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
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
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
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.
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
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 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 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 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
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
