The Unwell Neonate

Question 1

What are the problems presenting in the early weeks of infant life?

Answer 1

• Neonates - recognition of serious illness.
• Neonatal jaundice.
• Crying babies / infant distress.
• Infant colic.
• Vomiting in the newborn.

Question 2

Which neonates are at highest risk of serious illness?

Answer 2

• Low birth weight babies (preterm or small for gestational age).
• Those with a previously recognised medical problem e.g. congenital anomaly.
• Babies from socially disadvantages families.

Question 3

What role does fever play in recognition of serious illness in the neonate?

Answer 3

• Full sepsis evaluation and admission should be considered for any neonate with temperature >38°.
• Sepsis can be present with a normal or low body temperature.
• Temperature instability / difficulty maintaining body temperature.

Question 4

What role does feeding play in recognition of serious illness in the neonate?

Answer 4

• If the volume taken in previous 24 hours is less then 50% of normal, this is cause for concern.

Question 5

What role does urine output play in recognition of serious illness in the neonate?

Answer 5

Less than 4 wet nappies in 24 hours indicates a significant decrease in fluid intake.

Question 6

What role does peripheral circulation play in recognition of serious illness in the neonate?

Answer 6

• Generalised pallor of recent onset, mottling, cold periphery or sluggish capillary return (capillary refill time >2 seconds).

Question 7

What role do responsiveness and activity play in recognition of serious illness in the neonate?

Answer 7

• Poor responsiveness to stimulation - a weak cry - is cause for concern.
• Decreased activity / movement and increased sleeping are cause for concern.

Question 8

What role does breathing difficulty play in recognition of serious illness in the neonate?

Answer 8

• The signs of respiratory distress in the neonate are tachypnoea (RR > 60/min), recession, expiratory grunt, nasal flaring and cyanosis. These are all important in recognising the unwell neonate.

Question 9

Describe apnoea in the neonate.

Answer 9

• Defined as a pause in respiration of >20 seconds.
• May be central (e.g prems), obstructve (e.g. URTI with pharyngeal mucous, GOR, blocked nose) or combined.

Question 10

What role does vomiting play in recognition of serious illness in the neonate?

Answer 10

• Any vomiting in excess of normal post-feed posseting must be treated seriously in the neonate.
• Bile-staining indicates bowel obstruction (e.g. malrotation with volvulus).

Question 11

Describe jaundice in the neonate.

What are the risk factors for severe hyperbilirubinaemia?

Answer 11

• All babies develop elevated serum bilirubin levels, to a greater or lesser degree, in the first week of life.
• This is due to increased production (accelerated RBC breakdown), decreased removal (transient liver enzyme insufficiency), and increased reabsorption (enterohepatic circulation).
• Risk factors for severe hyperbilirubinaemia:
  
  • ​With short neonatal hospital stays, jaundice may not be apparent - and certainly has not yet peaked - at the time of hospital discharge.
  • Therefore, infants at risk for severe hyperbilirubinaemia should be identified so they can be observed closely both while in the hospital and after dischatge.
  • Low birth weight and prematurity.
  • Infants born at 35-37 weeks gestation - who are often treated as full-term infants - are more likely to breast-feed poorly and to have significant weight loss than their full-term counterparts.

Question 12

What should the healthy term infant be doing by the 3rd day of life?

Answer 12

• By the 3rd day of life, the healthy term infant should stop losing weight, have lost no more than 10% of birth weight, be passing milk stools (non-meconium) at leat 2-3x per day, wet at least 5-6 nappies per day and latch well on to the breast.
• The mother should experience some engorgement and expect to feed the infant a minimum of 6-8x / day.

Question 13

What is the most common reason for hospital readmission in the first 2 weeks of life?

Answer 13

Neonatal hyperbilirubinaemia

Question 14

How is hyperbilirubinaemia treated?

Answer 14

Phototherapy

Question 15

What is the effect of breastfeeding on neonates at risk of jaundice?

Answer 15

• Jaundice is 3x more likely to occur in breast-fed than formula-fed infants, and progression to severe hyperbilirubinaemia is 6x more likely.
• Very few reported cases of Kernicterus but all but one were breast-fed.

Question 16

What is jaundice in the first 24 hours of life suggestive of?

Answer 16

• Uncommon.
• Suggests haemolysis and requires investigation and early treatment.
• Pathological until proven otherwise.
• May be haemolytic (Rhesus / ABO incompatibility and others).
• Think of sepsis as a cause.

Question 17

Describe how haemolysis from blood-type incompatibilities can affect neonates.

Answer 17

• Haemolysis from blood-type incompatibilities plays a significant role in neonatal hyperbilirubinaemia, and moderate jaundice usually develops in infants with ABO incompatibilites.
• Antibodies to minor antigens occur in ~1.5-2.5% of obstetric patients.
• Some of the most common atypical antibodies such as anti-Lea, anti-Leb and anti-I do not cause foetal or neonatal haemolysis.
• However, most of the minor antigens can cause foetal anaemia and hydrops. The most serious antibodies include anti-E, anti-Kell, anti-c and anti-Fya.

Question 18

What are the other (non-antigen) causes of haemolysis?

Answer 18

• Haemolysis can result from other inherited or congenital causes.
• Hereditary spherocytosis or elliptocytosis can be present in the newborn.
• G6PD deficiency is often overlooked, and difficult to recognise. Jaundice may not develop until after the 4th day post-delivery. It is more prevalent in infants of East Asian, Greek, and African descent.

Question 19

Describe physiological jaundice in the neonate.

Answer 19

• Common.
• No treatment required if the bay is well and jaundice is mild.
• Marked jaundice at any age requires investigation and possibly treatment.
• Think sepsis in an unwell baby.
• DOES NOT occur on day 1 of life.
• Peaks around day 3.
• Is resolved by day 10.

Question 20

Describe prolonged jaundice in the neonate.

Answer 20

• 1% of all normal, healthy babies remain jaundices at 3 weeks of age.
• BUT - it may indicate serious disease.
• Prolonged jaundice beyond 2 weeks of age may indicate serious disease and requires investigation.
• Babies with persistent jaundice at 3 weeks of age and beyond must be referred urgently for investigation.
  
  • Therefore, all babies with jaundice after this age must be investigated whatever the absolute level of bilirubin.

Question 21

What is the most important distinction to make in a neonate with prolonged jaundice which requires investigation?

Answer 21

The most important distinction to make is if the jaundice is unconjugated - (extension of physiological jaundice) or conjugated (due to obstructive liver disease) - with abnormal LFTs.

Question 22

What are the differentials for unconjugated prolonged jaundice in the neonate?

Answer 22

• If jaundice is unconjugated, so long as haemolysis, hypothyroidism and urine infection are excluded, the cause is breast milk jaundice.
• This is harmless and reuires no further action.

Question 23

Describe conjugated hyperbilirubinaemia.

Answer 23

• Results from the failure of clearance from the body of the bilirubin which has ben already combined with glucuronic acid to form the soluble glucoronide.
• This generally implies an obstruction of large or small branches of the biliary tree.
• The problem is not so much the conjugated bilirubin, which is non-toxic, but the pathological underlying cause.
• Biliary atresia is the commonest (1:10000) treatable cause of neonatal cholestasis and the prognosis is best if diagnosed early.

Question 24

How is neonatal jaundice generally managed?

Answer 24

• Check maternal hx - FHx of spherocytosis; raised maternal blood group antibodies; marked bruising of infant at delivery.
• Examine baby looking for evidence of dehydration, infection and liver disease.
• Considering measuring bilirubin level.

Question 25

How is neonatal jaundice measured?

Answer 25

• Jaundice can be determined visually (by inspection by blanching the skin in a well-lit room), transcutaneously (by ictometer), and by venous assay.

Question 26

What is Kramer’s rule?

Answer 26

• This describes the cephalocaudal progression of jaundice in term.
• This is useful in deciding whether or not a baby needs to have the SBR measured.
• Kramer divided the infant into 5 zones, the SBR range associated with progression to the zones is as follows:

Question 27

How does phototherapy treat neonatal jaundice?

Answer 27

• Phototherapy causes photoisomerisation of bilirubin into a water-soluble form which can be excreted by the kidney.
• It effectively decreases th SBR in jaundiced newborn infants and decreases the need for exchange blood transfusion.

Question 28

Describe breastmilk jaundice.

Answer 28

• This occurs infrequently, peaks in the 2nd/3rd week, and may persist at moderately high levels for 3-4 weeks before declining slowly.
• It is a diagnosis of exclusion.
• In an otherwise well infant, it is considered a benign condition.
• If feeding with breast milk is stopped, the serum bilirubin usually falls, however this would very rarely be indicated.

Question 29

What is a normal (physiological) amount of crying for a young infant?

Answer 29

The average baby of 6-8 weeks cries / fusses for up to 3 out of 24 hours.

Question 30

What is colic?

Answer 30

• Excessive crying (colic) is defined as >3 hours / day for >3 days / week.
  
  • However, many babies are presented with lesser amounts of crying, as parents perceive it as excessive.
• Infants with ‘colic’ are well and thriving.
• There is usually no identifiable medical problem.
• Parents are often distressed, exhaused and confused, having received conflicting advice from various health professionals and lay sources.

Question 31

Describe the features of infant colic.

Answer 31

• Crying develops in the early weeks of life and peaks around 6-8 weeks of age.
• Usually worse in late afternoon or evening.
• May last several hours.
• The infant may draw up legs as if in pain, but there is no evidence that colic is attributable to an intestinal problem or wind.
• Usually improves by 3-4 months of age.
• A thorough hx and examination must be conducted to exclude any significant illness.

Question 32

What are the diagnoses to consider in crying babies / infant distress?

Answer 32

• Reflux oesophagitis
• Cow’s milk protein or lactose intolerance
• Urinary tract infection
• Otitis media
• Raised ICP
• More acute onset of irritability and crying should not be diagnosed as colic.
• ​A specific cause is usually present:
  
  • Intercurrent illness
  • Corneal foreign body / abrasion
  • Incarcerated inguinal hernia

Question 33

What maternal problem could present with crying baby / infant distress?

Answer 33

• Maternal post-natal depression may be a factor in presentation.
• Postnatal depression responds well to supportive counselling procedures with rapid and substantial improvement in maternal mood as well as benefits in terms of maternal experiences of infant problems.

Question 34

What investigations should be carried out into infant colic?

Answer 34

If the history is typical and examination is negative, no investigations are required.

Question 35

Describe the management of infant colic.

Answer 35

• The parents require careful explanation and reassurance that their infant is not unwell or in pain, and that the unsettled behaviour will improve with time.
• At the same time they need empathetic acknowledgement of their anxiety and stress, and ongoing support from within and outside the family.
• Hypoallergenic formula milk (casein hydrolysate) had a clear beneficial effect on infantile colic.
• Conclusion: infantile colic should preferably be treated by advising carers to reduce stimulation and with a 1 week trial of a hypoallergenic formula milk.
• Consider admission to hospital if child is considered at risk of non-accidental injury or parental exhaustion.

Question 36

Describe vomiting in the newborn.

Answer 36

• Infants may vomit mucus, occasionally blood-streaked, in the first few hours after birth.
• This vomiting rarely persists after the first few feedings; it may be due to irritation of the gastric mucosa by material swallowed during delivery.
• In the majority of instances, it is simply regurgitation from overfeeding or from failure to permit the infant to eructate swallowed air.
• When vomiting occurs shortly after birth and is persistent, the possibilities of intestinal obstruction and increased ICP must be considered.
• A hx of maternal polyhydramnios suggests upper GI (oesophageal, duodenal, ileal) atresia.
• Bile-stained emesis suggests intestinal obstruction beyond the duodenum and requires investigation.

Question 37

How is duodenal atresia diagnosed?

Answer 37

• Upright abdominal film showing the characteristic ‘double-bubble’ sign that confirms the diagnosis of duodenal atresia.
• Note the dilated stomach (thin arrow) and dilated proximal duodenum (thick arrow).

Question 38

Who is affected by hypertrophic pyloric stenosis (HPS)?

Answer 38

• HPS affects 3/1000 babies born.
• It is more likely to affect full-term, first-born male infants and affects female infants less frequently.
• HPS is more common in Caucasians.
• ~15% have FHx.

Question 39

Describe the treatment for hypertrophic pyloric stenosis.

Answer 39

• The vomiting of pyloric stenosis may begin any time after birth, but does not assume its characteristic pattern before 2nd-3rd week.
• The treatment is pyloromyotomy.

Question 40

Describe normal gut rotation.

Answer 40

• In the normal embryo, physiologic herniation of the gut through the umbilicus at 6 weeks is accompanied by a 270° counterclockwise rotation of the developing intestine around the SMA.
• By 10-12 weeks, the intestine returns to the abdomen and assumes its normal adult anatomical position.
• Normal small bowel mesentery has a broad attachment stretching diagonally from the duodenojejunal junction (in the left upper quadrant) to the caecum (in the right lower quadrant).

Question 41

Describe the ways in which malrotation can result in intestinal obstruction.

Answer 41

• Malrotation can cause intestinal obstruction in 3 possible ways:

1. Obstruction of the duodenum may result from congenital peritoneal bands (Ladds bands) which run over the duodenum from the caecum in the right upper quadrant.
2. A midgut volvulus.
3. Internal hernia in the mesentry.

Question 42

What are the non-obstructive causes of neonatal vomiting?

Answer 42

• Milk allergy
• Adrenal hyperplasia of the salt-losing variety
• Galactosaemia
• Hyperammonaemias
• Organic acidaemias
• Increased ICP
• Septicaemia
• Meningitis
• UTIs