The Neonate

Question 1

How do you recognise the sick neonate?

Answer 1

• poor feeding
• dry nappies
• not passed mec
• appears jaundiced
• temp lower than 36 degrees
• temp higher than 37.5 degrees
• high resp rate/grunting when breathing
• high or low HR
• low o2 sats
• less active, less responsive or more irritable than usual
• bulging or depressed fontanelle

Question 2

How is temperature regulated in the neonate?

Answer 2

• temperature control is emulated by the hypothalamus, it is matured by 35 wks
• normal core temp of 36.5 degrees is the temperature where heat production and loss should be balanced
• babies have a large surface area to body area through which to lose heat -> this can be compounded by thin skin and a lack of brown adipose tissue (especially in pre term infants)

Question 3

Why is thermoregulation more important in the pre term neonate?

Answer 3

• they have immature/absent thermoregulatory mechanisms
• larger surface to body area
• immature thin skin
• reduced/absent brown adipose tissue
• limited ability to move and shiver to preserve heat

Question 4

How is heat lost in the neonate?

Answer 4

• hyperthermia is defined as a temp below 36.5 degrees
• conduction -> direct heat loss to solid surfaces
• convection -> heat loss to currents of air
• evaporation -> heat lose when water evaporates from the skin
• radiation -> heat loss via electro magnetic waves from skin to surrounding surfaces

Question 5

What are some of the effects of hypothermia?

Answer 5

• increased energy expenditure - if prolonged can lead to hypoglycaemia and slow weight gain
• reduced surfactant production and increased oxygen consumption exacerbating any existing respiratory distress
• babies may subsequently develop pulmonary hypertension and metabolic acidosis
• the risk of these are increased in the sick neonate

Question 6

How can hypothermia be prevented?

Answer 6

• maintain a thermo-neutral environment
• skin to skin contact
• hot cots/radiant warmers

Question 7

How is glucose metabolised in the neonate?

Answer 7

• glucose provides about 80% of the energy available to the fetus before birth, diffuses across placenta from mother
• glycogen stored in the liver during pregnancy provides glucose during labour and early postnatal period

Question 8

What is hypoglycaemia?

Answer 8

• for symptomatic babies blood glucose should be maintained >2.5mmol/l
• for babies deemed ‘at risk’ but asymptomatic blood glucose should be actively managed if <2 mmol/l
• blood glucose levels fall immediately after delivery and are at the lowest approx 1 hour after delivery
• after 2-3 hours levels begin to rise and usually stabilises by about 24 hours of age
• blood glucose levels after this time are generally dependent on feeding

Question 9

What are some of the risk factors for hypoglycaemia?

Answer 9

• sepsis
• hypothermia
• prematurity
• IUGR
• SGA
• LGA
• maternal diabetes
• maternal medication such as beta blockers
• hypoxic ischaemic encephalopathy

Question 10

What are some of the symptoms of hypoglycaemia?

Answer 10

• jitteriness
• high pitched cry
• seizures - extreme
• poor feeding
• drowsiness
• lethargy
• apnoea - extreme
• however, most will be asymptomatic

Question 11

How can hypoglycaemia be prevented?

Answer 11

• skin to skin
• early feeding
• monitoring blood glucose

Question 12

What is neonatal jaundice?

Answer 12

• jaundice is the yellow colouration of the skin and sclera resulting in an accumulation of bilirubin in the blood
• in most infants this is part of normal transition to ex utero life but in some infants the rise is excessive and can be harmful
• very high levels of jaundice can be neurotoxic, leading to death or long term disability
• prolonged jaundice can be an indication of underlying pathology and requires investigation

Question 13

How is bilirubin metabolised in the neonate?

Answer 13

• it is produced during the normal breakdown of red blood cells
• neonates have more red blood cells in their bodies and the cell life span is shorter therefore they produce more bilirubin
• neonates liver is immature and so not able to break down all the bilirubin and so levels in the blood rises
• as the liver matures it becomes better able to break down bilirubin so that it can be excreted from the body

Question 14

What are the two different types of jaundice?

Answer 14

• physiological
  —> usually occurs >24 hours age typically around 3 days
  —> often doesn’t require treatment
  —> should resolve within 2 weeks
  —> not normally associated with underlying disease
• pathological
  —> usually presents within 24 hours of age
  —> persists beyond 2 weeks of age
  —> pale stools/dark urine
  —> often associated with underlying disease

Question 15

What are some of the causes and risk factors of neonatal jaundice?

Answer 15

• breastfeeding - in the first few days of life whilst mothers’ milk supply becomes established
• previous sibling with jaundice requiring phototherapy
• significant bruising
• East Asian ethnicity
• prematurity
• infection
• ABO or other blood incompatibilities
• Rhesus iso-immunisation
• liver abnormalities
• red cell abnormalities resulting in blood cells breaking down more quickly/more red blood cells

Question 16

What are the symptoms of jaundice?

Answer 16

• yellow tinge to the skin
• lethargy
• poor feeding
• dark urine
• pale stools
• seizures
• arching of neck and back

Question 17

How can jaundice be diagnosed?

Answer 17

• visual check of skin and sclera
• transcripts bilirubin screening
• SBR

Question 18

How can jaundice be treated?

Answer 18

• ensure adequate feeds
• phototherapy
• exchange transfusion
• manage any underlying conditions

Question 19

What could happen if jaundice goes untreated?

Answer 19

• if it goes untreated and rises high enough, bilirubin can cross the blood-brain barrier and the infant is at risk of kernicterus (bilirubin encephalopathy) leading to brain damage

Question 20

Why are preterm and sick neonates at particular risk of infection?

Answer 20

• all neonates are at risk of infection because their immune systems are not yet fully established, however preterm or sick neonates are at particular risk because:
  
  • immature skin which is easily damaged
  • immature immune response
  • birthweight <1500g
  • delayed feeding
  • invasive procedures
  • increased handling and by more people increase risk of cross infection
  • exposure to maternal infection

Question 21

What are the different types of infection in the neonate?

Answer 21

• congenital infection -> present at birth, infection direct from mother
  —> herpes, syphillis, cytomegalovirus, hepatitis B, HIV
• early onset sepsis -> onset birth to 1 week, infection from birth canal
  —> rapid onset, usually more severe
  —> GBS, E.coli, listeria
• late onset sepsis -> onset beyond 1 week, maternal or external source of infection
  —> slower onset and more common
  —> GBS, CONS, E.coli, enterobacter, MRSA

Question 22

What is GBS and what are some of the risk factors?

Answer 22

• it is a significant cause of infection in neonates and infants
• risk factors
  —> preterm
  —> PROM
  —> GBS carrier
  —> pyrexia
  —> previous child with GBS
• sepsis, pneumonia and meningitis are common sequelae of this infection

Question 23

What are some of the signs and symptoms of infection?

Answer 23

• temperature instability
• lethargy
• poor feeding
• respiratory distress
• apnoea/tachyapnoea
• bradycardia/tachycardia
• rash
• vomiting/diarrhoea
• abdominal distension

Question 24

What investigations should be undertaken if infection is suspected?

Answer 24

• SEPSIS considered
• blood culture
• fbc and crp
• prophylactic antibiotics
• chest x-ray
• swabs
• lumbar puncture