Introduction to Neonatology Flashcards
small for dates causes: maternal
smoking
maternal pre-eclamptic toxaemia
small for dates causes: foetal
chromosomal e.g. edwards
infection e.g. CMV
small for dates causes: placental
abruption
small for dates causes: other
twin problems
common problems in small for dates babies
- Perinatal Hypoxia
- Hypoglycaemia
- Hypothermia
- Polycythaemia
- Thrombocytopenia
- Hypoglycaemia
- Gastrointestinal problems (feeds, NEC)
- RDS, Infection
long term problems in small for dates babies
- Hypertension
- Reduced growth
- Obesity
- Ischaemic heart disease
name 2 common respiratory problems in preterm babies
respiratory distress syndrome
bronchopulmonary dysplasia
respiratory distress syndrome: prevention
antenatal steroids
respiratory distress syndrome: treatment
surfactant
early extubation
N-CPAP
minimal ventilation
bronchopulmonary dysplasia: features
- Overstretch by volu-baro-trauma
- Atelectasis
- Infection via ETT
- O2 toxicity
- Inflammatory changes
- Tissue repair - scarring
bronchopulmonary dysplasia: treatment
o Patience
o Nutrition & growth
o Steroids (!)
minor respiratory problems in premature neonates and treatment
apneoa
irregular breathing
desaturations
caffeine
N-CPAP
brain complications in premature neonates
intraventricular haemorrhage
periventricular leucomalacia
post haemorrhagic hydrophalus
what is the most common limiting factor for good term prognosis in premature babies
intraventricular haemorrhage
intraventricular haemorrhage: prevention
AN steroids
intraventricular haemorrhage: treatment
symptomatic
drainage
patent ductus arteriosus
• Pressure in Ao > PA = L R shunt
• Additional blood to pulmonary circulation
o Over perfusion of lungs
o Lung oedema
• Steal from systemic circulation
o Systemic ischaemia
• Consequences
o Worsening of respiratory symptoms
o Retention of fluids (low renal perfusion)
o Gastrointestinal problems (GE ischaemia
GI problems in premature neonates
NEC necrotising entero colitis
nutrition
necrotising entero colitis
• Ischaemia and inflammatory changes
• Necrosis of bowel
• Surgical intervention is often required
• Conservative management is sometimes possible
o Antibiotics and parenteral nutrition
nutrition issues in premature babies
Preterm babies have enormous nutritional requirements that are unparalleled anywhere else in medicine. Patients often triple their size during their hospital stay. Building new functional tissues from compounds provided artificially.
outcome of extreme prematurity
The outcome is unpredictable at time of birth, and often very uncertain even on discharge home. Ultrasound of brain by the end of the 1st week. Surprising deterioration in cognitive and behavioural between 2nd and 6th years. Also, some unexpected improvement between 2nd and 6th year of life. Extremely limited data on subjective quality of life in adulthood.
- 1/3 die
- 1/3 have normal life or mild disability
- 1/3 have moderate or severe disability for lifetime
- 1 in 6 is entirely normal at 6 years old
- Subjective quality of life was not different in ex preterm compared to ex term controls
foetal circulation
- Oxygenated blood via umbilical vein – ductus venosus
- Some blood via foramen ovale to left atrium – left ventricle – aorta
- Some of blood to right ventricle – pulmonary artery – patent ductus arteriosus from PA to Ao
- Saturations SaO2 in foetal body is 60-70%
ductus arteriosus
The ductus arteriosus protects the lungs against circulatory overload. Allowing the right ventricle to strengthen. It carries low oxygen blood.
ductus venosus
The ductus venosus is the foetal blood vessel connecting the umbilical vein to the IVC. The blood flow through it is regulated via a sphincter. It carries mostly oxygenated blood.
normal vital signs of a full term new born: BP
- 1 hr 70/44
- 1 day 70 +/- 9 / 42 +/-12
- 3 days 77 +/- 12 / 49 +/- 10
normal vital signs of a full term new born: RR
- 30-60/min
* Periodical breathing
normal vital signs of a full term new born: HR
- Normal 120-160 bpm
- Tachycardia > 160 bpm
- Bradycardia <100 bpm
thermoregulation in neonates
In the womb maternal thermoregulation maintains the babies temperature. New-born babies lack shivering thermogenesis thus need a metabolic production of the heat. Brown fat is well innervated by sympathetic neurones. Cold stress leads to lipolysis and heat production.
loss of heat in neonates
• Radiation o Heat dissipated to colder objects • Convection o Heat loss by moving air • Evaporation o We are born in the water • Conduction o Heat loss to surface on which baby lies
physiological jaundice: when does it occur
2-3 days of life
physiological jaundice: when does it disappear
7-10 DOL in term
up 21 in premature
physiological jaundice: how does it happen
75% bilirubin comes from haemoglobin. Metabolised, conjugated in liver. Bilirubin is lipid soluble thus crosses haemato-encephalic barrier. At high concentrations cause irreversible changes in the brain – kernicterus
physiological jaundice: how can it be treated
Blue light converts bilirubin to water soluble form and increases oxidation of bilirubin.
fluid balance in term newborns
Full term infant is able to maintain fluid / electrolyte balance. Weight loss up to 10% is normal. Loss is due to: shift of interstitial fluid to intravascular and diuresis. It is normal not to pass urine for the first 24 hrs!
• Less fat in body composition • Increased loss through kidney: o Slower GFR o Reduced Na reabsorption o Decreased ability to concentrate or dilute urine • Increased Insensible Water Loss (IWL) o Via immature skin and breathing o Physiological IWL is 20-40 ml/kg/day but could be up to 82 ml/kg/day in 750-1000 g
physiological anaemia of the newborn
- RBC production is 10% of in uterus DOL 7
- Born with - Hb 15-20 g/l
- Week 10 - Hb 11.4 g/l
- Increase production of Erythropoietin
- Week 20 - Hb 12.0 g/l
anaemia of prematurity
o Reduced erythropoiesis.
o Bloodletting – most important cause!
common post natal problems: skin colour
jaundice
pallor
plethora
cyanosis
common post natal problems: skin rashes
benign milia miliaria erythema toxicum neonatorum infections sebaceous naevus
common post natal problems: skin birthmarks
o Capillary haemangiomas o Mongolian blue sports o Port wine stains o Stork marks o Giant melanocytic naevi o Café au lait spots
what can exacerbate physiological jaundice?
dehydration
onset of jaundice when is always pathological?
24 hrs of life
neobron pallor
Pallor is a clinical sign and not a diagnosis. It suggests anaemia and may be congenital or acquired. Decrease in haemoglobin may be secondary to bleeding internal or external. Decreased production by bone marrow or increased destruction of RBC may also cause anaemia. Disseminated intravascular coagulopathy can also cause it. The most common cause of anaemia in preterm is iatrogenic secondary to blood sampling.
newborn plethora
Plethora is a condition marked by an excess volume of blood causing swelling and a reddish complexion. A cause of this might be polycythaemia which has implications in terms of blood viscosity.
newborn milia
This is white papules on the tip of the nose caused by hyperplastic sebaceous glands. The effect of the transplacental hormones. The disappear with desquamation
newborn miliaria
Miliaria are the result of obstruction to immature sweat glands. They are commonly seen secondary to thermal stress, crops of lesions over the face, scalp and trunk. Miliaria crystallina are superficial vesicles with a diameter of 1-2 mm. The skin is not inflamed. Miliaria rubra aka prickly heat are papules and pustules from obstruction in the mid-epidermis.
newborn erythema toxicum
The cause this maculo popular rash is unknown but it mostly clears after 1-2 week. It occurs in 30-70% of normal term neonates. It is very rare in the pre term. No treatment is required.
newborn skin indections
These are relatively rare. Non benign pustular rashes with the commonest cause being staph aureus. Consider herpes.
newborn sebaceous naevus
These are hamartomatous lesions sensitive to androgens. Androgens are produced during puberty causing the lesions to become larger and more wart like. There is risk of malignant degeneration (basal cell carcinoma) in adulthood therefore elective removal should be considered.
newborn capillary haemangiomas
Also known as strawberry naevus and intradermal haemangiomas. A cluster of dilated capillaries appear within the 1st month. They are raised and bright red with discrete edges. They can be found on any part of the body. They usually regress after 1st year. They vary in severity from salmon patch
newborn mixed haemangioma
These have a deep vascular component. If vision is under threat then they require treatment. There are a vascular anomaly. Histologically they are abundant endothelial cells with narrow vascular channels. They are the commonest tumours of the eyelids and orbits in childhood.