Neonatology Flashcards
What cells produce surfactant?
Type II alveolar cells
What are the two sides to the surfactant?
The hydrophilic side that faces the water, and the hydrophobic side that faces the air
What is the action of surfactant?
Increases the lung compliance
Why would the alveoli collapse without surfactant?
Due to the surface tension of the water surrounding them
What is compliance?
When the surfactant reduces the force needed to expand the alveoli and therefore the lungs during inspiration
How does surfactant increase lung compliance?
Reduces the surface tension of the fluid in the lungs to keep the alveoli inflated and maximise their surface area
How does surfactant promote equal expansion of all alveoli?
As an alveolus expands, the surfactant becomes more thinly spread and therefore the surface tension increases, making it more difficult to expand further
At what gestation do alveolar cells become mature enough to start producing surfactant?
24-34 weeks gestation
What stimulates the first breath?
Birth, temperature change, sound and physical touch
What is released by the baby in response to the stress of labour that stimulates respiratory effort?
Adrenalin and cortisol
What happens during the first breaths the baby takes?
The alveoli expand for the first time, decreasing pulmonary vascular resistance
What changes to the cardiovascular system do the first breaths trigger?
Decrease in pulmonary vascular resistance causes fall in pressure in right atrium, causing left atrial pressure to be greater and the closure of the foramen ovale.
What changes happen to the cardiovascular system after birth?
Closure of foramen ovale and ductus arteriosus
Ductus venosus stops functioning
Pressure becomes greater in left atrium
What are the key problems that would trigger the need for neonatal resuscitation?
Hypoxia- placenta can’t carry out normal gaseous exchange during contractions
Hypothermia- large surface area: weight ratio and are born wet
May have aspirated meconium
What are the key steps in neonatal resuscitation?
Warm them Calculate APGAR score Stimulate breathing Inflation breaths Chest compressions
How can you warm the baby?
Get them dry as quickly as possible
Warm delivery rooms and heat lamps
Put in plastic bag if <28 weeks
What is the APGAR score?
Used to indicate progress after the first minutes after birth
What does APGAR stand for?
Appearance Pulse Grimmace (response to stimulation) Activity Respiration
How often should the APGAR score be calculated?
At 1, 5 and 10 minutes
How can you stimulate breathing immediately after birth?
Shake vigorously
Place head in neutral position to keep airway open
Check for airway obstruction
When are inflation breaths given?
When the neonate is gasping or not breathing despite adequate initial stimulation
How many inflation breaths are given?
Two cycles of five inflation breaths
If no response- 30 seconds of ventilation breaths
When performing inflation what should be used?
Air for term babies
Air + oxygen for pre-term babies
When should chest compressions be started in neonates?
If HR< 60 despite resuscitation and inflation breaths
What is HIE and what causes it?
Hypoxic-ischaemic encephalopathy
Caused by prolonged hypoxia
Why is there a delay in umbilical cord clamping?
There is still a large volume of fetal blood in the placenta after birth. Delaying clamping gives time for the blood to enter the fetal circulation, improving haemoglobin, iron stores and blood pressure
What is the one downside of delaying cord clamping?
Increases instance of neonatal jaundice
How long should cord clamping be delayed after birth?
At least one minute
What is the neonatal period?
The first 4 weeks of life
What is the care given to neonates immediately after birth?
Skin to skin contact Clamp to umbilical cord Dry baby and keep warm Vitamin K Label baby Measure weight and length
Why are babies given a vitamin K infusion?
Babies are born with vitamin K deficiency, and it is a normal part of blood clotting
How is vitamin K given to babies?
IM injection
What are the benefits of immediate skin to skin contact?
Helps warm baby
Improves mother baby interaction
Calms baby
Improves breast feeding
What care should happen to the neonate after mum and baby are out of delivery room?
Initiate breast (or bottle) feeding Newborn examination within 72 hours Blood spot test Newborn hearing test First bath within few days
What is the blood spot screening test?
Heel prick blood spot that looks for 9 congenital conditions
What day does the blood spot screen occur?
Day 5
What conditions are screened for in the blood spot test?
Sickle cell disease
CF
Congenital hypothyroidism
Congenital metabolic disorders (6)
Within what time frame after birth should a NIPE be performed?
Within 72 hours
At what point is the newborn exam repeated?
At 6-8 weeks by GP
What questions should be asked at a NIPE?
Has meconium been passed?
Is baby feeding ok?
Family history of congenital heart, eye or hip problems?
What are pre and post ductal saturations?
Measures oxygen level before and after ductus arteriosus
What are normal saturations in a neonate?
> 96%
No more than 2% difference between pre and post ductal sats
Where is the ductus arteriosus located?
Along the arch of the aorta (connects aorta and pulmonary artery)
When does the ductus arteriosus usually stop functioning?
1-3 days after birth
What are duct-dependent conditions?
Congenital heart conditions that rely on the mixing of blood across ductus arteriosus for survival
How might duct dependent conditions be picked up?
By comparing pre and post ductal saturations
Where are pre-ductal saturations measured and why?
Baby’s right hand- receives blood from right subclavian artery which branches from the aorta before the ductus arteriosus
Where are post-ductal saturations measured?
In either foot- both receive blood from the descending aorta which occurs after the ductus arteriosus
What is Talipes?
Clubfoot- when the ankles are in the supinated position
What is positional talipes?
Where the muscles are slightly tight around the ankle but the bones are unaffected so will resolve with time
What is structural talipes?
When the bones of the foot and ankle are affected so must have referral to orthopaedic surgeon
What are the key injuries that can occur at birth?
Caput succedaneum Cephalohaematoma Facial paralysis Erbs palsy Fractured clavicle
What is caput succedaneum?
Oedema on the scalp outside the periosteum
What causes caput succedaneum?
Pressure to a specific area of the scalp during a traumatic, prolonged or instrumental delivery
What is the periosteum?
A layer of dense connective tissue that lines the outside of the skull and doesn’t cross the sutures
What is a cephalohaematoma?
Collection of blood vessels between the skull and periosteum
What causes a cephalohaematoma?
Damage to blood vessels during a traumatic, prolonged or instrumental delivery
What is the difference between the lump in caput succedaneum and cephalohaematoma?
Crosses suture line in caput succadaneum but not cephalohaematom
What are the risks associated with a cephalohaematoma?
Risk of anaemia and jaundice (blood collects and breaks down, releasing bilirubin)
What is the usual cause of facial nerve injury at birth?
Forceps delivery
What is an Erbs palsy?
Damage to the brachial plexus leading to weakness of shoulder abduction, external rotation, arm flexion and finger extension
What causes Erbs palsy?
The result of injury to the C5/6 nerves in the brachial plexus during birth
How is the affected arm affected in Erbs palsy?
'Waiters tip' appearance: Internally rotated shoulder Extended elbow Pronated, flexed wrist Lack of movement
What is Erbs palsy associated with?
Shoulder dystocia
Traumatic or instrumental delivery
Large birth weight
What are the most common causative organisms of neonatal sepsis?
*Group B strep E.coli Listeria Klebsiella Staph aureus
Why is Group B strep the most common cause of neonatal sepsis?
It is a common harmless bacteria found in the vagina, that can be transferred to the baby during labour
What are the risk factors for developing neonatal sepsis?
Vaginal GBS colonisation GBS sepsis in previous baby Maternal sepsis, chorioamnionitis or fever >38 Prematurity PROM/ PPROM
What are the clinical features of neonatal sepsis?
Fever Reduced tone/ activity Poor feeding Respiratory distress/ apnoea Vomiting Tachy/ bradycardia Hypoxia Jaundice Seizures Hypoglycaemia
What are the red flags to look for to suspect neonatal jaundice?
Sepsis in mother Signs of shock Seizures Needing mechanical ventilation Respiratory distress Sepsis in another baby (multiple pregnancy)
What should be done if there is one risk factor or clinical feature of neonatal sepsis?
Monitor obs and clinical condition for 12 hours
What should be done if there are two or more risk factors or clinical features of neonatal sepsis?
Start broad spectrum antibiotics
When should antibiotics be given in suspected neonatal sepsis?
If there is 1 or more red flag features
If there are two or more risk factors/ clinical features
What should be done before giving antibiotics in neonatal sepsis?
Blood cultures taken
Check baseline FBC and CRP
(Perform LP if infection strongly suspected)
What are the first line antibiotics used in neonatal sepsis?
Benzylpenicilllin and Gentamycin
or Cefotaxime
How do you monitor neonatal sepsis?
Check CRP at 24 hours
Check blood culture at 36 hours
When would you consider stopping antibiotics in neonatal sepsis?
If baby is clinically well, blood cultures are negative after 36 hours and CRP<10
What is HIE?
Hypoxic ischaemic encephalopathy
When does HIE occur?
In neonates as a result of hypoxia during birth
What can HIE cause?
Cerebral palsy
Death
When should you suspect HIE?
In neonates when there are events that could lead to hypoxia during the perinatal or intrapartum period
If there is pH<7 on umbilical artery blood gas
Poor Apgar scores
Features of HIE seen
Evidence of multiorgan failure
What are the common causes of HIE?
Maternal shock
Intrapartum haemorrhage
Prolapsed cord
Nuchal cord
What is nuchal cord?
Where the cord is wrapped around the babies neck
What are the different grades of HIE?
Mild- resolves within 24 hours
Moderate- can take weeks to resolve
Severe- Up to 50% mortality, 90% develop cerebral palsy
How is HIE managed?
MDT team:
Supportive with neonatal resuscitation and optimal ventilation, circulatory supporty, nutrition, acid base balance and seizure treatment
What may be considered in HIE to protect from hypoxic injury?
Therapeutic hypothermia
What is therapeutic hypothermia?
Actively cooling the core temperature to 33/34 degrees for 72 hours to reduce inflammation and neurone loss
What is jaundice?
Abnormally high levels of bilirubin in the blood
What kind of bilirubin to RBC’s contain?
Unconjugated
Why is there unconjugated bilirubin in the blood?
Released when RBC’s break down
Where is unconjugated bilirubin conjugated?
In the liver
How is conjugated bilirubin excreted?
Via the biliary system into the GI tract
Via the urine
What is bilirubin a breakdown product of?
Haem from haemoglobin
Why do fetuses have more bilirubin than adults?
There is a higher concentration of RBC’s in neonates
RBC’s are more fragile and break down more rapidly
Less developed liver function
How is bilirubin excreted in a fetus?
Via the placenta
Why is there a normal rise in bilirubin shortly after birth?
The baby can no longer rely on the placenta to excrete it
When does physiological jaundice usually present and how long does it usually take to resolve?
Mild yellowing of skin/ sclera from 2-7 days, but usually resolves by 10 days
What are the two overlying causes of neonatal jaundice?
Increased production of bilirubin or
Decreased clearance of bilirubin
What are the causes of increased production of bilirubin in the neonate?
Haemolytic disease of the newborn ABO incompatibility Haemorrhage Intravascular haemorrhage Cephalo-haematoma Polycythaemia Sepsis/ DIC G6PD deficieny
What are the causes of decreased clearance of bilirubin in the neonate?
Prematurity Breast milk jaundice Neonatal cholestasis Extrahepatic biliary atresia Endocrine disorders Gilbert syndrome
When is jaundice pathalogical?
In the first 24 hours of life
Why are premature babies more likely to get jaundice?
Process of physiological jaundice is exaggerated due to immature liver
What is the key complication of neonatal jaundice?
Kernicterus
What is kernicterus?
Brain damage due to high bilirubin levels
What is breast milk jaundice?
When babies that are breast fed are more likely to have neonatal jaundice
Why are breastfed babies more likely to have neonatal jaundice?
Components in breast milk inhibit ability of liver to process bilirubin
Breastfed babies more likely to be dehydrated if not feeding adequately, which can lead to slow passage of stools and increased absorption of bilirubin in intestines
What is haemolytic disease of the newborn?
Disease where there is premature haemolysis of neonatal RBC’s
What causes haemolytic disease of the newborn?
Rhesus disease
ABO incompatibility
G6PD deficiency
Spherocytosis
How does rhesus haemolytic disease occur?
When a rhesus negative D mother has a rhesus positive child, the blood will mix and the mother will produce antibodies against the rhesus D antigen (sensitised). In the second pregnancy, the anti-D antibodies can cross the placenta and cause haemolysis, anaemia and high bilirubin levels in the fetus or newborn
What is ABO incompatibility?
When group O mothers have an IgG anti-A-haemolysin antibody that can cross the placenta and haemolyse the red cells of a group A infant
When does jaundice for ABO incompatibility peak and is it worse or better than rhesus disease?
Less severe than rhesus disease
Peaks in first 12-72 hours
What is G6PD deficiency?
Genetic disorder where body doesn’t produce enough of G6PD enzyme which helps RBCs work
Who is most affected G6PD deficiency?
Males
Mediterranean, middle-eastern and african-americans
When is jaundice classified as prolonged?
> 14 days in term babies
>21 days in prem babies
What investigations are done to look into jaundice?
FBC and Blood film Conjugated bilirubin lvels Blood type testing (ABO/ Rhesus) Direct Coombs test TFTs Blood/ urine cultures G6PD levels
What is the Coombs test?
Direct antiglobulin test for haemolysis
How is neonatal jaundice managed?
Plot bilirubin levels on treatment threshold chart
Phototherapy
Exchange transfusion
What is the action of phototherapy?
Converts unconjugated bilirubin into isomers that can be excreted in the bile and urine without conjugation in the liver
What does phototherapy involve?
Removing all clothing and putting on eye patches to protect eyes. Light box shines blue light on baby’s skin.
What is the main reason we treat neonatal jaundice?
To prevent kernicterus
How does kernicterus present?
Less responsive
Floppy
Drowsy
Poor feeding
What are the main causes of jaundice starting <24 hours?
Congenital infection Haemolytic disorders: -Rhesus incompatibility -ABO incompatibility -G6PD deficiency -Spherocytosis
What are the causes of jaundice at 24 hrs- 2 weeks?
Physiological Breast milk Infection Haeomlysis Bruising Polycythaemia
What are the causes conjugated of jaundice at >2 weeks?
Bile duct obstruction
Neonatal hepatitis
What are the causes of unconjugated jaundice at > 2 weeks?
Physiological Breast milk Infection Hypothyroidism Haemolytic High GI obstruction
What gestation is classified as prematurity?
Birth before 37 weeks gestation
What are the different classifications of prematurity?
Extreme preterm= <28 weeks
Very preterm= 28-32 weeks
Moderate- late preterm= 32-37 weeks
What are the risk factors for premature birth?
Social deprivation Smoking Alcohol Drugs Over/ underweight mother Maternal comorbidities Twins Personal/ family history
Why is there an attempt to delay birth as long as possible in premature pregnancies?
There is a dramatic improvement in prognosis with each additional week of gestation
What are the two options of trying to delay birth before 24 weeks gestation?
Prophylactic vaginal progesterone
Prophylactic cervical cerclage
What is prophylactic cervical cerclage?
Putting a suture in the cervix to hold it closed
What options are available for improving outcomes in suspected preterm labour?
Tocolysis with nifedipine
Maternal corticosteroids
IV magnesium sulphate
Delayed cord clamping
What is tocolysis?
Using mediation (nifedipine) to suppress labour
What are the key issues that can occur in early life as a result of premature delivery?
Respiratory distress syndrome Hypothermia Hypoglycaemia Poor feeding Apnoea and bradycardia Neonatal jaundice Intraventricular haemorrhage Retinopathy Necrotising enterocolitis Immature immune system--> Infection
What are the long term effects of premature birth?
Chronic lung disease of prematurity Learning/ behavioural difficulties Susceptibility to infections Hearing/ visual impairment Cerebral palsy
What is apnoea?
Periods where breathing stops spontaneously for > 20 seconds OR for >10 seconds with oxygen desaturation or bradycardia
What is apnoea often accompanied by?
A period of bradycardia
In which babies is apnoea very common?
Premature neonates (almost all <28 weeks gestation)
What causes apnoea in neonates?
Immaturity of the autonomic nervous system that controls respiration and heart rate
What may apnoea be a sign of?
Developing illness: Infection Anaemia Airway obstruction CNS pathology GORD Neonatal abstinence syndreom
How is apnoea of prematurity managed?
Attach apnoea monitors, which make a sound when apnoea is occuring
Tactile stimulation can then be used to prompt the baby to restart breathing
What can be used in babies to prevent apnoea and bradycardia?
IV caffiene
What is retinopathy of prematurity?
Abnormal development of blood vessels in the retina of premature babies, leading to scarring, retinal detachment and blindness
At what point in development does blood vessel development usually start?
Around 16 weeks
At what gestation is retinal blood vessel development usually complete?
37-40 weeks
What stimulates retinal blood vessel formation?
Hypoxia (normal state of the retina during pregnancy)
Why does being born prematurely increase the risk of retinopathy?
Premature exposure to higher oxygen levels removes the stimulant for normal blood vessel development. When hypoxic environment recurs, retina responds by producing excessive blood vessels and scar tissue which may regress and cause retinal detachment
What are the 3 zones of the retina?
Zone 1= optic nerve + macula
Zone 2= between zone 1 and ora serrata
Zone 3= outside ora serrata
When are babies screened for premature retinopathy?
30-31 weeks GA in babies born <27 weeks
4-5 weeks in babies born after 27 weeks
What babies should be screened for ROP?
Those born before 32 weeks
<1/5kg
How frequently should retinopathy screening be performed in premature babies and when can it stop?
Every 2 weeks
Can stop once retinal vessels enter zone 3
How are babies screened for retinopathy?
Opthalmologist monitors retinal vessels as they develop and looks for additional findings (Plus disease)
How is retinopathy of prematurity treated?
Systemic targeting of the retina to stop new blood vessels developing with transpupillary laser photocoagulation
Who are most affected by respiratory distress syndrome and why?
Premature neonates (<32 weeks) born before the lungs start producing adequate surfactant
What is seen on CXR of respiratory distress syndrome?
‘Ground glass appearance’
What causes respiratory distress syndrome in preterm neonates?
Inadequate surfactant leads to high surface tension within alveoli, leading to lung collapse as they find it harder to expand. This leads to hypoxia, hypercapnia and respiratory distress
What is given to mothers with suspected preterm labour and why?
Antenatal steroids to increase production of surfactant and reduce incidence or RDS
How is RDS managed?
Intubation and ventilation
Endotracheal surfactant
CPAP
Supplementary oxygen
What is CPAP?
Continuous positive airway pressure (via nasal mask to keep lungs inflated)
What are the short term complications of respiratory distress syndrome?
Pneumothorax Infection Apnoea Intraventricular haemorrhage Pulmonary haemorrhage Necrotising enterocolitis
What are the long term complications of respiratory distress syndrome?
Chronic lung disease of prematurity
Retinopathy of prematurity
Neurological, hearing and visual impairment
What are the clinical signs of respiratory distress syndrome?
Tachypnoea >60
Increased work of breathing (Chest wall recession, nasal flaring etc)
What is necrotising enterocolitis?
Disorder affecting premature neonates where part of the bowel becomes necrotic
Why is necrotising enterocolitis a life threatening emergency?
Death of the bowel tissue can lead to bowel perforation, leading to peritonitis and shock
What are the risk factors for developing necrotising enterocolitis?
Very low birth weight Prematurity Formula feeds Respiratory distress/ assisted ventilation Sepsis Congenital heart disease
How does necrotising enterocolitis present?
Intolerance to feeds Vomiting with green bile Generally unwell Distended, tender abdomen Absent bowl sounds Blood in stools
What investigations can be done into necrotising enterocolitis?
Blood tests
Abdominal Xray
What blood tests are done to diagnose necrotising enterocolitis?
FBC
CRP
Capillary blood gas
Blood culture
What may abdo Xray show with necrotising enterocolitis?
Dilated loops of bowel
Bowel wall oedema
Pneumatosis intestinalis
Pneumoperitoneum
What is pneumatosis intestinalis?
Gas in the bowel wall
What is pneumoperitoneum?
Free gas in the peritoneal cavity
How is necrotising enterocolitis managed>
Nil by mouth with IV fluids, TPN and antibiotics.
Immediate surgical referral
What is TPN?
Total parenteral nutrition= method of feeding that bypasses the GI tract by giving formula straight into veins
What are the key complications of necrotising enterocolitis?
Perforation and peritonitis Sepsis Death Strictures Abscess formation Recurrence Long term stoma Short bowel syndrome
What is neonatal abstinence syndrome?
Withdrawal symptoms that happen in neonates of mothers that used substances in pregnancy
What substances cause neonatal abstinence syndrome?
Opiates Methadone Benzodiazepines Cocaine Amphetamines Nicotine or cannabis Alcohol SSRI antidepressants
When after birth does withdrawal usually begin?
3-72 hours
What are the signs and symptoms of substance withdrawal in the neonate?
Irritability Increased tone High pitched cry Not settling Tremors Seizures Yawning Sweating Unstable temperature and pyrexia Tachypnoea (fast breathing) Poor feeding Regurgitation or vomiting Hypoglycaemia Loose stools with a sore nappy area
How is substance abuse managed before delivery
Mothers encouraged and supported to cut back/ stop
Alert in notes so neonate can have extra monitoring and management
How are babies with abstinence syndrome managed?
Monitor on NAS chart for at least 3 days
Urine sample to test for substances
Medical treatment if severe
What medical treatment options are available for: 1. Opiate withdrawal?
2. Non-opiate withdrawal?
- Morphine sulphate
2. Phonebarbitone
What are the main conditions arising in pregnancy?
Fetal alcohol syndrome Congenital rubella syndrome Congenital varicella syndrome Congenital cytomegalovirus Congenitla taxoplasmosis Congenital zika syndrome
In what period of pregnancy does alcohol consumption have the greatest effect?
First 3 months
What does drinking alcohol in early pregnancy lead to?
Miscarriage
Small for dates
Preterm delivery
What is fetal alcohol syndrome?
Specific effects and characteristics found in children of mothers that consumed significant alcohol during pregnancy
What are the common characteristics of fetal alcohol syndrome?
Microcephaly Thin upper lip Smooth flat philtrum Short palpebral fissure Learning/ behavioural difficulties Hearing/ vision problems Cerebral palsy
What causes congenital rubella syndrome and when is pregnancy is riskiest?
Maternal infection with rubella during pregnancy (particularly first 3 months)
What should be given to prevent congenital rubella syndrome?
MMR vaccine (NOT during pregnancy)
What are the features of congenital rubella syndrome?
Congenital cataracts
Congenital heart disease (PDA, pulmonary stenosis)
Learning disability
Hearing loss
Why is chickenpox infection dangerous in pregnancy?
Can lead to varicella pneumonitis, hepatitis or encephalitis, fetal varicella syndrome or severe neonatal varicella infection
What should be done if a woman id exposed to chickenpox in pregnancy?
If had prev chickenpox, they’re safe
If unsure about immunity, test VZV IgG levels
If no immune, treat with IV varicella immunoglobulins
What should be done if a women presents with chickenpox rash in pregnancy?
Treat with oral aciclovir if >20 weeks gestation
In what percentage of pregnancy chickenpox cases does congenital varicella syndrome develop?
Around 1%
What are the typical features of congenital varicella syndrome?
FGR Microcephaly Hydrocephalus Learning disability Scars/ skin changes on dermatomes Limb hypoplasia Cataracts and eye inflammation
What is the cause of congenital cytomegalovirus?
CMV infection during pregnancy
What are the features of congenital CMV?
FGR Microcephaly Hearing loss Vision loss Learning disability Seizures
What is toxoplasma gondii?
A parasite
What causes toxoplasmosis infection?
Spread by contamination with faeces from a cat that is a host of the parasite
What are the classic triad of features in congenital toxoplasmosis?
Intracranial calcification
Hydrocephalus
Chorioretinitis
How is the zika virus spread?
By host Aedes mosquitos
Sex with someone infected
What are the features of congenital zika syndrome?
Microcephaly
FGR
Intracranial abnormalities
What is SIDS?
Sudden infant death syndrome
When does SIDS usually occur?
Within first 6 months of life
What are the risk factors for SIDS?
Prematurity
Low birth weight
Smoking during pregnancy
Male baby
What measures can be taken to minimise the risk of SIDS?
Put baby on back when unsupervised Keep head uncovered Keep cot clear Maintain comfortable room temp Avoid smoking Avoid co-sleeping
What is classified as a neonate?
Infant <28 days
What is classified as an infant?
From birth to 1 year
What is classified as a low birth weight?
<2500 g
What is classified as a very low birthweight?
<1500g
What is classified as extremely low birth weight?
<1000g
Why is a C-section more likely to cause transient tachypnoea of the newborn?
Because the infants chest has not been squeezed through the birth canal, so the lung liquid is not drained so it take several hours for the fluid to be completely absorbed
What can be given to infants with continued respiratory depression due to mothers opiate analgesia?
Naloxone
