Exam #4: Pediatric Thorax & Lung Exam Flashcards
How is the chest wall in the infant and newborn different from adults?
1) At birth the ribs are composed mainly of cartilage & project at right angles from the spine
2) Rib cage is more circular
3) AP diameter to lateral diameter ratio DECREASES during the first three years
4) Stiffened rib cage (better for breathing)
How is the diaphragm of the infant different from the adult?
1) Angle of insertion in adults is oblique vs. HORIZONTAL in infants, which leads to DECREASED contraction efficiency
2) With age there is a change in the oxidative capacity of the muscle & neuromusuclar transmission undergoes maturation
Take home: Breathing gets easier as we get older; thus, breathing is HARDER & MORE EASILY FATIGUED for the infant
When does alveolar multiplication stop?
Roughly 2 years–>continues after birth
In addition to alveolar multiplication, what other changes happen in the lungs after birth?
1) Alveoli increase in size
2) Airway lumen increases
3) Capillary network remodels itself
*All of these improve breathing over time
What is the general take home message about the anatomical difference between the newborn lung & the adult lung?
1) Newborn anatomy is significantly different from the adult
2) Newborns are MORE susceptible to respiratory distress & failure
What are the initial steps of the respiratory examination?
General impression
A
B
Cs
What is the normal respiratory rate of the newborn (<28 day old)? How does this change with age?
40-60 bpm
Slows
Describe the breathing pattern in the infant.
- Obligate nasal breathers
- Periodic breathing is normal (irregular fast–>slow)
- Patterns differ during awake & sleep
What is apnea in the newborn?
Absence of breathing for >20 seconds
How long do you need to take a respiratory rate for in an infant?
1 min
How will respiratory rate change with a fever?
Increase
What can poor feeding be a sign of in an infant?
Respiratory distress
What immunization is often associated with post-tussive emesis?
Whooping cough
What is respiratory distress?
Both EFFORT & RATE
What are signs of respiratory distress in an infant?
1) Retractions
2) Head-bobbing
3) Grunting & moaning
4) Nasal flaring
How does sound transmission different from a pediatric patient to an adult?
Sound transmits EASIER due to relative lack of body mass
What is a technique to calm an older child while listening to lung sounds?
Don’t look at them
What is a way to make kids expire forcefully for lung sounds?
Ask them to blow the otoscope light out
How do you quiet an infant for cardiac exam?
- Feeding
- Parent holding
- Rocking
- Sleeping
- Pacifier
What is acrocyanosis? Is this a normal or abnormal finding?
Peripheral cyanosis that is normal in the neonate & not worrisome
- Hands & feet are blue but center is pink
What is central cyanosis? Is this a normal or abnormal finding?
Cyanosis in the central regions of the body; this is ALWAYS ABNORMAL
What is the hyperoxitest? When should it be implemented?
This is a test to determine the etiology of central cyanosis. This is how it is performed:
1) Check ABG
2) Provide 100% for 10 min
3) Recheck ABG
*If the rise of p02 is >100mmhg, the cause is probably pulmonary
Where is the apical impulse in the newborn?
4th or 5th intercostal space just medial to the midclavicular line
What can shift the apical impulse in the newborn?
Pneumothorax
Dextrocardia
Diaphragmatic hernia
What can an enlarged liver be an early sign of in the newborn?
Heart failure
What is the normal newborn heart rate?
120-160 bpm
At what point is the newborn heart rate not only slow, but also concerning?
Less than 100 bpm
What is the diagnosis of a fixed heart rate above 220 in a newborn?
SVT
*Note that this can lead to heart failure
What is diminished vigor of heart sounds indicative of in infants?
Heart failure
What is the difference between S1 & S2?
S2 is higher in pitch
Is it normal to hear heart murmurs in the first dew days after birth?
Yes
Outline the fetal circulation and major differences from the adult circulation.
- Umbilical vein brings OXYGENATED blood to the fetus from the placenta
- Half of this blood bypasses the fetal liver via the “Ductus Venosus”
- IVC–>RA–>LA “Foramen Ovale”
- Blood that makes it into the RV goes through the pulmonary trunk to the “Ductus Arteriosus” to the descending aorta, bypassing the fetal lungs
- Blood goes back to the placenta via the “Umbilical Arteries”
What is a Patent Ductus Arteriosus?
- Birth defect in which the Ductus Arteriosus (pulmonary tunk–>descending aorta) does not closure
- With changes after birth in the circulatory pressures, high aortic pressure shunts blood into the pulmonary trunk
What are the diagnostic indicators of a PDA?
1) “Machinery Murmur”
2) Harsh, loud, continuous murmur heard at the 1st- 3rd intercostal spaces and the lower sternal border
What is the likely etiology of weak pulses in the infant?
Low CO
Increased peripheral vasoconstriction
What is a “bounding” pulse associated with?
PDA
What is the likely etiology of diminished femoral pulses in the infant?
Coarctation of the aorta
What is Coarctation of the Aorta?
Coarctation of the Aorta is characterized by constriction of the aorta (varying length)
What is the definition of a hypertensive newborn?
BP > 80/50 mmHg
What is an innocent murmur?
- Common in the 3-7 age group
- Usually at the mid left sternal border
- Midsystolic
- 2-3/6 intensity
- Heard better supine or when holding breath
- More commonly heard during periods of higher metabolic rate (i.e. fever)
*Heard least when standing
List the indications for referral of the newborn to a Cardiologist.
1) Abnormal cardiac size
2) Abnormal EKG
3) Diastolic murmur
4) Loud murmur accompanied by a thrill
5) Cyanosis
6) Abnormally strong or weak pulses
How should you check capillary refill?
Above the level of the heart
What is normal capillary refill?
Less than 2 seconds
What are the three cardinal signs of a severe (life-threatening) CHD in the newborn?
1) Cyanosis
2) Decreased systemic perfusion
3) Tachypnea
What is the initial step in management of a patient with signs of life-threatening CHD?
Prostaglandin E (PGE)
