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
Contraindication to breastfeeding
HIV positive
HCV positive with cracked nipples
Human T cell lymphotropic virus +ve
Herpetic breast lesions
Varicella 5 days prior
Active TB (until >2wks with treatment)
Cocaine, cannabis, alcohol use
Galactosemia
Drugs: Chemo, Immunosuppresants, Lithium, Clozapine
Cranial injuries
caput succedaneum: oedema, diffuse swelling to skin/subcutaneous tissue
cephalohaematoma (1-2%): subperiosteal btw periosteum/bone. onset in hours lasting 2 weeks. does not cross sutures.
subgaleal: subaponeurotic btw apneurosis/periosteum due to shearing emissary veins. fluctuant/boggy. potential massive blood loss. crosses suture lines. can cause consumptive coagulopathy.
extradural: between skull/dura. classically middle cerebral artery.
subdural: between dura/arachnoid. rare but most common ICH.
subarachnoid (subependymal): between arachnoid/pia mater. communicates CSF.
Craniosynostosis
definition: premature closure of the cranial sutures (single 85%, multi 15%)
- primary: premature closure of one of more sutures
- secondary: from failure of brain growth/expansion
incidence: 1/2000 (10-20% assoc syndrome)
complications: raised ICP, inhibition brain growth, impaired cognition/growth/feeding/weight/vision/hearing/speech
management: plastic surgery with 3D CT
Developmental Dysplasia Hip
incidence: 1:1000
2 forms: typical or teratologic (cause)
RFs: female (80%), family hx (12-30%), tight uterine space, breech, 1st born, other moulding issues
associations: congenital torticollis, metatarsus adductus, clubfoot
pathology:
- significant lig laxity (estrogen, relaxin) allowing spontaneous dislocation
- secondary flattening acetabulum, muscle contractures and joint capsule tightening
- L to R 3:1
clinical: barlow/ortolani, galeazzi sign
- hip abduction <75 degrees, adduction > 30 degrees
imaging: US: high false positives week 0-4
- alpha angle: line from ileum to roof acetabulum
treatment:
- <6m Pavlik harness (95% success dysplasia, 80% dislocation)
- 6m-2yrs: closed reduction with hip spica
- >2yrs or failed rx: open reduction
complications: iatrogenic avascular necrosis femoral epiphysis, pressure ulcers
Diaphragmatic Eventration
cause: part of diaphragm replaced fibroelastic tissue but diaphragm intact
etiology: congenital/acquired (phrenic nerve injury)
CXR: elevated diaphragm
Management: oxygen, NG feeds, surgery
Diaphragmatic hernia
aetiology: traumatic or congenital 1/10,000
pathogenesis: abdominal viscera to herniate into chest causing lung hypoplasia and pulmonary artery hyperplasia
location: 80-90% left side, Bochdalek 90%, Morgagni 2-6%
outcome: lung hypoplasia, pulmonary HTN
clinical: barrel chest, scaphoid abdomen, absent breath sounds
treatment: surgery, ventilation, NGT
outcome: resp distress birth-weeks, 67% survival
long term outcome: PPHN, GOR, FTT, neurodev delay
Dobutamine
class: synthetic catecholamine (same basic structure as dopamine)
effect: predominantly beta 1 and small amount beta 2 with selective alpha 1
use: low CO state
Dopamine
class: endogenous catecholamine
mechanism: DA> beta> alpha
Encephalopathy
Incidence: 9:1000
Definition: pH34wks, no other explanation
+ AGPAR 0-3 at 5 mins, multi system involvement
Aetiology: 80% acute, 3% prenatal, 3% non HIE
- mild: hyperalert, hyperexcitable, normal tone
- moderate: hypotonia, decreased movements, sometimes seizures
- severe: stuporous, flaccid, absent reflexes, seizures
Prognosis: poor if MRI findings, increased lactate, EEG findings
- mild: likely normal
- moderate: 20-35% sequelae
- severe: 75% die in neonatal periods
Investigations
MRI: poor outcome bilateral thalamic/internal capsule/brainstem lesions
EEG: burst suppression, isoelectricity, low voltage
Bronchopulmonary sequestration
incidence: 1/10,000
definition: non-functioning mass lung tissues that lacks normal communication with the tracheobronchial tree
Pathophysiology:
- 95% left lung
- located in or outside normal lung with own viscera
- receives blood supply from systemic circulation
clinical: respiratory distress, pneumonia
- many patients asymptomatic
Feeding cleft palate/micrognathia
cleft palate: sucking problems
micrognathia: airway problem
- cleft: poor suction, usually require bottle or NG top up
- micrognathia: tongue to far back to attach to nipple, may need nasopharyngeal tube to keep airway patent and tongue forward in feed
treatment:
- SP within 24 hours of birth
- squeezable bottle
- feed in semi-upright position to minimise nasal regurg milk
- burp regularly
GBS sepsis
organism: strep agglacticae gram +ve cocci
epidemiology: 30% women colonised
transmission: 50% transmission w/o prophylaxis
- increased PROM, chorio, prematurity, heavy titre, intrapartum fever, previous GBS disease
- most significant is SPROM
risk factors GBS positive: DM, teenager, tampons,
early onset disease:
- sepsis (50%), pneumonia (30%), meningitis (15%)
- mortality: 4.7%
later onset (>7 days) and no relationship to maternal status:
- bacteraemia (50%), meningitis (30%), focal (20%)
- 2.8% mortality
screening: LVS 1-5 weeks prior to delivery
diagnosis: culture
treatment: benpen + gen +/-cefotaxime
Hearing impairment
Bilateral hearing impairment 1/1000
Non syndromic
- connexin-26 deficiency most common (50% non syndromic)
Syndromic
- Waardenburg: neural crest syndrome
- Branchial-oto-renal
- Pendred: assoc with goitre
- Usher: assoc retinitis pigmentosa
- Jervell and Lange-Nielsen: long QT
Hearing loss
Infectious pathogens
Congenital: CMV, Rubella, Toxoplasma, Treponema pallidum
Acquired: Borrellia burgdorferi, EBV, Haem influenzae, Lassa virus, Measles, Mumps, Neisseria meningitidis, Enteroviruses, Plasmoadium falciparum, Strep pneumonia, VZV
Hearing testing
Newborn: auditory brain response
- summation of AP from 8th CN to midrain
Older infants: behavioural observed audiometry
Toddlers: visual reinforced audiometry
School age: standard pure tone audiometry
Audiograms (dB)
- mild 20-40, mod 40-60, severe 60-80, profound> 80
Sensorineural: loss at higher frequency
Conductive: loss at lower frequency
HIE
incidence: 5/1000
Pathophysiology: decreased cerebral perfusion
- antenatal: impaired maternal oxygenation, impared placental perfusion, fetal haemorrhage
- intrapartum: placental abruption/prolapse/cord true know, maternal hypotension/fever, foetal OP position
- post natal: resp distress, CVS disease, anaemia, shock
Secondary insult
- Impaired cerebral blood flow, cerebral hypoxia, anaerobic met, increased lactate and death of some neurons
- hypothermia effective - Delayed neuronal dealth 6 to 100 hrs with neuronal cell apoptosis via accumulation excitory AA (glutamate), opens NMDA channels, influx Ca and cell damage
Outcome: cause of most significant neuronal loss
- increased iNa/Ca with swelling/edema
- increased NO/free radicals injury cells
Clinical
- birth: initial hypotonia/poor resp effort/weak cry
- hours: LOC, hypotonia, apnoea, bradycardia
- days: cerebral oedema, brainstem compromise, seizures
Management
- hypothermia for stage 2/3
Outcome:
- 20-30% die neonatal period, 25-50% neuro comorbidity
Risk adverse outcome
- pH25 (72% death), Apgars 0-30 5/20m, decerebrate posturing, absent resps 20mins, abnormal motor 2/52, EEG abnormal 48hrs
Hydrops Fetalis
2 or more: ascites, pleural effusion, pericardial effusion, oedema, polyhydramnios
Immune vs non-immune
Pathogenesis:
- Obstructed lymphatic drainage
- Increased capillary permeability
- Increased venous pressure
- Decreased osmotic pressure
Clinical: LGA, decreased fetal movements, maternal preeclampsia/anaemia, preterm labour, birth trauma, PPH
Prognosis: earlier is worse, perinatal mortality 50-98%
Hyperinsulinaemia
Infant DM mother
- increasd fetal BGL, hypertrophy B cell, neonatal hyperinsulinaemia
- resolves 2-4 days
B-W syndrome
- 50% transient hypoglycaemia due to hyperinsulinaemia
Persistent hyperinsulinaemia hypoglycaemia of infancy
- gene mutation in ATP dep K channel in beta cell membrane
IUGR
definition: weight
symmetric: early onset disease, affect celll number eg. chromosomal, malformations, teratogens, infections, HTN
asymmetric: late onset (2nd/3rd tri), decreased weight normal length/HC, preservation carotid blood flow, eg poor nutrition, PET
etiology: 1/3 genetic, 2/3 environmental (40% SGA unknown cause)
- maternal: malnutrition, hypoxemia, thrombosis, vasculopathys, virus/parasite, substance abuse, toxins, high altitude
- placental: placental injuries, single umbilical artery, velamentous umbilical cord insertion, placental hemangioma
- neonatal: karyotype, genetic syndrome, congenital abnormalities, twins
issues: hypothermia, hypoglycaemia, polycythemia, hyperviscosity, impaire immune function
associations: increased mobidity/mortality
- increased neonatal death, IHV, NEC, RDS, BPD
- no association PVL
Bronchogenic cyst
location: next to midline structures
definition: abnormal budding of tracheal diverticulum
clinical: wheeze, WOB, spontaneous pneumothorax, infection
treatment: always resect
Malrotation
- gut straight tube stomach to rectum
- rotation from week 5
Malrotation/Volvulus
incidence: 1/5000
associations: 30-60% assoc CDH, omphalocele, gastroschisis, duodenal atresia, meckels, stenosis, hirschsprungs etc
presentation: 50% by 1 month and up to 1 year from volvulus or ladd bands
clinical: bilious vomiting, abdominal pain, distension, tenderness, peritonisis, blood stool
complications: vascular compromise with SMA obstruction and necrosis 6-12hrs, SBS, SBO
investigations: AXR (gasless abdo, duodenal obstruction with double bubble), barium enema (normal 20%, malposition caecum may be seen), upper GI contrast study (displaced duodenum, malposition ligament Treitz on right side abdo, duodenal obstruction with double bubble/bird beak)
management: surgical ladd procedure with reduction volvulus, release lasdd bands and widen base mesentery
outcome: mortality 3-%, recurrent malrotation 2-8%
Maternal ITP
pathophysiology: IgG from mother can cross placenta and react with fetal plateletes
clinical: symptomatic mother with identifiable platelet Ab should commence on treatment with steroids/IVIG
management: FBC in neonate, rarely platelet transfusion
Meconium Aspiration Syndrome
Meconium: 10-15% births
MAS: in 5% with meconium
Pathophysiology: meconium aspirated in utero or with 1st breath
- small airway obstruction causing resp distress
- may lead to pneumomediastinum/pneumothorax
- overdistension of chest
Treatment: intubation for suction, supportive, exogenous surfactant, iNO, mechanical ventilation
Outcome: 30% ventilation, 3-5% die, improves within 72 hours
Meconium ileus
associated CF
cause: absense of pancreatic enzymes with viscous/mucousy meconium
clinical: similar LBO with abdominal distension/vomiting
AXR: mec in colon with proximla dilation
treatment: gastrograffin enema, disempaction, laparotomy
Meconium plug
definition: firm mass with loss water content
risk factors: small left colon, maternal DM, mothers CF, antenatal Mg, Hirschsprung’s
Midgut malrotation
Non-rotation:
- midgut returns to abdomen with no further rotation
- not as dangerous because base of mesentery still wide
- foregut in normal position, midgut on right side of abdomen, hindgut on left
Malrotation: (most common type)
- failure of caecum to move into the right lower quadrant and sits subhepatic
- duodeno/jejunum remains in position of non-rotation
- caecum/colon have partial rotation.
- the mesentery (and the SMA within it) is a narrow stalk which can twist
- Ladd’s bands from the caecum to the RUQ and can cross/obstruct the duodenum.
Milrinone
class: bipyridine inodilator
mechanism: cAMP PDE-3 inhibitor
effect: inotropy, CO
use: low CO state
MZ Twins
0.5% risk
Fertilization of 1 oocyte with division later
- MCDA division d 4-8
- MCMA division d 8-12
Monochorionic or Dichorionic
Risks: neurological, mortality, congenital abnormalities
Necrotising enterocolitis
incidence: 3/1,000 and 6% infants
- only 13% NEC occurs in term infants
onset: usually
preterm risk factors: immature mucosal barrier/permeability/immune system (no IgA at birth), slow gut motility
term risk factors: comorbities (CHD, asphyxia, sepsis, polycythemia, resp)
pathophysiology: ischaemic necrosis intestinal mucosa with inflammation, invasion of gas forming organisms into muscularis and venous system. Mucosal oedema, haemorrhage and transmural necrosis occur. Heals with fibrosis and stenosis.
Feeds: 90% NEC in milk fed infants. Risk decreased with slower increase in feeds, early commencement, human milk and probiotics.
clinical: apnoea, lethargy, poor feeding, temp instability, feed intolerance (distension, tender, PR bleeding, bilious vomiting)
AXR: abnormal gas pattern/dilation, possibly sentinal loop of bowel, pneumotosis intestinalis
bloods: increase lactate/glucose, decrease Na
treatment: supportive (gut rest, NGT aspirated), medical with IV antibiotics(fails 50%), surgical (resection if needed)
complications: sepsis, DIC, strictures
outcome: mortality 20-30%, 50% no long term issues
Neonatal Abstinence Syndrome
heroine/methadone:
- most babies withdraw
- onset
- tremors and hyperirritability
- commonly: increased tone/reflexes, fever, tachypnoea, vomiting, diarrhoea, fist sucking
- less commonly: sneezing, yawning, hiccips, convulsions, apnoeas
alcohol: uncommon
phenobarb: onset 7 days to 2-4 months, same as above
cocaine: withdrawal uncommon
SSRIs:
- serotonin discontinuation syndrome
- onset
- mild symptoms: CNS, motor, resp, GI, temp instability
Treatment:
- quiet environment, minimal stimulation
- scores >8 x3, >12 x2
- morphine, phenobarbitone
- mortality
Neonatal asphyxia
definition: acidosis and multiorgan effects
progressive hypoxia/hypercapnia causing:
- Acidosis pH<7
- Early onset encephalopathy
- CP
- Exclusion other causes
effect:
CNS: HIE, infarction, ICH, seizures, edema, hypotonia
CVS: ischaemia, poor contractility, tricuspid insuff, hypotension
Pulm: HTN, pulm haemorrhage, RDS
Renal: tubular/cortical necrosis
Adrenal: haemorrhage
GI: performation, ulceration, necrosis
Metabolic: SIADH, hyponatraemia, hypoglycaemia, hypocalcaemia, myoglobinuria
Skin: subcut fat necrosis
Haem: DIC
Neonatal CMV
incidence: leading cause congenital infection 0.7%
Maternal CMV IgM: 75% false positive due to delayed clearance, reactivation, cross reactivity
Transmission: (greatest infection)
- primary: 30% transmission (85% asymptomatic, 15% symptomatic)
- secondary: 1% transmission (99% asymptomatic, 1% symptomatic)
Fetal diagnosis: fetal US/MRI, amniocentesis
Postpartum ix: CMV IgM serology, urine/saliva/blood PCR within 3 weeks
Treatment: antivirals if symptomatic for 6 weeks
Sequelae symptomatic: early mortality 5-10%, microcephaly 35-50%, seizures 10%, chorioretinitis 10-20%, dev delays 70%, SNHL 25-50%
Outcome:
- more severe if primary in 1st trimester
Neonatal fluids
TBW: prem 80%, term 75%
ECF: prem 70%, term 45%
Weight loss first week 10-15%: 5% ECF
Sources of water loss:
Kidneys: need 2ml/kg/hr, 2% CO
- prems: decreased GFR/tubular Na+Bicarb reabsorption/secretion K+H/capacity to concentrate+dilute urine
Skin: evaporation via skin
- 24 weeks: 200ml/kg/day, term: 20ml/kg/day
- radiant warmers increase loss by 50%
Respiratory: 50% insensible losses in infant
- antenatal steroids mature skin/kidneys
Overall:
- 50% loss skin/resp
- 50% loss kidneys
Neonatal growth
Weight: 15g/kg/day
Length: 1cm/week
HC: 0.7cm/week
Nutrition: 100-120kcal/kg/day approx 180ml/kg/day formula
Neonatal Hepatitis B
Acute infection in pregnancy transmission:
- 1st 10%
- 2nd/3rd 75%
Vertical transmission:
- 90% (HBeAg +ve), 10% (HBeAg -ve)
- mode of delivery does not alter transmission
Chronic rate:
- 90% neonates
Of chronic carriers:
- 25% die to HCC
Treatment:
- administration IVIg and vaccination
No risk with breastfeeding/vaginal delivery
Neonatal hepatitis C
Transmission:
- babies to anti-HCV positive but HCV RNA negative NO RISK
- 5-10% risk babies born to anti-HCV/RNA positive
Clinical:
- paediatric HCV infection usually asymptomatic for many years
Follow up: HCV PCR at 2 months, and Anti-HCV antibodies at 18 months
No risk with breast feeding
Needle stick injury 0-5%
Treatment: interferon, interferon-ribavirin
Neonatal HIV
Low risk MTCT (on HART therapy or commenced on HART and viral load
- risk of transmission
- allow vaginal delivery
- commence on single agent AZT
High risk MTCT:
- risk of transmission >2%
- LSCS
- commenced double agent AZT/ART and PCP prophylaxis
Breast feeding on HART
- 1-5% risk
Without any intervention (developing country)
- 20% if bottle fed, 40% breast fed
Neonatal HSV
Primary HSV:
- seroconverion >30 weeks (25-50%): administer antivirals w36 to birth
- seroconversion
Active lesions:
- deliver via LSCS
Transmission:
- 85% neonatal HSV acquired perinatally
-
- 5% postnatally acquired
Risk factors:
- scalp eletrode/vacuum increases transmission
- LSCS decreases transmission
Treatment:
asymptomatic high risk/symptomatic:
- LP, bloods, surface swabs and commence IV aciclovir
- IV aciclovir improved neurological outcome
asymptomatic low risk
- monitor for clinical symptoms
Risk of disease:
- primary genital lesion: 50% infection
- secondary genital lesion:
Prognosis:
- infections >70% progress to disseminated disease
- >70% mortality for disseminated disease
Neonatal hypoglycaemia
definition: BGL
incidence: transient low BGL 10% newborns
pathogenesis:
- loss on contunours transport of glucose
- BGL maintained by hepatic glycogen breakdown immediately after birth
- stores deplete 8-12 hrs
pathophysiology:
- Inadequate glucose supply: IUGR
- impaired glucose utilisation: hyperinsulinaemia, IEM
- increased glucose utilisation: hyperinsulinaemia, hypotheramia, hepatic dysfunction, anaerobic glycolysis (ischaemia), sepsis, polycythaemia
management:
- oral feeds
- IV dextrose
- glucagon, diazoxide, pancreatectomy
outcome:
- brain injury, CP, DD, small head circumference
Neonatal lupus
Neonatal Lupus (maternal SLE)
pathophysiology: IgG antibodies to ENA (anti Ro/SSA or anti-La/SSB) cross placenta between weeks 12-16
incidence: 1% babies develop disease
symptoms: CHB, cutaneous lesions, hepatitis, thrombocytopaenia, neutropaenia
treatment: pacing, heart transplant
Neonatal milk
Protein: whey dominant
Lipid: 50% caloric intake in milk
Carb: 40% caloric intake, 90% lactose absorbed
Ca/PO4: bone mineralisation
Na: important growth factor, stimulate cell proliferation/protein synthesis
Iron: limited in breast milk
Neonatal pulmonary haemorrhage
incidence: 10% extreme prems, 75% of patients
risk factors: RDS, PDA, haemorrhagic disease newborn, erythroblastosis foetalis, surfactant, alveolar haemorrhage
cause: haemorrhagic pulmonary oedema with PDA and left to right shunt with high pulmonary flow, of left sided heart failure
CXR: non specific streaky changes
treatment: suction, ET adrenaline, HFOV, surfactant
Neonatal seizures
Almost all symptomatic to underlygin cause
- ie. primary epilepsy syndromes are rare
cause:
- cranial: encephalopathy, haemorrhage, infarct
- metabolic: hypoglycaemia, hypocalcaemia, hypomagnesia
- infective
- chromosomal abnormalities
- IEM: aminoacidurias, urea cycle defects, organic acidurias
- drug withdrawal/intoxication
- neonatal epilepsy syndromes: benign neonatal convulsions, benign neonatal familial convulsions, early myoclonic encephalopathy, early infantile epileptic encephalopathy
outcome:
- early death 35%, neurological impairment 20-60%, DD 55%, post natal epilepsy 20-30%
treatments: phenobarb, phenytoin
Neonatal ventilation
Goals: oxygenation/ventilation
Oxygenation: FiO2 and MAP
Ventilation: TV and RR
Permissive hypercapnia
- pH 7.25-7.35, pCO2 40-60mmHg, BE 0 to -4
Settings: RR 60, Ti 0.35 secs
Types:
- IPPV
- SIMV: synchronised intermittent mandatory ventilation
- SIPPV: synchronised intermittent positive airway pressure vent
- PSV: pressure support ventilation
Nitric Oxide PPHN
Definition: selective pulmonary vasodilator
Indications: PPHN >34wks, CDH
Mechanism: binds guanylate cyclase increasing cGMP and vasodilation
- vasodilates well ventilated regions reducing VQ mismatch
Toxicity: binds Hb to form methaemaglobin systemically, may cause pulmonary injury/thrombocytopaenia
Sildenafil (PDE5 inhibitor) can be used in longer term management
Noradrenaline
class: catecholamine
mechanism: alpha>beta
effect: similiar to adrenaline but less vasodilation (beta 2)
use: septic shock, vasodilation
Osteopaenia of prematurity
risk factors: prem/LBW, TPN>4weeks, BPD, long term steroids, NEC
clinical: onset 3-12 weeks, decreased Ph/Ca, increased ALP, fractures
diagnosis: XR
management: calcium, phosphate supplementation
Outcomes IUGR
Growth:
- catch up 6-12 months
- severe SGA (15%) shorter throughout life
Neurodevelopmental:
- risk of neurodev/cognitive issues
- poorer school performance
- attention issues in girls
Physical:
- increased IHD, HTN, stroke, DM, hypercholesterolaemia
Parenteral nutrition
Target 100kcal/kg/day to gain 15g/kg/day
Lipid 30% energy PN: 1-2g/kg/day=1kcal/ml
Carb (dextrose) 60% energy PN: 3.4kcal/ml
Protein 10% energy PN: 2-3g/kg/day=4kcal/g
Na: 2-3mmol/kg/day
Ca: 1-2mmol/kg/day
IRON NOT PART TPN
Needs selenium if PN>2 months
Perinatal stroke
incidence: 1/4000
defintion: CVA weeks 20 weeks gestation to 28 days postnatally
clinical: seizures, lethargy, hypotonia, feeding difficulties, apnea
risk factors:
maternal RF: cocaine, prothrombotic disorders
placental RF: PET, chorioamnionitis, vasculopathy
newborn RF: prothrombotic disorders, CHD, meningitis, systemic infection
types:
1. Arterial ischaemic: abnormal coagulation 1/2 cases.
- seizures, encephalopathy, unilateral hemiparesis, exaggerated reflexes
- normal development 20-33%, motor disability common
2. Cerebral sinovenous thrombosis
- venous infarct, placental lesions, involve supeficial veins (superior saggital sinus/lateral sinuses)
- >95% survive neonatal period, 20% mortality, 60% deficits, 20% normal
3. Haemorrhagic
- haemorrhagic conversion of ischaemic infart OR
- primary intraparenchymal haem from vascular abnormalities
- periventricular haemorrhagic infarction 15-20% IVH
- neonatal alloimmune thrombocytopenia
Posterior urethral valves
incidence: 1:8000 males
definition: obstructive membrane in posterior male urethra secondary to abnormal development
diagnosis: ultrasound, VCUG
side effects: renal and resp failure (low AF)
treatment: endoscopic valve ablation
PPHN
Hypoxic baby normal CXR
Pregnancy Drug Categories
Category A = no risk shown in human studies
Categpry B = no risk shown in animal studies OR some risk in animal studies but not confirmed on human studies
Category C = either definite risk in animal studies OR no data in human or animal studies
Category D = some risk (but the benefit may exceed the risk e.g. in life threatening circumstances)
Category X = contraindicated in pregnancy
Premature physiology
Fluid requirement: 2-3ml/kg/hr insensible losses due to immature skin, lack of subcut tissue, large SA
Drugs: immature renal clearance dependent gestation/age
Renal: poor urine concentrating (7.5-30mOsm/kg/day)
Nutrition: deficit folate (decrease 1st week then low 2-3m), vitamin D, Vit A
Prematurity prognosis
Survival
- 23: 15%
- 24: 56%
- 25: 80%
- 500-600g: 20%
- 1250-1500: 90%
- 1500-2500: 95%
Positive predictors: antenatal steroids, female, singleton
Long term associations: T2DM, obesity, CVD (HTN, IHD)
IVH and periventricular leukomalacia
timing5 days (50% day 1, 75% first 3 days)
cause: spontaneous (prems), less commonly haem disturbances, vasc malformations, trauma, vit K deficiency
risk factors: prem, RDS, pneumothorax, HIE, hypotension, reperfusion injury, thrombocytopenia, hypervolemia, HTN, PDA
etiology: 30% prems
pathogenesis: occurs subependymal germinal matrix: site origin embryonal neurons and foetal glial cells that migrate to cortex and blood vessels are immature
- PVL occurs after grade IV IVH due to venous congestion: periventricular haemorrhage/necrosis with focal necrotic lesions and diffuse white matter changes (assoc CP as impacts corticospinal tracts)
grading:
grade 1 (35%): subependymal only or
grade 2 (40%): bleeding in ventricle without dilation (10-50% ventricle)
grade 3: IVH with ventricular dilation (>50% ventricle)
grade 4: IV and parenchymal
clinical: 25-50% no sx, impaired neuro, PVL silent until CP in infancy
prevention: antenatal steroids
management: surveillance, shunt
RDS
Incidence:
Risks: prematurity, GDM, twins, LSCS, Precipitous delivery, maternal hx, asphyxia, male/white
Protective: steroids, maternal HTN
Pathophysiology:
- insufficient surfactant (mature levels 35wks)
- high surface tension: atelectasis/poor gas exchange with VQ mismatch
- atelectasis, hyaline membrane formation, edema
Clinical: onset resp distress in minutes, fine rales, peak at 3 days
CXR: fine reticular markings with air bronchograms
Treatment: steroids, surfactant first few hours (improved survival, decreased air leak/BPD)
Retinopathy of prematurity
definition: developmental vascular proliferative disorder
- most common cause of cortical blindness
risk factors: prematurity (
pathophysiology:
- retinal vascularisation weeks 15 to 36 (ongoing in prems)
- initial injury due to hypotension/hypoxia/hyperoxia causing them to grow abnormally with increasd permabilit causing oedema/haemorrhage
- vasc endothelial growth factor/IGF-1 involved
classification
- stage 1: flat white lin demarcate vasc/avasc retina
- stage 2: fibrous ridge into vitreous
- stage 3: new blood vessels and fibrous tissue in a ridge into vitreous
- stage 4: partial retinal detachment
- stage 5: total retinal detachment
prognosis
- stage 1/2: usually regress but surveillance until vascularisation complete
- stage 3: usually regresses, may need tx, assoc refractory errors/squint
- stage 4/5: retinal detatchment, poor visual prognosis
Rh/ABO incompatibility
(erythroblastosis foetalis)
cause: destruction fetal RBC by maternal IgG
- Ab produced when fetus produce Ag not expressed by mother
types:
Rh haemolytic disease (most common alloimmune HDN)
- 90% D Ag, 10% C or E Ag
- prenatally, abortion, delivery
- Rh+ blood from fetus into mother and mother develops IgM then IgG anti-D (IgG crosses placenta to cause disease)
- when also ABO incompatible Rh+ cells removed by existing Anti-A Anti-B IgM causing less severe disease
ABO incompatibility (less severe)
- some mothers naturally anti-A/anti-B IgG from nature
- disease can occur in 1st pregnancy
- 15% all pregnancies, only HDN 4%
- increased SBR at 24hrs
- Coombs, ABO incompatibility, spherocytes
- may need pRBC at weeks due to slow haemolytic disease
Diagnosis: decreased Hb, increased retic, polychromasia
- Kleihauer test: determine fetal Hb in maternal blood (fetal Hb acid resistant)
- Coombs test: presence of maternal Ab on neonatal RBC
Treatment: Anti-D antenatally/delivery, transfusions, exchange transfusions, IVIG
Talipes equinovarus
incidence: 1/1000, mostly bilateral
pathogenesis: hypoplastic tarsals/talus with secondary generalised limb hypoplasia
causes
- congenital (75%)
- teratologic: NMDs (myelomeningocele, arthrogyrposis)
- positional: in utero deformity
clinical: hindfoot equinus/varus, foreffot adduction
treatment: Ponseti method with serial casting, tendon transfer 20%
Teratogens
cause 10% of all anomalies
1st trimester: more likely to cause problems/MC
Major teratogens:
ACEi: trimester 2/3 renal abnormalities
aminoglycosides: damage to kidney
EtOH: FAS, IUGR, behaviour/cognitive
lithium: Ebstein anomaly, macrosomia
MTX: IUGR, hypotonia, congenital anomalies, DD
NSAIDs: closure DA in third trimester
phenytoin: craniofacial, nail, cardiac, IUGR, neuroblastoma, bleeding
prednisone: oral clefts
smoking: IUGR, facial clefts
sodium valproate: NTDs, facial, cardiac, limb, hypospadias
trimethoprim: teeth problems trimesters 2/3
vitamin D: supravalvular aortic stenosis, hypercalcaemia
warfarin: embyopathy weeks 6-9, cartilage defects (esp nasal)
Therapeutic hypothermia
Indication: stage 2/3 encephalopathy
Mechanism: downregulates secondary mediators of injury with decreased apoptosis/glutamate/free radicals/NOP/lactate and oedema
Contraindications:
Method: 6hrs, target 32-34 degrees, 48-72hrs, rewarm slowly 0.5 degrre/hr max, continuous rectal probe
Side effects: bradycardia, hypotension, PPHN, coagulopathy, hypoglycaemia, hypokalaemia, pulmonary edema, sepsis
Outcome: death 46% if cooled, 60% without
Transcobalamin II deficiency
incidence: autosomal recessive
pathophysiology: TC-II principle transport vehicle of B12
investigations: serum B12 normal
clinical: FTT, diarrhoea, vomiting, glossitis, neurological abnormalities in 1st week of life
treatment: large dose parenteral vitamin B12
TTN
Preterm or term/VD or LSCS
Pathophysiology:
- retained fluid from foetal circulation
- decreased pulmonary compliance
- increased dead space
Clinical: early onset resp distress, chest clear
CXR: fluid in fissures, vasc markings, flat diaphragms
Treatment: usually FiO2
TTTS
vascular connections all MC twins
TTTS 10-15% MZ
- trigger hypovolaemia in donor twin, causing vasoactive peptides, HTN and shunting to recipient
Donor: oligohydramnios
Recipient: polyhydramnios, HTN, hydrops fetalis
Management: US, amnioreduction in recipient, laser ablation, selective foetal reduction
Twin Anaemia Polycythaemia Sequence
atypical form TTTS
discrepant Hb concentrations WITHOUT poly/oligohydramnios
donor twin: low MCA velocity
recipient twin: high MCA velocity
Types hearing loss
Conductive: most is acquired
- anomalies pinna, external auditory canal, TM, ossicles, congenital cholesteatoma, TM perforation, ossicular discontinuity, tympanosclerosis, acquired cholesteatoma, masses middle ear, salivary gland tumours
Sensorineural: congenital or acquired
- genetic, infectious, autoimmune, anatomic, traumatic, ototoxic
Vasopressin
class: endogenous peptide
mechanism: V1R, V2R, V3R, OTR receptors
effect: antidiuresis, SVR/PVR, platelet aggregation
use: septic shock
Vitamin K deficiency bleeding
Early (0-24 hours)
- site: cephalo, subgaleal, ICH, GI, umbilical, intaabdominal
- risks: maternal drugs (phenobarb, phenytoin, warfarin, rifampicin, isoniazid)
- prevention: antenatal maternal vit K
- incidence: rare
Classic (2-7 days)
- site: GI, ENT, ICH, cutaneous, circumcision, injection site
- risks: vit K deficiency, BF
- prevention: IM Vit K birth
- incidence: 2% if no vitamin K
Late (1-6 months)
- site: ICH, GI, cutaneous, ENT, injection sites, thoracic
- risks: Vit K malabsorption, CF, cholestasis, biliary atresia, BF
- prevention: parental/oral Vit K
