Neonatology Flashcards
Adrenaline
class: catecholamine
mechanism: beta>alpha
- beta 1/beta 2 effects prominent at lower doses
effect: ionotrophy/chronotrophy, peropheral vasoconstriction (beta 1)/dilation (beta 2)
use: cardiac arrest, low output state
Aneurysm Vein of Galen
definition: most common AVM in infants and increases in size with age
clinical: cardiac failure (80% CO), hydrocephaly, cranial bruit, SAH
diagnosis: ultrasound
management: surgery but >50% can’t be corrected
prognosis: early death if not corrected

Antenatal steroids
Weeks 24-34 if probable delivery within 1 week
Benefits:
- decreased RDS/NEC/IVH/sepsis/DD
Anaemia of prematurity
Pathophysiology:
- EPO made fetal liver/kidney and increases gestation
- preterm have lower EPO/Hct at birth
- EPO decreases at birth
- RBC 45-50d in ELBW (term 60-80d)
Clinical:
- normocytic, normochromic anaemia with low retics
- onset 3-12 weeks, asymptomatic till 70
- symptoms: tachycardia, FTT, hypoxia, apnoea
Management:
- limit blood samplings
- Iron supplementation 1st year 2-4mg/kg
Apnoea of prematurity
definition: cessation of resp airflow
incidence:
- 33-35wks: 50%
pathogenesis:
- physiological immaturity of central/peripheral chemoreceptors, neuronal signals
- +/- impaired resp drive or poor airway patency
- usually mixed obstructive/central apnoea
clinical: increased frequency wks 2-3, resolves wk 37
management: monitoring, NIPPV, methylxanthines (caffeine/theophylline) stimulate resp neural ouput
Bell staging for NEC
Stage 1 (suspected) with feed intolerance, AXR distension
- 1A grossly bloody stools
- 1B grossly bloody stools
Stage 2 (proven) with pneumatosis intestinalis and portal venous gas
- 2A mildly ill
- 2B moderately ill (met acidosis, thrombocytopaenia)
Stage 3 (advanced) AXR dilation/pneumatoses/ascites and systemic effect
- 3A bowel intact
- 3B bowel perforation
Benefits Breastmilk
GI: growth, motility, hormones, GF, anti-inflammatory agents, NEC prophylaxis, beneficial microbes, increased gastric emptying/lactase, decreased mucosal permeability
Antimicrobial: lactoferrin, lysozyme, IgA secreted into BM (10% milk protein), WBCs (90% neutrophils/macrophages), lacrobacillus/bifidobacteria
Decreased infections: lower hospitilisations, less severe illness, less gastro/resp/OM/UTI/sepsis
Long term: decreased obesity, DM1, IBD, allergies, cancer, adult CVD, better neurological outcome
Bilateral Vocal Cord Paralysis
incidence: 3rd most common congenital laryngeal anomaly producing stridor
associations: myelomeningocele, Arnold-Chiari malformation, hydrocephalus
clinical: high-pitched inspiratory stridor
diagnosis: flexible laryngoscopy
treatment: may require temporary trache
prognosis: resolve by 6-12 months
Birth fractures
nasal septum
clavicular: most common
humerus: 0.2/1000, most common long bone
femur: 0.13/1000
skull: linear and depressed, usually assisted delivery
dislocations: very uncommon
Birth nerve injuries
brachial plexus: most common 0.2%
facial nerve: forceps/compression against sacrum. affects manibular branch with drooping nasolabial fold. resolves
phrenic nerve: assoc brachial plxus injury. resp involvement day 1.
laryngeal nerve: hoarse voice/stridor.
spinal cord: very rare. upper cervical more common.
BPD/CLD
Disease of bronchioles and acini in premature infants
Definition: reliance on oxygen/resp support >28days or >36/40
Incidence: 97% in BW
Risks: prematurity (23-32wks), IUGR (
Pathophysiology: airway injury/inflammation, parenchymal fibrosis, oxygen toxicity, disruption of lung development due to surfactant
Classification at 36 weeks:
Mild: RA
Moderate: FiO2
Severe: FiO2>30% and/or PPV
Clinical: may have wheeze
CXR: diffuse haziness (atelectasis, inflammation, oedema), cystic changes
Management: high CO2, wean oxygen, nutrition, diuretics, Vit A, low dose dexamethasone
Prognosis: most improve 2-4 months and wean off oxygen, PFTs may not improve (decreased FEV1/FVC/TLC), hyperresponsiveness with asthma like symptoms
Causes Hydrops Fetalis
Aneuploidy most common 24 weeks
- Genetic: 10%, aneuploidy, congenital MD, skeletal dysplasia, single gene defect
- Metabolic storage disease: 1-15%, auto recessive
- Cardiovascular abnormalities: 40%, structural, arrhythmias, vasc abnormalities
- Thoracic abnormalities: obstruct venous return
- Pleural effusions
- Anaemia: 10-27%, alpha thal
- Infections: 8%, Parvo B19, TORCH
- GI malformations
- GU malformations
- TTTS
Choanal atresia
incidence: 1/5000 (2/3 unilateral)
definition: obliteration of posterior nasal aperture
clinical: cyanosis, worse with feeding, relieved by crying
diagnosis: probe with catheter
treatment: early surgery
associations: CHARGE, T21, Treacher-Collins, Apert’s, Crouzon’s
Closure of sutures
Posterior fontanelle: 2 months
Anterior fontanelle: 2 years
Coronal: 3 months
Lamboid: 1 year
Metopic: 2 years

Complications BPD
- Pulmonary/systemic HTN
- L ventricular hypertrophy
- Tracheobronchomalacia, tracheal/bronchial stenosis, glottic/subglottic damage
- sleep hypoxemia
- Resp infections
- Neurodevelopmental problems
Complications PN
Line: sepsis, extravasation, phlebitis
Metabolic: hyperglycaemia, nephrocalcinosis, hyperlipidaemia, hyperammonaemia, bone disease
Liver: 25% neonates >2wks, deranged LFTs (esp GGT, conj bilirubin), cholestasis
Congenital CMV
MOST COMMON perinatal/congenital infection
organism: herpesvirus DNA virus
epidemiology: 50% pregnant women seropositive, 10% reactivate during pregnancy
tranmission: low transmission via secretions
incubation: 3-12 weeks
pregnancy: infection 1st trimester highest risk, 3rd trimester highest rate
clinical:
10% symptoms at birth:
- growth: microcephaly, SGA
- haem:anaemia, thrombocytopaenia, petechiae, purpura
- GI: hepatosplenomegally, jaundice, elevated LFTs
- neuro: seizures, brain periventricular calcifications/cysts/ventriculomegaly
- eye: chorioretinitis, optic atrophy, central vision loss
90% asymptomatic: then develop unilateral hearing loss, behavioural issues
Congenital Laryngeal Cleft
incidence: 1: 10,000
definition: cleft to the posterior laryngotracheal wall
- gap between trachea and oesophagus
clinical: cough, cyanosis, pulmonary infections
treatment: thickened feeds, surgery
Congenital Lobar Emphysema
incidence: 1/25,000
pathophysiology: progressive massive uniform dilation of a lobe due to obstruction of developing airway
- deficiency of cartilage in defect
clinical: 1/3 present at birth, all by 1 yr with increased WOB due to compression of lung
- increased risk infection
- decreased AE over lesion
- 15% assoc CHD
CXR:
- hyperinflated area extending across mediastinum
- mediastinal shift and contralateral lung partial collapse
- LUL (50%)>RUL>RML>lower lobes (10%)
treatment: early resection

Congenital Myotonic Dystrophy
associated: decreased fetal movements, polyhydramnios
clinical: hypotonia, respiratory distress, facial weakness, muscle atrophy
diagnosis: triplet repeat studies (CTG repeat), mildly elevated CK
Congenital rubella
transmission: highest risk infection in 1st trimester and after 36 weeks
risk of defects: highest in first 16 weeks
- <8wks: 100%
- 8-12wks: 50%
- 12-20wks: 20%
- >20wks: 1%
congenital symptoms:
prenatal: abortion, stillbirth
post natal (infection
- IUGR, cataracts/retinopathy, microcephaly, cardiac (PDA/PPS), sensorineural deafness, blueberry muffin, haem (LN/hepatosplenomegally, thrombocytopaenia, anaemia), long bone radiolucencies, pneumonitis, renal tract abnormalities
post natal (infection>12 wks gestation)
- retinopathy and deafness only
diagnosis: maternal seroconversion
Congenital syphilis
organism: treponema pallidum
transfer: transplacental, extrauterine
congenital: chorioretinitis, glaucoma, periositis, hepatosplenomegally
clinical: symptoms 1-2 weeks
- mucosal/cutaneous disease (peeling or skin, rash palms/soles)
- pneumonitis/myocarditis
- LN
- bone
diagnosis: PRP, VDRL, THTA
treatment: IV benzyl penicillin 10 days
-
Congenital toxoplasmosis
source: cats
incidence: 0.2/1000
transmission: 1st trimester 15%, 2nd 30%, 3rd 60%
clinical:
- more congenital abnormalities if in 1st trimester
- most asymptomatic at birth but 85% SNHL/DD
- classic tetrad: chorioretinitis, hydrocephalus, IC calcifications
- also: hydrops anaemia, blueberry muffin spots, purpura, seizures, hepatomegally
diagnosis: paired maternal/infant serology
- then CSF, CT, opthalmology, audiology
treatment:
- during pregnancy: spiramycin
- amnio +ve: pyrimethamine + sulphadiazine
- neonatal: pyrimethamine for 1 year + folinic acid
Congenital VZV
pregnant women exposure >5 mins evaluated
- no action if previous infection/positive serology
- ZIG within 96 hours after exposure if non immune
- aciclovir
fetal VZV
- in 10-15% of maternal chickenpox
fetal VZV syndrome
- microcephally, low IQ, seizures, skin scarring, ipsilateral limb hypoplasia
congenital diagnosis
- amniocentesis confirms infection
- ultrasound confirms symptomatic infection
perinatal VZV
- risk 7 days before and 2 days after delivery and requires ZIG
- outside this period only high risk infants
















