Neonates Flashcards
Risks to newborn of maternal DM with insulin
2-3x greater risk of congenital abnormality
- Sacral agenesis (caudal regression syndrome)
- Situs inversus
- Holoprosencephaly
- Congenital heart disease
Risks to newborn of maternal HTN
Before 20/40: miscarriage
After 20/40:
- IUGR
- placental insufficiency
- placental abruption or previa
Risk to newborn of maternal hyperthermia
Days 14-30 after conception increases the risk of NTDs
Risk to newborn of SLE
Before 20/40: miscarriage
After 20/40:
- still birth
- prematurity
- congenital heart block
Risk of maternal parvovirus B19 (causes erythema infectiosum - 5th disease)
Infection btwn 10 & 24 wks can result in 10% risk of foetal severe anaemia, heart failure, hydrops fetalis, and death
Risk of maternal varicella
Infection during 1st trimester (8-20wks) can result in 1-2% risk of limb reduction defects, IUGR, microphthalmia, chorioretinitis, skin scarring, DD, microcephaly
Risk of maternal CMV
Before 27 wks, 5% risk of symmetric IUGR, microcephaly, periventricular calcifications, intellectual disability, hearing loss
Risk of maternal rubella
0-8 wks - deafness (85%)
9-12 wks - cataracts (52%)
12-30 wks - heart defects (16%)
Toxoplasmosis
Increasing risk as GA increases
- Hydrocephalus
- Blindness
- Intellectual disability
Maternal syphilis -> congenital syphilis
Esp after 5 mths GA
- Abnormal teeth and bones
- Intellectual disability
- Proteinuria
Maternal HSV -> neonatal HSV
Local infection - skin, eyes, mouth
CNS - HSV encephalitis
Both local and CNS
TORCH
Toxoplasmosis
Other (syphilis, parvovirus)
Rubella
CMV
HSV
Most common causes of neonatal sepsis
GBS, E Coli
Clinical features of neonatal sepsis
APGARS <6
Temperature instability
Resp distress
Lethargy
Irritability
Poor feeding
Tachycardia
Bradycardia - uncommon
Describe TTN
In late pre-term infants 34-37 wks
Inadequate clearance of lung fluid at birth
Present with tachypnoea, grunting, nasal flaring, mild intercostal/subcostal recessions, cyanosis
OE: chest clear
CXR: prominent pulmonary vasculature, fluid in the fissures, flattening of the diaphragms (from overaeration), plural fluid
NO air bronchograms or reticular granularity (present in RDS)
CXR TTN
Prominent pulmonary vasculature, fluid in the fissures, flattening of the diaphragms (from overaeration), plural fluid
NO air bronchograms or reticular granularity (present in RDS)
Incidence of RDS
Inversely proportional to gestational age
White males > F
Describe RDS
Due to surfactant deficiency and immature alveoli
Surfactant reduces alveolar surface tension, which decreases the pressure which is required to keep alveoli inflated
Alveoli don’t expand adequately -> atelectsis, less functional RC, inadequate ventilation of the lungs, hypercapnia, hypoxaemia
Surfactant constituents and production
1) Lecithin (65%)(dipalmitoylphosphatidylcholine)
2) Surfactant proteins SP-A, -B, -C, -D (phosphatidylglycerol, apoproteins)
3) Cholesterol
As GA increases, more surfactant is synthesised and stored in Type II alveolar cells.
Mature levels at >35 wks GA
CXR RDS
Low lung volumes
Air bronchograms
Diffuse, fine, reticulogranular ground glass haziness
DDx RDS
In setting of hypoxia, hypercapnia and metabolic acidosis -
GBS sepsis
Congenital heart disease
Ante and perinatal corticosteroid treatment to prevent RDS
Given at 23-24 wks if risk of preterm labour
+/- 34-36 wks - betamethasone or dexamethasone
Intratracheal surfactant therapy within 30-60 mins of delivery
Indications for prophylactic abx for GBS
- Positive 36 wk vaginal/rectal culture
- Prior infant with GBS
- GBS bacteruria during pregnancy
- Unknown culture in setting of fever, preterm labour or PROM
Neonatal resp syndromes
TTN - wet lungs
RDS - surfactant def.
GBS
PPHN
Apnoea - CNS/ob/mixed
MAS
CDH
PTX
Pneumomediastinum
BPD
Pulm haemorrhage
Describe PPHN
Pulmonary vascular resistance remains elevated after birth, causing pulm-systemic (R-L) shunting of blood via fetal circulatory pathways (aka PDA or PFO).
Causes severe hypoxia refractory to O2 administration
PPHN - O2 requirements
O2 requirements vary widely within a relatively short period of time as PVR frequently oscillates. Observed clinically as SpO2 lability.
PPHN - risk factors
MAS, RDS, CDH
Pulmonary infections
Pulm hypoplasia
Hyperviscosity or polycythaemia
Birth asphyxia
Sepsis
Hypoglycaemia
Hypothermia
Maternal NSAID or SSRI use
In utero closure of ductus arteriosus
PPHN - CVS signs
Prominent precordial pulse
Tricuspid regurg (harsh systolic murmur LLSB)
Loud, narrowly split 2nd heart sound (P2)
PPHN - ECHO findings
Elevated pulm artery pressure
Atrial septal flattening
R-L shunting of blood across DA or FO
Neonatal apnoea causes
Most frequent - sleep associated hypoxaemia and GOR
Also - infections, CNS, metabolic, cardiac, drug, environmental and anatomic
Newborn periodic breathing
Respiratory pauses of 5-10 secs with < 20 secs of resp btwn pauses
Normal in premature infants and resolves with age
Apnoea of prematurity
Periodic breathing WITH apnoea (> 20 secs), occurs in preterms.
Usually resolves by 37 wks
Side effects of caffeine (used to stimulate resp drive)
Jitteriness
Tachycardia
GI distress
Feeding intolerance
MAS - factors that cause in utero passage of meconium
Placental insufficiency
Maternal HTN
Oligohydramnios
Maternal substance use
Chorioamnionitits
Fetal distress/hypoxia
CXR MAS
Patchy infiltrates
Later progress to hyperinflation with flattening of the diaphragm
PTX and air leaks are common due to ball valve effect of mec plugs
Most common type of oesophageal atresia?
Type C (blind pouch + distal tracheal oesophageal fistula)
Presentations at birth that warrant screening for CMV
IUGR and prematurity
Jaundice
Thrombocytopaenia
Microcephaly
Components of APGAR score
Appearance (colour)
Pulse
Grimace (reflex irritability)
Activity (tone)
Respirations
Causes HIGH maternal alpha fetoprotein
Neural tube defects (e.g., spina bifida, anencephaly)
GI: Omphalocele, gastroschisis
Sacrococcygeal teratoma
Placental abnormalities
Cystic hygroma
Renal: polycystic kidney or absent kidney, urinary obstruction, congenital nephrosis
Osteogenesis imperfecta
Threatened abortion
Decreased maternal wt
IUGR
Causes low AFP
Down syndrome
Increased maternal weight
Fetal demise
Hydatidiform mole
Trisomy 18 (Edward Syndrome)
Incorrect gestational age (older than calculated)
Acute bilirubin encephalopathy and kernicterus pathophysiology
Bilirubin deposition in the basal ganglia and certain brainstem nuclei
Acute bilirubin encephalopathy and kernicterus signs
Hypertonia
Retrocollis (neck ext)
Opisthotonos
Recurrent apnoea
Acute bilirubin encephalopathy and kernicterus sequelae
Athetoid CP
SN deafness
Seizures
Developmental delay
Neuro-cognitive impairment
Oculomotor dysfunction
TSB escalation of care threshold
34 umol/L below the exchange transfusion threshold
DDx hyperbilirubinaemia
Isoimmune haemolytic disease (Rh disease)
What’s a subgaleal haemorrahge?
Haemorrhage btwn the aponeurosis and periostium
What’s a caput succedaneum?
Fluid btwn the periosteum and the scalp
What’s a cephalohaematoma?
Haemorrhage between the periosteum and the skull
What is sodium valproate used for?
GTC, absence, myoclonic, partial, akinetic
Carbamazepine
GTC, partial
Clonazepam
Absence, myoclonic, infantile spasms, partial, Lnnox-Gastaut, akinetic
Phenytoin
GTC, partial, status
Vigabatrin
Infantile spasms (with steroids), TS (no steroids)
1st line AED for absence seizures?
Sodium valproate
