Neonatology Flashcards
Antenatal steroids are protective against (5)
NEC IVH RDS Systemic infection in the first 48 hours of life Neonatal mortality
Ventilation: PaO2 is influenced by… (3)
- FiO2
- MAP
- Gas exchange surface area and diffusion
Ventilation: PaCO2 is influenced by… (3)
- Tidal volume
- RR
- Gas exchange surface area and diffusion
Risk factors for cerebral palsy
Low birth weight
Chorioamnionitis
Elevated cytokines: IL-1, IL-6, IL-8, TNF-alpha
Maternal thyroid disease
Multiple births - twins x6 risk, triplets x15 risk
Maternal thrombophilia
Other congenital abnormalities
HHHFNC vs CPAP
- Post-extubation support: HHHFNC equivalent to CPAP
- Significantly less nasal trauma seen with HF - Primary respiratory support: CPAP superior to HHHFNC
Advantage and disadvantage of HHHFNC
- Mechanism: generation of pharyngeal pressure, supports inspiration, washes out deadspace, heating and humidification
- Advantage: less nasal trauma, can continue to breastfeed, parental/nursing preference
- Disadvantage: possibly remain on respiratory support for longer, no clear weaning regimen established
NIPPV
- CPAP with superimposed inflations set to peak pressure
- Mechanism:
- -> Pressure delivery: increased MAP, increases recruitment and FRC
- -> Decreased WOB
Advantages of NIPPV
- Reduced extubation failure –> more effectively than CPAP
- May benefit severe apnoea
- No increased GI side effects
Disadvantages for NIPPV
- No evidence for:
- -> Increased TV
- -> Reducing inflammation
- No effect on CNLD or mortality
Surfactant administration
- InSurE technique: intubate, surfactant, extubate
- Reduces need for ventilation and BPD
Synchronised ventilation vs IMV
- Significantly reduced risk of PTX and duration of ventilation
- No significant longer term effects on death or BPD
Volutrauma
- Causes significant lung injury (most significant)
- Mechanism in preterm:
- -> Very compliant chest walls - accepts high tidal volume
- -> Synergistic effects with biotrauma and oxytrauma
- -> Likely to receive resuscitation with manual ventilation
- In preterm lambs, lung injury due to:
- -> Oedema and air leak, inflammatory response, decreases lung compliance
Volume guarantee ventilation
Good for: - Rapidly changing compliance - Weaning - Post-surgery, relaxed muscle Bad for: - Large air leaks (>60%) - BPD - different areas of lung fill differently
Long-term benefits of VG ventilation vs pressure-limited ventilation
- Decreased death or BPD at 36wk CGA
- Decreased PTX
- Decreased duration of ventilation
- Decreased hypocarbia
- Decreased PVL w/ or w/o grade III-IV IVH
- Not associated with any increased adverse outcomes
Other complications of maternal gestational diabetes
- Temperature instability
- Hypocalcaemia
- Hypomagnesemia
- Cardiomegaly/HOCM
- Lumbosacral dysgenesis, caudal regression
- Small left colon syndrome
- Renal anomalies
- Renal vein thrombosis
Risk factors for prematurity
- Maternal age: extremes of age
- Maternal drug use
- Uterine malformation
- Cervical weakness e.g. previous midtrim pregnancy loss, cone Bx etc
- Multiple pregnancies
- Infection e.g. chorioamnionitis
- PIH/PET/Eclampsia: delivered early to maintain maternal health
- APH/placenta praevia
- Amniotic fluid volume: oligo and polyhydramnios
- Foetal anomalies
Magnesium sulphate
- Neuroprotective role for antenatal MgSO has been proven
- NNT to benefit 1 baby avoiding CP is 63
- Beneficial effect on gross motor development in EARLY childhood
- Administer before 30 weeks
Survival rates and gestational age
- Excluding babies who die before NICU admission/not resuscitated
- <24 wks: 43%
- 24 wks: 66%
- 25 wks: 84%
- 26 wks: 88%
- 27 wks: 94%
- 28-32 wks: 97%
Long-term outcomes of extreme prems
- Neurodisability can occur in <26 weekers, even in absence of obvious CNS damage/hamorrhage
- Higher than expected ADHD, autistic features, learning difficulties
- Final stature, IQ and visual function can all be impaired
- -> Still able to carry out activities of daily living
Preterm complications: pulmonary immaturity
- Apnoea
- RDS
- CLD
- PTX/air leak/pneumonia can occur
Preterm complications: fragile capillary network in subependymal area
- High risk of IVH –> esp in swings of cerebral perfusion pressure and CO2 levels
- Large IVH can cause venous infarction or hydrocephalus
Preterm complications: White matter injury
- PV white matter are susceptible to ischaemic damage esp if sensitised to foetal inflammation
- Preterms less able to tolerate asphyxia
Preterm complications: thermal instability
- Hypothermia exacerbates RDS and inc mortality
- If environmental temp low, baby will expend energy to generate heat at the expense of GROWTH
Preterm complications: feed intolerance
- Immature, absent suck-swallow and gag reflex
- Requires NG feeding
- Poor gut motility
Preterm complications: PDA
- Increases risk of heart failure
- RF for IVH, NEC and CNLD
- Increases shunting from aorta to pulmonary arteries –> pulm congestion and reduced systemic blood flow during diastole
Preterm complications: ROP
- Hyperoxia delays vascularisation of retina, VEGF release –> abN angiogenesis
- Peripheral retina becomes hypoxic
- Zones: periphery –> central
- Stages 1-5
- Plus dz: dilatation and tortuosity of posterior pole retinal vessels, assoc. w/ worse outcomes
Preterm complications: jaundice
- High RBC mass and poor liver conjugation –> hyperbili inevitable
- Poor BBB and acidosis –> higher risk of kernicterus
Preterm complications: renal immaturity
- Inability to concentrate urine or excrete an acid load, low HCO3 threshold
- Can result in late metabolic acidosis –> failure to gain wt
- Tx: NaHCO3 and breast feed/preterm formula feeds
Preterm complications: Metabolic disturbance
- Hypoglycemia, hypoCa, hypoMg, hypoNa, hypernat
- Rickets of prematurity due to low Phos > hypoCa
Preterm complications: infection
- Relative immunodeficiency, central and umbilical lines
- Maternal and nosocomial infections
Preterm complications: haematological
- DIC
- Vit K def
- Iatrogenic or Fe def anaemia
- Aim for haematocrit >0.35
- Physiological nadir ~5-7 wks where Hb can fall to 70 and Hct 0.25
Preterm complications: surgical
- UDT
- Inguinal and umbi hernias
Breast milk fortifier
Commenced for preterms <32 weeks
Ferrous sulphate (Fe) supplements
- Prevention of Fe deficiency anaemia
- Infants <2kg or <34 wks should be commenced on Fe supps from day 14 unless on formula feeds
Growth: target weight gain for preterms <2000g
15g/day
Growth: target weight gain for neonates >2000g
Wt: 20g/day
Lth: 0.7-1cm/wk
HC: 0.7-1cm/wk
Indications to start TPN (5)
- Preterms <30 wks and/or <1000g
- Preterms >30wks who are unlikely to establish full enteral feeds by 7 days
- Severe IUGR with abnormal doppler flow studies
- NEC
- GIT abnormalities
Predictors of outcome in HIE: APGAR scores
- <2 at 10min is assoc. w/ death or moderate disability at 18-22mths
- 0 at 10min is assoc. w/ death or severe disability at 18-22mths
Predictors of outcome in HIE: umbi cord arterial/venous pH
Lower arterial pH within 60min after birth associated with death and injury in 2nd wk after birth
Predictors of outcome in HIE: base deficit
Meh
Predictors of outcome in HIE: lactate
- Lactate >4.4 predictive of severity of encephalopathy when COMBINED with uric acid, LDH and CK
- On its own, poor predictor of good outcome
Predictors of outcome in HIE: Sarnat scores
- Stage II and III at 24hrs after birth associated with death and disability at 18-22mths
Predictors of outcome in HIE: aEEG
Abnormal aEEG by 48 hours after
birth can predict death or disability at
18–22 months
Predictors of outcome in HIE: MRI
Major neonatal MRI abnormalities
predict death or severe disability at
18 months