Preterm Neonate

Question 1

The preterm infant

Answer 1

Born before 37 completed weeks of gestation- limits of viability at 22-24 weeks

Accounts for
5-9% of all births

85% of perinatal morbidity and mortality

Question 2

Prematurity by gestational age

Answer 2

Term neonate - 37-41/40
Near-term - 34-36/40
Moderate premature - 32-33/40
Sever premature- 28-31/40
Extremely premature - <28/40?

Question 3

Prematurity by weight

Answer 3

Low birth weight
<2500g 2.5kg

Very low
<1500g 1.5kg

Extremely low

<1000g or 1.0kg

Incredibly low

<750g or 0.75kg

Question 4

Causes of prematurity

Answer 4

Abruption, where the placenta separates from the uterus during pregnancy

Incompetent cervix, where the cervix painlessly and gradually opens before the time isis supposed to

Infection - chorioamnionitis

Question 5

The well preterm infant

Answer 5

Sleeps between care

Peaceful at rest

Responsive during care

Can be active and resistant

Has a warm skin and warm extremities

Mucous membranes are pink and moist

Cardiopulmonary parameters normal

Urine output 0.5 - 1ml / kg / hour

Question 6

The well preterm infant

Answer 6

Needs monitoring of breathing

Needs monitoring of core and peripheral temperature

May needs tube feeding / support

Risk of jaundice

Risk of infection

Risk of hypotension

Question 7

The well preterm infant

Answer 7

Getting the neonatal energy triangle right is key to having a well preterm infant

Maintaining adequate oxygenation

Thermoregulation

Metabolic stability (glucose levels)

Question 8

The sick preterm infant

Answer 8

Signs and symptoms

Recurrent bradycardia with episodes of apnoea

Hypothermia

Hypoglycaemic

Hyperglycaemia with extreme stress

Question 9

The sick preterm

Answer 9

Can be floppy, quiet and inactive

Shows signs of distress

Arterial blood gases abnormal

Tachycardia

Tachypnoea

Hypotension

Oliguria

Question 10

Lungs

Answer 10

Very premature at highest risk for respiratory distress syndrome

Recurrent apnoea - methylxanthenes

Support

Supplementary oxygen- avoid 100% oxygen due to retinopathy of prematurity

Nasal continous positive airways pressure or CPAP

Intubation and mechanical ventilation

Question 11

Respiratory distress syndrome

Answer 11

Lack of surface and structural immaturity of the lungs

Collapsed airspace’s

Hyper expanded air spaces

Pulmonary hypertension and shunting - blood passing through lungs with being oxygenated and or releasing carbon dioxide

Chronic hypoxia and hypercapnia

Question 12

Surfactant

Answer 12

Brakes down surface tension between water molecules and allows the water to spread out

Allows easier expansion of the alveoli during inspiration and prevents alveolar surfaces from sticking together and collapsing after expiration

Premature Babies start to produce surfactant from 26- 28 weeks, but it is not until 35 weeks that they have a normal amount of surfactant

Question 13

Hypothermia

Answer 13

Thermal stress

All premature babies at risk

Very premature most at risk

Thermal stress includes both too hot and too cold

A thermoneutral environment is critical

Core should be maintained at 36.5 -37.7

Question 14

Hypothermia

Answer 14

Premature babies are prone to low body temperature physiologically as they

Have low brown fat stores

Have thin body shell

Have limited ability to vasoconstriction

Loose heat readily if wet

Question 15

Hypothermia

Answer 15

The biological effects of hyperthermia increases

respiratory distress due to decreased surfactant efficiency

Oxygen consumption

Utilisation of calorie Reserves and so cause hypoglycaemia

Postnatal weight loss

Question 16

Hypoglycaemia

Answer 16

In term babies

Body fat deposition almost doubles after 34 weeks reaching 15% total body weight at term

Glycogen stores increase significantly from 31 weeks through to term

At birth glycogen and fat reserves are used until feeding is established

Question 17

CNS in premature infants

Answer 17

Inadequate suck/swallow reflex <34/40

Immature autonomic regulation resulting in apnoeic spells and bradycardia

High risk of intraventircular haemorrhage (IVH)

Increased risk of developmental problems such as learning difficulties, speech and language delay, and autism

Question 18

Intraventricular haemorrhage

Answer 18

Risk factors for intraventricular haemorrhage

The smaller the baby
The more premature the baby
Respiratory distress syndrome 
Unstable or swinging blood pressure
Other medical conditions 

IVH occurs
As a result of immature and fragile blood vessels

Most often in the first few days of life and is rare after the first month of age

Question 19

Intraventricular haemorrhage

Answer 19

Grade 1 and 2 haemorrhage is likely to resolve without any long term effects

Grade 3 and 4 haemorrhage has higher risk of resulting in white matter loss called ‘preiventricular leukomalacia (pVL)

With PVL the child is likely to go onto develop cerebral palsy

Increased risk of hydrocephalus

Question 20

Eyes

Answer 20

High levels of tissue oxygenation results in abnormal retinal vessel growth which is called retinopathy of prematurity (ROP

ROP can lead to retinal detachment and blindness

ROP is also associated with increased incidence of myopia and strabismus

Question 21

GI tract

Answer 21

Infants <34/40 have inadequate coordination of sucking and swallowing reflexes - tube fed

Gastro - oesophageal reflux is very common

Risk of aspiration

Question 22

Infection

Answer 22

Often infection is the cause of premature delivery

Sepsis or meningitis’s if four time more likely in premature babies

Low threshold for taking blood cultures and starting antibodies- needed to combat gram negative and gram positive bacteria

Necrotising enterocolitis (NEC) can lead to general sepsis and death very rapidly

Question 23

Necrotising enterocolitis (NEC)

Answer 23

Disease of the GI tract in premature inflamts

Inflammation of IG tract wall , and bacterial invasion / infection

Feeding is instigated slowly and carefully monitored

If NEC suspected stops enteral feeds and starts antibiotics

If no improvement with medical treatment the. The child may need surgery and be left with a short bowel

Question 24

Kidneys

Answer 24

Limited renal function

Biological basis of this is the glomeruli and nephrons are immature at birth

Physiological effects
Concentrating and diluting limits of urine are decreased
Glycosuria and amino acid Uris are commonly detected

Extreme care with fluid balance, glucose and electrolytes is required

Question 25

Summary

Answer 25

Premature babies are at risk of many problems that affect all body systems

Need to be nurses in a specialist units

Getting things wrong can result in life long problems

Families will need information and support, possibly for a long time to come