Birth Asphyxia

Question 1

What is asphyxia?

Answer 1

Asphyxia is the failure to initiate and maintain spontaneous and adequate breathing within 60 seconds of birth

Question 2

What causes asphyxia?

Answer 2

Asphyxia occurs as a result of impairment in gas exchange resulting in a decrease in oxygen in the blood and an excess of carbon-dioxide that leads to acidosis

Question 3

Clinical features of asphyxia?

Answer 3

1. Delay in breathing
   - An asphyxiated baby does not breathe at 1 minute (immediately after birth the baby is supposed to gasp and cry)
2. Bradycardia
   - heart rate below 100 beats per minute
3. Central cyanosis
   - blue tongue
4. The baby is floppy or has poor muscle tone
   - does not move very much and is poorly responsive to stimuli

Question 4

How are Apgar scores used in resuscitation?

Answer 4

used as an indicator of the effectiveness of the resuscitation
- Apgar scores are not useful indicators of the need for resuscitation, since resuscitation must begin long before the one-minute Apgar score is calculated

Question 5

Pre-disposing maternal factors of asphyxia?

Answer 5

1. Pre-eclampsia or eclampsia
2. Abruptio placentae, placenta praevia or ante-partum haemorrhage and History of previous neonatal deaths (NND)
3. Prolonged rupture of membranes (PROM)
4. Underlying medical conditions - infection, diabetes, essential hypertension
5. Maternal exhaustion
6. Placental insufficiency
7. Cephalopelvic disproportion(CPD)

Question 6

Pre-disposing labour and delivery factors of asphyxia?

Answer 6

1. Operative vaginal delivery
   - forceps or vacuum-extraction
2. Breech or other abnormal presentation and difficult delivery
3. Caesarean section
   - indication for C/S or anaesthetic drugs
4. Prolonged labour
   - latent phase >8 hrs, first stage >7 hrs and second stage >30 minutes in multipara and 1 hour in primigravida
5. Prolapsed umbilical cord or cord compression
6. Sedative or analgesic drugs given before delivery as well as use of traditional medicines

Question 7

Pre-disposing foetal conditions of asphyxia?

Answer 7

1. Prematurity
2. Post-maturity
3. Multiple births
4. Foetal distress
5. Intra uterine growth restriction (IUGR)
6. Macrosomia
7. Immaturity of pulmonary system
8. Cerebral damage
9. Meconium aspiration
10. Abnormal lie
11. Congenital abnormalities

Question 8

Patho-physiology of asphyxia?

Answer 8

• Asphyxia results from persistently impaired gas exchange in the foetus during the perinatal period with consequent hypoxia, hypercapnia and consequently, acidosis
• The foetus is able to cope with a certain degree of hypoxia and initially manages to preserve the function of vital organs, however, when the situation is persistent, there is consequent hypoxic injury with necrotic damage to the tissues

Question 9

How does asphyxia affect the organs?

Answer 9

1. Brain injury referred to as hypoxic/ischemic encephalopathy (HIE) occurs due to impaired cerebral blood flow
   - This may manifest early with abnormal neurology like irritability, seizures, abnormal tone and posture, apnoeic episodes or irregular respirations;
2. Cardiac injury can result in arrhythmias and cardiac arrest;
3. kidney injury causing acute tubular necrosis with haematuria, anuria, oliguria or polyuria.
4. The gastrointestinal tract may also become necrosis and this may manifest with abdominal distension, food intolerance, bloody stools.

Question 10

What is hypoxic-ischemic encephalopathy?

Answer 10

where a the neonate has experienced acute brain injury as expressed by encephalopathy as a consequence of hypoxia

Question 11

How can HIE be graded?

Answer 11

1. mild
2. moderate
3. severe

Question 12

Neonatal resuscitation?

Answer 12

A-Airway
If secretions, suction
B-Breathing
Bag and Mask ventilate if not breathing
C-Circulation
Iv fluids/ CPR/Inotropes
C-Coma
Intubation
C-Convulsions
Phenobarbitaone 20/kg loading dose, if seizures are controlled, then maintainance of 5/Kg. If not controlled repeat loading dose , then paraldehyde
D-Don’t ever forget glucose/ Dehydration
Check RBS and treat if <2.5 mmol/<45mg/dl
Treat with 2ml/kg of 10% dextrose solution.