Common problems in prematurity Flashcards
(113 cards)
1
Q
How can the gestational age on an infant be determined in not known from ultrasound scanning?
A
based on appearance and neurological findings : Ballard score (6 points for physical, 6 points for neuromuscular signs of maturity)
2
Q
What are 12 things accounted for by the Ballard score to determine gestational age?
A
- Birthweight
- Skin - thickness, colour
- Ears: pinna, recoil
- Breast tissue
- Genitalia
- Breathing
- Sucking and swallowing
- Feeding
- Cry
- Vision, interaction
- Hearing
- Posture - extended (premature) vs flexed
3
Q
After what age of prematurity is the prognosis now excellent due to modern neonatal care?
A
excellent prognosis after 30 weeks’
4
Q
What are 2 examples of parental involvement in neonatal care for preterm infants?
A
- Skin-to-skin contact between infant and parent (Kangaroo care) to promote bonding
- Mother giving baby expressed milk (in syringe) via nasogastric tube, allowing close eye and skin contact between mother and baby
5
Q
What are 16 medical problems of preterm infants?
A
- Need for resuscitation and stabilisation at birth
- Respiratory: RDS, pneumothorax, apnoea and bradycardia
- Hypotension
- PDA
- Temperature control
- Metabolic: hypoglycaemia, hypocalcaemia, osteopenia of prematurity
- Nutrition
- Infection
- Jaundice
- IVH/PVL
- Necrotising enterocolitis
- Retinopathy of prematurity
- Anaemia of prematurity
- Iatrogenic
- Bronchopulmonary dysplasia (BPD)
- Inguinal hernias
6
Q
What are 4 respiratory problems of preterm infants?
A
- Respiratory distress syndrome
- Pneumothorax
- Apnoea and bradycardia
- Bronchopulmonary dysplasia (BPD)
7
Q
What are 4 metabolic problems of preterm infants?
A
- Hypoglycaemia
- Hypocalcaemia
- Electrolyte imbalance
- Osteopenia of prematurity
8
Q
What is another name for respiratory distress syndrome?
A
hyaline membrane disease- proteinaceous exudate seen in airways on histology
9
Q
What is respiratory distress syndrome?
A
- deficiency of surfactant, which lowers surface tension
- surfactant deficiency leads to widespread alveolar collapse and inadequate gas exchange
10
Q
What normally produces surfactant and what is it?
A
type II pneumocytes of the alveolar epithelium
mixture of phospholipids and proteins
11
Q
What are 2 reasons why surfactant deficiency can occur in term infants?
A
- Maternal diabetes
- Genetic mutations in surfactant genes (rare)
12
Q
What can be done to help prevent respiratory distress syndrome in preterm delivery is anticipated?
A
glucocorticoids given antenatally to the mother
13
Q
What are 3 problems that antenatal steroids given to the mother help to prevent in the newborn?
A
- RDS
- Bronchopulmonary dysplasia
- Intraventricular haemorrhage (IVH)
14
Q
What are 4 clinical signs of respiratory distress syndrome in the newborn?
A
- Tachypnoea over 60 breaths/minute
- Laboured breathing with chest wall recession (particularly sternal and subcostal indrawing) and nasal flaring
- Expiratory grunting in order to try and create positive airway pressure during expiration and maintain functional residual capacity
- Cyanosis if severe
15
Q
In what time period do the signs of RDS develop in the neonate?
A
within 4 hours of delivery (often at delivery)
16
Q
What is the characteristic chest x-ray appearance of RDS?
A
diffuse granular or ‘ground glass’ appearance of lungs and air bronchogram, where larger airways are outlined
heart border indistinct
17
Q
What are 2 aspects of treatment for RDS?
A
- Raised ambient oxygen
-
Surfactant therapy
- surfactant directly into lungs via tracheal tube or catheter
- Additional respiratory support may be provided non-invasively with CPAP or high-flow nasal cannular therapy, or invasively with mechanical ventilation via tracheal tube
18
Q
What are 2 options for mechanical ventilation?
A
- Intermittent positive pressure ventilation
- High frequency oscillation
19
Q
What are 3 things that invasive mechanical ventilation is adjusted based upon in RDS?
A
- Oxygenation
- Chest wall movements
- Blood gas analyses
20
Q
What is the risk of excess oxygen in the neonate? 2 things
A
hyperoxia can be damaging from excess free radicals, and increased risk of reinopathy of prematurity if sats >95%
21
Q
What are 2 risks of low oxygen saturations to the neonate?
A
- Necrotising enterocolitis
- Death
22
Q
What does oxygen therapy now involve in neonatal resuscitation?
A
start with 21-30% oxygen in preterm infants, avoiding sats over 95%
use air in term infants
23
Q
How can pneumothorax come about in a preterm infant?
A
air from overdistended alveoli may track into the mediastinum, resulting in pulmonary interstitial emphysema
in up to 10% of infants ventilated for RDS, air leaks into the pleural cavity and causes a pnemothorax
24
Q
What are 3 clinical signs of pneumothorax in the preterm infant?
A
- Chest movement reduced on affected side
- Reduced breath sounds on affected side
- Increased oxygen required
25
What is the treatment of tension pneumothorax?
decompression by inserting chest drain
26
How can you try and prevent pneumothorax in the management of the preterm neonate?
ventilate with lowest pressures that provide adequate chest movement and satisfactory blood gases
27
What is the triad of symptoms common in very low birthweight pre-term infants?
apnoea + bradycardia + desaturation
28
How do the symptoms of apnoea + bradycardia + desaturation typically occur in the preterm infant?
infant stops breathing for 20-30 seconds, causing bradycardia
or breathing continues but against closed glottis
29
What are 8 possible underlying causes of the apnoea + bradycardia + desaturation in preterm neonates that need to be excluded?
1. Hypoxia
2. Infection
3. Anaemia
4. Electrolyte disturbance
5. Hypoglycaemia
6. Seizures
7. Heart failure
8. Aspiration due to GORD
30
What is often the cause of apnoea + bradycardia + desaturation in preterm infants?
due to immaturity of central respiratory control
31
What are 3 possible treatments for apnoea + bradycardia + desaturation in preterm infants caused by immaturity of central respiratory control?
1. Gentle physical stimulation - usually with start breathing again
2. Caffeine - respiratory stimulant
3. CPAP or mechanical ventilation if apnoeic episodes are frequent
32
What are the risks of hypothermia in the preterm infant?
causes increased energy consumption, may result in **hypoxia** and **hypoglycaemia**, failure to **gain** **weight** and are an independent risk factor for **mortality** soon after birth
33
What are 4 reasons why preterm infants are particularly vulnerable to hypothermia?
1. Have large surface area relative to their mass, so greater heat loss than heat generation
2. Skin is thin and heat-permeable - transepidermal water loss is important in the 1st week of life
3. Little subcutaneous fat for insulation
4. Often nursed naked and cannot conserve heat by curling up or generate heat by shivering
34
How can the temperatures of preterm babies be maintained? 2 key ways
incubators or initially with overhead radiant heaters
35
What do incubators provide in addition to heat? What is the benfit of this?
ambient **humidity**, which reduces transepidermal heat loss
36
What are the 4 methods of heat transfer that can be utilised to prevent hypothermia in a preterm infant?
1. Convection
2. Radiation
3. Evaporation
4. Conduction
37
What are 3 ways to prevent hypothermia in an infant by convection?
1. Raise temperature of ambient air in incubator
2. Clothe, including covering head
3. Avoid draughts
38
What are 2 ways to prevent hypothermia in an infant by radiation?
1. Cover baby
2. Double walls for incubators
39
What are 2 ways to prevent hypothermia in an infant by evaporation?
1. Dry and wrap at birth, if extremely preterm, place baby's body directly into plastic bag at birth without drying
2. Humidify incubator
40
What is 1 way to prevent hypothermia in an infant by conduction?
nurse on heated mattress
41
What is the common effect of the patent ductus arteriosus in preterm infants?
shunting of blood from left to right is most common
42
What may be the symptoms of PDA in preterm infants? 8 things
1. may be asymptomatic
2. apnoea
3. bradycardia
4. increased oxygen requirement
5. difficulty in weaning from artificial ventilation
6. bounding pulses - due to increased pulse pressure
7. prominent precordial impulse
8. systolic murmur may be audible (machinery)
43
What will happen in preterm infants with PDA as circulatory overload increases?
signs of heart failure may develop
44
How can more accurate assessment of a preterm infant's circulation if they have PDA?
echocardiography
45
When do you treat PDA in preterm infants and how?
if symptomatic
pharmacological closure with **indomethacin** or **ibuprofen**
46
How do indomethacin and ibuprofen work to treat PDA?
they are prostaglandin synthetase inhibitors
47
If indomethacin/ ibuprofen fail to close a symptomatic PDA what is the next treatment?
surgial ligation
48
What are 5 things that determine the fluid requirements of a preterm neonate?
1. Gestational and chronological age
2. Clinical condition
3. Plasma electrolytes
4. Urine output
5. Weight change
49
What amount of feed is uually required on the first day of life and by the fifth day of life?
1. 60-90ml/kg in first day
2. By fifth day, 150-180 ml/kg
50
Why do preterm infants have a high nutritional requirement?
rapid growth: infants born at 28 weeks gestation double birthweight in 6 weeks and treble in 12 weeks
(term babies double weight only in 4.5 months and treble it in a year)
51
At what gestation of birth are infants mature enough to suck and swallow milk?
those born from 35-36 weeks' gestation
52
What will preterm infants born before 35-36 weeks require to feed?
orogastric or nsogastric tube, with enteral feeds introduced as soon as possible (preferably breast milk)
53
In those preter infants receiving breastmilk, what needs to supplement the breast milk? 4 things
* phosphate
* protein and calories (in breast milk fortifier)
* calcium
54
What is sometimes done if the mother's breast milk is not available to feed extremely preterm neonates?
**donor breast milk** fed to neonate in some neonatal units
55
What formula feeds are given to preterm infants if formula feeding is required?
special infant formulas designed to meet increased nutritional requirements of preterm infants
56
What is a disadvantage of giving formula milk rather than breast milk to preterm infants?
formula milks don't provide protection against infection or other benefits of breast milk
57
When is parenteral nutrition often required for preterm infants?
very immature or sick infant (typically \<1kg birthweight)
58
How is parenteral nutrition given to preterm infants if needed? 2 options
**peripherally inserted central line** (PIC or long line), or an **umbilical venous catheter**, paying strict attention to **aseptic** technique both during insertion and when lines are accessed
59
What are 2 key risks of central lines meaning parentreal nutrition may be given via a peripheral vein?
Sepsis and thrombosis of a major vein
60
What is a risk of parenteral feeding via a peripheral vein, which is sometimes employed?
extravasation may cause skin damage wtih scarring
61
What is a risk of cow's milk based formula milk for preterm infants?
increased risk of necrotising enterocolitis
62
What now means that osteopenia of prematurity is rare?
provision of adequae phosphate, calcium and vitamin D
63
Why are preterm babies at risk of iron-deficiency anaemia?
iron is mostly transferred to the fetus during the last trimester, so if preterm they have low iron stores
also due to los of blood from sampling and inadequate erythropoietin response
64
What is done to prevent iron deficiency in preterm neonates?
iron supplements, started at several weeks of age and continued after discharge home
65
Why are preterm infants at an increased risk of infection? 2 reasons
1. **IgG is** mostly transferred across the placenta in the **last** **trimester** and no IgA or IgM is transferred
2. **Infection in or around cervix** often a reason for preterm labour and may cause infections shortly after birth
66
What is the most abundant immunoglobulin in human breast milk?
IgA (IgG and IgM also present but in lower concentrations)
67
When do most infections in preterm infants occur?
after **several days of age**
68
Where are most infections in preterm infants derived from?
most are nosocomial - often from indwelling catheters or mechanical ventilation
69
At what age is necrotising enterocolitis typically seen in preterm infants?
first few weeks of life
70
What are 3 key risk factors for necrotising enterocolitis?
1. Ischaemic injury
2. Bacterial invasion
3. Being fed with cow's milk formula rather than only breast milk
71
What is a method for reducing the risk of necrotising enterocolitis?
supplementing milk feeds with prebiotics and probiotics
72
What are 6 features of the presentation of necrotising enterocolitis?
1. Feed intolerance
2. Vomiting - may be bile-stained
3. Abdominal distension
4. Fresh blood in stool
5. Shock
6. Requirement for mechanical ventilation - due to abdo distension and pain
73
What are 4 characteristic features of necrotising enterocolitis on x-ray?
* distended loops of bowel
* thickening of bowel wall with intramural gas
* gas in portal venous tract
* bowel perforation
74
What imaging may be most useful to diagnostic necrotising enterocolitis?
abdominal x-ray
75
What are 2 methods to identify bowel perforation caused by necrotising enterocolitis?
1. Abdominal x-ray
2. Transillumination of abdomen
76
What is the treatment for necrotising enterocolitis?
* stop oral feeding and give **broad-spectrum antibiotics** to cover both aerobic and anaerobic organisms
* **parenteral nutrition** always needed, mechanical ventilation and circulatory support are often required
* **surgery** for bowel perforation
77
What is the mortality associated with necrotising enterocolitis?
20%
78
What are 3 long-term risks of necrotising enterocolitis?
1. Development of strictures
2. Malabsorption - if extensive resection
3. Poor neurodevelopmental outcome
79
What proportion of very low birthweight infants have brain haemorrhages?
20%
80
How can brain haemorrhages be detected in preterm infants?
cranial ultrasound scans
81
Where do brain haemorrhages most typically occur in preterm infants?
in the **germinal matrix** above the **caudate nucleus** - contains fragile network of blood vessels
82
When following birth do most intraventricular haemorrhages occur?
within first 72 hours of life
83
What are 3 situations when intraventricular haemorrhages in preterm infants are more common?
1. Following perinatal asphyxia
2. Severe RDS
3. Pneumothorax
84
What is the difference between small and large brain haemorrhages in preterm infants in terms of the location?
small haemorrhages confined to germinal matrix, but larger haemorrhage extends into the ventricles
85
What is the most severe type of brain haemorrhage in preterm infants and what can it lead to?
unilateral _haemorrhagic infarction_ involving the **parenchyma** of the brain
usually results in **hemiplegia**
86
What can be a sequela of large intraventricular haemorhage (IVH)?
* may impair drainage and reabsorption of cerebrospinal fluid (CDF) allowing CSF to build-up under pressure
* this dilatation may resolve spontaneously or progress to **hydrocephalus**
87
What can occur due to hydrocephalus secondary to intraventricular haemorrhage?
can cause cranial sutures to separate, head circumference to increase rapidly and anterior fontanelle to become tense
88
What are 2 aspects of the management of hydrocephalus secondary to IVH?
1. Initially: removal of CSF by **lumbar** **puncture** or **ventricular** **tap** (symptomatic relief)
2. **Ventriculoperitoneal** **shunt** may be required
89
What disease to about half of infants with progressive post-haemorrhagic ventricular dilatation go on to develop?
cerebral palsy
90
What factor increases the risk of cerebral palsy following IVH?
parenchymal infarction
91
What can happen to the brain tissue itself following ischaemia or inflammation even int he absence of haemorrhage?
periventricular white matter brain injury
92
How might periventricular white matter brain injury be diagnosed?
1. may be an **echo-dense area** or '**flare**' initially within the brain parenchyma on ultrasound
2. this may resolve within a week, or **cystic** **lesions** may become visible on ultrasound 2-4 weeks later, indicating definite loss of white matter
93
What is periventricular leukomalacia?
bilateral multiple cysts following periventricular white matter brain injury
94
What is the risk of periventricular leukomalacia and what proportion does this affect?
spastic diplegia, often with cognitive impairment - 80-90% risk if posteriorly sited
95
Why can IVH and periventricular leukomalacia both go undetected? 2 reasons
1. as they can occur in the absence of abnormal clinical signs
2. third of premature infants \<32 weeks' gestation who go on to have cerebral palsy have normal cranial ultrasound
96
What is retinopathy of prematurity?
* vascular proliferation at the junction of vascularised and non-vascularised retina
* may progress to retinal detachment, fibrosis and blindness
97
What are 3 possible adverse outcomes from the vacsular proliferation in the retina in retinopathy of prematurity?
1. Retinal detachment
2. Fibrosis
3. Blindness
98
What iatrogenic intervention can increase the risk of retinopathy of prematurity?
uncontrolled use of high concentrations of oxygen
99
What are 2 groups of susceptible infants to retinopathy of prematurity?
1. Low birthweight \<1500g
2. \<32 weeks' gestation
100
What intervention is performed for all infants at risk of retinopathy of prematurity?
screening by an ophthalmologist
101
What therapy can be given in retinopathy of prematurity and what does it achieve?
laser therapy - reduces visual impairment
(intravitreal anti-VEGF being investigated)
102
In what proportion of very low birthweight infants does severe bilateral visual impairment occur?
1% (mostly infants \<28 weeks' gestation)
103
What are infants still requiring oxygen requirement at postmenstrual age of 36 weeks described as having?
bronchopulmonary dysplasia (previously called chronic lung disease, CLD)
104
What is thought to be the cause of bronchopulmonary dysplasia (previously chronic lung disease)?
from delay in lung maturation, but may also be from pressure and volume trauma from artificial ventilation, oxygen toxicity and infection
105
What is typically seen in a CXR of an infant with bronchopulmonary dysplasia (previously CLD)?
widespread areas of opacification, sometimes with cystic changes
106
What is the management of bronchopulmonary dysplasia? 2 aspects
1. Some infants need prolonged artificial ventilation, but most are weaned onto CPAP or high-flow nasal cannula therapy followed by additional ambient oxygen, sometimes over several months
2. Corticosteroid therapy - may facilitate earlier weaning, reduces oxygen requirements
107
What are thought to be the risks of corticosteroid therapy for a baby with bronchopulmonary dysplasia? What is done as a result?
* concern about increased risk of abnormal neurodevelopment including cereral palsy
* use is limited to short, low-dose courses
108
What is sometimes done for babies who continue to need oxygen and are diagnosed with bronchopulmonary dysplasia?
some may go home while still receiving additional oxygen
109
What are 3 things that can cause death/ need for intensive care that are associated with bronchopulmonary dysplasia?
1. May die of intercurrent **infection**
2. **Pulmonary** **hypertension**
3. **Pertussis and respiratory viral infection** (syncytial or rhinovirus) can cause respiratory failure necessitating intensive care
110
What are 9 aspects of management of preterm infants following discharge (i.e. ongoing care)?
1. Home oxygen for bronchopulmonary dysplasia + respiratory reviews to safely wean
2. RSV prophylaxis in winter (palivizumab)
3. Cardiac monitoring - check for pulmonary hypertension
4. Dietician input - phosphate, iron and vitamins
5. Primary immunisations
6. Monitoring for inguinal hernias - at greater risk
7. Ophthalmology review - to monitor any reinopathy of prematurity, determine if treatment required
8. Low threshold for hospital readmission - usually respiratory problems
9. In addition to healthy child programme, growth and neurodevelopment will be monitored
111
What proportion of very low birthweight infants develop cerebral palsy?
5-10%
112
What is the most common impairment in low birthweight infants?
learning difficulties
113
What are 7 aspects of development that are impaired in very low birthweight infants?
1. Fine motor skills e.g. threading beads
2. Concentration, with short attention span
3. Behaviour problems, epecially attention deficit disorders
4. Abstract reasoning e.g. mathematics
5. Processing several tasks simultaneoulsy
6. Hearing impairment - small proportion
7. Refractive errors and squints - many require glasses (small proportion blind in both eyes)
