NEONATOLOGY Flashcards
SURFACTANT: where is it produced
Type II alveolar cells
SURFACTANT: Role
Keeps alveoli inflated
Maximises SA of alveoli
Increases lung COMPLIANCE
SURFACTANT: When is it produced in gestation?
Between 24-34 weeks gestation
Cardio-respiratory changes at birth
Thorax squeezed as body passes through vagina to help clear fluid from lungs
Adrenaline and cortisol released in response to stress of labour, stimulating respiratory effort
Decreased pulmonary vascular resistance (expansion of alveoli) —> fall in pressure in right atrium —> L atrial pressure higher —> closure of foremen ovale
Prostaglandins keep ductus arteriosus open. At birth there is fall in prostaglandins —> closure of ductus arteriosus (becomes ligamentum arteriosum)
Ductus venosus stops functioning at birth, structurally closes after a few days and becomes ligamentum venosum
Basic principles of neonatal resuscitation
- Warm the baby
- Calculate APGAR score (at 1, 5 and 10 minutes) while resuscitation continues
- Stimulate breathing (e.g. drying vigorously), place baby’s head in neutral position to keep airway open. Check for any airway obstruction (e.g. meconium)
- Inflation breaths (2 x cycles of 5 inflation breaths, if no response - 30 seconds of ventilation can be used, if still no response - chest compressions coordinated with the breaths)
- Chest compressions - if HR < 60bpm despite resuscitation and inflation breaths (3:1 ratio with breaths)
- Severe situations - IV drugs and intubation considered
Consequence of prolonged hypoxia during neonatal resuscitation
Hypoxic-ischeamic encephalopathy
APGAR score
Appearance (blue, blue extremities, pink)
Pulse ( absent, <100, >100)
Grimace (response to stimulation - no response, little response, good response)
Activity (muscle tone) - floppy, flexed arms and legs, active
Respiration (absent, slow/irregular, strong/crying)
Delayed umbilical cord clamping
In healthy, term babies - delay cord clamping for at least 1 minute (improves haemoglobin, iron stores and BP, and reduces intraventricular haemorrhage and necrotising enterocolitis)
- but also increases neonatal jaundice
Normal care after birth
Skin to skin Clamp umbilical cord Dry baby Keep baby warm Vitamin K Label baby Measure weight and length
Importance of Vitamin K after birth
Babies are born with deficiency of vitamin K
IM injection of vit K in thigh shortly after birth
(Important in clotting and preventing bleeding)
Blood spot screening
Screens for 9 congenital conditions
Taken on day 5 (8 at the latest)
Results take 6-8 weeks to come back
What congenital conditions does the blood spot screen for ?
Sickle cell CF Congenital hypothyroidism Phenylketonuria Medium chain acyl-CoA dehydrogenase deficiency Maple syrup urine disease Isovaleric acidaemia Glutamic acidaemia Homocystin
Birth injuries: CAPUT SUCCEDANEUM
Oedema collecting on scalp, outside periosteum
Cause: pressure to specific area of the scalp during traumatic, prolonged, instrumental delivery
Fluid outside the periosteum so can cross suture lines
Generally mild/no discolouration
Doesn’t require treatment - usually resolves
Birth injuries: CEPHALOHAEMATOMA
Collection of blood between skull and periosteum
Cause: damage to BV during delivery
TRAUMATIC SUBPERIOSTEAL HAEMATOMA
Does not cross suture lines !! As below periosteum
Discolouration of affected area
Usually resolves without treatment within a few months - risk of anaemia and jaundice, so baby should be monitored
Birth injuries: FACIAL PARALYSIS
Delivery can cause damage to facial nerve
Associated with forceps delivery
Function usually returns within a few months
Birth injuries: ERB’S PALSY
Result of injury to C5/C6 nerves in the brachial plexus during birth
Associated with shoulder dystocia, traumatic or instrumental delivery and large birth weight
Weakness of: shoulder ABduction and external rotation, arm flexion and finger extension
“Waiters tip” appearance
- internally rotated shoulder
- extended elbow
- flexed wrist facing backwards
- lack of movement in affected arm
Birth injuries: Fractured clavicle
Picked up during newborn examination
- lack of movement or asymmetry of movement in the affected arm
- asymmetry of shoulders, with affected lower than normal shoulder
- pain and distress on movement of arm
Confirmed by USS or X-ray
Conservative management, might need immobilisation, usually heals well
Main complication: brachial plexus injury
Neonatal sepsis: common organisms
Group B strep E. Coli Listeria Klebsiella Staphylococcus aureus
Neonatal sepsis: Risk factors
Vaginal GBS colonisation
GBS sepsis in a previous baby
Material sepsis, chorioamnionitis or fever above 38
Prematurity (<37 weeks)
Early (premature) rupture of the membrane
Prolonged rupture of membranes (PROM)
Neonatal sepsis: Clinical features
Fever Reduced tone/activity Poor feeding Respiratory distress/apnoea Vomiting Tachycardia or bradycardia Hypoxia Jaundice within 24hrs Seizures Hypoglycaemia
Neonatal sepsis: RED FLAGS
Confirmed or suspected sepsis in mother
Signs of shock
Seizures
Term baby needing mechanical ventilation
Respiratory distress starting more then 4hours after birth
Presumed sepsis in another baby in a multiple pregnancy
Neonatal sepsis: TREATMENT
Risk factor or clinical feature present: monitor the observations and clinical condition for at least 12hrs
2 or more risk factors or clinical features: START ABX within 1 hour
1 single red flag: START ABX within 1 hour
Blood cultures taken before abx given
Check baseline FBC and CRP
If any signs of meningitis: LP
Early onset neonatal sepsis: Antibiotic choice
1st line: BENZYLPENICILLIN IV & GENTAMICIN IV
2nd line/gram -ve cover: CEFOTAXIME IV
if gram negative confirmed stop benzylpenicillin !
Late onset neonatal sepsis (after 72 hours): antibiotic choice
Evidence of localised infection:
FLUCLOXACILLIN IV & GENTAMICIN IV
Suspected sepsis AND meningitis:
add CEFOTAXIME to any current antibiotics or commence AMOXICILLIN, CEFOTAXIME, and GENTAMICIN
MENINGITIS abx choice when causative pathogen unknown
AMOXICILLIN & CEFOTAXIME
MENINGITIS abx choice - confirmed gram -ve infection
CEFOTAXIME (stop amoxicillin)
for at least 21 days
MENINGITIS - group b strep
abx choice
BENZYLPENICILLIN (for at least 14 days) plus GENTAMICIN (for 5 days)
Group B strep septicaemia
abx choice
BENZYLPENICILLIN (stop gentamicin)
for at least 10 days
Hypoxic-ischaemic encephalopathy: staging system
SARNAT STAGING
Respiratory distress syndrome: CXR appearance
“Ground glass” appearance
Necrotising enterocolitis: X-ray findings
Dilated loops of bowel
Bowel wall oedema
Pneumatics is interstinalis (gas in bowel wall)
Pneumoperitoneum - indicates perforation
Gas in portal veins
