Week 5 - E - Preterm Infant - Risk factors, Temp, Sepsis, R.D.S, P.D.A, I.V.H, N.E.C, Retinopathy of Newborn

Question 1

What is a preterm labour? What is a term labour? When is the onset of labour considered post-term and induction should probably be considered?

Answer 1

Preterm labour - labour occurring before 37+0 weeks gestation (37 completed weeks of gestation) A term labour is labour occuring between 37+0 and 40+6 weeks gestation Post term labour is labour that occurs after 42 weeks of completed gestation - so after 41+6 weeks

Question 2

What happens to the placenta after 42 weeks gestation?

Answer 2

After 42 weeks gestation, the placenta starts to age and will eventually fail hence why induction is usually carried out when gestation reaches 42 weeks Aim is to reduce stillbirth rates

Question 3

Over half of deaths in childhood occur during the first year of a child’s life What are two strong influences on these deaths occuring?

Answer 3

Children born prematurely and born with a low birth weight

Question 4

What is the normal birth weight for a term baby?

Answer 4

Normal birth weight for a term baby 2.5kg (5pounds 8 ounces) to 4kg (8 pounds 13 ounces)

Question 5

What are risk factors for a baby being born a low birth weight or being born prematurely?

Answer 5

Maternal age, smoking and disadvantaged circumstances

Question 6

Which babies are most at risk of stillbirths and neonatal deaths?

Answer 6

Babies born to mothers of a black/black British or Asian/Asian British background in the UK Babies born to teenage mothers or mothers aged 40+ Babies born to mothers living in poverty

Question 7

State the causes of preterm births (if you can try rank the causes in order)

Answer 7

Spontaneous preterm labour is the most common cause of preterm birth

Multiple pregnancy

Preterm prelabour rupture of membranes (P-PROM)

Pregnancy associated hypertension

Question 8

There are different risk factors for the causes of pre-term labour Name some risk factors for preterm labour Also state 4 causes again

Answer 8

Risk factors

• Interval of <6 months between pregnancies
• Conceiving via IVF
• Smoking, drinking alcohol and drug abuse during pregnancy
• Poor nutrition or chronic condition - high BP, diabetes

Causes of preterm pregnnacy

Spontaenous pre-term, multiple pregnancy, PPROM, pregnancy induced hypertension

Question 9

The smaller and earlier in gestation the baby the quicker they get cold, the more fragile the lungs, the less good they are at breathing, the fewer reserves they may have and the more likely you are to find a pulse oximeter useful. What can be carried out immediately after the birth of a pre-term baby to ensure the baby is kept warm?

Answer 9

It is important to immediately keep the baby warm Using a suitable plastic bag and radiant heater is a good way to do this in a pre-term baby

Question 10

Common problems due to prematurity include: Hypothermia Hypoglycaemia Sepsis Also the foetal system is immature (respiratory, GI, cardiac) What system immaturity problems may present in a premature baby? Which of these problems is the major cause of death from prematurity?

Answer 10

Respiratory distress syndrome - the major cause of death from prematurity Patent ductus arteriosus Intraventricular haemorrhage Necrotizing enterocolitis

Question 11

What causes respiratory distress syndrome in a premature baby?

Answer 11

RDS is the major causes of death from prematurity It is due to a deficient alveolar surfactant production which is mainly confined to premature babies - insufficient surfactant leas to alveolar collapse and the baby becomes exhausted re-inflating the alveoli with each breath and respiratory failure follows

Question 12

What should be offered to all women at risk of pre-mature delivery from 23-35 weeks?

Answer 12

Betamethasone (2 doses) or dexamethasone (4 doses) IM should be offered to all mothers at risk of premature delivery from 23-35 weeks gestation - this is because it helps with foetal surfactant production and therefore reduces the risk of mortality from respiratory distress syndrome

Question 13

What are the two main risk factors for necrotizing enterocolitis?

Answer 13

The two main risk factors for necrotizing enterocolitis are prematurity and formula fed babies

Question 14

How does prematurity increase the chances of necrotizing enterocolitis?

Answer 14

The premature infant has immature lungs and immature intestines. Therefore, any decrease in oxygen delivery to the intestines, because the lungs cannot oxygenate the blood adequately, will damage the lining of the intestinal wall. This damage to the bowel wall will allow bacteria that normally live inside the intestine to invade the wall of the intestine and cause local infection and inflammation (NEC) that can eventually lead to rupture or perforation of the intestine.

Question 15

How does prematurity relate to intraventicular haemorrhage?

Answer 15

Prematurity relates to intraventricular haemorrhage because preterm infants already have unsupported blood vessels in the brain - therefore the instability of blood pressure with birth trauma and respiratory distress increases the likelihood of a rupture (haemorrhage)

Question 16

What neonates is intraventricular haemorrhage suspected in? What complications can arise from intraventricular haemorrhage?

Answer 16

Suspect in neonates who have rapidly deteriorating health in the 1st week after birth Complications - decreased IQ, cerebral palsy nd hydrocephalus

Question 17

Why can intraventricular haemorrhag lead to hydrocephalus?

Answer 17

If the haemorrhage continues to leed, this can compress the ventrciles and obstruct the flow of CSF leading to a build up of CSF - hydrocephaly - Hydrocephalus is a condition characterized by excessive accumulation of fluid in the brain

Question 18

Common problems of prematurity Temperature control Feeding/nutrition Sepsis System immaturity / dysfunction * respiratory distress syndrome- RDS * patent ductus arteriosus- PDA * intraventricular haemorrhage- IVH * nectrotising enterocolitis- NEC Why is thermal regulation ineffective in preterms?

Answer 18

Low BMR - basal metabolic rate Insufficient fat accumulation (brown fat accumulates in late third trimester of pregnancy) High ratio of surface area to body mass - easy to lose heat

Question 19

What are the 4 ways in which heat is lost in the baby? What are the two main ways?

Answer 19

Radiation and convection are the two main ways in which heat is lost

• Radiation - surrounding environment is colder
• Convection - wind blows heat of the baby
• Conduction - baby is placed on a colder surface
• Evaporation - the liquid on the baby evaporates - liquid becoming gas

Question 20

Wrapping the baby in a suitable plastic bag with a radiant heater has already been discussed for keeping a pre-term baby warm WHat are other methods for preventing hypothermia? What temperature is aimed for?

Answer 20

Skin to skin care - mother is very warm from the delivery and therefore perfect for maintaining baby temperature Prewarmed incubator Transwarmer mattress Aim for temp - 36.6 to 37.2 degrees

Question 21

Hypothermia increases severity of all preterm morbidities How can it lead to hypoglycaemia? (already a risk in preterms)

Answer 21

Hypothermia causes increased metabolism which means increased use of the foetal glucose - increased use of foetal glycogen stores therefore and eventually the glyocgen stores will become depleted leading to hypoglycaemia

Question 22

There is an increased risk of nutritional compromise in the premature infant They have limited nutritional reserves, gut immaturity and limited metabolic pathways What amount of weight is normal for an infant to lose in the few days following birth?

Answer 22

Normal for the infant to lose up to 10% of their birth weight in the days following delivery

Question 23

Neonatal sepsis can occur as Early Onset Sepsis (EOS) whee the sepsis is mainly due to bacteria acquired before and during delivery and Late Onset Sepsis (LOS) where the sepsis is mainly due to bacteria acquired after delivery (nosocomial or community acquired) What organisms usually cause EOS? What does nosocomial mean?

Answer 23

EOS - usually caused by Group B strep or gram negative organisms Nosocomial - (of a disease) originating in hospital

Question 24

What is the name of the bacteria that is also known as GroupB strep? Which gram negative is known as be a cause of neonatal meningitis?

Answer 24

Bacteria that is also known as Group B strep - streptococcus agalactiae E.coli is a rare causative agent of neonatal meningitis

Question 25

What organsisms are associated with late onset sepsis?

Answer 25

Coagulase negative staphylococci Gram negative organisms Staph Aureus

Question 26

Name two coagulase negative staphylococci?

Answer 26

Staph epidermis - skin commensal Staph saprophyticus - part of the normal vaginal flora

Question 27

What test is used to differentiate between staph coagulase negative staph organsisms? What colour are coagulase negative and positive staph on an agar plate?

Answer 27

Novbiocin resistance is used to differentiate between staph negative organisms Staph saprophyticus - novobiocin resistant Coagulase positive staph (staph aureus) - shows up golden on agar plate for coagulation test Coagulase negative staph - shows up white on agar plate

Question 28

Quick Note - INcubators INcrease INfection Why do incubators increase infection?

Answer 28

There are cold spots in incubators which are hot spots for microbial contamination shown to grow staphylococci which are the main cause of late onset sepsis in the neonate

Question 29

What is the treatment to a child with suspected sepsis of an unknown origin?

Answer 29

IV amox, gent and metronidazole Follow meningitis protocols if this is suspected instead

Question 30

WHat is given if a line infection is suspected?

Answer 30

Vancomycin is given (add gentamicin if gram-negative organisms are suspected in the child)

Question 31

What are the clinical features of respiratory distress syndrome?

Answer 31

Tachpnoea - greater than 60/min Gryunting Nasal flaring Intercostal recessions Cyanosis

Question 32

What causes RDS and how is it treated?

Answer 32

It is caused by a deficiency of alveolar surfactant production due to the baby being premature - this insufficiency leads to alveolar collapse and the infant is exhausted by having to re-inflate the alveoli with each breath This can lead to respiratory failure Treatment Maternal betamethasone - can be given from 24+0 and 34 +6 weeks Giving surfactant and usually ventilation

Question 33

What causes intraventricular haemorrhage?

Answer 33

This is caused by preterm infants having unsupported blood vessels in the brain and therefore with the instability of blood pressure at birth and the birth trauma and respiratory distress - this can cause the blood vessels to burst

Question 34

Where about in the brain do the unsupported blood vessels lie?

Answer 34

The unsupported blood vessels that burst in IVH lie in the subependymal germinal matrix

Question 35

There are four types of IVH. These are called “grades” and are based on the degree of bleeding.

• * grade I - hemorrhage confined to germinal matrix
• * grade II - IVH without ventricular dilatation
• * grade III - IVH with ventricular dilatation
• * grade IV - intraventricular rupture and hemorrhage into the surrounding white matter

What is the neurodevelopmental delay and mortality associated with grades 1&2 intraventricular haemorrhage?

Answer 35

Grades 1 and 2 - Neurodevelopmental delay - up to 20%

Mortality - up to 10%

Question 36

What is the neurodevelopmental delay and mortality associated with grades 3&4 intraventricular haemorrhage?

Answer 36

Grade 1 and 2 : * Neurodevelopmental delay up to 20% * Mortality 10% Grade 3 and 4: * Neurodevelopmental delay up to 80% * Mortality 50

Question 37

What are the complications of intraventricular haemorrhage again?

Answer 37

Decreased IQ Cerebral palsy Hydrocephalus Also there is the associated neurodevelopmental delay and mortality

Question 38

What are the signs seen on an xray in nectrozing enterocolitis?

Answer 38

Pneumoatosis intestinalis - air in the gut wall seen on xray Also Rigler’s sign

Question 39

Retinopathy of prematurity is a problem associated with prematurity in infants When does it usually occur? When is screening for this recommended?

Answer 39

This is rare and will usually occur 6-8 weeks after delivery Screening is recommended in infants born <32 weeks gestation

Question 40

What happens in retinopathy of prematuity?

Answer 40

Retinopathy of prematurity (ROP) is an eye disease that can happen in premature babies. It causes abnormal blood vessels to grow in the retina, and can lead to blindness.