Neonatology Flashcards
When does the CVS start developing ?
Third week (heart starts beating at the beginning of the fourth week)
Describe how the foetal circulation works
- Oxygenated blood via the umbilical vein: ductus venosus
- Some blood via foramen ovale to left atrium - left ventricle - aorta
- Some blood to right ventricle to pulmonary artery
- Patent ductus arteriosus from PA to Ao
- Saturation SaO2 in foetal body is 60-70%
What is the function of ductus arteriosus?
- Protects lungs against circulatory overload
- Allow the right ventricle to strengthen
- Carries low oxygen saturated blood
What is the ductus venosus?
A foetal blood vessels connecting the umbilical vein to the IVC (blood flow regulated via sphincter) which carries mostly oxygenated blood
What happens to the foetal circulation after birth?
- Ductus arteriosus becomes a ligament
- Foramen ovale closes and leaves a depression
- Ductus venosus becomes a ligament
- Umbilical vein becomes a ligament
- Umbilical arteries become ligaments
What are the normal signs of a full term newborn?
- HR: 120-160 bpm
- RR: 30-60/min
- BP 1hr age: systolic is 70
- BP after 1 day: systolic is 70 +/- 9
- BP after 3 days: systolic is 77 +/- 12
How do babies thermoregulate?
- Maternal thermoregulation in the womb
- Newborn babies lack shivering thermo genesis thus needs a metabolic production of the heat
- Brown fat well innervated by symp. neurons
- Cold stress leads to lipolysis and heat production
How can babies lose heat?
- Radiation
- Convection: heat loss by moving air
- Evaporation: we are born in water
- Conduction: heat loss to surface on which the baby lies
How can a newborn baby’s breathing be assessed?
- Blood gas determination
- PaCO2 5-6 kPa and PaO2 8-12 kPa
- Transcutaneous pCO2/O2 measurement
- Capnography
- Minute ventilation
- Flow volume loop
When is jaundice in a neonate physiological?
- Appears on day 2-3
- Disappears within 7-10 days in term infants and up to 21 days in premature infants
How can jaundice be treated?
- Phototherapy
- Exchange transfusion
How does fluid change in a newborn?
- Weight loss up to 10% is normal: shift of interstitial fluid to intravascular and diuresis
- It is normal not to pass urine for the first 24hrs
- Slower GFR
- Increased insensible water loss
At what weight is a baby born too small?
2500g
What are the causes of babies being small for their dates?
- Maternal: pre-eclampsia
- Foetal: chromosomal, infection
- Placental: placental abruption
- Twin pregnancy
What are the common problems for a baby who is born too small for their dates?
- Perinatal hypoxia
- Hypoglycaemia
- Hypothermia
- Polycythaemia
- Thrombocytopenia
- GI problems (feeds, NEC)
What are the long term problems for a baby who is born too small for their dates?
- Hypertension
- Reduced growth
- Obesity
- Ischaemic heart disease
When is a baby classed as preterm?
- Preterm = <37 weeks
- Extremely preterm = <28 weeks
What can happen to a preterm baby’s respiratory system and how can it be managed?
- RDS
- Prevention: antenatal steroids
- Early treatment: surfactant
- Early extubation: N-CPAP and minimal ventilation
What are the potential consequences of mechanical ventilation in preterm babies?
- BPD/CLD
- Overstretch by volu-baro-trauma
- Atelectasis
- Infection via ETT
- O2 toxicity
- Inflamm. changes
- Tissue repair: scarring
How can BPD/CLD be treated?
- Patience
- Nutrition and growth
- Steroids
What are the minor respiratory problems that can occur in preterm babies and how can they be treated?
- Apnoea
- Irregular breathing
- Desaturations
- Caffeine and N-CPAP
What can happen in the brain of a preterm baby?-
- Intraventricular haemorrhage
- Peri-ventricular leucomalacia (poorly developed white matter around the ventricles
How can IVH be managed in preterm babies?
- Prevention: antenatal steroids
- Treatment: symptomatic and ?drainage
What are the consequences of PDA?
- Lung oedema and systemic ischaemia
- Worsening of resp symptoms
- Retention of fluids: low renal perfusion
- GI ischaemia: necrotising entero-colitis
What is NEC and how is it treated?
- Ischaemic and inflammatory changes
- Necrosis of the bowel
- Surgical intervention is often required
- Conservative: antibiotics and parental nutrition
What are the nutritional requirements of a preterm baby?
- Enormous requirements
- Patients often triple their size during hospital stay
What are the risk factors for sepsis in term babies?
- PROM (premature rupture of membranes
- Maternal pyrexia
- Maternal Group B Strep carriage
How is presumed sepsis managed in term babies?
- Admit to NNU
- Partial septic screen (FBC, CRP, cultures) and blood gas
- Consider CX/LP
- 1st line: IV penicillin and gentamicin
- 2nd line: IV vancomycin and gentamicin
- Add metronidazole if surgical/abdo concerns
- Fluid management and treat acidosis
- Monitor vital signs and support resp and CVS systems as required
Which organisms commonly cause neonatal sepsis?
- Group B Strep
- E coli
- Listeria
- Coagneg staph (lines in situ
- H influenzae
What are the complications of Group B Strep sepsis?
- Meningitis
- DIC
- Pneumonia
- Respiratory collapse
- Hypotension
- Shock
What are the potential consequences of congenital infections?
- IUGR
- Brain calcifications
- Neurodevelopmental delay
- Visual impairment
- Recurrent infections
- Microcephaly
- Deafness
- Heart defects: cardiomegaly or PDA
- Bone abnormalities
- Anaemia, neutropenia and thrombocytopenia
- Pneumonitis
What are the features of transient tachypnoea of the newborn (TTN)?
- Self limiting
- Presents within 1st few hours of life
- Grunting, tachypnoea, oxygen requirement and normal gases
- Delay in clearance of foetal lung fluids
How can TTN be managed?
- Supportive
- Antibiotics
- Fluids
- O2
- Airway support
What are the risk factors for meconium aspiration?
- Post dates
- Maternal diabetes
- Maternal hypertension
- Difficult labour
What are the symptoms of meconium aspiration?
- Cyanosis
- Increased work of breathing
- Grunting
- Apnoea
- Floppiness
How can meconium aspiration be investigated?
- Blood gas
- Sepsis screen
- CXR
How can meconium aspiration be treated?
- Suction below cords
- Airway support: intubation and ventilation
- Fluids and IV antibiotics
- Surfactant
- NO or ECMO
Which investigations should be done for the “blue baby”?
- History and exam
- Sepsis screen
- Blood gas and blood glucose
- CXR
- Pulse oximetry
- ECG and ECHO
- (Hyperoxia test - 100% oxygen for ten minutes to see if it improves their blood gas)
What are the differentials for a blue baby?
- TGA
- Tetralogy of Fallot
- TAPVD
- Hypoplastic left heart syndrome
- Tricuspid atresia
- Truncus arteriosus
- Pulmonary atresia
How can hypoglycaemia be managed in neonates?
- Possible admission to NNU
- Enteral feed is possible
- Monitor blood glucose
- Start IV 10% glucose
- Increase fluids
- Increase glucose conc. (needs central IV access)
- Glucagon
- Hydrocortisone
What are the risk factors for developing hypoglycaemia in a new born?
- Gestational diabetes
- Big babies
- Twin to twin transfusion - IUGR
How can hypothermia be managed in newborns?
- Incubation
- Sepsis screen and antibiotics
- Consider thyroid function
- Monitor blood glucose
What are the causes of birth asphyxia?
- Placental problem
- Long, difficult delivery
- Umbilical cord prolapse
- Infection
- Neonatal airway problem
- Neonatal anaemia
Describe the stages of birth asphyxia
- 1st: cell damage occurs (within minutes without O2)
- 2nd: reperfusion injury due to toxin release (days-weeks)
How can hypoxic ischaemic encephalopathy be managed
- Supportive
- Fluid restriction
- Monitor for renal and liver failure
- Resp and CVS support
- Treat seizures
- Therapeutic hypothermia
What are the causes of failure to pass stool in newborns?
- Constipation
- Large bowel atresia
- Imperforate anus +/- anus
- Hirschsprungs disease
- Meconium ileus
How does a diaphragmatic hernia present and how can it be managed?
- Males>females
- Can be syndromic
- Usually pulmonary hypoplasia
- Intubation, resp support, surgery and ECMO
What is neonatal abstinence syndrome?
-Withdrawal from an addictive substance taken by the mother during pregnancy (opioids, BZDs, cocaine, amphetamines etc.)
How can neonatal abstinence syndrome be diagnosed and monitored?
- Finnegan scores
- Urine toxicology
- Maternal comorbidity
- Social and discharge planning
How can neonatal abstinence syndrome be treated?
- Comfort e.g. swaddling
- Morphine
- Phenobarbitone
What investigation might you do in a baby with plethora?
FBC
What are the three components of the energy triangle?
- Pink
- Warm
- Sweet
What are the symptoms of hypoglycaemia in a baby?
- Jitteriness
- Temp instability
- Lethargy
- Hypotonia
- Apnoea and irregular respirations
- Poor sucking/feeding
- Vomiting
- High pitched or weak cry
- Seizures
- Can be asymptomatic
Which areas should be assessed for retraction in a baby
- Substernal
- Subcostal
- Intercostal
- Suprasternal
Which issues are associated with cleft lip/palate?
- Feeding issues
- Airway problems
- Associated anomalies: need hearing screen, ECHO and remember genetic abnormalities
Which conditions can be picked up on red reflexes of the eye?
- Cataracts
- Retinoblastoma
Which abnormality is associated with spinal dimples?
Spina bifida
How can fixed talipes (clubfoot) be managed?
- Vigorous manipulation
- Strapping
- Casting
- Surgery
