Pediatric Lung Diseases Flashcards
(42 cards)
1
Q
Respiratory Distress Syndrome aka?
A
Hyaline Membrane Disease
2
Q
Most common cause of respiratory failure in preterm infant
A
RDS
3
Q
- Lung disease in a preterm infant resulting from what?
- Major cause of morbidity and mortality in infants born prior to ___ wks gestation
- What has changed clinical course and decreased morbidity and mortality rates?
A
- insufficient surfactant
- 30
- Exogenous surfactant
4
Q
Incidence and severity ↑’d in male infants. Why?
A
↑’d circulating androgens ↓ lung maturity and surfactant production by type II pneumocytes
5
Q
Risk factors:
Increased Incidence
in the following?
6
A
- Low gestation
- Male sex
- White race
- Maternal diabetes
- C-section pre-onset of labor
- Perinatal asphyxia
- Maternal hypertension
6
Q
Why is maternal diabetes a risk factor for RDS?
A
↑’d insulin ↓’s lung maturation and surfactant production
7
Q
Risk factor: Decreased incidence for RDS?
4
A
- Prolonged rupture of membranes
- Chronic congenital infections
- Maternal substance abuse
- Antenatal corticosteroid exposure
8
Q
2 Major Issues in PP of RDS?
A
Immature lungs
Lack of surfactant
9
Q
Infants may be born in:
what of lung development? (two stages)
At these stages what developmental issues might be a problem? 2
A
- Canalicular stage
16-26 wks - Saccular stage
24-38 wks - May have primitive airspaces with undifferentiated pneumocytes
- No juxtaposition of airway epithelium and capillaries
10
Q
What happens during the canalicular phase of development in the fetus for the lungs? 3
A
- Last generations of the lung periphery formed
- Epithelial differentiation
- Air-blood barrier formed
11
Q
What happens during the saccular phase of development in the frtus for the lungs? 2
A
- Expantion of air spaces
2. Surfactant detectable in amniotic fluid
12
Q
Surfactant:
- Appears in fetal lung at _____wks
- Made by what cells?
- Adequate amounts not produced until about ___ wks
- What are the functions of surfactant? 3
A
- 23-24
- type II pneumocyte
- 35
- Reduces surface tension in alveolar spaces
- Facilitates lung expansion
- Prevents alveolar collapse
13
Q
Very premature infants frequently have:
2
These may further contribute to what?
A
- Excessively compliant chest walls
- Weakness of the respiratory muscles
Alveolar collapse
14
Q
Pathophysiology of RDS?
7
A
- Alveolar collapse alters nl ventilation/perfusion relationship
- Produces pulmonary shunting → progressive arterial hypoxemia → metabolic acidosis
- Hypoxemia and acidosis → vasoconstriction → decreased pulmonary blood flow (pulmonary hypertension)
- May produce R→L shunting through PFO and PDA → worsening hypoxemia
- Pulmonary blood flow may subsequently increase
- –Decreased vascular resistance and persistence of PDA - ↑’d pulmonary blood flow leads to accumulation of fluid and protein in interstitial and alveolar spaces
- Protein in alveolar spaces deactivates surfactant
15
Q
- Atelectasis and ↑’d dead space → ?
- Intrapulmonary and extrapulmonary shunting → ?
- Atelectasis, ↑PaCO2, hypoxemia →?
- ↑PaCO2 → ?
- Hypoxemia → ?
A
- ↑PaCO2
- hypoxemia
- tachypnea
- respiratory acidosis
- metabolic acidosis
16
Q
Hyaline Membrane Disease aka?
A
RDS
17
Q
- Lungs appear how?2
- _____________ line most of remaining airspaces
- Hyaline membranes are made up of what that has leaked from where?
- HMD and epithelial necrosis is less severe in infants treated with what?
A
- solid and
- congested with diffuse atelectasis
- Hyaline membranes
- plasma proteins leaked from damaged epithelium
- surfactant
18
Q
Clinical Course:
- PE? 5
- CXR will show? 3
- Blood gas will show? 3
A
Physical exam
- progressive tachypnea,
- subcostal and sternal rtxns,
- grunting,
- cyanosis and
- ↓ breath sounds present in minutes to hours of life
CXR
- ↑ density of both lung fields with reticulogranular infiltrates,
- air bronchograms, and
- elevation of diaphragm
Blood gas
- Hypoxemia,
- hypercarbia, and
- metabolic acidosis
19
Q
- Severity of respiratory failure ↑’s during first ___ days of life
- In infants > ______ wks respiratory status usually improves by 1 wk of life
- In infant less than ____ wks course is usually prolonged and complicated by what? 5
A
- 2-3
- 32-33
- 26-28
- volutrauma and/or
- barotrauma,
- PDA,
- infection, and
- intraventricular hemorrhage
20
Q
- Treatment of HMD/RDS?
- What does it decrease the need for?
- Reduces incidence of what?
A
- Exogenous surfactant has drastically changed course of disease
- Rapidly ↓’s need for oxygen and mechanical ventilation
- Reduces incidence of gas leaks
21
Q
Other treatment measures:
- Where should treatment take place?
- Monitoring of what?
- Adequate respiratory support that includes?
A
- Careful stabilization in delivery room and NICU
- Proper monitoring of cardiopulmonary function
- Oxygen,
- CPAP,
- mechanical ventilation
Proper thermal, metabolic and nutritional support
22
Q
Prevention of RDS?
2
A
- Prevention of premature delivery
2. Antenatal corticosteroids
23
Q
How do Antenatal corticosteroids help with prevention of RDS?
3 (on what kind of timeline?)
What happens after 24 hours on steriods?
A
Rapid change (within 15 hrs) in lung structure
- Improved compliance
- ↑’d lung volume
- ↓’d capillary protein leak
Slower (>24 hrs) ↑ synthesis and secretion of surfactant by type II cells
24
Q
Complications of RDS? 2
What may this be seen with administration of?
Usually occurs when and with what kind of severity?
A
- Hemorrhagic pulmonary edema
- Capillary rupture and interstitial fluid
May be seen with exogenous surfactant
- Usually occurs in first 5-7 days of life
- May be rapidly fatal
25
What kind of pathophysiological features lead to these complications?
1. Low lung volumes
2. Air bronchograms/atelectasis
3. hyponatremia
Need to give O2 early?
26
SIDS definition?
“the sudden unexpected death of an infant less than 1 year of age, with onset of the fatal episode apparently occurring during sleep, that remains unexplained after a thorough investigation, including performance of a complete autopsy and review of the circumstances of death and the clinical history”
27
1. Relative sparing during ___ month of life with sharp ↑ in ____ month of life
2. Peak incidence at ____of age
3. 75% of deaths occur between ________ age
4. 95% occur before ____ of age
5. Age based on what?
6. Occurs predominantly during the _____?
1. 1st, 2nd
2. ~ 3 months
3. 2 and 4 mo
4. 9 mo
5. gestational
6. night
28
Considered the most important preventable risk factor for SIDS
-The ↑ in risk is dose dependent
Risks from this may include? 4
Maternal smoking
-Risk further ↑’d if both parents smoke
1. Fetal hypoxemia
2. Inhibition of airway growth and development
3. ↓’d ability to arouse to noxious stimuli
4. ↑’d susceptibility to respiratory tract infections
29
1. Pacifiers: Shown to reduce what?
2. AAP recommends pacifier use throughout the day until __ months
3. AAP recommends pacifier use at night while sleeping until ___ months
1. arousal threshold
2. 6
3. 12
30
Prone position is a risk for to develop what?
why?
1. hypercapnia
1. Rebreathing of expired air
2. Hypoxemia
3. Upper airway closure
4. Arousal deficit
31
CF: Syndrome of what three things?
1. chronic sinopulmonary infections,
2. malabsorption and
3. nutritional abnormalities
32
1. CF gene encodes for what?
2. CFTR functions as an ___________and controls the movement of what?
3. Mutations in the CF gene impairs this movement, critically altering ________ in the lung?
1. the cystic fibrosis transmembrane conductance regulator (CFTR) protein
2. ion channel, salt and water into and out of cells
3. host defense
33
Organ Dysfunction in CF:
1. Sinuses – 2?
2. Lung – 2?
3. Pancreas – 2?
4. Intestine – 2?
5. Liver – 1?
6. Vas Deferens – 1?
7. Sweat gland – 1?
1.
- Sinusitis,
- nasal polyps
2.
- Endobronchitis,
- bronchiectasis
3.
- Exocrine Insufficiency
- CF Related Diabetes
4.
- Meconium ileus
- Constipation/DIOS
5. Focal sclerosis
6. failure to develop
7. salt-losing dehydration
34
1. What kind of inheritance is GF?
2. What chromosome is the CF gene found on?
3. What is the most common mutation?
1. Autosomal recessive inheritance
2. CF gene is a large gene on chromosome 7
3. ΔF508 is the most common mutation
35
CF diagnosis:
1. Rosenstein et al, 1998 – Cystic Fibrosis Foundation consensus conference? 3
2. Guidelines for Diagnosis of Cystic Fibrosis in Newborns through Older Adults: Cystic Fibrosis Foundation Consensus Report (Farrell et al, 2008)?
3
1.
- One or more symptoms or positive “newborn screen”
- Known mutations
- CFTR dysfunction – Sweat chloride, epithelial potential diff.
2.
- Cystic Fibrosis is a clinical diagnosis
- Newborn screening – Sweat Electrolytes, Mutations
- Emphasis on the Process
36
-CFTR Carrier Testing
2 tests
-how many mutations do they detect?
-turnaround time?
1. Genzyme Genetics
97 CF mutations
Turnaround time ~1-2 weeks
2. Ambry Genetics
~1,300 CF mutations
Turnaround time ~ 1 month
37
“End Stage” Lung Disease in CF
What do you find? 4
1. Bronchiectasis
2. Infection
3. Inflammation
4. Mucous Plugging
38
Severe airflow obstruction
FVC>FEV1>FEF25-75 and
Increased RV, FRC lead to what?
3
1. Abnormal distribution of ventilation
2. Decreased exercise tolerance
3. Abnormal oxygenation
39
What bacteria is most prevalent in infections in CF patients below the age of 17?
After 17?
Staph aureus
Pseudomonas
40
Current Treatments
| 8
1. Airway clearance therapy
2. Antibiotics – inhaled (TOBI®), oral, IV
3. Inhaled mucolytics
4. Bronchodilators
5. Enzyme replacement
6. Fat soluble vitamins – A, D, E, K
7. Azithromycin®
8. Ibuprofen
41
What meds are there for airway clearance?
| 5
1. CPT,
2. Flutter®,
3. Acapella®,
4. Vest®,
5. IPV
42
What meds are there for inhaled mucolytics?
| 2
1. Pulmozyme®,
| 2. hypertonic saline
