Neonatal Medicine Flashcards
Define CLD
Infants who still have an oxygen requirement at a postmenstrual age of 36 weeks are
described as having BPD (bronchopulmonary dysplasia)
Describe the pathophysiology of CLD
Describes the condition post-treatment of premature infants for RDS
- The lung damage is now thought to be mainly from delay in lung maturation, but may also be from pressure and volume trauma of artificial ventilation, oxygen toxicity and infection
- Pathology
- Result of a paradoxical combination of hypoxia and oxygen toxicity.
- There is initial capillary wall damage, interstitial fluid seepage and
ensuing pulmonary oedema, which is followed by loss of ciliated epithelium
and bronchiolar mucosal necrosis. - Areas of both hyperexpansion and
are seen. - This is followed by eosinophilic exudate and squamous metaplasia and may
ultimately lead to interstitial fibrosis/fibro-proliferative bronchiolitis.
What are the investigations for CLD? What would you expect?
CXR: characteristically shows widespread areas of opacification (ill-defined reticular
markings), sometimes with cystic changes
How do we manage CLD?
- Prophylaxis:
- Corticosteroids for women in suspected, diagnosed or established preterm labour <34 weeks (consider iff 34-36 weeks)
- Respiratory Support
- High flow oxygen
- Via nasal cannula or incubator oxygen
- CPAP
- Invasive ventilation
- Give surfactant
- High flow oxygen
- Medications
- Corticosteroids e.g. dexamethasone if ≥ 8 days old and on ventilator (may facilitate earlier weaning from ventilator, often lowers oxygen requirements in short term) - but risk of abnormal neurodevelopment including CP so only low short dose
-
Caffeine citrate
- If ≤ 30 weeks corrected gestational age. Start within 3 days of birth
- Consider if preterm and apneic
-
Nitric oxide
- Only if pulmonary hypoplasia or pulmonary hypertension
- Long-term Mx
- Mild: Gradually wean off oxygen prior to discharge, often wheezy for first 3 months
- Moderate:
- Go home on oxygen - facilitates gradual weaning
- Vaccinate against RSV (pavalizumab)
- Flu vaccine once > 6 months
- Severe
- Recurrent need for ventilation → arrest in lung development
- Somatic growth without lung growth
- Progressive further damage → cannot sustain life off ventilator
Define cleft lip
o Results from failure of fusion of the frontonasal and maxillary processes
o May be unilateral or bilateral
Define cleft palate
Results from failure of fusion of the palatine
What causes a cleft lip and palate?
o May be a part of a syndrome e.g. chromosomal disorders
Most inherited polygenically
o Some are associated with maternal anticonvulsant therapy
How do we manage a cleft lip and palate?
- Usually diagnosed antenatally - gives parents time to process, not a shock
- Cleft lip and palate MDT - early referral
- Paediatrician
- Orthodontist
- Speech and language therapist
- Dietician
- Audiologists
- Craniofacial surgeons
- Parent support groups (Cleft lip and palate association)
- Feeding
- Most babies will breast feed normally
- May require support e.g. dental plates
- Early feeding assessment and intervention may be required e.g. specialised teat/NG feed
- Potentially airway problem (Pierre-Robin sequence) - airway mx
- Pre surgical lip taping, oral appliances or pre-surgical nasal alveolar holding (PNAM) → narrow cleft
- Surgery
- Cleft lip: 3 months
- Cleft palate: 6-12 monthsº
Define congenital diaphragmatic hernia
A congenital birth defect of the diaphragm in which the abdominal structures enter the thorax
What is the most common type of diaphragmatic hernia?
The most common type is one in which a diaphragmatic opening on the posterior left side allows abdominal contents to protrude into the thorax
When do diaphragmatic hernias get diagnosed?
Antenatally
What is the incidence of diaphragmatic hernias?
1 in 4000 births
What is the pathophysiology of diaphragmatic hernias?
Can result in pulmonary hypoplasia and hypertension which causes respiratory distress shortly after birth
Pathophysiology: failure of pleuroperitoneal canal to close completely
What are the clinical features of diaphragmatic hernias?
o Neonates will have cyanosis and respiratory distress at birth
o Usually with failure to respond to resuscitation or respiratory distress
o Most common: left-sided herniation of abdominal contents through the posterolateral foramen of the diaphragm (Bochdalek hernia)
o This will cause the apex beat and heart sounds to be displaced to the right, with poor air entry in the left
o NOTE: vigorous resuscitation may cause a pneumothorax in the normal lung
How is the diagnosis of diaphragmatic hernia confirmed?
Diagnosis is confirmed by X-ray→shows intestinal loops in the thorax
How are diaphragmatic hernias managed?
Antenatal
o MDT with birth at neonatal surgical centre
Resuscitation after birth
o Intubate–avoid face mask to minimize gastric distention
o Positive pressure ventilation +/- HFOV
o Wide-bore NGtube (8Fr)
o IV and arterial access
o Sedation and muscle relaxation
oPersistent pulmonary hypertension of the New-born- Common and may require iNO
Surgery
o Delayed surgical repair → Stable and improving pulmonary hypertension
oDiaphragmatic defect is closed with primary repair or synthetic patch
ECMO - extracorporeal membrane oxygenation
o If pulmonary hypertension not improving
Mortality high if lungs hypoplastics
Define Sudden Infant Death Syndrome.
Deaths that occur suddenly and unexpectedly in infants.
What is the incidence of SIDS? How has it changed?
200 death in the UK in 2018. (0.3 deaths/1000 live births).
Incidence has fallen due to Back to Sleep campaign
What happens in most cases of SIDS?
After 1 month of age, in most instances of sudden death in a previously well infant, no cause
is identified even after a detailed autopsy, and the death is classified as sudden infant death
syndrome (SIDS)
What is the peak age of SIDS?
2-4 months but can occur throughout first year of life
What are the RFs of SIDS? How can the be prevented?
- 55% boys
- LBW (5 fold increase)
- Mothers < 20 yrs (5 fold increase)
- Sleeping in same bed (should have separate cot in same room for first 6 months of life)
- Smoking during pregnancy
- Sleeping on sofa or armchair with infant
- Overheating by heavy wrapping and high room temperature (avoid by head should be uncovered and the blanket tucked in no higher than the shoulders)
- Baby in parents’ bed when they are tired, have taken alcohol, sedative medicines or drugs)
- If possible breastfeed infant (preventativ
What do you do in the case of SIDS?
- Paediatrician to record a comprehensive account of resuscitation (if done), the history from paramedics (if brought in by ambulance) and finding on complete examination - including absence of signs of external injury
- Occasions police involvement and a member of police child protection team accompanies paediatrician who explains what has happened and takes a detailed hx from each of them
- Parents offered opportunity to see baby, hold it and photos + gather mementos
- Parents should be reassured that police involvement standard protocol
- Local coroner informed - postmortem performed by paediatric pathologists
- Multiagency information sharing meeting is convened to discuss death
Define a large-for-gestational age infant.
Large-for-gestational-age (LGA) infants are those above the 90th weight centile for their gestation.
What are large-for-date-infants features of?
Most are healthy, large infants, but it is a feature of infants of mothers with diabetes or a baby with certain genetic syndromes (e.g. Beckwith–Wiedemann syndrome).
What are the problems associated with large-for-date infants?
- birth trauma, especially from shoulder dystocia at delivery (difficulty delivering the shoulders from impaction behind maternal symphysis pubis) which can result in birth injuries, e.g. brachial plexus nerve injury or fractures
- birth asphyxia from a difficult delivery which may cause hypoxic brain injury or death
- hypoglycaemia due to hyperinsulinism
- polycythaemia
- breathing difficulty from an enlarged tongue in Beckwith–Wiedemann syndrome.
Define preterm. What are the subtypes?
Preterm = < 37 weeks
o Near term = 34 – 36 weeks
o Extreme preterm = < 28 weeks
What is the prognosis of preterm babies?
The appearance, likely clinical course, chances of survival and long-term prognosis depend on the gestational age at birth
o 23-25 weeks: encounter many problems, need many weeks of intensive care and have a high overall mortality
o > 30 weeks’ gestation have an excellent prognosis
What are the causes of increased risk of preterm?
o Multiple pregnancies
o Asymptomatic intrauterine infection
o Preterm rupture of membranes – due to cervical incompetence
o Age < 17 or > 35 years
o Lower socio-economic status
o Over or underweight
o Smoking, alcohol abuse, drugs (especially cocaine)
o Uterine anomalies (bicornuate, septate)
o Cervical incompetence: previous terminations, late miscarriages or surgery
What are the common conditions in preterm?
o Need for resuscitation and stabilisation at birth
o Respiratory: RDS, CLD of prematurity (BPD), pneumothorax, apnoea
o Neurology: Intraventricular haemorrhage/periventricular leukomalacia
o GI: necrotising enterocolitis
o Cardiovascular: hypotension, patent ductus arteriosus,
o Metabolic: hypoglycaemia, hypocalcaemia, electrolyte imbalance, osteopaenia of prematurity
o Others: nutrition, infection, jaundice, retinopathy of prematurity, anaemia of prematurity, iatrogenic, inguinal hernias
Fill.
How should you maintain fluids and nutrition in preterm infants?
Parental involvement is still key in neonatal care e.g. mother can give baby expressed
breast milk in syringe via nasogastric tube, allowing close eye and skin contact
between mother and baby
Fluid balance: preterm infant’s fluid requirements can vary with gestational age
o Usually, 60-90ml/kg on 1st day of life increasing by 20-30 ml/kg per day to 150-180 ml/kg per day by about day 5 of life
How common is neonatal jaundice?
50% of all neonates become visibly jaundiced.
What causes physiological neonatal jaundice?
o Marked physiological release of haemoglobin from the breakdown of RBCs because of the high Hb concentration at birth
o Red cell life span of newborn infants is shorter than in adults (70 days vs 120 days)
o Hepatic bilirubin metabolism is less efficient in first few days of life
Why is it important to notice neonatal jaundice?
o May be a sign of another disease e.g. haemolytic anaemia, infection
o Unconjugated bilirubin can get deposited in the brain, especially in the basal ganglia→leading to kernicterus
Define Kernicterus.
encephalopathy resulting from deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei
What causes Kernicterus?
May occur when the level of unconjugated bilirubin exceeds the albumin-binding capacity of bilirubin of the blood→this free bilirubin is fat-soluble→can cross BBB
What are the acute manifestations of Kernicterus?
lethargy, poor feeding
How does Kernicterus present in severe cases?
irritability, increased muscle tone causing baby to lie with an arched back (opisthotonos), seizures, coma
What can be a consequence of developing Kernicterus?
Infants who survive may develop choreoathetoid cerebral palsy (due to damage of the basal ganglia), learning difficulties and sensorineural deafness
How has the incidence of Kernicterus changed in the recent years?
Kernicterus used to be an important cause of brain damage in infants with severe rhesus haemolytic disease, but has become rare because of the introduction of prophylactic anti-D immunoglobulin for Rh-negative (rhesus-negative) mothers.
However, a few cases of kernicterus continue to occur, especially in slightly preterm infants (35–37 weeks) and dark-skin-toned infants in whom jaundice is more difficult to detect.
At what stage do babies become clinically Jaundiced?
Babies become clinically jaundiced when the bilirubin level reaches about 80 μmol/l.
How do we classify neonatal jaundice?
- Jaundice < 24 hrs of age
- Jaundice at 24 hrs to 2 weeks of age
- Jaundice > 2 weeks of age
What are the causes of jaundice < 24 hours of age?
Haemolytic disorders (usually results from Haemolysis - incredibly important to identify as the bilirubin is unconjugated and can rise very rapidly and reach extremely high levels.)
- Rh (rhesus) incompatibility
- ABO incompatibility
- G6PD deficiency
- Spherocytosis, pyruvate kinase deficiency
Congenital infection
- When is rhesus haemolytic disease identified?
- How does it present?
- What other antibodies may develop?
- Affected infants are usually identified antenatally and monitored and treated if necessary
- The birth of a severely affected infant, with anaemia, hydrops and hepatosplenomegaly with rapidly developing severe jaundice, has become rare.
- Antibodies may develop to rhesus antigens other than D and to the Kell and Duffy blood groups, but haemolysis is usually less severe.
- How common is ABO incompatibility?
- What type of antibodies are produced?
- How does it present?
- What test can be done?
- When does it peak?
- This is now more common than rhesus haemolytic disease.
- Most ABO antibodies are IgM and do not cross the placenta, but some group O women have an IgG anti-A-haemolysin in their blood, which can cross the placenta and haemolyse the red cells of a group A infant. Occasionally, group B infants are affected by anti-B haemolysins.
- Haemolysis can cause severe jaundice but it is usually less severe than in rhesus disease. The infant’s haemoglobin level is usually normal or only slightly reduced and, in contrast to rhesus disease, hepatosplenomegaly is absent.
- The direct antibody test (Coombs test), which demonstrates antibody on the surface of red cells, is positive.
- The jaundice usually peaks in the first 12 hours to 72 hours.
What is this?
Bilirubin chart of bilirubin level and time from birth. It also shows the threshold for starting phototherapy and need to perform an exchange transfusion. Charts vary with gestational age; this is for infants ≥ 38 weeks gestational age. Plotting the bilirubin values, as shown for this infant with ABO incompatibility, allows the rate of rise to be readily determined and if preparation needs to be made for an exchange transfusion.
Summarise the counselling for neonatal jaundice.
CLD - ill defined reticular markings
Describe the pathophysiology of HIE
- In perinatal asphyxia, gas exchange, either placental or pulmonary, is compromised or
ceases altogether → leads to cardiopulmonary depression → Hypoxia, hypercarbia and respiratory acidosis follow - Most cases occur following a significant hypoxic event immediately before or during
labour or delivery, such as:- Failure of gas exchange across the placenta (excessive or prolonged uterine
contractions, placental abruption, ruptured uterus) - Interruption of umbilical blood flow (e.g. cord compression including shoulder
dystocia, cord prolapse) - Inadequate maternal placental perfusion, maternal hypotension and
hypertension - Compromised foetus (anaemia, IUGR)
- Failure of cardiorespiratory adaptation at birth (failure to breathe)
- Failure of gas exchange across the placenta (excessive or prolonged uterine
- Neuronal damage in HIE may be immediate from primary neuronal death or may be
delayed from reperfusion injury causing secondary neuronal death from secondary
energy failure- Reperfusion injury: tissue damage caused when blood supply returns to tissue
after a period of ischaemia. The absence of oxygen and nutrients from blood
during the ischaemic period creates a condition in which the restoration of
circulation results in inflammation and oxidative damage through the
induction of oxidative stress rather than (or along with) restoration of normal
function
- Reperfusion injury: tissue damage caused when blood supply returns to tissue
What is the management of necrotising enterocolitis?
- Stop oral feeding (NBM)
- Parenteral nutrition
- For confirmed cases - stop feeding for 7 ddays
- Broad spectrum antibiotics
- Cover both aerobic and anaerobic organisms
- e.g. cefotaxime and vancomycin
- Respiratory support - may require high ventilation pressures due to abdominal distension
- Fluids - CV support
- Surgery
- Indicated if:
- Perforation
- Failure to respond to medical treatment
- Laparotomy with resection of necrosed bowel with either a primary anastomosis or a defunctioning stoma
- Indicated if:
