Neonatology Flashcards
Define neonate
From birth to 28 days of age
Admission to neonates
Birth - labour ward
PNW - postnatal week
Home - exchange transfer
Transfer from another hospital
Define early onset neonatal sepsis (EONS)
Sepsis occuring within the first 48-72 hours of life
Common PC for neonates
Prematurity Respiratory distress - grunting Cyanosis Jaundice Poor feeding Weight loss Know congenital abnormalities Fractures/skull swelling Concerns about sepsis
Causes of EONS
Chorioamnionitis perinatally via direct contact in the birth canal and haematogenous spread
Main organism of EONS
Group B streptococcus - most common - gram-positive coccus - present in 25% of pregnant women's genital tract - infection via direct contact E-coli Coagulase-negative straphylococcus H influenzae Listeria monocytogenes
Risk factors for EONS
Invasive group B strep infection in previous baby
Maternal group B strep colonisation, bacteruria or infection in current pregnancy
Prelabour rupture of membranes
Preterm birth following spontaneous labour
Suspected or confirmed rupture of membranes for more than 18 hours in a preterm birth
Intrapartum fever higher than 38
Parental antibiotic treatment for invasive bacterial infection at anytime during labour - red flag
Suspected or confirmed infection in another baby in the case of multiple pregnancy - red flag
Clinical indicators suggestive of infection
Altered behaviour or responsiveness
Altered muscle tone (for example, floppiness)
Feeding difficulties (for example, feed refusal)
Feed intolerance, including vomiting, excessive gastric aspirates and abdominal distension
Abnormal heart rate (bradycardia or tachycardia)
Signs of respiratory distress
Respiratory distress starting more than 4 hours after birth (Red Flag)
Hypoxia (for example, central cyanosis or reduced oxygen saturation level)
Jaundice within 24 hours of birth
Apnoea
Signs of neonatal encephalopathy
Seizures (Red Flag)
Need for cardio–pulmonary resuscitation
Need for mechanical ventilation in a preterm baby
Need for mechanical ventilation in a term baby (Red Flag)
Persistent fetal circulation (persistent pulmonary hypertension)
Temperature abnormality (lower than 36°C or higher than 38°C) unexplained by environmental factors
Signs of shock (Red Flag)
Unexplained excessive bleeding, thrombocytopenia, or abnormal coagulation (International Normalised Ratio greater than 2.0)
Oliguria persisting beyond 24 hours after birth
Altered glucose homeostasis (hypoglycaemia or hyperglycaemia)
Metabolic acidosis (base deficit of 10 mmol/litre or greater)
Local signs of infection (for example, affecting the skin or eye
Red flag signs for suggestive neonatal infection
Systemic antibiotics given to mother for suspected bacterial infection within 24hr of birth
Seizures
Signs of shock
Resp distress starting more than 4 hours after birth
Need for mechanical ventilation in term baby
Suspected or confirmed infection in co-twin
Differential diagnosis for EONS
Transient Tachypnoea of the newborn (TTN) - in term babies, causes tachypnoea and increased work of breathing
Surfactant deficient lung disease / respiratory distress syndrome (RDS) - especially in preterm infants can cause tachypnoea and increased work of breathing
Meconium Aspiration - can cause the baby to be born in poor condition, with respiratory distress, and may require intubation. Meconium aspiration can cause a rise in CRP.
Haemolytic Disease of the Newborn - can present with jaundice within the first 24 hours of life.
Investigations for EONS
FBC CRP Blood cultures Relevant swabs/cultures LP - if suggestive of meningitis
Management of EONS
IV benzylpenicillin with gentamicin
- if cultures + then continue for 7-10 days
- up to 14 days if CSF also +
- raised CRP but - cultures 5 days
Define jaundice
Yellow colouring of skin and sclera caused by the accumulation of bilirubin
Epidemiology of neonatal jaundice
60% of term infants
80% of preterm infants
Physiological causes of jaundice
Physiological - jaundice in a healthy baby born at term is normal
Starts at day 2-3, peaks at day 5 and resolved by day 10
- increased RBC breakdown-
- immature liver
Pathological causes of jaundice
Onset less than 24 hours = Haemolytic disease
- haemolytic disease of the newborn (rhesus)
- ABO incompatibility
- GPD deficiency
- spherocytosis
Onset after 24 hours
- likely dehydrated
- increased haemolysis due to bruising/cephalohematoma
Unwell neonate = congenital or post-natal infection
Prolonged jaundice - > 14 days in term and 21 days in preterm
- infection
- metabolic - hypothyroid/pituitarism, galactosaemia
- breast milk jaundice - well baby, resolves between 1.5-4 months
- GI - biliary atresia, choledhocal cyst
Define preterm birth
Delivery before 37 weeks
- extreme = before 28 weeks
- very = 28-32 weeks
- moderate to late = 32 to 37 weeks
Epidemiology of preterm birth
15 million babies born premature each year
- 60,000 in UK
Number one cause of neonatal death globally
number 1 cause of death for under 5s
Risk factors for premature birth
Previous preterm delivery
Multiple pregnancy
Smoking and illicit drug use in pregnancy
Being under or overweight in pregnancy
Early pregnancy - within 6 months of previous pregnancy
Problems involving cervix, uterus or placenta - including infection
Certain chronic conditions such as diabetes and hypertension
Physical injury/trauma
Investigations for premature birth
Blood gas - assess resp and metabolic state of infant
FBC - high risk of infection, thrombocytopenia and anaemia
U+Es and creatinine - electrolyte and fluid balance
Blood culture
CRP
Blood group and Direct Coombs Test/Direct Antiglobulin Test - blood transfusion and jaundice
CXR - if showing signs of resp distress
AbdoX - central venous and arterial access inserted through umbilical vein and arteries
Cranial USS - assess for signs of haemorrhagic, ischaemic and infective factors
Initial management of preterm birth
Planned delivery in hospital with in tertiary level neonatal hospital
Antenatal steroids
Magnesium sulphate - neuroprotective
Guidelines around resuscitation of extreme pre-term infants
Less than 23 weeks - resuscitation not performed
23-23+6 weeks - decision not to start resuscitation in best interests of baby especially if parents agree
24 and 24+6 weeks - resuscitation commenced unless baby thought to be severely compromised
After 25 weeks - appropriate to resuscitate and start intensive care
Features of intraventricular haemorrhage
Parenchymal bleed due to immature BBB
Bleed during birth due to increased maternal and baby BP
Leads to cerebral palsy - managed by early physiotherapy
Features of surfactant deficiency
Difficulty breathing
Cyanosis
Intercostal recession
Increased RR, HR and reduced SaO2
Formation of lungs
Type 1 pneumocytes - needed for gas exchange - form at 32 wks Type 2 pneumocytes - produce surfactant - form at 24 weeks
Investigations for infant respiratory distress
Blood gas - usually type 1 resp failure = low O2 and high CO2
CXR - acute respiratory distress syndrome
- cloudy, speckly = ground-glass sign
Differential diagnosis of respiratory distress in a newborn
Surfactant deficiency
Infection
Pneumonia
Management of surfactant deficiency
Antenatal steroids if signs of premature labour
Artificial surfactant - 1 per 12 hours
Long term = ventilation
Complications of long term ventilation of newborns
Bronchopulmonary dysplasia
- fibrosis of lung
- damage due to barotrauma
Most common in those ventilated from 32-36 weeks +
Increased risk of asthma and chest infections
Features of a patent ductus arteriosus
Machinery murmur - loudest at upper left chest
Breathlessness
Poor exercise tolerance
Rapid HR
Define patent ductus arteriosus
Unclosed hole in the aorta
- oxygenated blood travels from aorta into pulmonary artery
Management of PDA
Ibuprofen - anti-prostaglandin effect
Surgical ligation if unsuccessful
Define NEC
Nectrosting Encephalitis
- overgrowth of gut bacteria -> infection
Features of NEC
Vomiting + diarrhoea Feeding intolerance Abdo distention Blood in stools Tachycardia
Ix for NEC
Abdo x-ray
- pneumatosis intestinalis = train track sign
Mx for NEC
Nil by mouth
IV abx
Total parenteral nutrition
Surgical mx for perforated intestine - removal of affected section
Neurodevelopmental outcomes of premature babies
More premature = higher likelihood of neurodevelopmental impairment
- infants born at 22 weeks, around 1/3 will have no or mild disability
- increases to 75% at 26 weeks
Risk factors for neonatal jaundice
Prematurity, low birth weight or small for dates Previous siblings requiring phototherapy Exclusively breast fed Jaundice < 24 hours Infant of diabetic mother
Clinical presentation of neonatal jaundice
Colour - sclera, gums and blanche the ski
Drowsy - difficult to rouse, not waking for feeds
Neurology - altered muscle tone
Other - signs of infection, poor urine output, abdo mass/organomegaly, stool remains black
Ix for neonatal jaundice
Transcutaneous bilirubinometer
- >35/40 gestation and > 24hrs for 1st measurement
Serum bilirubin
- if <35/40 gestation, < 24hrs old or TCB > 250 micromol/L
Only if appear jaundiced to naked eye
Mx for neonatal jaundice
Interpret bilirubin using treatment threshold graphs
- gestation specific - the more premature infant the lower level of bilirubin tolerated before neurological impairment
If above live initiated phototherapy and monitor bilirubin
Do not give additional fluids unless indicated
Exchange transfusion
- prevent further bilirubin increase
- via umbilical artery or vein
IV Immunoglobulin
- adjunct to phototherapy in rhesus haemolytic disease of ABO haemolytic disease
Complications of neonatal jaundice
Kernicterus
- bilirubin-induced brain dysfunction
- irreversible neurological damage to to high bilirubin
Define meconium aspiration syndrome
Spectrum of disorders marked by various degrees of respiratory distress in the newborn infant
- follows the aspiration of meconium stained amniotic fluid either antenatally or during birth
Pathophysiology of meconium aspiration syndrome
Meconium stained amniotic fluid (MSAF) caused by in-utero peristalsis
- result of foetal hypoxic stress or vagal stimulation due to cord compression
Once aspirated can stimulate the release of vasoactive and cytokine substances
- activate inflammatory pathways
- inhibits effect of surfactant
Common features of MAS-related respiratory distress of the newborn
Partial or total airway obstruction - due to thick sticky consistency of meconium
-> atelectasis and ball-valve effect with air trapping
Foetal hypoxia - due to V/Q mismatch, increase of pulmonary vasculature, mechanical obstruction, airway oedema or surfactant inactivation
Pulmonary inflammation
- release of pro-inflammatory cytokines - tumour necrosis factor and interleukins
- contribute to lung tissue, injury, surfactant inactivation and infection
Infection
- inflammation process predisposes lung to increased risk of infection and chemical pneumonitis
Surfactant inactivation
- increases surface tension of alveoli
- reduces efficiency of gas exchange and exacerbates foetal hypoxia
Persistent Pulmonary Hypertension
- due to remodelling of pulmonary vasculature in response to hypoxia, vasoactive mediators and V/A mismatch
Risk factors for MAS
Gestational Age > 42 weeks
Foetal distress - tachycardia / bradycardia
Intrapartum hypoxia secondary to placental insufficiency
Thick meconium particles
Apgar Score <7
Chorioamnionitis +/- prolonged pre-rupture
Oligohydramnios
In utero growth restriction Maternal hypertension, diabetes, pre-eclampsia or eclampsia, smoking and drug abuse
Investigations for MAS
Diagnosis of exclusion CXR - increased lung volumes - asymmetrical patchy pulmonary opacities - pleural effusions - pneumothorax or pneumomediastinum - multifocal consolidation - due to chemical pneumonitis Infection markers - FBC - CRP - blood cultures
Ddx of MAS
Transient tachypnoea of the newborn - usually resolves in 24hrs without intervention - no hypoxia or cyanosis Surfactant deficiency - causes resp distress - more commonly seen in pre-term infants - no MSAF at delivery Persistent pulmonary hypertension - PDA
Management of MAS
Observation Routine care - infant warmer - continuous O2 sats - nutritional support - IV fluids Ventilation/O2 therapy - nasal cannula - CPAP - intubation and mechanical ventilation Antibiotics - if clinical suspicion of infection - stopped if negative blood cultures return Surfactant Inhaled Nitric Oxide - pulmonary hypertension Corticosteroids
