Neonatology Flashcards
Gestational Age
Time from start of last period
Embryonic Age (Foetal Age)
Time from fertilisation (formation of zygote)
Estimated using ultrasound
- 1st trimester: crown rump length
- 2nd/3rd trimester: head circumference and femur length
Gestational Age (2)
Embryonic Age + 14 days
Which is more commonly use in clinical practice: Gestational Age or Embryonic Age?
Gestational Age
Stages of Ovulation (According to CM) (6)
- Follicular phase
- Dominant follicle development
- Lutenizing hormone surge
- Ovulation
- Corpus luteum formation
- Luteal phase
3 Stages of Gestation
Germinal stage
Embryonic stage
Foetal stage
Stages of Gestation - Germinal Stage
conception to implantation
Stages of Gestation - Embryonic Stage
To Approx. Week 9
Stages of Gestation - Foetal stage
Approx. Week 9 to Birth
Human Chorionic Gonadotropin (hCG)
- hormone detected on pregnancy tests
- syncytiotrophoblast releases the hormone hCG which enters the mother’s blood stream
- stimulates the corpus luteum of the ovary to produce progesterone to maintain the pregnancy
Ectoderm fait (external)
Cells derived from the ectoderm ultimately give rise to the:
- Epidermis
- Central nervous system
- Peripheral nervous system
- Eyes
- Internal ears
- Many connective tissues of the head
Mesoderm fait (middle)
Cells derived from the mesoderm ultimately give rise to:
- Skeletal muscles
- Blood cells and blood vessel linings
- Cardiovascular system
- Excretory systems incl kidneys
- Reproductive organs
- Visceral smooth muscular coats
- Serosal linings of all body cavities, ducts and internal organs
( Excluding in the head and limbs, they are the source of connective tissues, cartilage, bones, tendons, ligaments and dermis )
Endoderm fait (internal)
Cells derived from the endoderm ultimately give rise to epithelial linings. This includes linings of:
- Full alimentary tract (GI tract)
- Respiratory system
- Glands opening onto the GI tract and glandular cells of associated organs such as the liver and pancreas
Clinical indications for Neonatal EEG (3)
- Assess the severity of brain dysfunction and determine prognosis
- Detect seizures and assess response to treatment
- Assess cerebral maturation
Considerations for neonatal EEG (4)
- Size and vulnerability
- Myelination and sulcation
- Skull thickness
- State of baby (medication/sedation)
Recommended electrodes for neonatal (2)
- self-adhesive wet gel with snap lead wire
- self-adhesive wet gel with pre-attached lead wire
Disadvantage of cup/disc electrodes
impedance gel risks skin damage, pressure injury
Electrodes used in practice for clinical neonatal EEG
Disposable hydrogel electrodes
Extra-cerebral electrodes in neonatal EEG montage (7) + state what is key
Key: ECG & respiratory
Other: Left & right EOG, Left & Right EMG, Sp02
What area of the scalp is mainly missing electrodes in the limited montage and why?
Frontal lobe
- poorly developed
- lots of artefact
What is the benefit of EMG electrodes in the EEG montage?
- To differentiate seizure types (myoclonic, tonic, spasms)
- Can aid in lateralization
Limited EEG study
(Reasons why / benefits)
- Therapeutic hypothermia protocol
- Setups done out-of-hours
- Prolonged recordings (>24 h)
Full head EEG study
- Investigate seizures
- Investigate neonatal epileptic encephalopathy
- Better characterization of severely abnormal background in TH
Timebase of neonatal EEG
15mm/s
Information needed before starting neonatal EEG (5)
Age of baby
Time of birth
History of pregnancy issues
History of birth
Medication
What does APGAR score stand for?
Appearance (skin colour)
Pulse rate
Grimace
Activity (tone)
Respiratory effort
What is the purpose of APGAR score?
Used to help guide need for immediate treatment
When is APGAR done and how are the results interpreted?
Done: 1/5 mins
Results:
7+ normal
4-6 low
<= 3 critically low
Patient’s post menstrual age
Gestational age + chronological age
Parts of ECG Analysis (5)
Rate
- Fast (broad/ narrow)/slow
- Regular/ irregular
Rhythm
Axis
Intervals and voltages
Repolarisation
Normal Features in Paediatric ECG (7)
Sinus tachycardia when sick
Sinus arrhythmia
Isolated PACs + PVCs
Narrow QRS
2:1 Wenkebach during sleep
Notched T waves in V2/V3
Notched P waves V2/V3 in older children
3 Key Features of Normal Sinus Rhythm
P before every QRS
QRS after every p
Normal p wave axis
Congenital Heart Disease Death Incidence
0.8 per 1,000 births
How does CHD present? (6)
- Antenatal screening
- Postnatal pulse oximetry screening
- Cardiogenic shock- low output state
- Incidental finding
- Discharge exam
- Cardiac failure
Name the embryonic stage:
Primitive Gut Tube -> respiratory system
Early embryonic stage
Name the embryonic stage:
Respiratory Diverticulum -> bifurcates in two buds = primary bronchi
Week 4
Name the embryonic stage:
Pseudoglandular Stage
(bronchopulmonary segment will become a specific portion of the lung - the lungs resemble the development of tubuloacinar glands)
Weeks 8-16
Name the embryonic stage:
Canalicular Stage
(the respiratory bronchioles develop)
Weeks 16-26
Name the embryonic stage:
Terminal Sac Stage
(Alveoli Develop)
> 26 Weeks
4 Factors Affecting Breathing
Chemical (chemoreceptors in the carotid arteries and the aorta)
Mechanical (foetal chest compression during birth – reduces the negative pressure)
Thermal (skin thermoreceptors - change in temperature)
Sensory factors (tactile skin receptors)
Surfactant
Naturally produced at end of 2nd & 3rd trimester
90%lipids 10%proteins
Purpose: Lowers the surface tension at the air-water interface in the alveoli
Causes for resp complications of newborn (3)
- Delayed adaptation (maladaptation)
- Exiting conditions (surgical or congenital anomalies)
- Acquired conditions
Most common cause of respiratory distress in term newborns?
Transient Tachypnoea of Newborn (TTN)
4 Term Newborn Resp Pathology
Transient Tachypnoea of Newborn (TTN)
Meconium Aspiration Syndrome (MAS)
Persistent Pulmonary Hypertension of the Newborn
(PPHN)
Pneumothorax
2 Preterm Newborn Resp Pathology
Respiratory Distress Syndrome (RDS)
Chronic Lung Disease
What is TTN and what effect does it have? (1,2)
Delay in clearance of lung fluid (after c-section)
- Low pressure on the thorax
- Low reabsorption of alveolar fluid via Na channels in the lung epithelium due to low circulating catecholamines
How long does TTN usually take to settle?
24-48 hrs
How can TTN be managed? (2)
O2 therapy
Respiratory support (HF, CPAP)
What does TTN look like on an XRay? (2)
Fluid in the horizontal fissure
Streaky infiltrates with hyperinflation and peripheral haziness
What does MAS look like on XRay? (3)
Hyperinflation
Course diffuse patchy consolidations on both sides.
Some subtle pleural fluid on both sides (arrowheads)
What is involved in aspiration of meconium in MAS? (3)
Mechanical obstruction
Chemical pneumonitis
Inactivation of surfactant
Who is at increased risk of MAS?
postdates newborns (>42 weeks)
How can MAS be managed? (4)
O2 therapy
Respiratory Support
Surfactant therapy
NO therapy/ECMO
What is PPHN?
Pulmonary hypertension leading to right-to-left shunt
Causes of PPHN (5)
Birth asphyxia
Meconium aspiration
Sepsis
Diaphragmatic hernia
Primary disorder – less common
Presentation of PPHN
cyanosis, difference in pre- and post-ductal saturations
Management of PPHN (6)
O2 therapy
Mechanical ventilation support
Circulatory support
Surfactant therapy
NO therapy or sildenafil – pulmonary vasodilator
ECMO
Diagnosis of PPHN (2)
XRay or Echo
Management of pneumonia (2)
antibiotic treatment
respiratory support
Most common cause of neonatal pneumonia
Group B streptococcal infection (GBS)
Risk factors for neonatal pneumonia (4)
Prolonged rupture of the membranes (PROM)
Maternal infection
Fever
Chorioamnionitis
What does pneumonia look like on XRay? (3)
Bilateral perihilar streaking
Atelectasis of the right middle lobe, probably due to mucus impaction of the bronchus
Position of the nasogastric catheter indicating mediastinal shift
What is a pneumothorax?
Free air in pleural cavity
How can a pneumothorax be managed? (3)
respiratory support (O2 therapy, mechanical ventilation)
spontaneous resolution
needle aspiration/chest drain
Risk factors for respiratory distress syndrome (5)
Prematurity
Maternal diabetes mellitus
Sepsis
Hypoxemia and acidemia
Hypothermia
Natural course of RDS? (2)
Getting worse over 24-72hrs Improvement with antenatal steroids
How can RDS be managed? (4)
Antenatal steroids
Postnatal surfactant therapy (prophylaxis/rescue)
O2 therapy
Respiratory support (prevention of alveolar collapse): HF, CPAP, MV
What is bronchopulmonary dysplasia?
Chronic lung disease
bronchopulmonary dysplasia (definition)
O2 requirements at 28 days of life or at 36 weeks corrected
Who is at risk of neonatal chronic lung disease?
low birthweight infants (20-30%)
What is a major cause of mortality & morbidity in low birthweight infants?
Chronic lung disease
How can neonatal chronic lung disease be managed? (5)
Respiratory support
Nutritional support
Corticosteroids
Diuretics
Sildenafil if PPHN
Name 2 respiratory neonatal congenital anomalies and surgical conditions
Choanal Atresia
Congenital Diaphragmatic Hernia
How can Congenital Diaphragmatic Hernia be managed? (4)
Intubate and ventilate from birth
Pass NG tube
Support for PPHN
Surgical repair
How can Choanal Atresia be managed?
Oral airway
Surgical correction
What is the best predictor of survival in PPHN?
Cardiac function
Diagnosis of PPHN (6)
History and Physical Exam
Pre and post ductal saturation
Labile or profound hypoxaemia
Differential cyanosis
Chest XRay
ECHO
TAPSE
tricuspid annular plane systolic excursion
Systolic longitudinal displacement of the lateral tricuspid annulus towards the apex, measured using M-mode echocardiography in the apical four-chamber view to assess right ventricular function
General management for PPHN (5)
- Normothermia
- Noise and stress reduction
- Sedation
- Normalise pH
- Ventilatory Management
Therapeutic intervention for PPHN (6)
- Optimise Ventilation
- Oxygen
- Surfactant
- Nitric Oxide
- Haemodyamic Considerations
- Corticosteroids
What are the 3 Functional Properties of Lungs Addressed by Routine PFTs?
- Airflow (inspiratory & expiratory)
- Lung Volumes & Capacities (TLC, RV, FRC)
- Alveolar-Capillary Gas Transfer (CO uptake over time)
Abnormalities in these 3 functional properties of lungs addressed by routine PFTs?
1.Obstructive ventilatory
2. Restrictive ventilatory
3. Gas transfer limitations or impairments
