Neonatology Flashcards
When does the cardiovascular system begin to develop?
End of the third week
When does the heart begin to beat?
Beginning of the fourth week
When is the critical period of heart development?
Day 20-50 after fetilisation
Where does oxygenated blood originate from in foetal circulation?
Umbilical vein
Passes through Ductus Venosus
What is ductus venosus?
Foetal blood vessel connecting umbilical vein to IVC
What type of blood is carried by ductus venosus
Mostly oxygenated
How does blood get to the foetal aorta from the right atrium?
Passes through foramen ovale (to LA->LV->Aorta)
Passes from Right Ventricle (to PA -> through Patent Ductus Arteriosus->Aorta)
What is the saturation of foetal blood?
60-70%
What is the function of ductus arteriosus?
- Protect lungs against circulatory overload
- Allows right ventricle to strengthen
- Carries low oxygen saturated blood
What does the ductus arteriosus go on to become?
A ligament
What does the ductus venosus go on to become?
A ligament
What does the umbilical vein go on to become?
A ligament
What do the umbilical arteries go on to become?
Ligaments
What happens to foramen ovale after birth?
Closes and leaves depression
What is normal newborn respiratory rate?
30-60 breathes per minute
Periodical breathing
What is normal newborn heart rate?
120-160 b/min
What defines tachycardia in a newborn?
> 160 b/min
What defines bradycardia in a newborn?
<100 b/min
What factors help to regulate temperature in newborns?
Brown fat - lipolysis triggered by cold -> heat production
In utero - maternal thermoregulation
What are some non-invasive methods of measuring newborn respiratory function?
- Blood gas determination
- Trans-cutaneous pCO2/O2 measurement
What are some invasive methods of measuring newborn respiratory function?
- Capnography
- (Tidal volume -> Minute ventilation)
- Flow-volume loop
On what day does physiological jaundice present?
DOL 2-3
Disappears ~7-10 DOL in term, <21 in premature
What irreversible change in the brain can be caused by high levels of bilirubin?
Kernicterus
What treatments are available for newborn jaundice?
Exchange transfusion
Phototherapy
What are fluid losses caused by in newborns?
- Shift of interstitial fluid
- Diuresis (But normal not to pass urine for first 24hrs)
What are fluid losses caused by in premature infants?
- Increased loss through kidney (Slower GFR, Reduced Na reabsorption,
- Increased Insensible Water Loss
What causes physiological anaemia of newborn?
Reduced RBC production compared to in uterus
Increase in EPO between wk 10-20
What causes anaemia of prematurity?
- Reduced erythropoeises
- Infection
- Blood letting
What is classified as small for gestational age?
-Born under 10th weight centile
What is classified as severe small for gestational age?
-Born under 0.4th weight centile
What are some maternal causes for small for gestational age?
- Maternal smoking
- Maternal Pre-Eclamptic Toxemia (PET)
What are some foetal causes for small for gestational age?
- Choromosomal abnormalities (Trisomy 18)
- Foetal Infection (eg CMV)
What are some placental causes for small for gestational age?
-Placental abruption
Why can twin pregnancies result in small for gestational age babies?
-Donated circulation from one baby to another
What are some common problems associated with small for dates?
- Perinatal Hypoxia
- Hypoglycaemia
- Hypothermia
- Polycythaemia
- Thrombocytopenia
- Hypoglycaemia
- GI problems
- RDS, Infection
What are some long term problems associated with small for dates?
- Hypertension
- Reduced growth
- Obesity
- Ischemic heart disease
What is classifies as premature?
<37 weeks
What is classified as extremely premature?
<28 weeks
What is classified as low birth weight?
<2.5kg
Very low - <1.5, Extremely - <1
What is used for prevention of respiratory distress syndrome (RDS)?
Antenatal steroids
What can be used in treatment of broncho-pulmonary dysplasia (BPD/CLD)?
- Patience
- Nutrition and growth
- Steroids (Dex)
What can be used in treatment of broncho-pulmonary dysplasia?
Patience
Nutrition and growth
Steroids
What treatment may be used for minor breathing problems (Apnoea, irregular breathing, desaturations)?
- Caffeine
- NCPAP
What treatment may be used for Intraventricular haemorrhage?
Prevention - AN steroids
Treatment - Sympthomatic
Drainage?
What can be the result of patent ductus arteriosus (PDA)?
- Worsening respiratory symptoms (Over-perfusion of lungs>Oedema)
- Systemic ischaemia (eg GI ischaemia)
- Retention of fluids
- GI problems
What treatments are available for Necrotising Entero-Colitis (NEC)?
- Surgical intervention often needed
- Conservative management sometimes possible (Antibx + Parenteral nutrition)
What are the outcomes of extreme prematurity?
1/3 dies
1/3 normal life/mild disability
1/3 moderate/severe disability
What treatments are used in Post-Haemorrhagic Hydrocephalus?
Shunting (Peritoneal)
Roughly under what birth weight would be considered small for gestational age at term?
2.5kg
What is used in early treatment of respiratory distress syndrome?
Surfactant
Early extubation
Non-invasive support
Minimal ventilation
What features may be seen in bronchopulmonary dysplasia (BPD/CLD)?
- Overstretch by volu-baro-trauma
- Atelectasis
- Infection via ETT
- O2 toxicity
- Inflammatory changes
- Tissue repair - scarring
-What are the reasons that cause physiological jaundice in newborns?
-Increased red cell breakdown
Plus
-Immaturity of hepatic enzymes
-> Unconjugated hyperbilirubinaemia
When should jaundice be considered always pathological?
If <24 hours
What may plethora be potentially caused by?
Polycythaemia
What is erythema toxicum?
A maculo-papular rash common in normal term neonates.
Fades by end of first week
What are mongolian blue spots?
Blue-grey pigmentations on lower back + buttocks - caused by accumulation of melanocytes
What is a naevus simplex?
Flat pink lesion caused by capillary dilatation. Commonly at forehead and back of neck - gradually fades
What is a port wine stain (naevus flammeus)?
Flat/slightly raised wine-coloured lesion caused by mature dilated capillaries in superficial dermis. Do not regress.
(Associated with Sturge Weber + Klippel-Trenaunay)
What is a strawberry naevus?
Raised and bright red lesion with discrete lesions - caused by a cluster of dilated capillaries.
Usually regresses after 1 yr.
What are the three major considerations of the ‘energy traingle’?
Hypothermia
Hypoglycaemia
Hypoxia/anoxia
What are some risk factors of hypoglycaemia in neonates?
Limited glucose supply -Premature babies -Perinatal stress Hyperinsulinism -Infants of diabetic mothers Increased glucose use -Hypothermia -Sepsis
What is considered hypoglycaemia in neonates?
Blood sugar <2.0 mmol/l
List some symptoms of hypoglycaemia in neonates?
- Jitteriness
- Temperature instability
- Lethargy
- Hypotonia
- Apnoea, irregular respirations
- Poor suck / feeding
- Vomiting
- High pitched or weak cry
- Seizures
- Asymptomatic
How should cold stress be treated?
- Dry quickly
- Remove wet linens
- Use warm towels/blankets
- Provide radiant warmer heat
- Use heated/humidified oxygen
What areas of a baby can be used to assess for respiratory retractions?
- Substernal
- Subcostal
- Intercostal
- Suprasternal
What issues may be caused by cleft lip/palate issues?
Feeding issues
- Special bottles and teats
- Can still attempt breast feeding
Airway problems
Associated anomalies
- Need hearing screen
- Need cardiac echo
- Remember trisomies
What is the treatment of cephalohaematoma?
No treatment requires - resolution in 3-4 wks
List some signs of sepsis in neonates?
- Baby pyrexia or hypothermia
- Poor feeding
- Lethargy or irritable
- Early jaundice
- Tachypnoea
- Hypo or hyperglycaemia
- Floppy
- Asymptomatic
What are some neonatal risk factors for sepsis?
- PROM (Premature rupture of membranes)
- Maternal pyrexia
- Maternal GBS carriage
What is the management of presumed sepsis in a neonate?
-Admit
-Partial septic screen (FBC, CRP, blood cultures) and blood gas
-Consider CXR, LP
-IV penicillin and gentamicin 1st line
2nd line - vanc + gent
Add metronidazole if surgical/abdo concerns
-Fluid management
What are the commonest organisms that cause neonatal sepsis?
- Group B strep
- E.coli
- Listeria
- Coag-neg staphylococcii
- Haem. influenzae
What complications may arise from GBS sepsis?
-Meningitis, DIC, pneumonia and respiratory collapse, hypotension and shock
List some common causes for neonatal respiratory distress?
- Sepsis
- TTN (Transient tachypnoea of newborn)
- Meconium aspiration
What investigations should be used for ‘the blue baby’?
- Examination and history
- Sepsis screen
- Blood gas and blood glucose
- CXR
- Pulse oximetry
- ECG
- Echo
List some differential cardiac diagnoses for ‘the blue baby’?
- TGA
- Tetralogy of Fallots
- TAPVD
- Hypoplastic left heart syndrome
- Tricuspid atresia
- Truncus arteriosus
- Pulmonary atresia
What treatment should be used for hypoglycaemia in neonates in NNU?
- May manage with enteral feeds
- Monitor blood glucose
- Start IV 10% Glucose
- Increase fluids
- Increase glucose concentration
- Glucagon
- Hydrocortisone
What are some causes of birth asphyxia?
- Placental problem
- Long, difficult delivery
- Umbilical cord prolapse
- Infection
- Neonatal airway problem
- Neonatal anaemia
What are some causes of failure to pass stool in neonates?
- Constipation
- Large bowel atresia
- Imperforate anus +/- fistula
- Hirshsprung’s disease
- Meconium ileus (Think CF)
What treatments may be used for diaphragmatic hernia?
- Intubation at birth
- Respiratory support
- Surgery
- ECMO
What treatments may be used for Neonatal Abstinence Syndrome?
Monitoring - Finnegan Scoring
-Urine toxicology
Treatment
- Comfort
- Morphine
- Phenobarbitone
