Neonatology Flashcards
(151 cards)
1
Q
SGA
A
small for gestational age
used for neonates with a birth weight less that the 10th centile or 2 standard deviations from the population norm
o This definition only considers the birthweight without any consideration of the in-utero growth or physical characteristics at birth
o Severe SGA is birthweight <3rd centile
2
Q
IUGR
A
IUGR is used for neonates with clinical features of malnutrition and growth restriction, irrespective of birth weight centile
o It is a failure to fulfil growth potential with faltering growth in-utero
3
Q
Maternal Causes of IUGR
A
Malnutrition Low BMI Maternal substance abuse inc. smoking Chronic disease Hypertensive disorders Anti phospholipid syndrome Previous SGA Material age <16 or >35 Nulliparity or grand multiparity
4
Q
Foetal Causes of IUGR
A
Chromosomal abnormalities Genetic syndromes Major congenital abnormalities Congenital infections Metabolic disorders
5
Q
Placental causes of IUGR
A
Pre-eclampsia
Abruption
6
Q
Classification of IUGR
A
- Symmetrical IUGR is due to a cause early in pregnancy (foetal factors above). The head circumference, length and weight are all reduced
- Asymmetrical IUGR is due to a cause later in pregnancy. The weight is reduced but other factors are normal
7
Q
IUGR Investigations
A
Undergo serial growth scans (plotted customised growth charts) every 2 weeks from 28 weeks’ gestation to assess the following
- Foetal head circumference, abdominal circumference, and femur length
- Liquor volume
- Uterine artery Doppler
o Where this shows reversal or absent diastolic flow, delivery of the foetus is indicated. If preterm, give steroids
o If it shows reduced pulsatility/notching, continue surveillance - Occasionally CTG is also performed
For severe IUGR consider serological testing for TORCH infections, or pre-natal diagnosis with karyoptyping
8
Q
Why does oligohydramnios occur in IUGR
A
o Oligohydramnios occurs in IUGR as there is shunting of blood to the head to protect the developing brain. This deceases renal perfusion, lowering urine output
9
Q
How to manage previous mothers with previous SGA
A
they should be commenced on 75mg aspirin OD from booking
- Where women have anti-phospholipid syndrome they should take clexane alongside aspirin from booking
10
Q
Complications of IUGR
A
- Asphyxia
- Hypothermia
- Hypoglycaemia
- Jaundice
- Pre-term delivery
- Perinatal mortality (death in utero after 24 weeks, or death in the first 7 days postnatal)
In the longer term these infants are prone to poor growth and neurodevelopmental outcomes. They may also demonstrate the thrifty phenotype, and develop metabolic disorders.
11
Q
Circulation in Utero
A
foetus is dependent on the umbilical vein, providing oxygenated blood from the maternal circulation via the placenta. Some of this blood passes to the foetal liver (into the hepatic sinusoids) through the portal sinus, but the majority passes into the ductus venosus and bypasses the liver
Blood in the ductus venosus travels to the inferior vena cava, which also drains the lower limbs, abdomen, and pelvis. This blood then passes into the right atrium, alongside deoxygenated blood returning from the head and arms
- Some of this blood will pass out of the pulmonary trunk. However, due to high pressure within the lungs, most of it will pass through the ductus arteriosus into the descending aorta
- The rest of the blood from the right atrium will pass through the foramen ovale and into the left atrium, passing out of the left ventricle to the ascending and descending aorta to pefuse the body
The deoxygenated blood will then flow to the placenta through the two umbilical arteries. The blood is oxygenated in the placenta and then passes back into the foetus through the umbilical vein.
12
Q
Changes at Birth with Circulation
A
At birth, when maternal circulation is removed and the lungs become filled with air, major changes to the foetal circulation must take place
During labour the fluid filling the lungs is drained, and at birth with the first breath, the remaining fluid is absorbed. This decreases the pulmonary vascular resistance dramatically as the lungs can expand
13
Q
What happens as a result of reduced pulmonary vascular resistance
A
Blood can then flow from the right ventricle into the pulmonary circulation, returning to the left atrum
o This increase in left atrial pressure, coupled with a decrease in right atrial pressure, closes the foramen ovale by pushing the septum primum against the septum secundum
14
Q
How are baby’s lungs able to expand with their first breath
A
The ability for the lungs to expand in the first breath is reliant on the presence of sufficient lung surfactant
- Surfactant production occurs from around 20 weeks and is complete at term
- Surfactant is a form of interstitial fluid that reduces alveolar surface tension (secreted by type II alveolar cells), increasing lung compliance
15
Q
What happens to foetal circulation after birth?
A
The umbilical arteries, umbilical vein, and ductus venosus close in response to thermal and mechanical stimuli
o After around 3 months’ post-partum these will be obliterated
- The ductus arteriosus closes almost immediately after birth by muscular contraction in response to bradykinin due to oxygenated blood flow
o Anatomical closure follows this physiological closure after a few days
16
Q
Why might a neonate not take their first breath spontaneously
A
Several reasons for this, and almost all relate to a respiratory rather than cardiac arrest
- Asphyxia, where the foetus experiences a lack of oxygen during labour
- Deprivation of oxygen in utero e.g. cord prolapse/ abruption, meaning that the foetus attempts to breathe in utero and apnoea follows
- Birth trauma
- Maternal analgesics or anaesthetics
- Prematurity and lack of surfactant
- Congenital lung malformation
Where an infant does not take their first breath, immediately transfer them to a neonatal resuscitation trolley
17
Q
Infant Resuscitation Algorithm
A
Dry the baby, remove wet towels, and wrap the baby in a new towel. Cover their head with a hat
- Start the clock
- Assess the baby’s heart rate (auscultation), chest movement, colour, and tone
18
Q
What is the first thing that must be achieved in resuscitation?
A
The first thing that must be achieved is aeration of the lungs, which can only be confirmed when the chest is seen to passively move.
- Open the airway by placing the head into neutral position
- Give 5 inflation breaths over 30 seconds
o Inflation breaths are best given using a neopuff device with mask (or bag-valve-mask) using air, at 30 cmH2O for 3 seconds per breath
- Re-assess heart rate, chest movement, colour, and tone
19
Q
What happens if chest has not expanded and HR has not increased after inflation breaths?
A
re-check the head position and call for help
- Give 5 further inflation breaths
- If these measures have failed to expand the lungs, apply an SpO2 monitor to the right hand to gain a pre-ductal saturation recording. Try 5 inflation breaths after each of the following manoeuvres
o Move on to two-person airway control, with a jaw thrust manoeuvre
o Look inside the mouth and suction anything visible, insert a guedel airway
o If there is someone competent present, consider tracheal intubation
- Ensure to re-assess the baby every 30 seconds
20
Q
What happens if you intubate but heart rate does not increase and chest does not expand
A
consider DOPE - Displaced ET tube - Obstructed ET tube - Patient o Tracheal obstruction o Lung disorders o Shock o Upper airways obstruction - Equipment failure
21
Q
What happens after chest movement is seen and HR improves after intubation ?
A
you can assume that the lungs have been aerated. The baby will usually breathe for themselves at this point. If the baby does not start to breathe on their own, move on to ventilation breaths
- Give 30 ventilation breaths at 30 cmH2O for 1 second per breath
- Repeat this in 30 second cycles, with re-assessment of the baby between cycles, until it starts to breathe on its own
22
Q
What do you do if the chest starts moving after ventilation breaths but heart rate is not improving?
A
give 5 further inflation breaths with good passive chest movement and re-assess. If heart rate is still <60, commence chest compression
- Grip the chest with both hands so that the thumbs can press on the lower third of the sternum
- Give 3 compressions to one inflation breath
- Re-assess heart rate every 30 seconds, stop when heart rate >60
23
Q
What drugs should you use if HR is less than 60 despite adequate ventilation and chest compression
A
Adrenaline Bicarbonate Dextrose Saline Drugs should be given via an umbilical venous catheter
24
Q
Definition of neonate
A
Infant <28 days old
25
Hypoxic Ischaemic Encephalopathy
HIE is injury to the brain occurring due to perinatal asphyxia, significant hypoxic events immediately before and during labour have many potential causes
- Placental failure e.g. abruption, uterine rupture
- Cord failure e.g. cord prolapse, shoulder dystocia
- Inadequate maternal placental perfusion
- Failure of cardiorespiratory adaptation at birth
26
Clinical Manifestation of HIE
tend to become apparent within the first 48 hours of life
In mild cases there may be irritability and trouble feeding
- In more severe cases there may be abnormalities in tone and movement, seizures, and multi-organ failure
o Encephalopathy, persistent pulmonary hypertension, myocardial dysfunction, metabolic derangements, DIC, and renal failure
27
APGAR Measurements
Evaluates newborn baby on five criteria, and is designed to see if a child needs immediate intervention
A Appearance, this is skin colour
P Pulse, this measures heart rate and is measured through a stethoscope
G Grimace, this is a measurement of reflex irritability in response to mild stimulation e.g. a pinch
A Activity, this is muscle tone
R Respiration
28
APGAR Scoring
Each of the five criteria is scaled from 0 to 2, therefore the maximum score is 10. Different score bandings are summarised below
- <3 is critically low
- 4 – 6 is fairly low
- 7 – 10 is generally normal
APGAR score is taken at 1 and 5 minutes after birth (and later if necessary). It is not able to predict the need for long term care
- However, a score <3 beyond 5 minutes increases the risk of the child developing neurological damage e.g. cerebral palsy
29
Physical Examination of the Newborn
carried out within 72 hours of birth
involves a ‘top to toe’ physical assessment, alongside several specific screening tests
- Auscultation of heart and examination of pulses
- Hip movement in all planes to detect congenital hip dysplasia
- Ophthalmoscopy of eyes to check for congenital cataracts
- Check for undescended testes. If the testes have not descended by 1 – 2 years, an operation may be advised
30
Physical Examination of the Newborn: General Appearance
- Do they look particularly small or large?
- Look for pallor, cyanosis, and jaundice
- Assess movements and tone of the four limbs. Are they moving equally, and in a flexed position?
31
Physical Examination of the Newborn: Cardiorespiratory + General
The position of the heart should be assessed by palpating the apex beat. The doctor should then auscultate for any murmurs, and measure the heart rate (should be 100 – 160). Femoral pulses should be measured
- Lungs should be auscultated for added sounds, and the respiratory rate measured (30 – 60)
- Abdominal examination should look for any herniae, organomegaly, and the general shape of the abdomen
32
Physical Examination of the Newborn: Head
head circumference is then measured, as well as an assessment of the overall shape, sutures, and fontanelles. Observe the face and the ears
- Look for accessory skin tags or preauricular sinuses. These are usually normal, but additional hearing tests are recommended
- Assess the face for syndromic or dysmorphic features
33
Physical Examination of the Newborn: Eyes and Vision
In high risk infants e.g. premature, family history of eye problems, permanent squint, the doctor should check that the infant is being seen by an opthalmologist
- An opthalmoscope is used to check for the red reflex
- This may absent in retinoblastoma, corneal scarring or congenital cataracts (more common in Down’s, rubella, and galactosaemia)
- The pupils and alignment of the eyes are noted, as well as the completeness of the iris
34
Physical Examination of the Newborn: Mouth
Look in the mouth for cyanosis, dentition, and the completeness of the palate
- Digitate the palate, but also ensure to look at it when the baby is crying
- Epstein’s pearls may be present in the midline, and are a normal variant
35
Physical Examination of the Newborn: Limbs
Assess the limbs, looking at the palms and counting the fingers, and then the feet and toes.
36
Physical Examination of the Newborn: Genitalia and Anus
Genitalia should be examined
- In boys check for hypospadias, hydrocele, hernia and undescent of testes
- In girls, the labia should be parted to check for ambiguous genitalia e.g. 5α-reductase deficiency, CAH
The anus should be checked for patency and position
- Passage of meconium does not necessarily indicate a perforate anus
37
Physical Examination of the Newborn: Spine and Hip
The spine should be checked (inspection and palpation) for any deformities or surface changes.
Examination of the hip can follow. The infant should be placed supine on a flat surface with the hip partially abducted and fully flexed to 90 degrees. Hold each leg with one hand, grip the femur so that the middle finger is over the greater trochanter, the index is over the lesser trochanter, and the thumb is just medial to the knee
38
Physical Examination of the Newborn: Hip Findings
- Abduct the hip by pressing outwards on the greater trochanter. If the hip is dislocated it will relocate with a clunk = Ortolani positive
- Adduct the hip and push posteriorly, trying to push the head of the femur out of the acetabulum. If the hip is dislocatable it will clunk over the posterior edge of the acetabulum = Barlow positive
39
Physical Examination of the Newborn: Reflexes
check for Moro reflex
- Place the infant supine on a flat surface. Flex the infants head on to the body, and then release the head
- The infant should abduct their arms at the shoulders and flex the elbows and wrists, the hands will be open; this may be followed by adduction of the shoulders. The baby will usually cry
40
When is the heel prick test carried out
5 – 8 days
41
What diseases does the heel prick test detect
- Sickle cell disease
- Cystic fibrosis
- PKU
- Congenital hypothyroidism
- MCADD
- Homocysteinuria
- Maple syrup urine disease
- Gutaric aciduria type 1
- Isovaleric acidaemia
42
Hearing Scan
The hearing scan is performed in hospital, by a health visitor, or at the GP. This should usually take place within 2 weeks of birth
43
Which two hearing tests can be used?
1. The automated otoacoustic emission (AOAE). This places a probe in the ear, which will emit clicks, acoustic energy will be produced in response to this if the cochlea is normal, this acoustic energy is detected
2. The automated auditory brainstem response (AABR). This presents a stimulus to the child’s ear and detects electrophysiological responses from the brainstem using scalp electrodes.
The benefit of this is that it can detect deafness due to the pathway from the cochlea to the brainstem, as well as problems with the cochlea itself
Neither test can detect problems from the brainstem to the auditory cortex
44
Abnormal Findings: Benign
- Peripheral cyanosis of hand and feet is common in day one, and not necessarily worrying
- Traumatic cyanosis can also occur, usually from cord around baby’s neck or from face/brow presentation
- Swollen eyelids and distortion of shape of head from delivery, including caput succedaneum
- Subconjunctival haemorrhages from delivery
- Epstein pearls along the midline of the palate
- Cysts of gums or floor of moth (epulis or ranula)
- Breast enlargement ± lactation
- White vaginal discharge or small withdrawal bleed
- Umbilical hernias are common, especially in afro-caribbean infants, and will usually resolve
- Positional talipes, indicated as the foot can be fully dorsiflexed to touch the leg. This requires simple physiotherapy exercises
45
Abnormal Findings: Significant Abnormalities
- Natal teeth should be removed to prevent aspiration
- Polydactyly and syndactyly should be referred to plastics
- Heart murmurs are usually not worrying and resolve in the first few days, but as some are caused by congenital heart disease there should be referral to cardiology
- Midline abnormality over spine or skull will need further investigation with USS to rule out spinal bifida occulta
- Palpable bladder can be an indication of urinary outflow obstruction
46
Oesophageal Atresia +/- trachea oesophageal fistula: Presentation
Oesophageal atresia can be detected at many different stages
- Polyhydramnios in utero
- Persistent salivation and drooling from the mouth at birth
- Coughing and choking during feeding ± cyanosis
47
Oesophageal Atresia +/- trachea oesophageal fistula: Diagnosis + Management
Diagnosis is made on the basis of x-ray, with a radio-opaque tube passed to see if it reaches the stomach
Early surgery is essential, with continuous suctioning applied to a tube placed into the oesophageal pouch to prevent aspiration prior to this.
48
Oesophageal Atresia +/- trachea oesophageal fistula: :VACTERL
```
Almost half of patients with oesophageal atresia have associated syndromes
These are known by the mnemonic VACTERL
- Vertebral defects
- Anorectal malformations
- Cardiovascular defects
- Tracheo-oesophageal fistula
- Renal anomalies
- Limb deformities
```
49
Neonatal Small Bowel Obstruction: Causes
- Duodenal atresia/stenosis. This will show a ‘double bubble’ sign on x-ray, and is commonly associated with Down’s syndrome
o This can also occur in the jejunum and ileum
- Malrotation with volvulus
- Meconium ileus, usually in cystic fibrosis
50
Neonatal Large Bowel Obstruction: Causes
- Hirschprung disease
- Rectal atresia
- Imperforate anus
51
Ventral Body Wall Defects: Omphalocele
Exomphalos is centrally placed, and consists of the abdominal organs herniating through the umbilicus. The viscera are covered with a membrane
- The baby is usually stable at birth
- It is associated with a number of congenital anomalies
o Trisomy 13, 18, 21
o Cloacal extrophy e.g. meningomyelocele, bladder extrophy
o Beckwith-Wiedemann syndrome
52
Ventral Body Wall Defects: Gastroschisis
congenital defect of the abdominal wall, the organs have no covering membrane
- There is a higher risk of dehydration and collapse
- Associated conditions are less common but can include cleft lip, ASD, diaphragmatic hernia, and scoliosis
53
Respiratory Distress in New-born: Features
- Respiratory rate >60
- Laboured breathing e.g. chest wall recession (particularly sternal and subcostal), nasal flaring
- Expiratory grunting
- Cyanosis may be present in severe cases
54
Respiratory Distress in New-born: Pulmonary Causes
```
Transient tachypnoea of the newborn
Infection
Meconium Aspiration
Persistent pulmonary hypertension
Congenital Anomalies: diaphragmatic hernia, pulmonary hypoplasia, trachea-oesophageal fistula
Milk Aspiration
Pneumothorax
```
55
Respiratory Distress in New-born: Non-Pulmonary
```
Congenital Heart Disease
Intracranial birth trauma
HIE
Severe anaemia
Metabolic Acidosis
```
56
Respiratory Distress in New-born: Investigations
- Blood gases
- Pulse oximetry
- CXR
- Echocardiogram
- Blood and surface cultures
Broad-spectrum antibiotics are usually started early until the results of infection screen are available.
57
Transient Tachypnoea of the Newborn
commonest cause of respiratory distress in term infants
- It is caused by a delay in the resorption of lung fluid, and is therefore more common in infants born via C-section (particularly elective C-section where there have been no contractions)
This usually settles rapidly and without intervention. Additional ambient oxygen may be required
58
Meconium Aspiration
During labour the passage of fresh meconium (dark green, sticky, and lumpy) is a sign of foetal distress
- Asphyxiation leads infants to start gasping, and inhale the thick meconium
- Commence CTG monitoring and ensure obstetric review
Aspiration of meconium results in a chemical and mechanical pneumonitis. There is plugging of the airways, leading to patches of over-inflation and consolidation. Later complications include sepsis
- Babies born with meconium staining should be observed 2-hourly for 12 hours
o If there is any evidence of respiratory distress, pyrexia, or circulatory compromise there should be referral to neonatology
59
Persistent Pulmonary Hypertension of the Newborn
life-threatening condition usually associated with birth asphyxia, meconium aspiration, sepsis, or respiratory distress syndrome
- High pulmonary vascular resistance leads to right-to-left shunting within the lungs, atrial, and ductus arteriosus
These infants will be cyanotic however cardiac auscultation and echocardiography will indicate that congenital heart disease is not present
Most infants will require mechanical ventilation alongside inhaled vasodilators e.g. sildenafil, nitric oxide
60
Respiratory Distress Syndrome (RDS)
Developmental insufficiency of pulmonary surfactant production + structural immaturity; 1% of newborn infants, Most common cause of death of newborns
o Surfactant (secreted by type II pneumocytes, contains phospholipids and proteins) normally lowers surface tension of alveolar epithelium
o Leads to widespread alveolar collapse – Reduced surface area for gaseous exchange
• The more preterm the infant, the higher risk of RDS; common if <28wks gestation, more severe in boys than girls
o Rare at term; May occur in diabetic mothers or genetic conditions
61
Respiratory Distress Syndrome (RDS): Who is at risk
• The more preterm the infant, the higher risk of RDS; common if <28wks gestation, more severe in boys than girls
o Rare at term; May occur in diabetic mothers or genetic conditions
• Risk factors: Prematurity, maternal DM, C-section delivery, asphyxia
62
Respiratory Distress Syndrome (RDS): Prevention
Can be prevented through antenatal glucocorticoids to stimulate lung development and surfactant production
This must be betamethasone or dexamethasone, as prednisolone does not cross the placenta. Where steroids are not possible, there can be use of surfactant therapy
- This is surfactant derived from calf/pig lung extracts, instilled directly into the lung via a tracheal tube
63
Respiratory Distress Syndrome (RDS): Complications
Sepsis, BP dysplasia, PDA, pulmonary haemorrhage, HTN, FTT, IVH, PVL
64
Respiratory Distress Syndrome (RDS): Presentation
At delivery or within 4hrs of birth: >60 breaths per minute, laboured breathing + chest wall recession (sternal and subcostal) and nasal flaring, expiratory grunting (creating positive airway pressure during expiration) or cyanosis if severe
65
Respiratory Distress Syndrome (RDS): CXR
diffuse granular (ground glass) appearance and air bronchograms; heart border indistinct
66
Respiratory Distress Syndrome (RDS): Management
Instillation of surfactant via tracheal tube or catheter
• NIV (CPAP or high flow nasal cannula) or tracheal intubation + mechanical ventilation
o Mechanical ventilation (intermittent PPV) adjusted according to infant oxygenation, chest wall movement and blood gas analysis
o NIV is preferred where possible due to lower risk of complications
67
Respiratory Distress Syndrome (RDS): Term Infants
Similar symptoms; Need to admit to Neonatal unit, CXR for diagnosis, Respiratory support
68
How can infections pass from mother to foetus/neonate
- Across the placenta
- Ascending maternal infection and chorioamnionitis
- Perinatal infection acquired through the haematogenous or genital route
- Post-natal infection transmitted by breast feeding
69
Which key infections can have a significant impact on the foetus?
these are known as the TORCH infections
- Toxoplasmosis
- Other: parvovirus, VZV, hepatitis, HIV, listeria, group B strep, chlamydia, gonorrhoea
- Rubella
- CMV
- Herpes
70
How can congenital infections be diagnosed ?
- Maternal serology
- Foetal sampling e.g. amniocentesis, chorionic villus sampling, placental microscopy
- Infant sampling e.g. urine/ blood/ CSF culture, blood serology
71
Sources of infection in the neonate
early infection is <48 hours after birth and late infection >48 hours. Early infection is contracted from the uterine environment, whereas late infection is from the external environment.
72
Rubella
Rubella infection in the mother must be diagnosed by serology. Where this is confirmed, the risk and extent of foetal damage is dependent on the gestational age at the onset of maternal infection
- Before 8 weeks there can be deafness, congenital heart disease, and cataracts
- From 13 – 16 weeks there can be impairment of hearing
Due to this risk, at booking women are tested for their rubella immunity status and offered vaccination after pregnancy where relevant (the vaccine is contraindicated in pregnancy).
73
CMV
90% of foetus are normal at birth and through subsequent development
- 5% will have clinical features at birth e.g. IUGR, pneumonia, thrombocytopaenia, hepatosplenomegaly, petechiae, subsequent developmental difficulties as below
- 5% are normal at birth but with subsequent developmental problems e.g. sensorineural hearing loss, cerebral palsy, epilepsy, cognitive impairment
Early treatment with antiviral therapy (Ganciclovir) for infants with SNHL or CNS involvement reduces adverse impact on long-term neurodevelopment
o NB: No CMV vaccine is available, and pregnant women are not screened for CMV
74
Toxoplasmosis
Protozoan parasite which may result from raw/undercooked meat or faeces of recently infected cats; More common on continental Europe
;Most asymptomatic; Infected newborn infants are treated for 1yr with pyrimethamine and sulfadiazine
• 10% have manifestations – Retinopathy (Acute Fundal Chorioretinitis, which might interfere with vision), Cerebral calcification, Hydrocephalus
o Often have long-term neurological disabilities
75
Varicella Zoster
If <20wks gestation, 2% risk of developing severe scarring of skin, possibly ocular and neurological damage, digital dysplasia
• If 5 days before or 5 days after delivery, when foetus is unprotected by maternal antibodies and high viral load; 25% develop vesicular rash, mortality can be up to 30%
o Exposed susceptible mothers can be protected with VZV Ig and treated with Aciclovir
o Infants born in the high-risk period should receive VZV Ig, monitored closely and given Aciclovir if signs of infection develop
76
Syphilis
Congenital Syphilis rare in UK; Mothers with syphilis on antenatal screening, if fully treated within 1/12 or more prior to delivery, infant does not require treatment
• Characteristic rash on soles, hands, and bone lesions
• If any doubt over adequacy of maternal treatment, Infant Penicillin should be administered
77
Group B Strep
Group B strep is carried without symptoms in the genital tract of ~25% of women
- This can infect the foetus during labour, when membranes have ruptured
- The risk is particularly increased in PROM, P-PROM, or prolonged labour
Early onset GBS sepsis is a severe illness in the neonate, presenting with respiratory distress ± meninigitis
Currently there is no screening for this in the UK. However high risk labours (e.g. prolonged rupture of membranes, maternal intrapartum fever) are treated with IV penicillin to eradicate the bacteria in the genital tract
78
Group A Strep
associated with puerperal sepsis, and can occur during pregnancy leading to chorioamnionitis with a high risk of foetal death
- The foetal lungs are filled with infected amniotic fluid, leading to severe pneumonia
79
Listeria Monocytogenes
Listeria infections are rare but serious. The mother contracts the infection via unpasteurised milk, soft cheese and undercooked poultry
- In the mother it causes bacteraemia with mild flu symptoms
Passage to the foetus is via the placenta, with infection potentially causing spontaneous abortion, preterm delivery and fetal sepsis
- Features include meconium staining of the liquor, rash, septicaemia, pneumonia and meningitis
80
Neonatal Jaundice
Marked physiological release of haemoglobin from RBC breakdown due to high Hb concentration at birth; shorter newborn RBC lifespan (70 days)
o Hepatic bilirubin metabolism less efficient in first few days of life
o Preterm infants more susceptible to damage from hyperbilirubinaemia
81
When is jaundice not physiological
Jaundice cannot be physiological if it develops before 24 hours, or if it is a conjugated hyperbilirubinaemia
Unconjugated hyperbilirubinaemia is pathological if it occurs in the first 24 hours of life and/or lasts >14 days. Or if there is a total bilirubin >220, or the level is rising >85/day
82
Causes of Unconjugated Hyperbilirubinemia
- Breast milk jaundice (bilirubin <150mcmol/L)
- Infection
- Haemolytic anaemia
- Hypothyroidism
- GI obstruction
83
Causes of conjugated hyperbilirubinemia
caused by liver disease leading to cholestasis, this is either intrahepatic or extrahepatic. Causes include
- Bile duct obstruction e.g. biliary atresia, choledochal cyst
- Neonatal hepatitis syndrome
- Intrahepatic biliary hypoplasia e.g. alagille syndrome, Down syndrome
84
Causes of jaundice: <24 hours
```
Congenital Infection
Rhesus incompatibility
ABO incompatibility
G6PD Deficiency
Spherocytosis PKD
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85
Causes of jaundice: 24hrs-2 weeks
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Physiological
Breast Milk
Infection
Haemolysis
Bruising
Cephalohematoma
Polycythaemia
Dehydration
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86
Causes of jaundice: >2 weeks
```
Breast milk jaundice
Infection
Hypothyroidism
Haemolysis
Intestinal obstruction
Bile duct obstruction
Neonatal hepatitis
```
87
Management of Neonatal Jaundice
Avoid drugs that displace bilirubin from albumin – E.g. Sulfonamides, Diazepam
• Correct poor milk intake, dehydration (although no evidence for routine prevention)
• Phototherapy – 450nm (blue-green) visible light converts unconjugated bilirubin to water soluble, urine-secreted pigment; Infant eyes covered as bright light uncomfortable
o Can lead to temperature instability (infant is undressed), macular rash, and bronze discolouration of skin if jaundice is conjugated
o Continuous multiple = Intensive phototherapy if rapid rise or reached high level
6
• Exchange Transfusion – Small aliquots of blood via arterial line or umbilical vein removed and replaced with donor blood; Twice the infants blood volume is exchanged (180ml/kg)
88
Red Blood Cell Autoimmunization
RBC autoimmunization occurs when the mother mounts an immune response against the antigens on foetal red blood cells in her circulation. The resultant antibodies can then cross the placenta are cause foetal haemolysis
89
Red Blood Cell Autoimmunization: Other perinatal and foetal complications
o Hypoglycaemia
o Hepatosplenomegaly
o Hydrops fetalis from foetal anaemia
90
Red Blood Cell Autoimmunization: Suspected Foetal Anaemia
Where foetal anaemia is suspected on the basis of middle cerebral artery Doppler, there can be foetal blood sampling to confirm the diagnosis. This can be managed with foetal blood transfusion at 18 weeks
91
Red Blood Cell Autoimmunization: where can mother be sensitised
- The mother can be sensitised to the foetal blood at points of significant mixing e.g. ectopic pregnancy, TOP, APH, invasive uterine procedures, or delivery
- After these sensitising events, a Keihauer test can be undertaken to assess the number of foetal cells in the maternal circulation, and therefore the need for anti-D
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Rhesus Disease
Rhesus disease occurs when a rhesus negative mother is pregnant with a rhesus positive baby, and has previously been sensitised to the RhD antigen
- To prevent rhesus disease, all rhesus negative women are screened for anti-D at booking
Anti-D is given to rhesus negative women at 28 weeks, after delivery, and after any potentially sensitising event
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ABO Incompatibility
ABO incompatibility is now more common than Rhesus disease
| - Most ABO antibodies are IgM, and therefore don’t cross the placenta. In some women however there are IgG antibodies
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Biliary Atresia
Biliary atresia occurs where there is destruction or absence of the extra and intra-hepatic bile ducts, resulting in chronic liver failure without surgical intervention
- These patients are normal at birth, but fail to thrive as their disease progresses
- Pale stools and dark urine, alongside features of portal hypertension (hepatosplenomegaly) will develop
Investigations into biliary atresia can include gall bladder USS, TBIDA scanning (showing uptake into the liver, but no excretion into the bowel), and liver biopsy (showing duct destruction and fibrosis)
Management is surgical, and should occur as early as possible. This involves anastomosis of the jejunum to the patent bile ducts (hepatoportoenterostomy), this must occur before 40 days. If this fails, liver transplant is indicated
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Neonatal Hepatitis Causes
- Congenital infection e.g. TORCH, EBV
- In-born errors of metabolism
o Alpha-1 antitrypsin deficiency
o Galactosaemia. This is a rare disorder in which liver failure, cataracts and developmental delay occur due to an inability to reduce galactose. Management is with galactose-free diet
o Tyrosinaemia
- Cystic fibrosis
- TPN cholestasis
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Investigations in Neonatal Jaundice
Bilirubin levels can be measured by a transcutaneous bilirubinometer, or by measurement of serum bilirubin
Other investigations can include
- LFTs with split bilirubin
- Infection screen, including specific cultures where relevant
- Investigations for haemolysis
o Blood type and Rh determination of mother and infant
o Reticulocyte count
o Direct Coombs’ test
o Blood film and red cell enzyme assays
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Main Risk of Jaundice: Kernicterus
development of kernicterus
This is encephalopathy resulting from the deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei
- It is thought to be due to the level of unconjugated bilirubin exceeding the albumin-binding capacity of the blood, this is fat-soluble and can cross the BBB
- The neurotoxic effects of this include
o Lethargy and poor feeding are commonest
o Irritability, hypertonia (can present with opisthotonos), seizures, and coma
o In the long term there can be cerebral palsy, learning difficulties, and sensorineural deafness
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Neonate Seizure
typically repetitive, rhythmic (clonic) movements of the limbs persisting despite restraint
- Alongside this there are usually abnormal eye movements and changes in respiration
Confirmation of seizure is usually with EEG. Where this is established, there must be exclusion of hypoglycaemia or meningitis
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Causes of Neonatal Seizure
- HIE
- Cerebral infarction
- Metabolic derangement, including inborn errors of metabolism
- Intracranial haemorrhage
- Cerebral malformations
- Infection e.g. meningitis, congenital infection
- Drug withdrawal e.g. maternal opiates
- Kernicterus
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Neonatal Hypotonia: CNS Causes
o Cortical disease: HIE, cortical malformation
o Syndromic disease: Prader-Willi, Down’s
o Metabolic disease: hypoglycaemia, electrolyte disturbance, hypothyroidism
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Neonatal Hypotonia: NMD
o Spinal muscular atrophy
o Congenital myasthenia
o Congenital myopathy e.g. myotonic dystrophy, muscular dystrophy
o Metabolic disorders
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How to distinguish between central and peripheral disease in hypotonia
- Common features include ‘frog-leg’ posture, respiratory failure
- CNS disease can be termed floppy-strong, as the infant will have reasonable muscle strength and reflexes
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In which groups of neonates is hypoglycaemia particularly likely in the first 24 hours
- IUGR/SGA
- Preterm
- Infants born to diabetic mothers
- LGA or post-dates
This can relate to insufficiency of glycogen stores, or exposure to high intrauterine glucose leading to hyperinsulinaemia
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Symptoms of hypoglycaemia in the neonate
jitteriness, irritability, apnoea, lethargy, drowsiness, and seizures
Prolonged, symptomatic hypoglycaemia can cause permanent neurological disability
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Definition of Neonatal Hypoglycaemia
no agreed definition for neonatal hypoglycaemia, however the following is used as a guide for intervention with 10 – 20% dextrose. In other cases, use early and frequent milk feeding with frequent BMs
- BM <2.6 on two occasions
- BM <1.6 on one occasion
- Symptoms of hypoglycaemia
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Management of Neonatal Hypoglycaemia
• Early and frequent milk feeding to prevent hypoglycaemia
• Bedside BGM if at increased risk; if 2 values <2.6mmol/L despite regular feeding, or one low value (<1.6mmol/L), or symptomatic, administer IV glucose
o Concentration used can be 10%, to up to 20%; Aim to raise glucose >2.6mmol/L
o Confirm abnormal BGM by laboratory testing
o High concentration IV glucose by CVC to avoid extravasation
▪ Extravasation can cause skin necrosis and reactive hypoglycaemia
o If difficult to administer, or delay, or resistant to IV glucose, Glucagon can be used
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Neonatal Collapse: Presenting Features
- Hypothermia, respiratory distress, weak pulses, shock
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Neonatal Collapse: Infectious Causes
Group B strep, E.coli, herpes simplex, MRSA
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Neonatal Collapse: Cardiac Pathology
Congenital heart defects (coarctation, hypoplastic left heart, transposition), SVT, myocarditis
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Neonatal Collapse: Metabolic Disorder
Mitochondrial disease, urea cycle defect, organic acidosis, adrenal insufficiency, hypoglycaemia
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Neonatal Collapse: Trauma
Intracranial bleed, intraabdominal bleed
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Neonatal Collapse: Investigations
Blood gasses, ideally arterial
- U&Es, blood glucose, LFTs, FBC and clotting should also be assessed as a venous sample
Consider relevant cultures, and perform an ECG
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Neonatal Collapse: Management
In all cases, supportive management until definitive diagnosis can be made is essential. Use fluids and inotropes to maintain blood pressure
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Neonatal Collapse: Management -Suspected Cardiac
Following initial resuscitation, the most important differential to consider is a duct dependent cardiac lesion. This is suggested by the following features
- Cyanosis not responding to oxygen
- Poor/absent femoral pulses
- Heart murmur or cardiomegaly
- Difference in pre and post ductal saturation in transposition
- Difference in 4 limb BP in coarctation
If this is strongly suspected it is important to give prostaglandin E2 to maintain a PDA, and transfer urgently to a specialist centre
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Neonatal Collapse: Management-Likely Seizure
Where seizure is likely (unexplained tachycardia, recurrent apnoea), metabolic conditions should be strongly suspected and excluded
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Define a preterm infant
Preterm infants are defined as those born before 37 weeks’ gestation. However, the problems associated with prematurity only tend to become apparent in those born at <34 weeks’ gestation
- Infants born at 23 – 26 weeks tend to encounter many problems, and have a high overall mortality
- Infants born at >32 weeks have a very good prognosis
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Key Differences between a preterm and term infant
- Skin is very thin, and dark red
- The ears, breast tissue, and genitalia are all immature
- Apnoea is common, and the infant will usually need some respiratory support
- Faint cry and no coordinated sucking
- Extended limbs
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Supportive Care of the Preterm Infant: Oxygenation
Episodes of apnoea, bradycardia, and desaturation are very common in these infants. This is usually due to immature central respiratory control
- Gentle physical stimulation will usually normalise these factors
- If the episodes are frequent, CPAP is recommended
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Supportive Care of the Preterm Infant: Temperature
Temperature control is difficult due to lack of subcutaneous fat, large surface area, and thin skin. Hypothermia must therefore be prevented by considering convection, radiation, evaporation, and conduction
- Keep the baby well covered in a humidified incubator
- In neonatal resuscitation, place the baby into a plastic bag
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Supportive Care of the Preterm Infant: Nutrition
Preterm babies have significant nutritional requirements in order to develop adequately, and avoid hypoglycaemia. Nutrition is ideally enteral, using maternal expressed breastmilk that is fortified with extra phosphate and protein. This is usually through an oro- or nasogastric tube
- In very premature infants, TPN may be required
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Preterm Brain Injury
Brain haemorrhages occur in around ¼ very preterm infants
In most cases these haemorrhages are small, and will not cause long-term consequences. However, larger bleeds will lead to cerebral palsy (particularly where the bleed has led to hydrocephalus e.g. large interventricular haemorrhage)
- These haemorrhages can be detected on cranial USS
Periventricular white matter injury may occur in the absence of haemorrhage, due to ischaemia or inflammation. Where cystic lesions are visible, this represents loss of white matter
- Bilateral multiple cysts are called periventricular leukomalacia, and can also lead to cerebral palsy
122
Necrotising Enterocolitis
bacterial invasion of ischaemic bowel wall. Presentation is similar to bowel obstruction
- The infant stops tolerating feeds, bile-stained vomit can be aspirated from the stomach, abdominal distension, and PR bleeding
Abdominal x-ray is diagnostic; showing distended loops of bowel with thickened walls due to intramural gas
Stop oral feeding and give broad-spectrum antibiotics, alongside supportive measures
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Retinopathy of Prematurity
Retinopathy of prematurity occurs in babies born before 32 weeks, or those with a birth weight <1500g
- Babies at risk are frequently screened after birth with fundoscopy
ROP is caused by abnormal retinal vasculature development; normally the retinal vessels will grow from the optic nerve out to the peripheral retina. This process continues after birth
- In premature infants there is excess proliferation of developing blood vessels at the junction between the vascular and non-vascular retina
If ROP is not identified, ischaemia will cause the formation of abnormal retinal blood vessels that will bleed and lead to fibrosis. Fibrous scarring bands then form and contract, pulling on the retina and causing retinal detachment
- To prevent complications, treatment is with laser photocoagulation of the peripheral avascular retina, reducing oxygen demand
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Bronchopulmonary Dysplasia
Infants with oxygen requirement at a gestational age of >36 weeks are described as having bronchopulmonary dysplasia
- This is lung damage from artificial ventilation, oxygen toxicity, and infection
- X-ray will show opacification and cystic changes
Management is with slow weaning from ventilation to CPAP to additional ambient oxygen. Steroids can also be given.
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Risk Factors for Premature Delivery
Multiple gestation, prior preterm/low birthweight, gestations bleeding (Especially first and third TM), maternal weight, level of prenatal care, maternal work and nutrition status, medical conditions (DM and GDM, UTI, STI, HTN, IVF pregnancy, dyscrasias)
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Perinatal Asphyxia
Deprivation of oxygen to newborn infant that lasts long enough during birth process to cause physical harm (typically neurological = Hypoxic ischaemic encephalopathy = HIE, IVH)
o Also damages heart, lungs, liver, GI tract, kidneys
o Neurological defects can manifest as mental (e.g. Developmental delay or LD) or physical (e.g. Spasticity)
• Most commonly due to maternal hypotension or interference with infant cerebral perfusion (inadequate circulation or perfusion, inadequate oxygenation or ventilation)
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Perinatal Asphyxia: Presentation
Cyanosis, poor responsiveness, muscle tone and respiratory effort
o = Low Apgar score at 5mins
o Mild – Irritable, excessive response to stimulation, hyperventilation, hypertonia
o Moderate – Marked abnormalities of movement, hypotonic, seizures
o Severe – No normal spontaneous movements, ± tone, prolonged seizures, MOF
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Perinatal Asphyxia: Neuronal Function
o Neuroprotection can be offered (mild therapeutic hypothermia) if secondary injury
o Cerebral function monitoring (a-EEG) can detect abnormal background brain activity to confirm early encephalopathy and identify seizures
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Perinatal Asphyxia: Aetiology
* Failure of gaseous exchange – Excessive contraction, Abruption, Uterine rupture
* Interruption of umbilical blood flow – Dystocia, Cord prolapse
* Inadequate maternal perfusion/blood pressure abnormalities
* Compromised foetus – IUGR, Anaemia
* Failure of cardiorespiratory adaptation at birth
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Perinatal Asphyxia: Management
• Resuscitation and stabilisation to minimise neuronal damage
o Mild hypothermia (cooling to rectal 33-34 deg for 72hrs) beneficial if started within 6h of birth; NNT 8
• Respiratory support, Anticonvulsant therapy
• Fluid restriction – to prevent exacerbation of transient renal impairment
• Volume resuscitation and inotrope support for hypotension
• Monitor hypoglycaemia and other electrolytes (especially hypocalcaemia
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Perinatal Asphyxia: Prognosis
If mild HIE, complete recovery can be expected; if moderate with full recovery, with normal neuro exam and feeding well by 2/52 have good long-term prognosis
• If abnormalities persist beyond 2/52, full recovery unlikely
• Severe HIE – 30-40% mortality; over 80% of survivors have neurodevelopment disabilities especially cerebral palsy
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Large for Gestational Age
• Above 90th centile; most are normal and large
• Can occur due to maternal T1 or GDM, or congenital syndromes (e.g. Beckwith-Wiedermann)
• Associated with Birth trauma (due to Dystocia), Birth Asphyxia due to difficult delivery, Hypoglycaemia due to Hyperinsulinaemia, Polycythaemia
o Difficulty breathing can occur with BWS due to large tongue
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Talipes
Positional Talipes from IU compression is common; Normal foot size, mild deformity and can
be corrected into neutral position by passive manipulation
o If positional deformity is marked, passive exercises by PT can be arranged
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Clubfoot
Inversion or the foot, supinated, forefoot adducted and heel rotated inwards in PF
• Shorter foot, thinner calf muscles, fixed deformity
o Cannot be corrected completely; often bilateral
Can also be secondary to oligohydramnios, a
feature of a malformation syndrome, or
neuromuscular disorder (e.g. Spinal Bifida)
o Associated with Developmental Dysplasia of
the Hip (DDH)
• Ponsetti method – Plaster casting and Bracing for
several months; usually successful unless severe
condition which would require correctional surgery
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Vertical Talus
Foot is stiff and Rocker-Bottom in shape; Diagnosis
| confirmed on XR, surgery required
136
Talipes Calcaneovalgus
Dorsiflexion and Eversion of the foot due to
intrauterine moulding; often self corrects
• Passive foot exercises advised; association to DDH
137
Tarsal Coalition
Lack of segmentation between bones of the foot
• Coalitions = Fibrous or cartilaginous connections
between bones becoming symptomatic after
ossification; Progressive rigidity, limitation to foot motion
o Often more symptomatic during pre-adolescent years
o Corrective surgery may be required
138
Pes Cavus
High arched foot; Often associated with neuromuscular disorders when it presents in older
children (e.g. Friedreich Ataxia, Peroneal Muscular Atrophy); treatment if stiff/painful
139
Developmental Dysplasia of the Hip
Responds to conservative treatment if managed early; Late diagnosis leads to Hip Dysplasia which requires complex treatment including surgery
o Neonatal Screening as part of routine examination
o Barlow Manoeuvre – Checking if Hip can be dislocated posteriorly out of acetabulum
o Ortolani Manoeuvre – Relocation back into acetabulum on abduction
140
Developmental Dysplasia of the Hip: Presentation
Can present as limb or abnormal gait, asymmetry of skin folds, limited abduction or shortening of the affected leg
141
Developmental Dysplasia of the Hip: Diagnosing
Routine ultrasound screening is expensive and has high rate of false positives; Clinical examination might miss neonatal cases due to only mildly shallow acetabulum
o Useful for high-risk infants – Family History or Breech Presentation
142
Developmental Dysplasia of the Hip: Aetiology
Hereditary and Racial factors; Hormonal link (Relaxin) might be implicated; Can be acquired from restriction of infant movement for extended periods (e.g. Swaddling, Transport)
143
Developmental Dysplasia of the Hip: Management
Splint or Pavlik Harness placement to keep Hip Flexion and Abduction for /12; Repeat USS/XR
o Must be managed by experts, as necrosis of femoral head can result for poor technique; Satisfactory response from most patients
• Surgical management (Closed Reduction, or ORIF for older
patients) required for conservative management fails
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Down's Syndrome
3x21; Diagnosis by Clinical Evaluation, Rapid FISH; Can be identified during antenatal screening
o Latest advances in Maternal cfDNA screening in first trimester; 99% detection
• Echocardiogram, Bloods, Thyroid function, Auditory screening; Specialist care
• Significant risk of Dyspraxia, ADHD, ASD
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Klinefelter's Syndrome
XXY Genotype; notably difficult to identify;
• At risk of LD and breast cancer; Risk of offspring with sex chromosome aneuploidy
• Developmental delay, weakness, quietness/passivity, shyness, low self-confidence, taller than expected vs family, broad hips, gynaecomastia, smaller genitalia; Infertility, low sex drive
146
Turner Syndrome
* XO Genotype; 1/2500 females; High foetal lethality (99% of conception)
* Highly variable phenotype; Oedematous appearance, cardiac complications are key to dx
* Need to evaluate cardiac, renal malformations, thyroid function
* Increased risk of autoimmune disorders, later-onset risk of aortic dilatation, fertility issues
147
Fragile X Syndrome
* Most common inherited cause of intellectual disability (1/2500M, 1/5000F); Expansion of CGG repeats;
* Long face, prominent forehead and ears, large testes; Gaze aversion behavioural phenotype
148
Foetal Alcohol Syndrome
Wide spectrum of defects; most common preventable cause of birth defects
• 2-3/1000 births; Classic symptoms of Microcephaly, Ptosis, Short Palpebral Fissures, Washed-out Philtrum appearance, Thin upper lip
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Marfan's Syndrome
* Defect of Fibrillin-1 gene
* 1/15000 births; Myopia, Dolichostenomelia (long narrow limbs), Arachnodactyly (long fingers), MVP
* Requires cardiology consultation; Losartan and exercise restrictions
150
DiGeorge's Syndrome
* Square nasal bridge, Small alae nasi, Long-tapered fingers, Cleft-palate, Congenital Heart Disease (TOF, Truncus Arteriosus, VSD)
* Diagnosis by FISH/Microarray; Need to evaluate for additional cardiac and renal malformations, Immunology workup, Ca metabolism (Hypocalcaemia)
* Psychiatric disorders common; often difficult to manage
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Cleft Palate
• Cleft lip can be Uni or Bilateral; Failure of fusion of Frontonasal and Maxillary processes; If Bilateral, Pre-maxilla is anteverted
• Cleft palate due to fusion of palatine processes and nasal septum
• Both affect 0.8/1000 babies; Polygenetic inheritance mostly but can also be part of syndromes of multiple abnormalities
o Can also be associated with maternal anticonvulsant therapy
• Can make feeding difficult; Milk can enter the nose and cause coughing/choking; Special teat and feeding devices are available
o Orthodontic advice, prosthesis can help
o Infants more prone to Secretory Otitis Media and AOM
• Surgical repair of cleft lip at around 3/12; Palate 6-12/12
