capacity FRC
the volume of gas in the lungs that is in direct communication with the airways at the end of expiration; oxygen storage compartment; volume of gas left in the lung after a normal expiration
59
thoracic gas volume
total volume of gas in the thorax at the end of expiration
60
tidal volume
volume of gas in and out of the lungs in a single breath
61
pressure
transpulmonary vs transrespiratory
62
respiratory mechanics
compliance, resistance, time constant, forced expiratory maneuvers, forced oscillation technique, work of breathing
63
lung compliance
measure of elasticity; reciprocal: elestance
64
resistance
measure of the friction encountered by gas flowing through the nasopharynx, trachea, and bronchi and by tissue moving against tissue. reciprocal: conductance
65
equation of motion
relationship between pressure, flow, volume, and the elastic, resistive, and inertial components of the respiratory system
66
time constant
duration (expressed in seconds) necessary for a step (e.g., pressure or volume) change to partially equilibrate throughout the lungs; resistance * compliance
67
work of breathing
a measure of the energy expended in inflating the lungs and moving the chest wall
68
goal of respiratory support
optimize oxygenation and CO2 elimination with the lowest possible ventilator settings to minimize lung injury
69
RDS pathologic diagnosis
surfactant deficiency; risk factors: GA and low BW; predominant factors: elective deliveries, maternal DM and perinatal hypoxia-ischemia; white boys ;)
70
RDS pathophysiology
diffuse atelectasis; impaired or delay surfactant synthesis and secretion
71
is RDS genetic?
too rare to determine
72
RDS radiographic findings
diffuse reticulogranular pattern, giving the classic ground-glass appearance in both lung fields with superimposed air bronchograms
73
RDS clinical presentation
grunting, retractions, nasal flaring, cyanosis, increased oxygen requirement
74
RDS RX
positive pressure ventilation, surfactant therapy, inhaled NO, assessment of blood gas(pulse oximetry, noninvasive carbone dioxide monitoring-capnography; arterial sampling), acid-base therapy, CV management, ABX
75
positive pressure ventilation
invasive: via an endotracheal tube utilize a time-cycled, pressure-limited mode, or volume-controlled mode with synchronized ventilated breaths; jet, oscillator, and conventional
noninvasive: CPAP, Noninvasive positive-pressure ventilation (NIPPV) increases tidal and minute volumes, improves lung recruitment, decreases work of breathing, may reduce apnea of prematurity, and may reduce the need for mechanical ventilation
76
benefits of CPAP
maintenance of a constant airway opening pressure, establishment, and maintenance of functional residual capacity, reduction of pharyngeal or laryngeal obstruction, improvement of oxygenation, and release of surfactant stores
reduces barotrauma, volutrauma, airway damage, and risk of secondary infections, and enhances mucociliary transport.
77
surfactant therapy
4 types approved for use in the US; bovine, porcine and synthetic mix of SP-B and SP-C protein; no proven adverse effects; INSURE technique (INtubate, SURfactant, Extubate)
78
inhaled Nitric Oxide therapy (iNO)
for preterm infants at risk for developing BPD or in RDS that is complicated by pulmonary hypertension
79
pulse oximetry
Continuous noninvasive measurement of arterial hemoglobin oxygen saturation
80
UAC placement
high T6-T8 (above aortic bifurcation); low L3-L4
81
complication of UAC
blanching or cyanosis of part or all of a distal extremity or the buttock area, resulting either from vasospasm or a thrombotic or embolic incident
use heparin to avoid thrombi
flushing can cause retrograde blood flow and transient elevated BP
increase in bloodstream infection (ideal not more than 3 days)
Allen test for radial artery line to establish the presence of adequate collateral circulation to the fingers
82
acid-base therapy
use of sodium bicarbonate has adverse effects and not recommended
83
CV management of the RDS
decreased perfusion can be caused by lactic acidemia or metabolic acidosis (monitor BP via A-line), use of pressors and monitor cortisol levels
PDA complications
84
what can happen after surfactant administration to the CV system
unrecognized overdistension of the lungs by excessive mechanical ventilation support can decrease systemic venous return to the heart and result in a decrease in cardiac output. Xray will show: squeezed-heart silhouette and flattened diaphragm are found,
vital signs, peripheral pulses, capillary refill, and urine output as surrogate markers of adequate cardiac output.
85
ABX in RDS
pneumonia indistinguishable from RDS on x-ray
| Penicillin combined with an aminoglycoside is recommended for 48h until blood culture results are back
86
what is the major contributor to long injury?
mechanical ventilation
87
noninvasive respiratory support modalities
single level pressure support: CPAP, HFNC
bilevel: BiPAP, SiPAP
nasal NIPPV
88
CPAP in RDS
prevent collapse of alveoli at end-expiration, maintaining some degree of alveolar inflation; helps maintain functional residual capacity and to facilitate gas exchange; useful in treating apnea of prematurity
89
CDP continous distending pressure
can be provided by CPAP and PEEP
90
clinical indications of CPAP
```
delivery room resuscitation
RDS
post-extubation support
apnea
mild upper airway obstruction
```
91
types of CPAP
flow driven
bubble CPAP
ventilator-derived CPAP
92
HFNC
1-8 L/min; issues with sizing and leaks(no baseline pressure); use: after birth, post-extubation, apnea
93
noninvasive nasal ventilation
PEEP, PIP, RR, inspiratory time can be manipulated
94
CPAP complications
```
nasal trauma
lung overinflation
increase or air leaks
can increase intrathoracic pressure and decrease venous return and cardiac output
to high cause carbone dioxide retention
gastric distention (OG)
```
95
indication for assisted ventilation
absolute:
failure to initiate or sustain spontaneous breathing
persistent bradycardia
major airway or pulmonary malformations (diaphragmatic hernia, severe hydrops
sudden respiratory or cardiac collapse with As and Bs (not responding to mask ventilation or pulmonary hemorhage)
Relative: "50-50 rule"
likelihood of subsequent respiratory failure
surfactant administration
impaired gas exchange
worsening As
need to maintain airway patency
need to control carbon dioxide elimination
medication-induced respiratory depression (magnesium, anesthetics, analgesics)
sepsis, MAS, PPHN
96
General Principles of Assisted Ventilation
oxygenation
ventilation
time constant
97
PEEP/ positive end expiration pressure
baseline pressure, the lowest level to which airway pressure falls; PEEP increases mean airway pressure (mean Paw)
98
PIP/ peak inspiratory pressure
driving pressure, increases mean Paw; establishes the upper limit of the amplitude
99
determinants of oxygenation in Assisted Ventilation
```
fraction of inspired oxygen
mean airway pressure
PEEP
PIP
inspiratory time
frequency
gas flow rate
```
100
determinants of ventilation in Assisted Ventilation
```
tidal volume
amplitude PIP-PEEP
frequency
minute volume: conventional (freq*TV) high-freq (freq*TV square)
expiratory time (I:E ratio)
```
101
ventilation
carbon dioxide removal; tidal volume (TV) and frequency
102
tidal volume TV
amplitude of mechanical breath: the difference between PIP and PEEP
103
amplitude too high, newborn will do what?
infant's hypercapnic drive will be abolished, and the baby will "ride" the ventilator rate
104
amplitude too low, newborn will do what?
baby will compensate by increasing the spontaneous breathing rate
105
time constant
the time required to allow pressure and volume equilibration in the lungs; product of compliance and resistance
106
conventional mechanical ventilator vs high frequency
CMV delivers physiological tidal volumes HFV delivers TV that is less than physiologic dead space
107
CMV types
```
ventilatory modalities (control the type of ventilation)
ventilatory modes (determine the breath type)
```
108
control variables (ventilatory modalities)
time, pressure, volume, only one can be controlled
109
phase variables (ventilatory modes)
trigger, limit, cycle, PEEP
110
modes of ventilation
intermittent mandatory ventilation IMV: set rate, supported by PEEP
synchronized intermittent mandatory ventilation SIMV, supported by PEEP
assist/control A/C set minimal breath rate
pressure support ventilation PSV
111
starting TV reference
4-6ml/kg preterm; 5-8ml/kg term
112
starting PEEP reference
4-6 cm h2o
113
when infant is ready to wean?
improved gas exchange and pulmonary mechanics, more spontaneous breathing
114
what is most common reason for failure to wean
failure to wean
115
what is the best way to wean
change one parameter at the time (does NOT apply to HFOV), reduce the most harmful one first
116
what is the best predictive value of positive extubation
attention to spontaneous breathing
117
High Frequency Ventilation HFV
delivered gas volumes are less than the anatomic dead space and are provided to a patient at a very rapid rate; carbon monoxide is a product of frequency, set amplitude lower than CMV, shorter inspiratory time (less barotrauma); higher PEEP than CMV; does NOT mimic spontaneous breaths; airway resistance (not long compliance) is the major determinant of gas distribution
JET
OSCILLATOR
118
JET in what conditions?
active inspiration, passive exhalation; 360-450bpm
| "air leaks", pulmonary interstitial emphysema, E/T artesia or fistulas
119
HFOV in what conditions?
active inspiration, active exhalation; 8-15Hz (480-900bmp); best to deliver iNO;
120
monitoring ventilated infants
1. clinical evaluation
2. assessment of gas exchange
3. chest imagining
4. pulmonary functions and mechanics testing
5. extrapulmonary monitoring (ECHO)
121
oxygenation depends on what?
ventilation-perfusion matching
122
movement of CO2 depends on what?
alveolar ventilation
123
base deficit
product of metabolic acidosis; 3-5mEq/L health infant; 5-10 should be ok
124
complications od assisted ventilation
airway:
UPPER: trauma, abnormal dentition, esophageal perforation, nasal septal injury, acquired palatal groove
TRACHEA: mucosal metaplasma, subglottic cysts, tracheal enlargement, vocal cord paralysis, subglottis stenosis, necrotizing tracheobronchitis
LUNGS: VAP, air leaks, ventilator-induced lung injury, BPD
125
air leaks examples
pneumomediastinum (nitrogen washout?)
pneumothorax
pulmonary interstitial emphysema (PIE)
pneumopericardium (air from pleural space or mediastinum enters pericardial sac)
pneumoperitoneum (rupture or perforation of abdominal viscus
126
pneumothorax ventilator causes?
high inspiratory pressure and unevenly distributed ventilation
certain diseases: MAS, CF, pulmonary hypoplasia
clinical S&S:
ASYMPTOMATIC: none, just xray
Deterioration in labs or bedside monitoring findings
Acute clinical deterioration
127
tension pneumotorax clinical evaluation
agitation and worsening respiratory distress
diminished or absent breath sound sounds on affected side
contralateral shift of heart sounds at the PMI
mixed acidosis and hypoxemia on CBG
transillumination: increased light on involved side
128
tension pneumothorax RX
thoracentesis (needle aspiration)
| thoracostomy (chest tube)
129
PIE pulmonary interstitial emphysema
most compliant portion of the terminal airway ruptures, gas leaks into interstitial space
xray: fine linear or radial radiolucencies
130
pneumopericardium/cardiac tamponade
air completely encircling the heart
131
pulmonary injury sequence in VILI
barotrauma (too much pressure)
volutrauma ( too much gas, overdistention)
atelectrauma (repetitive opening and closing of lung units)
biotrauma (infection, inflammation, stress)
rheotrauma (inappropriate flow)
132
Bronchopulmonary Dysplasia BPD
chronic respiratory insufficiency
supplemental oxygen requirements
abnormal xray at 36 weeks GA
caused by: excessive TV
133
right to left shunting
high pulmonary resistance (early RDS, MAS)
134
left to right shunting
high systemic vascular resistance
135
nonpulmonary etiologies of respiratory distress
thermal instability, circulatory problems, cardiac diseases, neuromuscular diseases, sepsis, anemia, polycythemia, methemoglobinemia
136
agenesis
total absence of pulmonary parenchyma, supporting vasculature and bronchi; antenatal US: mediastinal shift without diaphragmatic hernia
137
pulmonary hypoplasia
result of deficient or incomplete development of the lung parenchyma leading to decreased number of distal airways, alveoli, and associated pulmonary vessels
primary
secondary: oligohydramnios (renal malformation, prolonged AF leak, placental abnormalities, IUGR
space-occupying lesion (hernia)
cystic lung disease
cardiac malformations (cardiomegaly)
absence ob abnormal diaphragmatic activity
138
congenital diaphragmatic hernia
(CDH) results from a developmental defect during the formation of the diaphragm that permits abdominal contents to herniate into the thoracic cavity
139
CDH types
```
posterolateral (Bochdalek) most common
anterior (Morgagni)
central
1 in 2000-3000 live births
more common on L side
```
140
CDH clinical presentation
severy respiratory distress, cyanosis, scaphoid abdomen, absence of breath sounds
xray: bowel loops in chest cavity, OG tube in thorax
141
CDH management
ECMO criteria
gentle ventilation and permissive hypercapnia HFOV, low PIP
preductal sat above 85%, postductal dont matter
CO2 less or equal to 65, pH at least 7.25
dont use iNO
delay surgical therapy until stable and improvement of PPHN
142
CDH long term complications
pulmonary
GERD
hypoxemia: developmental delay
scoliosis
143
Alveolar Capillary Dysplasia
fatal; hypoxemia and PPHN not responding to treatment in first 48 hours
144
congenital pulmonary lymphangiectasia
CPL, dilation of lymphatic vessels in multiple areas of the lungs
intractable respiratory failure, cyanosis, and hypoxia associated with bilateral chylothoraces in the first few hours of life
nonimmune hydrops
xray: hyperinflation of the lung with bilateral interstitial infiltrates and bilateral pleural effusions
DX: lung biopsy: increased fibrous tissue with dilation of cystic lymphatic spaces and collapsed alveoli
poor prognosis if symptomatic early
145
chylothorax
accumulation of lymphatic fluid (chyle) in the pleural cavity
xray: pleural effusion, compression of the lung on the affected side, and displacement of the heart to the opposite side
DX: analysis of pleural fluid
RX: supportive, spontaneous resolution within 4-6 weeks
146
Congenital Cystic Pulmonary Malformations
congenital pulmonary airway malformations
bronchopulmonary sequestration
bronchogenic cyst
congenital lobar emphysema
147
congenital pulmonary airway malformations
(CPAM) constitutes multiple different hamartomatous lesions arising from the abnormal branching of the immature bronchial tree
4 types
148
bronchopulmonary sequestration
```
(BPSs) are microscopic cystic masses of nonfunctioning lung tissue thought to arise from the primitive foregut. Usually not connected to the main airway, and their blood supply arises from the systemic circulation intralobar sequestration (ILS)
extralobar sequestration (ELS)
```
149
bronchogenic cyst
single cyst lined by respiratory epithelium and covered with elements of the tracheobronchial tree, including cartilage and smooth muscle
treatment: complete surgical excision
150
congenital lobar emphysema
postnatal overdistension of one or more segments or lobes of the lung
151
Pulmonary Arteriovenous Malformation
malformations are direct communications between the smaller pulmonary arteries and veins, allowing blood to bypass the capillary system
152
meconium
comprised of desquamated fetal intestinal cells, bile acids, minerals, and enzymes, including alpha1 antitrypsin and phospholipase A2, as well as swallowed amniotic fluid, lanugo, skin cells, and vernix caseosa
153
MAS mechanisms
complete or partial obstruction of airways, inflammation, complement activation and cytokine production, inhibition of surfactant synthesis and function, apoptosis of epithelial cells, and increased pulmonary vascular resistance
154
typical MAS infant
postmaturity, with evidence of weight loss; cracked, peeling skin; and long nails, together with heavy staining of nails, skin, and umbilical cord with a yellowish pigment
barrel chest
rales
xray: coarse, irregular pulmonary densities with areas of diminished aeration or consolidation
155
MAS suctioning
amnioinfusion: not recommended
intrapartum: not recommended
routine intubation and suctioning: not recommended
156
MAS NICU
```
supportive respiratory and CV care
ABX
HFOV
surfactant lavage
complicated by PPHN, iNO should be considered
```
157
neonatal pneumonia
early: 3-7 days, aspiration of infected amniotic fluid, ruptures membranes, birth canal bacteria; Group B Streptococcus (GBS), herpes simplex and other TORCH, candidal infections
late: VAP, hospital-acquired; viral can take longer to develop because of the virus incubation period
xray: nonspecific, but persist for weeks
158
neonatal pneumonia RX
broad spectrum ABX till culture comes back
early: amp and gent
late: vanco and gent or nafcillin and gent
159
Transient Tachypnea of the Newborn
TTN from pulmonary edema secondary to inadequate or delayed clearance of fetal alveolar fluid
48-72 hours
risk factors: premature or elective cesarean delivery without labor, large birth weight, maternal diabetes, maternal asthma, twin pregnancy, and male gender
transient nature of this disease
no specific RX
wheezing syndrome early in life
160
pulmonary hemorrhage
defined as a gush of blood through an endotracheal tube in intubated neonates associated with a worsening clinical picture, requiring increased ventilatory support and blood product transfusion
before 72 hours of life, median 40 hours
risk factors:extreme prematurity, surfactant administration, patent ductus arteriosus (PDA) with left-to-right shunting, multiple birth, and male gender
161
pulmonary hemorrhage patho
pathophysiology of pulmonary hemorrhage is believed to be secondary to a sudden decrease in pulmonary vascular resistance, causing increased left-to-right shunting and pulmonary vascular engorgement, pulmonary edema, and ultimately, rupture of pulmonary capillaries
162
pulmonary hemorrhage treatment
```
increase in PEEP (stops bleeding)
avoid suctioning
epinephrine: not sure
blood products
exogenous surfactant administration
prophylactic indomethacin
```
163
Pulmonary Air Leak Syndromes
```
pneumothorax
pneumomediastinum
pulmonary interstitial emphysema
pneumopericardium
pneumoperitoneum
subcutaneous emphysema
```
164
rib cage abnormalities
```
asphyxiating thoracic dystrophy (Jeune syndrome)
thanatophoric dysplasia
achondrogenesis
homozygous achondroplasia
osteogenesis imperfecta (severe form)
Ellis-van Creveld syndrome (chondroectodermal dysplasia)
hypophosphatasia
spondylothoracic dysplasia
rib-gap syndrome
```
165
Phrenic Nerve Injury
Phrenic nerve injury with paralysis of the diaphragm is an unusual cause of respiratory distress
C3 to C5
166
breathing activity fetus
11 weeks
167
neonatal respiratory activity
irregular with spontaneous changes alternating between eupnea, apnea, periodic breathing, and tachypnea
168
laryngeal chemoreflex
reflex-induced apnea
| response to instilling saline in the oropharynx
169
Hering-Breuer reflex
Stimulation of pulmonary stretch receptors through increasing lung volume causes shortening of inspiratory time, prolongation of expiratory time, or both
prevents long overdistention on CPAP
170
breathing neurotransmitters
adenosine, GABA, prostaglandins, endorphins, and serotonin(SIDS)
171
apnea
the cessation of breathing for greater than 15-20 seconds. Shorter events (<15 seconds) may also be identified as apnea if accompanied by oxygen desaturation and bradycardia
172
apnea types
central, obstructive, mixed
173
ABD definition
defined as >10 seconds if accompanied by bradycardia (HR <100 beats/minute) and desaturation (SpO2 <80%)
174
apnea clinical association
sepsis
intracranial hemorrhage, hypoxic-ischemic encephalopathy, and brain malformations
NEC
RSV
anemia
hypoglycemia, hypocalcemia and electrolyte imbalances, temperature instability, and metabolic acidosis
opiates, benzodiazepines, magnesium sulfate, and prostaglandin
175
ALTE vs BRUE
apparent life-threatening event(old definition) vs Brief Resolved Unexplained Events(new terminology)
176
apnea treatment
HFNC
Methylxanthines: aminophylline
theophylline and caffeine
Xanthine
177
nasal and nasopharyngeal lesions
```
Pyriform Aperture Stenosis
Nasolacrimal Duct Cysts
Choanal Atresia
Congenital Nasal Masses
Nasopharyngeal Teratoma
Mucosal Obstruction
Continuous Positive Airway Pressure Trauma
```
178
Oral and Oropharyngeal Lesions
micrognathia, glossoptosis, and posterior tongue displacement and subsequent airway obstruction
Pierre Robin sequence, Treacher Collins syndrome, Goldenhar syndrome, Crouzon disease, Down syndrome
Lymphatic Malformations
Oral Cavity Cysts
179
Laryngeal Lesions
```
Laryngomalacia (stridor)
Bifid or Absent Epiglottis
Laryngeal Cysts
Vocal Cord Paralysis
Laryngeal Web
Congenital Subglottic Stenosis
Subglottic Hemangioma
Laryngeal Cleft
Congenital high airway obstruction syndrome (CHAOS)
Intubation Trauma
```
180
Bronchopulmonary dysplasia
the most important respiratory complication of preterm birth, and it is associated with long-term respiratory morbidities
181
NIH BPD definition
severity-based definition of BPD into three categories based on the duration and level of oxygen therapy required:
mild
moderate
severe
182
BPD pathogenesis
injury to developing lung secondary to prolonged mechanical ventilation with high airway pressures and inspired oxygen concentration
183
BPD pathogenic factors
prematurity
pre- and postnatal infections
mechanical trauma from positive pressure ventilation
oxygen toxicity
pulmonary edema secondary to increased pulmonary blood flow from patent ductus arteriosus (PDA) acts on the immature alveolar and vascular structure of the immature lung
184
BPD pulmonary functions
low compliance, low to normal functional residual capacity (FRC), and high airway resistance
fibrosis, edema, overdistention, and collapse of lung parenchyma
increased work of breathing that contributes to the hypoventilation and hypercapnia
minute ventilation increased
CO2 retention
hypoxemia and require supplemental oxygen to maintain acceptable oxygenation levels
185
does surfactant reduce BPD
no
186
what can reduce BPD?
steroids NO
less invasive ventilation MAYBE/individualized
volume-targeted ventilation
targets in oxygen saturation (low YES, but cause NEC)
postnatal systemic corticosteroids YES, has side effects
inhaled steroide YES, but side effects
caffeine YES
vit. A YES
iNO ?
187
postnatal systemic corticosteroids
decrease bronchospasm
188
management of established BPD
```
respiratory support
bronchodilator therapy
corticosteroids therapy
management of pulmonary hypertension
fluid management
nutrition
infection prevention
```
189
ECMO
Extracorporeal membrane oxygenation
190
ECMO definition
cardiopulmonary bypass support for term and late preterm infants with severe, life threatening, hypoxic respiratory failure. Affected infants present within the first 2 weeks of life, and the majority of these also have persistent pulmonary hypertension of the neonate
allowing the lung to rest and recover until pulmonary arterial pressures decline and blood flow to the lung is restored
191
iNO inhaled Nitric Oxide
a noninvasive inhalational therapy that can elicit selective pulmonary vasodilation
192
PPHN persistent pulmonary hypertension of the neonate
pulmonary vascular resistance approaches or exceeds systemic vascular resistance, offering significant impedance to pulmonary blood flow
193
PPHN desaturated blood
Desaturated blood returning to the right heart is shunted to the systemic circulation (following the path of least resistance) across one or both persistent fetal channels, the patent ductus arteriosus (PDA) and the foramen ovale, resulting in marked cyanosis
194
what diagnosis will benefit from surfactant?
MAS, RDS, or pneumonia
195
what diagnosis will NOT benefit from surfactant?
CDH and HRF, nor in infants with isolated PPHN
196
ECMO types
venoarterial (VA) bypass
| venovenous (VV) bypass
197
oxygenation on ECMO
varying blood flow through the ECMO circuit. The higher the volume of cardiac output diverted through the membrane lung, the better the oxygen delivery from the ECMO circuit
198
blood flow in ECMO
80-100ml/kg; weaning at 10-20ml/kg
no pressors and vasodilators needed
mild sedation
199
ECMO anticoagulation
Systemic anticoagulation therapy with unfractionated heparin: Activated clotting times (ACTs), antifactor Xa assays or Thromboelastography (TEG)
Bivalrudin if heparin can NOT be used because of HIT
200
ECMO ventilator support
"lung rest" on CMV rate 10; PEEP(use higher), PIP
| maintain FRC and to allow for continued pulmonary toilet
201
advantage of VV ECMO
avoidance of carotid artery cannulation, bot NO cardiac support provided to the infant
202
ECMO criteria
Gestational age of 34 weeks or older
Normal cranial ultrasound or stable grade I or II intraventricular hemorrhage
Absence of complex congenital heart disease
Less than 10-14 days of mechanical ventilation
Reversible lung disease, including congenital diaphragmatic hernia
Failure of maximum medical therapy
No lethal congenital anomalies or evidence of irreversible brain damage
203
ECMO oxygenation criteria
```
Oxygenation Index (OI): OI = (MAP × FiO2 × 100)/PaO2
The usual criterion is OI of 35-60 for 0.5-6 hours.
```
Alveolar-Arterial Oxygen (Aado2) Gradient (at Sea Level)
AaDO2 = FiO2 (P − 47) − PaO2 − PaCO2 (FiO2 + (1 − FiO2)/R)
Usual criterion is AaDO2 > 605-620 mm Hg for 4-12 hours.
Partial Pressure of Arterial Oxygen
Usual criterion is PaO2 < 60 mm Hg for 2-12 hours.
Acidosis and Shock
Usual criterion is pH < 7.25 for longer than 2 hours or with hypotension
204
what exam needs to be done before ECMO
ECHO to R/O serious congenital heart disease
205
potent vasodilators
tolazoline, nitroprusside, prostoglandin E and prostoglandin D
206
Nitric Oxide NO
inhaled NO decrease pulmonary vascular resistance and improve pulmonary blood flow without compromising systemic blood pressure or worsening V/Q mismatch
207
NO life
short-life (seconds) dose 5-20ppm
208
testing for NO toxicity
methemoglobin
209
treatment alternative to iNO
Revatio (Sildenafil PDE5)-long-term not recommended
| Milrinone
210
tidal volume
amount fo gas moved during one normal inspiration and expiration
211
Functional Residual Capacity FRC
volume of gas left in the lung after a normal expiration
212
residual volume
minimum lung volume possible-air left in lung after max expiration
213
vital capacity
maximum amount of air that can be moved
214
total lung capacity
total amount of volume present in lung
215
minute volume
combination of tidal volume and respiratory rate
216
anatomic dead space
part of airway where NO gas exchange occurs
217
physiological deas space
alveoli that is ventilated but under or not perfused
218
V/Q ratio
balance between ventilation (airflow at the alveoli) and perfusion (blood flow entering the lungs)
219
V/Q mismatch
lungs are ventilated but not perfused
or lungs are perfused but not ventilated
leads to hypoxemia and hypercarbia
220
lung development is completed by what age?
16-18 years of age
221
asphyxia symptoms
progressive hypoxia, hypercarbia, acidosis
222
side effects of Prostoglandin E
apnea or respiratory depression
223
side effect of methylxanthine
gastroesophageal reflux
224
anatomic dead space
conducting airway
225
wasted ventilation
the amount of ventilation that does NOT participate in gas exchange
226
oxyhemoglobin dissociation curve
a relation between dissolved oxygen and the affinity for oxygen by the hemoglobin molecule
227
oxyhemoglobin curve shifts to the right
caused by decrease in pH
228
oxyhemoglobin dissociation curve shifts to the left
caused by increase in pH
229
chronic hypoxia caused what electrolyte imbalance
decreased chloride
230
respiratory distress may lead to what?
hypoglycemia
231
false reading on pulse oximetry is due to what?
phototherapy
232
PEEP may cause an increase in what?
PVR pulmonary vascular resistance
233
increased PEEP cause what?
barotrauma
234
what factor increases PVR
sepsis
235
side effect of surfactant
pulmonary hemorrhage
236
normal ABG values
pH (between 7.35 - 7.45);
CO2 (between 35 - 45 mmHg);
HCO3 (22-26 mEq/L)
237
"sigh: setting in HFV
decrease microatelectasis and recruit alveoli
238
how antenatal steroids work?
accelerate the rate of glycogen depletion
| results in thinning the intra-alveolar septa and increases the size of the alveoli.
239
burned out xray
over exposed xray
240
intrauterine pass of meconium theory include what?
maternal HTN
