Neonatology: Physiology; Resuscitation Flashcards
A baby presents with MAS and PPHN. What is the next appropriate investigation and why? [2]
Echocardiography:
- This investigation is indicated if there are signs suggestive of persistent pulmonary hypertension of the newborn (PPHN), which can coexist with MAS. Echocardiography evaluates pulmonary artery pressures, cardiac function, and excludes congenital heart disease.
Describe the management plan for a baby with MAS [+] and PPHN [1]
Initial stabilisation:
* Avoid routine intrapartum suctioning.
* If the neonate is vigorous (strong respiratory effort, good muscle tone, heart rate >100 bpm), proceed with standard neonatal care.
* If the neonate is not vigorous: perform direct laryngoscopy and tracheal suctioning to remove meconium from the airway before initiating positive pressure ventilation (PPV).
Respiratory support:
* Administer supplemental oxygen to maintain target oxygen saturation levels as per neonatal resuscitation guidelines.
* Initiate continuous positive airway pressure (CPAP) or mechanical ventilation if indicated by respiratory distress or hypoxaemia.
Surfactant therapy:
* Consider administration of exogenous surfactant in cases of severe respiratory distress or when mechanical ventilation is required.
Antibiotic therapy:
* Initiate empirical antibiotic therapy due to the risk of secondary bacterial infection. Adjust based on culture results and clinical course
Management of persistent pulmonary hypertension (PPHN):
* Employ inhaled nitric oxide (iNO) for infants with significant PPHN unresponsive to conventional ventilation and oxygen therapy.
* If iNO is unavailable or ineffective, consider extracorporeal membrane oxygenation (ECMO) as a last resort in specialised centres.
AVOID routine use of corticosteroids unless there are specific indications such as concurrent conditions requiring their use.
Describe the cardiac changes / process that happens directly at birth [4]
After first breath:
- decrease in pulmonary vascular resistance causes fall in pressure in right atrium
At this point:
- the left atrial pressure is greater than the right atrial pressure, which squashes the atrial septum and causes functional closure of the foramen ovale. The foramen ovale then structurally closes and becomes the fossa ovalis.
Prostaglandins are required to keep the ductus arteriosus open.:
- Increased blood oxygenation causes a drop in circulating prostaglandins. This causes closure of the ductus arteriosus, which becomes the ligamentum arteriosum.
Describe the respiratory changes / process that happens directly at birth [4]
During birth the thorax is squeezed as the body passes through the vagina, helping to clear fluid from the lungs
Birth, temperature change, sound and physical touch stimulate the baby to promote the first breath.
- A strong first breath is required to expand the previously collapsed alveoli for the first time
Adrenalin and cortisol are released in response to the stress of labour, stimulating respiratory effort
The first breaths the baby takes expands the alveoli, decreasing the pulmonary vascular resistance. The decrease in pulmonary vascular resistance causes a fall in pressure in the right atrium
What happens to the ductus venosus after birth? [1]
Immediately after birth the ductus venosus stops functioning because the umbilical cord is clamped and there is no blood flow in the umbilical veins. The ductus venosus structurally closes a few days later and becomes the ligamentum venosum.
Why does normal labour and birth lead to hypoxia? [1]
What is the clinical consequence of this? [3]
When contractions happen, the placenta is unable to carry out normal gaseous exchange, leading to hypoxia.
- Extended hypoxia will lead to anaerobic respiration and a subsequent drop in the fetal heart rate (bradycardia).
- Further hypoxia will lead to reduced consciousness and a drop in respiratory effort, in turn worsening hypoxia.
- Extended hypoxia to the brain leads to hypoxic-ischaemic encephalopathy (HIE), with potentially life-long consequences in the form of cerebral palsy.
What are three key issues that with regards to babies that can contribute to neonatal resuscitations
- Babies have a large surface area to weight ratio, and get cold very easily
- Babies are born wet, so they lose heat rapidly
- Babies that are born through meconium may have this in their mouth or airway
Describe in detail the principles of neonatal resusciation [2]
Warm The Baby:
- Get the baby dry as quickly as possible. Vigorous drying also helps stimulate breathing.
- Keep the baby warm with warm delivery rooms and management under a heat lamp
- Babies under 28 weeks are placed in a plastic bag while still wet and managed under a heat lamp
Calculate the APGAR Score
This is done at 1, 5 and 10 minutes whilst resuscitation continues
This is used as an indicator of the progress over the first minutes after birth
* It helps guide neonatal resuscitation efforts
Stimulate Breathing
* Simulate the baby to prompt breathing, for example by drying vigorously with a towel
* Place the baby’s head in a neutral position to keep airway open. A towel under the shoulders can help keep it neutral.
* If gasping or unable to breath, check for airway obstruction (i.e. meconium) and consider aspiration under direct visualisation
Inflation Breaths
- given when the neonate is gasping or not breathing despite adequate initial simulation.
- Two cycles of five inflation breaths (lasting 3 seconds each) can be given to stimulate breathing and heart rate
* If there is no response and the heart rate is low: 30 seconds of ventilation breaths can be used
* If there is still no response: chest compressions can be used, coordinated with the ventilation breaths
* Technique is very important in delivering effective inflation breaths. Get someone experienced to show you how to perform them. It is essential to maintain a neutral head position and get a good seal around the mouth and nose. Look for a rise and fall in the chest.
* When performing inflation breaths,** air should be used in term or near term babies**, and a mix of air and oxygen should be used in pre-term babies.
Chest Compressions
* Start chest compressions if heart rate remains below 60 bpm despite resuscitation and inflation breaths (see protocol)
* Chest compressions are performed at a 3:1 ratio with ventilation breaths
Time is precious during neonatal resuscitation.
Prolonged hypoxia increases the risk of []
Time is precious during neonatal resuscitation. Prolonged hypoxia increases the risk of hypoxic-ischaemic encephalopathy (HIE).
What are the scores used to calculate APGAR score?
Why do you delay clamping of the umbilical cord after birth? [1]
How long does this occur after birth? [2]
After birth there is still a significant volume of fetal blood in the placenta. Delayed clamping of the umbilical cord provides time for this blood to enter the circulation of the baby.
- Current guidelines from the resuscitation council UK state that uncompromised neonates should have a delay of at least one minute in the clamping of the umbilical cord following birth.
- Neonates that require neonatal resuscitation should have their umbilical cord clamped sooner to prevent delays in getting the baby to the resuscitation team. The priority will be resuscitation rather than delayed clamping.
A baby is born at term
What are the next immediate steps? [7]
Skin to skin
Clamp the umbilical cord
Dry the baby
Keep the baby warm with a hat and blankets
Vitamin K
Label the baby
Measure the weight and length
Why is Vit K given at birth? [3]
Babies are born with a deficiency of vitamin K:
- Vitamin K helps to prevent bleeding, particularly intracranial, umbilical stump and gastrointestinal bleeding
NB: As Vit K is via injection this can have the helpful side effect of stimulating the baby to cry, which helps expand the lungs.
Benefits of skin to skin contact at birth? [4]
- Helps warm baby
- Improves mother and baby interaction
- Calms the baby
- Improves breast feeding
Which 9 congenital conditions does the blood spot screening look for? [9]
- Sickle cell disease
- Cystic fibrosis
- Congenital hypothyroidism
- Phenylketonuria
- Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
- Maple syrup urine disease (MSUD)
- Isovaleric acidaemia (IVA)
- Glutaric aciduria type 1 (GA1)
- Homocystin
When does the newborn blood sport screening occur? [1]
Day 5
Name five common birth injuries [5]
- Caput Succedaneum
- Cephalohaematoma
- Facial Paralysis
- Erbs Palsy
- Fractured Clavicle
Describe what is meant by caput succedaneum [1]
Why does it occur? [1]
Caput succedaneum (caput) involves fluid (oedema) collecting on the scalp, outside the periosteum.
- Caput is caused by pressure to a specific area of the scalp during a traumatic, prolonged or instrumental delivery.
NB: The periosteum is a layer of dense connective tissue that lines the outside of the skull and does not cross the sutures (the gaps in the baby’s skull). The fluid is outside the periosteum, which means it is able to cross the suture lines
Describe the presentation of caput succedaneum [2]
Treatment? [1]
Soft, puffy swelling due to localised oedema
- Crosses suture lines
No skin discolouration
Treatment not required
Describe the cause of cephalohaematoma [1]
A cephalohaematoma is a collection of blood between the skull and the periosteum
- damage to blood vessels during a traumatic, prolonged or instrumental delivery. It can be described as a traumatic subperiosteal haematoma.
Describe the symptoms of cephalohaematoma [1]
The blood is below the periosteum, therefore the lump does NOT cross the suture lines of the skull.
- Additionally, the blood can cause discolouration of the skin in the affected area.
Describe the difference in presentation of caput succedaneum and cephalohaematoma [2]
Facial nerve injury is typically associated with a [] delivery. This can result in facial palsy (weakness of the facial nerve on one side).
Function normally returns spontaneously within a few months. If function does not return they may required neurosurgical input.
Delivery can cause damage to the facial nerve. Facial nerve injury is typically associated with a forceps delivery. This can result in facial palsy (weakness of the facial nerve on one side). Function normally returns spontaneously within a few months. If function does not return they may required neurosurgical input.
Which nerve roots are damaged in Erb’s palsy? [1]
C5/6
Describe the presentation of Erb’s palsy [5]
Damaged to the C5/C6 nerves leads to weakness of shoulder abduction and external rotation, arm flexion and finger extension. This leads to the affected arm having a “waiters tip” appearance:
* Internally rotated shoulder
* Extended elbow
* Flexed wrist facing backwards (pronated)
* Lack of movement in the affected arm
Describe the treatment of Erb’s palsy [1]
Function normally returns spontaneously within a few months. If function does not return then they may required neurosurgical input.
