Neonatology Flashcards
Remind yourself:
- Which cells produce surfactant
- When these cells start producing surfactant
- Consequences of reduced surfactant
- Type II alveolar cells
- Start maturing and producing surfactant around 24 weeks. Keep maturing, and increasing surfactant producing abilities, up until week 34
- Pre-term babies may have reduced surfactant which means there is increased surface tension in the alveoli which decreases lung compliance and can result in unequal pressures in alveoli
State some factors which contribute to clearing fluid from baby’s lungs during birth
- Baby’s thorax is squeezed through vagina
- First breath (expands the previously collapsed alveoli)
- Adrenaline & cortisol released in response to stress of labour stimulating respiratory effort
Hypoxia during birth is normal; true or false?
True, during contractions placenta unable to carry out normal gaseous exchange so hypoxia occurs
State some differences between a baby and adult that are relevant to resuscitation/must be considered
- Babies have large SA to volume ratio so get cold easily
- Born wet so loose heat quickly
- If born through meconium may have this in mouth or airway
What happens to fetal heart rate during hypoxia?
Bradycardia
Explain the APGAR score, including:
- 5 different categories
- Scores for each
Five principles of neonatal resuscitation include: warming the baby, APGAR score, stimulating breathing, inflation breaths & chest compressions.
Discuss how we keep babies warm
- Vigorous drying (also stimulates breathing)
- If <28 weeks, place in a plastic bag whilst still wet then put under heat lamp
- Keep babies warm under heat lamps
- Ensure delivery rooms are warm
Five principles of neonatal resuscitation include: warming the baby, APGAR score, stimulating breathing, inflation breaths & chest compressions.
How often should APGAR score be calculated?
- Do at 1, 5 and 10 minutes
- Indicates progress over first few minutes & helps guide resuscitation
*Lecturer said they don’t use APGAR in clinical practice
Five principles of neonatal resuscitation include: warming the baby, APGAR score, stimulating breathing, inflation breaths & chest compressions.
Discuss how we can stimulate and aid a baby’s breathing (excluding inflation breaths)
- Stimulate baby (e.g. dry vigorously with towel)
- Place head in neutral position (towel under shoulders can help)
- Check for airway obstruction (e.g. meconium) and consider aspiration if can visualise
Five principles of neonatal resuscitation include: warming the baby, APGAR score, stimulating breathing, inflation breaths & chest compressions.
Discuss the process/protocol for giving inflation breaths (i.e. when you give them and how many you give)
Give inflation breaths when gasping or not breathing
- 2 cycles of 5 inflation breaths (each lasting 3 seconds) can be given to stimulate breathing & HR
- If there is no response and HR is low, can give 30 secs of ventilation breaths
- If still no response, chest compressions coordinated with ventilation breaths should be used
**Use** **air in term or near term babies, can use mix of air & oxygen in pre-term babies.** **Monitor O2 sats throughout, do not exceed 95%.
Five principles of neonatal resuscitation include: warming the baby, APGAR score, stimulating breathing, inflation breaths & chest compressions.
Below what HR do we start chest compressions in neonates and at what ratio
- Start chest compressions if HR still <60bpm after inflation & ventilation breaths
- 3:1 with ventilation breaths
When do the current resuscitation council guidelines say you should cut the umbilical cord in uncompromised neonates?
What happens when you delay clamping of the cord?
What are advantages of delaying cord clamping?
What are disadvantages of delaying cord clamping?
- Uncompromised neonates should have delay of at least 1 minute. Neonates requiring resuscitation should have umbilical cord clamped sooner to prevent delays in resuscitation.
- At birth still a significant volume of blood in placenta and by delaying clamping of cord allow time for this blood to enter baby’s circulation ‘placental transfusion.’
- Advantages:
- Improved Hb stores
- Improved Fe stores
- Improved BP
- Reduction in intraventricular haemorrhage
- Reduction in NEC
- Disadvantages:
- Increase in neonatal jaundice (requiring more phototherapy)
Summary of neonatal life support
Talk through this graph regarding neonatal resuscitation
- Blood supply to baby is cut off
- Baby is stimulated to start breathing
- Lungs are filled with fluid… breathes, breathes and breathes but no oxygen can get into lungs so PaO2 falls
- Respiratory centre stops responding and they stop breathing so go into primary apnoea
- Spinal reflex kicks in and they start to gasp (if still in utero then still can’t get oxygen in lungs so PaO2 continues to fall and PaCO2 and acid continues to rise)
- Will stop gasping and go into terminal apnoea
- Whilst been hypoxic, HR has fallen and continues to fall
- If we then delivered them, inflated their lungs they would then start to gasp
- We would ventilate through gasping
*NOTE: when born you can’t tell if in primary or terminal apnoea. You will only know when they start to respond. When you do resuscitation, you move them backwards/left along the graph. Hence if they started breathing they were in primary apnoea and if they started gasping they were in terminal apnoea
State some important things that should happen immediately after birth
- Skin to skin
- Clamp the umbilical cord
- Dry the baby
- Keep the baby warm with a hat and blankets
- Vitamin K
- Label the baby
- Measure the weight and length
Why are babies given vitamin K?
- Babies born with vit K deficiency
- Helps prevent bleeding (particularly intracranial, umbilical stump & GI bleeding)
- Standard practice go give as IM injection in thigh (can also help to stimulate cry which helps expand lungs). Can also give PO but takes longer to act and is required at birth, day 7 and week 6
What are benefits of skin to skin contact?
- Helps warm baby
- Improves mother and baby interaction
- Calms baby
- Improves breastfeeding
What 3 tests/investigations should happen in first week of life? If relevant, state when they should be done.
- Newborn examination (within 72hrs)
- Newborn hearing test
- Blood spot test (taken on day 5, day 8 at latest)
How many drops is required from heel prick for blood spot screening test?
It tests for 9 congenital conditions; state some
- 4 drops
- Conditions it tests for:
- Sickle cell disease
- Cystic fibrosis
- Congenital hypothyroidism
- Phenylketonuria
- Homocystin
- Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
- Maple syrup urine disease (MSUD)
- Isovaleric acidaemia (IVA)
- Glutaric aciduria type 1 (GA1)
*Results take 6-8 weeks to come back
State some common causative organisms of neonatal sepsis- highlight two most common
- Group B streptococcus (GBS)
- Escherichia coli
- Listeria
- Klebsiella
- Staphylococcus aureus
Do we routinely screen pregnant women for GBS in UK?
- Don’t do routine screening but do opportunistic screening
- If mother is found to have GBS in vagina (a normal commensal in women’s vaginas) then they are given prophylactic abx during labour; these must be given at least 2hrs before birth
State some risk factors for neonatal sepsis
- Vaginal GBS colonisation
- GBS sepsis in previous baby
- Maternal infection (sepsis, chorioamnionitis, fever >38)
- Prematurity
- Early/premature rupture of membrane
- Prolonged rupture of membranes
State some clinical features of neonatal sepsis
Presents with non-specific signs:
- Fever
- Reduced tone and activity
- Poor feeding
- Respiratory distress or apnoea
- Vomiting
- Tachycardia or bradycardia
- Hypoxia
- Jaundice within 24 hours
- Seizures
- Hypoglycaemia
State some red flags for neonatal sepsis
- Confirmed or suspected sepsis in the mother
- Signs of shock
- Seizures
- Term baby needing mechanical ventilation
- Respiratory distress starting more than 4 hours after birth
- Presumed sepsis in another baby in a multiple pregnancy
When deciding whether to treat a baby for suspected neonatal sepsis there are clear NICE guidelines to follow; in summary, what would you do if:
- 1 risk factor or clinical feature indicating sepsis
- 2 or more risk factors or clinical features
- 1 or more red flags
- 1 risk factor or clinical feature indicating sepsis: moniroe observations & clinical features for at least 12hrs and use clinical judgement
- 2 or more risk factors or clinical features: start antibiotics
- 1 or more red flags: start antibiotics
*Just like with adult sepsis, abx should be given within 1hr
What investigations should be performed if you suspect neonatal sepsis?
Full sepsis screen:
- FBC
- CRP
- Blood cultures
- Lumbar puncutre
- CXR
- Urine dipstick/culture not usually done as urinary tract sterile at birth
What are the first line abx for neonatal sepsis?
- First line= benzylpenicillin and gentamycin
- Second line/alternative in lower risk: cefotaxime
Discuss how to decide when to stop abx in neonatal sepsis
- Check CRP at 24hrs and blood cultures at 36hrs; if baby is clinically well and blood cultures -ve at 36hrs and CRP <10 then consider stopping
- If still on treatment, check CRP, blood cultures +/- lumbar puncture on day 5 and stop abx if all are -ve and baby is clinically well
- Review baby regularly (at least every 24hrs)
What is hypoxic ischaemic encephalopathy?
What condition can it cause?
Brain damage (encephalopathy) due to oxygen deprivation (hypoxia) and decreased blood flow (ischaemia). Hypoxia in birth is normal but prolonged or severe hypoxia can lead to permanent brain damage resulting in cerebral palsy or even death.
State some potential causes of hypoxic ischaemic encephalopathy
Anything that leads to asphyxia (deprivation of oxygen) to the brain:
- Maternal shock
- Intrapartum haemorrhage
- Prolapsed cord, (causing compression of the cord during birth)
- Nuchal cord (cord is wrapped around baby’s neck)
What staging can be used to grade HIE? Describe each of the 3 stages (mild, moderate and severe) in terms of:
- Presentation/clinical features
- How long it takes to resolve/mortality
- Prognosis/risk of cerebral palsy
Sarnat staging
*In mild pupils are dilated & reactive, in moderate constricted & reactive, in severe variable & fixed
Discuss the management of hypoxic ischaemic encephalopathy
-
Supportive care in neonatal unit
- Ventilatory support
- Circulatory support
- Nutrition
- Acid base balance
- Seizure management
- Therapeutic hypothermia (option in certain cases)
- Follow up by MDT to assess development and any lasting disability
Therapeutic cooling may be used in some neonates with HIE. Discuss:
- Principles behind therapeutic cooling
- How baby is cooled and targets
- How long they are cooled for
- Aims
- Criteria
- Idea that primary neuronal death occurs at time of severe hypoxic & ischaemic insult. Secondary neuronal death occurs after period of at least 6hrs. Means there is a window to prevent the secondary neuronal death.
- In NICU, actively cool using cooling blankets and cooling hat. Target between 33 and 34 degrees C (measure using rectal probe)
- Cooled for 72hrs then gradually warmed to normal temp over 6hrs
- Aims to reduce inflammation & neurone loss to reduce risk of cerebral palsy, developmental delay, learning disability, blindness & death.
- Extensive criteria (so would look up) but key ones: gestation age >/=36 weeks, severe metabolic acidosis, history of event associated with hypoxia, evidence of moderate to severe HIE
There are lots of potential complications of therapeutic cooling (too many to list them all); state a few
- Arrhythmias (most commonly sinus brady)
- Reduced CO and hypotension
- Reduced surfactant production
- Increased pulmonary vascular resistance (which can lead to PPH)
- Anaemia
- Coagulopathy
- Renal impairment
- Liver impairment (most commonly hyperbilirubinaemia)
- Hypoglycaemia
- Hypocalaemia
- Seizures
- Skin breakdown
Remind yourself of the excretion of bilirubin
What is physiological jaundice?
Explain pathophysiology of physiological jaundice
- Jaundice that occurs in first few days of life (usually within first 2-7 days of life- pathological if in first 24hrs and lasts no longer than 10 days; due to normal physiology and not a pathological cause
- There is a high concentration of RBCs (high haematocrit) in fetus and neonate but these RBCs are more fragile and break down more rapidly than normal RBCs releasing lots of bilirubin. In utero, this bilirubin was excreted by placenta but once born the neonate’s liver must excrete the bilirubin; liver is not less developed/not fully developed hence there is a normal rise in bilirubin shortly after birth. Most babies remain otherwise healthy & well.
Jaundice in the first _____ is pathological. It needs urgent investigation & management as ______ is a common cause.
24hrs
Neonatal sepsis
Pathological causes of neonatal jaundice can be divided into:
- Increased bilirubin production
- Decreased bilirubin clearance
… state some examples for each
Increased production of bilirubin:
- Haemolytic disease of the newborn
- ABO incompatibility
- Haemorrhage
- Intraventricular haemorrhage
- Cephalo-haematoma
- Polycythaemia
- Sepsis and disseminated intravascular coagulation
- G6PD deficiency
Decreased clearance of bilirubin:
- Prematurity
- Breast milk jaundice
- Neonatal cholestasis
- Extrahepatic biliary atresia
- Endocrine disorders (hypothyroid and hypopituitary)
- Gilbert syndrome
Aswell as classifying causes of neonatal jaundice based on increased production and decreased clearance of bilirubin we can also classify based on when it presents. State some causes of jaundice in first 24hrs
- Rhesus haemolytic disease of newborn
- ABO haemolytic disease of newborn
- Hereditary spherocytosis
- G6PD deficiency
Aswell as classifying causes of neonatal jaundice based on increased production and decreased clearance of bilirubin we can also classify based on when it presents. State some causes of prolonged jaundice
Causes of prolonged jaundice
- biliary atresia
- hypothyroidism
- galactosaemia
- urinary tract infection
- breast milk jaundice
- prematurity
- congenital infections e.g. CMV, toxoplasmosis
Explain why breast milk jaundice can occur/why babies who are breastfed are more likely to develop neonatal jaundice
Several reasons:
- Components of breast milk inhibit livers ability to process bilirubin
- Breastfed babies more likely to become dehydrated if not feeding adequately and dehydration may lead to slowing of passage of stools and subsequent increased absorption of bilirubin in intestines
What is meant by premature jaundice/why does prematurity lead to jaundice?
In premature babies, the process of physiological jaundice is exaggerated due to the immature liver.
What is meant by prolonged jaundice? *Think about differences for full term & premature babies
- Jaundice >14 days in full term
- Jaundice >21 days in premature babies
Prolonged jaundice should prompt further investigations for an underlying cause (see previous flashcards for possible causes)
What investigations would you consider in a baby with prolonged jaundice?
- FBC: anaemia, polycthamia
- Blood film: may show Heinz bodies in G6PD
- Conjugated & unconjugated bilirubin
- Direct Coombs test: for haemolysis
- TFTS: for hypothyroidism
- Blood cultures, urine cultures, LP: if infection suspected
- Glucose-6-phosphate dehydrogenase levels: G6PD deficiency
Discuss the management of neonatal jaundice
-
Phototherapy
- Plot age (x axis) and total bilirubin level (y axis) on treatment threshold chart to see if they should be started on phototherapy
- If don’t meet treatment threshold, monitor baby & bilirubin levels (may be physiological) or treat underlying cause if one suspected (e.g. sepsis)
- If extremely high bilirubin levels, exchange transfusion (remove blood from neonate & replace with donor blood) may be needed
*NOTE: thresholds decrease with decrease in gestational age
Explain how phototherapy works
Explain how it is done/given
When must you recheck bilirubin after stopping phototherapy
- Phototherapy converts unconjugated bilirubin into isomers that can be excreted in the bile without requiring conjugation
- Remove all clothing except nappy, put eye patches on to protect eyes. Blue light is shone on baby’s skin (little or no UV used). Double phototherapy involves 2 light boxes.
- Measure bilirubin 12-18hrs after stopping (rebound bilirubin) to ensure levels have not risen above treatment threshold again
Kernicterus is a potential complication of neonatal jaundice; explain:
- What it is
- Presentation
- Potential complications
- Brain damage due to excess bilirubin levels (unconjugated bilirubin can cross BBB)
- Presentation:
- Less responsive
- Floppy
- Drowsy
- Poor feeding
- Complications:
- Cerebral palsy
- Learning disabilty
- Deafness
Define:
- Premature
- Moderate to late preterm
- Very preterm
- Extreme preterm
- Premature: birth before 37 weeks
- Moderate to late preterm: 32-37 weeks
- Very preterm: 28-32 weeks
- Extreme preterm: <28 weeks
State some associations/risk factors for prematurity
- Twins
- Personal of FH of prematurity
- Smoking
- Alcohol
- Drugs
- Over- or underweight mother
- Maternal comorbidities
During pregnancy, we can identify women who may be at risk of preterm delivery; state 2 categories of women we say are at risk
- History of preterm birth
- US shows cervical length of 25mm or less before 24 weeks gestation
State two options for trying to delay birth
- Prophylactic vaginal progesterone: putting progesterone suppository into vagina thought to work by preventing contractions that lead to preterm birth
- Prophylactic cervical cerclage: putting suture in cervix to hold it
When preterm labour is suspected or confirmed there are a few things we can try to help improve outcomes; state 4 options
- Tocolysis with nifedipine: CCB that suppresses labour
- Maternal corticosteroids: can be offered <35 weeks to reduce neonatal morbidity & mortality as it can increase surfactant production in baby
- IV magnesium sulphate: can be offered <34 weeks and helps to protect baby’s brain
- Delayed cord clamping or cord milking: increase circulating blood volume and Hb to baby