Physiology Flashcards
What are the respiratory anatomical differences between children and adults?
Higher anterior larynx/floppy epiglottis means minor injuries and slight swelling can rapidly compromise their ability to breath
What are the cardiovascular anatomical differences between children and adults?
Smaller blood volume means minor blood losses can have major clinical implications
What are the musculoskeletal anatomical differences between children and adults?
infants have relatively large head and prominent occiput - necks flex easily when lying supine which may contribute to airway compromise
The lack of complete ossification of the ribs and sternum mean the underlying structures are less protected - leads to the potential for pulmonary/mediastinal injury to occur without significant signs of external injury
What anatomical difference between children and adults predisposes them to hypothermia?
Relatively large surface area compared to volume
When is a child’s death classified as a miscarriage?
Before 24 weeks gestation
When is a child’s death classified as a stillbirth?
Between 24 weeks and 40 weeks in utero
When is a child’s death classified as a perinatal mortality?
Between 24 weeks and 41 weeks out of utero
When is a child’s death classified as a neonatal mortality?
Between the birth and 4 weeks after birth
When is a child’s death classified as a post-neonatal mortality?
Between 4 weeks after birth and 52 weeks after birth
What is the most common paediatric presentation?
Bronchiolitis/URTI/Croup
What is classed as a preterm baby?
A birth that occurs before 37 completed weeks of gestation
What is classed as a term baby?
A birth between 37 weeks and 41 weeks of gestation
What is classed as a post term baby?
A birth after 41 weeks of gestation
What is the normal weight of a baby?
2.5kg-4.0kg (5.5 lbs to 8.8 lbs)
What is large for gestational age?
Over 4.0kg
What is small for gestational age?
Under 2.5kg
What events happen during the 3rd trimester?
Daily weight gain of 24g during 3rd trimester
Approx 7g of fat per day in last 4 weeks
Transplacental transfer - iron, vitamins, calcium, phosphate and antibodies.
What are the challenges for baby during labour?
During contractions, the baby is in a hypoxic environment
Foetal Hb helps release O2 to help with this
Prolonged labour reduces foetal reserves
Placental insufficiency can make it difficult for baby to cope with the hypoxia - many reasons including maternal smoking or drug use, pre-eclampsia
Growth restriction or excess can also make it difficult for baby
The stress baby experiences increases cortisol and adrenaline, which enhances perinatal adaptation.
How can growth restriction affect labour?
Lack of reserves to help during labour
How can growth excess affect labour?
Large baby can be difficult to get out
How does a baby adapt perinatally?
First breath/cry causes alveolar expansion, prompting the change from foetal to newborn circulation
Decreased pulmonary arterial pressure increasing PaO2
Early/immediate skin-to-skin and suckling
How can we measure the baby’s perinatal adaptation?
Through the apgar score
What is the normal apgar score?
More or equal to 8
How is the apgar score calculated?
Scored out of 10
0, 1 or 2 per component
Component’s include RR, HR, Responsiveness, Tone, Colour
What should be done for baby immediately after birth?
Keep baby warm
Skin-to-skin contact is important for establishing breast feeding
Well grown term infants have little calorific intake in the first 24 hours
Allow attachment - babies are often very alert immediately after delivery and regulates hormonal and emotional response to infant
How is haemorrhagic disease of the newborn prevented?
Vitamin K is given in the newborn period preferably IM but can be given orally
What infections should be screened for in the newborn?
Based on maternal history
Hep B - consider immediate vaccination/immunoglobulin
Hep. C
HIV
Syphilis
TB
Group B Strep
How are babies monitored?
Anticipatory methods used to monitor babies at risk such as the newborn early warning score
What vaccines should mum have had in pregnancy?
Pertussis and influenza
What other vaccines should be considered for babies?
Hep B at birth and BCG in first month - depending on risk factors
What screening tests are done for newborns?
Hearing screen
Around Day 5 - sickle cell disease, Cystic fibrosis, congenital hypothyroidism and inherited metabolic disease such as PKU, MCADD, IVA, GA1, HCU
When is the newborn examination done?
Carried out at around 24 hours of age
What is examined on the head in a newborn examination?
overlapping sutures, fontanelles, forceps marks, moulding, cephalhematoma, caput succedaneum
What is examined in the eyes in a newborn examination?
size, red reflex, conjunctival haemorrhage, squints, iris abnormality
What is examined on the ears in a newborn examination?
position, external auditory canal, tags/pits, folding
What is examined in the mouth in a newborn examination?
shape, philtrum, tongue tie, palate, neonatal teeth, ebsteins pearls, sucking reflex
What is examined in the face in a newborn examination?
facial palsy, dysmorphism
What is examined in the respiratory system in a newborn examination?
chest shape, nasal flaring, grunting, tachypnoea, in-drawing, breath sounds
What is examined in the cardiovascular system in a newborn examination?
colour/saturation, pulses - femoral, apex, thrills/heaves, heart sounds
What is examined in the abdominal system in a newborn examination?
moves with respiration, distension, hernia, umbilicus, bile stained vomiting, passage of meconuim, anus
What is examined in the genitourinary system in a newborn?
normal passage of urine, normla genitalia, undescended testes, hypospadius
What is examined in the MSK system in a newborn?
movement and posture, limbs and digits, spine, hip examination
What is examined in the neurological system in a newborn examination?
alert, responsive, cry, tone, posture, movement, primitive reflexes
What is examined on the skin in a newborn examination?
erythema toxicum, congenital dermal melanocytosis, naevus flammeus, strawberry hemangioma
What is classed as extremely preterm?
<28 weeks
What is classed as very preterm?
28-32 weeks
What is classed as moderate or late preterm?
32-37 weeks
What are the risk factors of a preterm birth?
> 2 preterm deliveries increases the risk of another premature baby by 70%
Abnormally shaped uterus increases the risk of giving birth early by 19%
Women are 9 times more likely to give birth early if they have a multiple pregnancy
Interval of <6 months between pregnancies
Conceiving through IVF
Smoking, drinking alcohol, using illicit drugs
Poor nutrition, some chronic conditions such as high BP and diabetes, multiple miscarriages or abortions
What are the issues for preterm baby in early life?
- need more help to stay warm
- have more fragile lungs
- don’t breathe effectively
- Have fewer reserves
How can be alter care for preterm babies?
- delay cord clamping if possible by 1-3 mins
- Keep baby warm - plastic bag and radiant heater and hat
- Gentle lung inflation - PEEP important
- Use of saturation monitor - careful use of oxygen
How does hypothermia occur in preterm babies?
- Thermal regulation is ineffective due to:
- Low BMR
- Minimal muscular activity
- Subcutaneous fat insulation is negligible
- High ratio of surface area to body mass
How can hypothermia be managed in preterm babies?
- Wrap or bags
- Skin-to-skin care
- Transwarmer mattress
- Prewarmed incubator