A DIFFICULT DELIVERY

This baby will almost certainly have suffered an acute asphyxial insult as a result of cord compression while delivery of the body was prevented by the shoulder dystocia. The neonatal team should anticipate that the baby will require significant resuscitation and should ensure that a senior neonatologist is present. Obstruction of the fetoplacental circulation for more than a few minutes causes hypoxia, the fetus ceases breathing movements (primary apnoea), becomes bradycardic and circulation is directed to essential organs. Acidosis develops and, after a longer period of asphyxia, episodic reflex gasping occurs. If aeration of the lungs does not occur, these gasps diminish and a phase of terminal apnoea occurs, from which the fetus can only be saved by delivery and artificial ventilation. At delivery this baby will probably be apnoeic, bradycardic or asystolic, pale and floppy. Resuscitation of the newborn baby is unique. If there has never been aeration of the lungs, this must be achieved before any other interventions will work. The baby should be dried, covered and assessed for colour, tone, breathing and heart rate. If the baby is not breathing, the airway should be opened by placing the head in the neutral pos ition and five inflation breaths should be given. The first few inflation breaths may not produce chest movement because they act to displace lung fluid. The effectiveness of inflation breaths should be assessed by checking for an increase in heart rate. If this has not occurred it should be confirmed that the chest is being inflated before commencing cardiac compressions. This baby may also require adrenaline and sodium bicarbonate to be administered via an emergency umbilical venous catheter in order to achieve a return of cardiac output. The blood glucose should also be checked, especially as his mother had diabetes in pregnancy. After immediate resuscitation, the baby will need to be transferred to the neonatal unit for supportive and neuroprotective care. The outcome of acute asphyxia can be good if the episode is brief and effective resuscitation is provided. More severe asphyxia can lead to hypoxic-ischaemic encephalopathy (HIE) and death. In addition, shoulder dystocia is associated with brachial plexus injury and fracture of the clavicle and humerus.

Complications of birth asphyxia First days after resuscitation Long term (mostly after severe HIE)

Encephalopathy, seizures, cerebral oedema Cerebral palsy

Hypoventilation Seizures

Myocardial dysfunction Sensorineural hearing loss

Persistent fetal circulation Visual impairment

Renal dysfunction Learning difficulties

Hypoglycaemia, hyponatraemia

KEY POINTS

• If a baby is likely to have suffered severe asphyxia, senior assistance is required.

• Newborn resuscitation has a unique algorithm because the lungs have never been inflated with air.

• Birth asphyxia affects multiple organs, although most long-term complications are neurological.