Neonatology Flashcards
What is Jaundice?
Condition of abnormal high levels of bilirubin in the blood.
What is physiological jaundice in the newborn?
There is a high concentration of red blood cells in the neonate and foetus. The red blood cells are more fragile than normal red blood cells and the foetus and neonate also have less developed liver function. Fetal red blood cells break down more rapidly than normal red blood cells and release lots of bilirubin, normally this bilirubin is excreted by the placenta, however at birth the foetus no longer has access to a placenta to excrete bilirubin, this leads to a normal rise in bilirubin shortly after birth which causes a mild yellowing of skin and sclera from 2-7 days of age. Usually it will resolve completely by ten days.
What are the causes of jaundice in the first 24 hours?
Jaundice in the first 24 hours is always pathological Rhesus haemolytic disease ABO haemolytic disease Hereditary spherocytosis Glucose 6 phosphodehydrogenase
If the baby is less than 24hrs and is jaundice, what should you do?
They are at high risk of developing severe hyper bilirubin anemia and therefore must have their serum bilirubin urgently (within 2 hours)
What investigations should you do if there are still signs of jaundice after 14 days?
A jaundice screen is performed, this includes…
Conjugated and unconjugated bilirubin (raised conjugated bilirubin could indicate biliary atresia which requires urgent surgical intervention).
. Direct antiglobulin test (Coombs)
. TFTS
. FBC and blood film
. Urine for MC&S and reducing sugars
. U and Es and LFTS
What are the causes of prolonged jaundic3?
Biliary atresia Hypothyroidism Galactosaemia UTI Breast milk jaundice Congenital infections-CMV, toxoplasmosis
What are the circulation changes during birth?
Removal of placenta
Reduced pulmonary vascular resistance
Onset of breathing
Closure of the shunts (ductus venosus, ductus arteriosus, Foramen ovale)
What does the heel prick (Guthrie) check for?
This on the 5th day of life
It screens got common illnesses (sickle cell anaemia, cystic fibrosis, congenital hypothyroidism, common metabolic defects)
What clinical features are assessed in a newborn examination (within 24 hours of life)?
Head- red pupil reflex, hard and soft palate, fontanelle, facial dysmorphism, tongue/lip cyanosis.
Breathing- rate, rythm, resp distress?
CVS- rate, murmurs, check femoral pulses (coarctation of aorta)
Neuro- tone, reflexes, baby should be in flexed position, check spine and back for dimples, marks and spina bifida.
Hands and feet- check for palmar crease, talipes, extra digits
Abdomen- palpate for masses, check umbilical cord
Hips- check for developmental dysplasia of the hip
Genitalia
Hearing
Eyes- looking for retinoblastomas (very malignant and can spread to brain) and for cataracts (peripheral blindness within 6 weeks if not treats).
Give brief overview of the newborn examination…
. Document any birthmarks
. Plot newborn on growth chart
. Get senior input if you Are unsure of any findings
. Ask mum how she is feeling and if she has any concerns.
What would be contraindications to vaccinations?
Anaphylaxis to previous vaccine or vaccine component
Anaphylaxis to egg (yellow fever and influenza)
Immunocompromised (live attenuated)
What is the difference between perinatal and neonatal mortality rate?
Perinatal= number of stillbirths and neonatal deaths within the first week of life per 1000 live births
Neonatal= number of deaths per 1000 live births in the first 28 days
What are the two types of IUGR and what is meant by them?
Symmetrical IUGR= this is where there is a proportionally small head, length and weight
Asymmetrical IUGR= there is a small length and weight but the head circumference is preserved
What is the usual causes of symmetrical IUGR?
Intrauterine infections and chromosomal abnormalities
What are the causes of asymmetrical IUGR?
Placental insufficiency/ pre eclampsia
What investigations would you do at birth for IUGR?
Blood gas is typical on delivery to get a baseline on how unwell the infant is
What are the risk factors for prematurity/ IUGR?
Multiple pregnancy Maternal illness Placental insufficiency In utero infection Genetic disorder
What is meant by prematurity?
Any birth before 37/40 weeks gestation.
What is meant by IUGR?
Failure of the foetus to achieve genetic growth potential.
What is meant by SGA?
A newborn below a certain centile for that particular gestation, usually the 10th centile.
What is LBW?
Newborn weighing less than 2500g
What is VLBW?
Newborn weighing less than 1500g
What is a stillbirth?
Foetus born after 24/40 that never shows any signs of life.
What is neonatal death?
Death of a newborn within 28 days of delivery
How should you manage premature/SGA babies?
NICU
Very premature often need intubation, ventilation and surfactant.
Often need feeding support and to be closely monitored for complications.
Why are neonates susceptible to hypothermia?
They have thin skin
Little adipose tissue
Large body surface area compared to their weight
How can you prevent babies from losing heat?
Warm mattress/ skin to skin with Mum (conduction)
Keeping room temperature warm and avoiding droughts (convection)
Wrapping baby including hats and socks (evaporation)
Using incubator as radiant heat source (radiation)
What is the blood glucose level in a neonate with hypoglycaemia?
<2.6mmol/l
What are the causes of hypoglycaemia?
Decreased glucose production (preterm/metabolic errors)
Increased glucose demands (sepsis/hypothermia)
Hyperinsulinism (diabetic mother)
Endocrine problems
What are the symptoms of hypoglycaemia in a neonate?
Jitteriness, hypotonia, apnoeas +/- seizures (if they have seizures it’s severe)
What investigations would you do if you were suspecting neonatal hypoglycaemia?
Check blood temp and sugars regularly, if identified then you need to investigate driving cause.
Symptomatic or severe (<1.5mmol/l) hypoglycaemia should prompt a hypo screen which looks for endocrine and metabolic causes.
How would you manage an infant with hypoglycaemia?
1.6-2.6mmol/l- feed infant and consider increasing feed frequency and volume, most hypoglycaemic episodes are transient are not sinister.
<1.6mmol/l or asymptomatic- treat immediately with IV dextrose (10%), admit to neonatal unit and monitor blood sugars hourly until stable.
What is respiratory distress syndrome?
It is also known as hyaline membrane disease. It is a condition of prematurity caused by insufficient levels of surfactant, it is more prevalent the more premature an infant is. It manifests in a tachypnoea case newborn showing signs of resp distress.
What is the pathophysiology behind respiratory distress syndrome?
. Lack of surfactant May be bascule the infant is premature (surfactant is produced in the third trimester) or because the affect of surfactant has been inhibited by asphyxia. Surfactant lowers the alveolar surface tension allowing the lungs to open and close easily without collapsing. The loss of surfactant results in alveolar collapse.
What is the cycle of respiratory distress syndrome?
Alveolar collapse due to the surfactant leads to impaired gas exchange, this then leads to hypoxia and acidaemia which further impairs surfactants effect and again leads to alveolar collapse.
What are the risk factors for respiratory distress syndrome?
Main one is prematurity
Perinatal asphyxia- difficult birth, meconium aspiration, sepsis, congenital lung anomalies.
Maternal diabetes- lungs are delayed in their maturity.
What babies should recieve surfactant treatment?
Surfactant is produced by type 2 pneumocytes which are present from 20/40 gestation however there is an increased number during the final trimester.
All neonates born <28/40 should get surfactant after delivery and maternal antenatal steroids should be given.
Treatment with exogenous surfactant in respiratory distress syndrome reduces the mortality by 40%
What are the clinical features of respiratory distress syndrome?
Symptoms- distressed and unwell infant, poor feeding
Signs-
Tachypnoea (>60 breaths per minute)
Hypoxia
Respiratory distress (tracheal tug, head bobbing, nasal flaring, intercostal and subcostal recession)
Grunting (In an attempt to increase airway pressure and open collapsed alveoli).
When is the onset of respiratory distress syndrome?
Normally it is less than 4 hours after birth
What are the investigations of respiratory distress syndrome which are normally carried out?
Blood gases (they show hypoxia and metabolic acidosis(
CXR (show ground glass infiltrate with air bronchograms and reduced lung volume)
Important to screen for other causes of respiratory exists as so send blood cultures, FBC, U and Es and swabs from both mother and infant.
What are the differential diagnoses for respiratory distress syndrome?
Sepsis Complex heart disease Lung hypoplasia Pneumothorax Severe anaemia
What is the management of respiratory distress syndrome?
Oxygen to improve oxygenation, aiming for pO2 to be between 6 and 10
CPAP and mechanical ventilation to give sufficient pressure to open airways and prevent further lung collapse
Artificial surfactant to increase lung compliance and decrease alveolar surface tension
If possible give antenatal steroids to the mother prior to delivery in at high risk pregnancies
Correct hypothermia, acidaemia and hypoglycaemia.
What neurological damage is related to prematurity?
Intra ventricular haemorrhage and periventricular leukomalacia.
What is intraventricular haemorrhage?
Alteration in cerebral blood flow (from apnoea, acidaemia, hypotension) this results in bleeding in the fragile germinal matrix, which if severe enough will extend into the ventricles, the germinal matrix disappears in the 3rd trimester and as such is a condition seen in neonates which are born prior to 32 weeks gestation)
What is the pathophysiology behind periventricular leukomalacia?
Thought that hypoperfusion and excitotoxic cytokines cause damage to the oligodendroglia, which then results in white matter injury.
What are the risk factors for brain injury in a neonate?
VLBW (gestation <32 weeks) Difficult birth RDS Cardiovascular instability Sepsis Necrotising enterocolitis
What are the clinical features of brain injury in the neonate?
They are often asymptomatic, especially if the insult is small
Seizures and apnoeas may occur with big bleeds
Significant neurological insult may present as floppy infant and poor feeding
In terms of signs, there may be abnormal movements or tone
A large IVH May present as a hypovolaemia neonate (tachycardia and peripherally shut down).
What is the site of injury in IVH?
The germinal matrix
What are the risk factors for infection in a neonate?
Prematurity Maternal pyrexia in labour PROM LBW Long lines in situ Chorioamnionitis Maternal group B strep colonisation
What are the differential diagnoses for neonatal infections?
Congenital infections
Respiratory distress syndrome
Congenital heart problems
Necrotising enterocolitis
What investigations should be done if your suspecting neonatal infection?
Septic screen(nasal, throat,line swabs, bloods, cultures, urine dip, CXR, lumbar puncture).
What is the management of neonatal infections?
Antibiotic treatment should be commenced <1 hour if clinical suspicion of infection, do not delay whilst waiting for investigation!
Specific antibiotic regimens will differ but broadly
<72 hours after birth you should give IV penicillin and IV aminoglycoside
> 72 hours after birth you should give IV flucloxacillin and IV aminoglycosides
Plus acyclovir which covers potential HSV
Proven infections are treated for at least 7 days, 14 days for staph aureus infections and 21 days for meningitis.
What is the pathophysiology behind necrotising enterocolitis?
Infection and ischaemia occur in the bowel wall which leads to inflammatory oedema and haemorrhage. Untreated it can lead to bowel necrosis and subsequent perforation
What are the risk factors for NEC?
Prematurity Other concurrent illness Oral feeding VLBW IUGR LBW Perinatal asphyxia
How does a neonate with NEC usually present?
Usually around 1-2 weeks of age Classic Hx of abdominal distension and bilious aspirated in a clinically deteriorating neonate with bloody stools. Fluctuation in temperatures Neonatal collapse and death Apnoeas, bradycardia.
What investigations would you do for a neonate your suspecting of having necrotising enterocolitis?
Bloods (FBC, CRP, coagulation, blood gases (acidosis).
Abdominal x Ray
Screen for other sources of sepsis
What would you see on an x Ray of an abdomen in a neonate with NEC?
Pneumatosis intestinalis
What are the differentials for NEC?
Other causes of mechanical intestinal obstruction (volvulus)
Congenital bowel malformation
Hirschsprung disease
What is the management for NEC?
Keep infant NBM, Feed parenterally(TPN), place NG tube for aspirates.
IV ABx
Replacement off fluid and electrolyte losses, correction of coagulopathy and oxygenate well.
If bowel perforates or is not responsive to conservative management then laparotomy and bowel resection is indicated.
What is retinopathy of prematurity?
Eye disease that can happen in premature babies. It causes abnormal blood vessels to grow in the retina and can lead to blindness.
What are the risk factors for retinopathy of prematurity?
VLBW (30% of those born <1500g develop ROP)
Hyper oxygenation
Prematurity
What infants are screened for Retinopathy of prematurity in the UK?
Infants born <32 weeks gestation or <1500g will be screened in the UK
What are the 5 stages of ROP?
- Mild abnormal vessel growth
- Moderately abnormal vessel growth
- Severely abnormal vessel growth
- Partial retinal detachment
- Complete retinal detachment
What is the differential diagnosis for Retinopathy of prematurity?
Myopia
Congenital cataract
Congenital glaucoma
Cortical blindness
What is the management of retinopathy of prematurity?
Keep O2 sats 90-95% and aim to avoid big swings in oxygenation
Stage 1 and 2 will resolve independently
Stage 3+ will need laser treatment of the peripheral retina to prevent further vessel growth.
Why is neonatal jaundice important?
High levels of unconjugated bilirubin cross the blood brain barrier and cause permanent damage to neural tissue (kernicterus- bilirubin induced brain damage).
When is neonatal jaundice an emergency?
Onset of neonatal jaundice within the first 24 hours should be treated as an emergency.
