Resuscitation of the Newborn²⁸

Newborn resuscitation specifically refers to the resuscitation procedures at or immediately after the delivery of a newly born infant. There is a specific sequence of events centred on the respiratory and circulatory changes that occur in relation to the 'First Breath'. Therefore the recommended resuscitation procedures (Figure 3) emphasise the airway and breathing manoeuvres whilst the management of the circulation is left to the trained health care provider. Resuscitation of the newborn is unique in that it is, in most cases, predictable. It is only rarely an unexpected emergency procedure. Careful assessment of maternal and foetal factors, the mode of delivery and the obstetric care will predict the majority of newborns that will require resuscitation procedures.

It has been estimated that the use of simple airway measures could prevent newborn asphyxia occurring in 900,000 infants per year world-wide. Of the five million newborn deaths per year world-wide, 56% of which occur in 'out of hospital births', 19% have 'birth asphyxia' as a cause.⁹⁴ In the United Kingdom newborn mortality is much lower but with the increase in 'home deliveries' it has become increasingly important for the birth attendants and other health care professionals to be not only conversant with obstetric problems but also proficient in newborn resuscitation techniques.

The majority of newborn infants cry within a few minutes of birth and require little more than careful drying and then wrapping in a warm towel to prevent heat loss. If the baby does not cry, it should be gently stimulated by more vigorous drying with a towel or flicking the soles of the feet. More vigorous stimulation is contraindicated and can be potentially dangerous. Of those that do not cry most will only need clearing the airway and ventilation, very few will need full resuscitation including intubation, circulatory access and drug administration.

The newborn baby's initial cry and subsequent efforts at breathing must be carefully assessed to ensure that they result in adequate and sustained oxygenation of the lungs. Gasping without additional efforts at breathing are usually considered inadequate. Abnormal or absent ventilatory patterns will require immediate active intervention.

The initial assessment of the neonate is based on respiratory activity, colour and heart rate. These three parameters have been shown to be more accurate in the assessment of the newborn than the total Apgar scoring system^95,96.

The newborn can be classified into three groups.

1. Fit and healthy baby
   Vigorous effective respiratory efforts
   Centrally pink
   Heart rate > 100/minute

This baby requires no intervention other than drying, wrapping in a warm towel and, where appropriate, handing to the mother. The baby will usually remain warm by skin to skin contact with mother and may be put to the breast at this stage.

2. Breathing inadequately or apnoeic
   Central cyanosis
   Heart rate > 100/minute

This group of babies may respond to tactile stimulation and/or facial oxygen but often need basic life support.

3. Breathing inadequately or apnoeic
   Pale or white due to poor cardiac output and peripheral vasoconstriction
   Heart rate <100/minutes or No detectable heart rate (although this was documented up to 15 - 20 minutes before delivery.)

These babies sometimes improve with initial basic life support but normally require immediate intubation and positive pressure ventilation progressing to chest compressions, and full advanced life support including resuscitation drugs if the baby fails to respond. 

Newborn Basic Life Support (Figure 3)

Airway Open the airway by tilting the head into the neutral position and lifting the jaw upward by gentle pressure on the mandible. The airway can be cleared of residual debris and fluid by gentle suction of the mouth and nares. Aggressive pharyngeal suction can delay the onset of spontaneous breathing and cause laryngeal spasm and vagal bradycardia97. It is not indicated unless the amniotic fluid is stained with thick meconium or blood. If suction is required, a 10FG (or if preterm, 8FG) suction catheter should be connected to a suction source not exceeding -100mmHg. This should not continue for longer than 5 seconds in the absence of meconium. The catheter should normally not be inserted further than about 5cm from the lips.

Breathing

Check for breathing by look, listen and feeling for respiratory effects. The inspired air can be supplemented with oxygen from a loose fitting facemask or funnel. Effective ventilation can only be carried out by using a well-fitting facemask that covers the mouth and nose but does not cover the eyes or overlap the chin⁹⁸.

Self-inflating resuscitation bags refill independently of adjuvant gas flow. They should incorporate a pressure limited pop-off valve pre-set at 20 - 30 cm H2O. In a minority, this pressure may be inadequate to achieve lung expansion at birth and the facility to override this is useful for a few babies. The volume of the bag should be at least 500ml, so that the inflation pressure can be maintained for at least 0.5 seconds. Facemask T-piece resuscitation uses compressed air/oxygen fed to one arm of a T-piece attached to the facemask⁹⁹. The baby's lungs are inflated by occluding the open arm of the T-piece. It is obviously essential to have a safety pressure release system (set at 20 - 30 cm H2O) incorporated in the gas supply tubing. A method for monitoring the peak pressures will also be required. This system has the advantage that it requires only one hand for normal operation and the inflation pressures can be maintained for longer than with the self-inflating bags. It has been traditional to use 100% oxygen as the ventilating gas for resuscitation but there is data indicating that, in term babies, 100% inspired oxygen has little advantage and may increase oxygen free radical damage. Furthermore there is evidence that newborn resuscitation is as effective with air as with 100% inspired oxygen.^100-103 If gas-mixing facilities are available then a 40% inspired oxygen is recommended as the ventilating gas to expand the newborn lungs, but if cyanosis persists or the heart rate falls the inspired oxygen level should be raised.

The first five or six breaths require an inspiration held for 1 to 2 seconds. This prolonged inspiration will double the inspiratory volume and is more likely to establish the functional residual capacity needed by the baby to continue to breath spontaneously¹⁰⁴. After these initial breaths a normal ventilatory pattern can be used, ventilating at a rate of approximately 30-40 breaths per minute until spontaneous respiration is established.

If the baby does not respond to these initial face mask resuscitation manoeuvres or the heart rate falls below 100 beats per minute, the health care professional must proceed to tracheal intubation and advanced life support procedures immediately. 

(Continued ...)

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