Neonatology Flashcards
Define Birth asphixia - Hypoxic-ischaemic encaphalopathy
When a babies organs do not get enough O2 before, During or directly after birth. May lead to HIE which is a neonatal Brain injury secondary to prenatal, perinatal or postnatal asphixiation
0.1-0.2% of pregnancy
Aetiology
Mother inadequate O2 levels Cardiac/Resp issues Poor placental function Placental Abruption Low BP in mum Umbilical cord compression Drugs used in pregnancy
What is the APGAR score
used to assess the health of a new born baby
0 1 2 A - Activity Absent Flexed arms Active
and legs P -Pulses Absent <100bpm >100bpm G - Grimace Floppy Minimal Prompt A - Appearance Blue/pale Blue Limbs Pink R - Reflexes Absent Slow Vigorous
0-3 poor 4 - 6 is moderate and 7 - 10 means baby is doing well
Clinical Presentation of HIE
Suggestive criteria Normal CTG Hypoxic event present Poor APGAR Metabolic Acidosis in pH (<7) Multisystem dysfunction within 72hrs
Symptoms and Signs
BLUE BABY AND DEC PULSE
MILD: irritable, increase tone and reflexes, staring eyes, poor feeding
MOD: Lethargy, Reduced tone and reflexes, seizures
SEVERE: Coma, reduced tone, Absent reflexes, prolonged seizure, multi-organs failure
Ix for HIE
APGAR score - taken at 1, 5 and 10 minutes - <3 after 10 minutes indicates poor outcome
Cerebral Function Monitor - (CFM)
MRI Brain
Rx of HIE
Resp and circulatory Support
Fluid Balance - avoidance of cerebral oedema
management of seizures - Anticonvulsants
whole body cooling for up to 72 hours to 33 or 34 degrees
Complications of HIE
CP
Learning difficulties
epilepsy
Hearing and Visual impairment
Prognosis of HIE
Mild - Majority have no sequelae
Mod - 40% serious long term complications; 15% minor disability
Severe - 30% mortality, 50% severe disability, 10% moderate disability
Small for Date causes
PET
Chromosomal - Edwards syndrome
Infection (e.g. CMV)
Twin Pregnancy
Common Problems of a small for date baby
Perinatal Hypoxia Hypoglycaemia Hypothermia Polycythaemia Thrombocytopaenia GI problems (Feeds/NEC) RDS and Infection
Long Term Problems:
Hypertension
Reduced Growth
Obesity
Ischaemic heart disease
Categories of preterm births
Preterm = <37wks
Extremely Pre-term = <28wks
Low B/W = <2500g
Very LowB/W = <1500g
Extremely Low B/W = <1000g
Common Problems in preterm babies
AN SYSTEM CAN BE HIT Resp Circulatory Metabolic/nutrition Immune/Infection Brain GI Haematology Renal Skin
(All this has Done is remind me of the systems I don’t have time to study)
3 letters Quiz RDS IVH PVL NEC PDA BPD ROP PHH
NAS
HIE`
Respiratory Distress syndrome Intraventricular Haemorrhage periventricular leucomalacia Necrotising enetro-colitis Persistent Ductus Arteriosus Broncho-pulmonary displasia Retinopathy of Prematurity Post-Haemorrhage Hydrocephalus Neonatal Abstience syndrom Hypoxic-ischaemic encephlopathy
RDS
Prevention
Antenatal Steroids
Early Treatment
Neonatal Surfactant -and then as little as possible
Early extubation
non-invasive support (N-CPAP)
minimal ventilation
BPD
Overstretched by volu-baro-trauma Atelectasis Infection via ETT O2 toxicity Inflammatory changes Tissue repair --> Scarring Treatment Patience Nutrition Steroids (!)
IVH
Most common limiting factor for good long term prognosis
Grades I - IV (IV having a 75% adverse outcome)
Prevention
AN Steroids
Treatment
Symptomatic
Drainage???
PDA
Pressure Ao >PA –> L to R shunt
Additional Blood to pulmonary Ventilation –> over perfusion of lungs –> Lung Oedema
+
Steal form systemic circulation -> systemic ischaemia
Consequences of PDA
Worsenig of respiratory system + retention of fluids (low renal perfusion)
GI ischaemia
NEC
Ischamic and inflammatory Bowel Changes Necrosis of the Bowel Surgical Intervention is often required Conservative management is sometimes possible Antibiotics and Parenternal Nutrition
Preterm Nutrition
Enormous part of neonatal medicine
Some Pts will triple weight during time in hospital
Aids in building new functional tissues from compunds provided artificially
Purpose of the Ductus arteriosus
Protects the Lungs from Circulatory overload
Allows Right Ventricle to Strengthen
Carries low O2 saturated blood
Purpose of Ductus Venosus
Foetal Blood vessel connecting umbilical vein to IVC
Blood Flow regulated via a sphincter
Carries mostly Oxygenated blood
Normal HR of a full term new Born
HR - 12-160
Tachy at >160
Brady at <100
BP at 1 hour old
70/44mmHg
BP at 1 day old
70 (+/-9)/42 (+/-12) mmHg
BP at 3 days
77 (+/- 12) / 49 (+/- 10)
Respiratory rate of a new borm
30 - 60 BPM - Periodical Breathing
Thermoregulation
Maternal Thermoregulation in the Womb
New born babies lack shiver response tus need metabolic production of heat
Brown fat well innervated by sympathetic neurons
Cold stress leads to lipolysis and therefore thermoregulation
Loss of heat
Radiation Heat dissipated to colder objects Convection Heat loss by moving air Evaporation We are born in water Conduction Heat loss to surface when baby lies on it
Non-invasive assessment of newborn breathing
Blood gas determination
PaCO2 5-6 kPa, PaO2 8-12 kPa
Transcutaneous pCO2/O2 measurements
Invasive Assessment of newborn breathing
Capnography Tidal Volume 4-6ml/kg Minute ventilation Tidal Volume x Resp Rate Flow-volume loop
Physiological Jaundice
Appears on DOL 2-3
Disappears within 7-10 DOL in term infants and up to 21 in premature
Very common; 60% term and 80% preterm
0% breast fed jaundice at 30 DOL
More on physiological Jaundice
7-% biliruben comes from Hb
Metabolised and conjugated in the liver
Biliruben is lipid soluble and so hemato-encephalic barrier
At high concentrations it causes changes in the brain - KERNICTERUS
Blue light cenverts Biliruben to water soluble and so increases oxidisation of biliruben
Fluid Balance in Premature babies
Less fat in body composition increased loss via kidneys Slower GFR Reduced Na absorption Decreased ability to concentrate or dilute urine Increased insensible water loos (IWL) Premature skin and breathing physiologcial IWL is 20-40ml/kg/day but could be up to 80ml/kg/day in 750 - 1000g
Physiological anaemia in newborns
RBC production is 10% of in utero DOL 7 born with 15-20g/l Hb week 10 11.4 g/l hb Increased production of EPO Week 20 12g/l Hb Anaemia in prematurity Reduced erythropoesis Infection Blood letting - Most important cause
