56. Principles of cardiopulmonary resuscitation
Pathophysiology of asphyxia394
Role and responsibilities of the midwife401
Having read this chapter the reader should be able to:
• discuss in detail the role and responsibilities of the midwife prior to, during and following a neonatal resuscitation
• describe the signs that indicate that resuscitation is required
• describe the equipment and how it is used
• demonstrate/simulate a neonatal resuscitation technique, discussing how effective resuscitation is achieved.
Resuscitating the baby incorporates some of the fundamental principles used when resuscitating an adult but requires a different approach. However, the predisposing factors may be very different, often because the baby has not yet established respiration in the extrauterine environment. The aim of neonatal resuscitation is to initiate or sustain extrauterine life, limiting any cerebral damage.
This chapter focuses on recognition and action, suggested equipment and the midwife’s role and responsibilities. The reader is encouraged to compare and contrast the care given when resuscitating an adult (see Chapter 55).
The midwife may recognise the potential for neonatal compromise according to the known maternal or fetal risk factors. Such examples include:
• maternal disease, e.g. hypertension, diabetes mellitus
• maternal substance abuse
• previous poor obstetric or neonatal history, e.g. previous stillbirth, neonatal death
• known malpresentation, e.g. breech
• fetal abnormality
• prolonged rupture of membranes
• abnormalities of the fetal heartbeat indicative of fetal compromise
• heavy maternal sedation
• precipitate delivery
• instrumental or operative delivery, especially under general anaesthetic
• obstetric emergency, e.g. prolapsed cord, antepartum haemorrhage, shoulder dystocia, eclampsia.
However, the need for neonatal resuscitation can occur without any warning, predisposing factors or obvious cause thus emphasising the importance for all midwives to be trained in and practise the skills of neonatal resuscitation. The presence of two midwives at delivery (wherever the venue) is a safeguard that allows one to care for the woman, and the other to begin resuscitation of the baby. However, the first element of resuscitation must be to call for appropriate assistance. The midwife must know how to do this, whether in hospital or in the community. In hospital it may be one emergency number to ring; in the community the paramedic service may be called using 999 (or if on a mobile with little/no signal 112) and the midwife must be familiar with their local arrangements.
A baby may require resuscitating at other times in the postnatal period; the fundamental principles of resuscitation apply in the same way. Examples include:
• occlusion of the airway, e.g. choking, feeding problems or mucus
• undetected congenital abnormality
• retained effects of respiratory depression after the effect of naloxone has subsided
Pathophysiology of asphyxia
Asphyxia occurs when there is insufficient oxygen and excessive carbon dioxide and lactic acid in the blood. The consequence of this is a failure to breathe, which ultimately causes the baby’s metabolism to shift from aerobic to anaerobic respiration. A metabolic acidosis is created. An anoxic baby may be in any one of four phases, depending on the level of intrauterine hypoxia:
2. primary apnoea
4. terminal apnoea.
It is rarely possible to assess at birth which of these phases the baby is in. It is necessary to respond and then to assess the measures of progress.
Resuscitation can be successfully completed with a minimal amount of equipment, in any environment, whether home or hospital. In the hospital environment it is likely that a standard resuscitaire with additional equipment will be available. At home a chest of drawers or table may be utilised, but care should be taken to avoid draughts.
Ideal requirements include:
• a flat surface
• towels and gloves (somewhere to wash hands if time permits)
• food-grade plastic wrapping (for preterm babies <30 weeks)
• a radiant heater
• a clock, with a second hand
• oxygen/air source with flow regulation, reservoir and adjustable pressure relief valve (these should be checked prior to the delivery to ensure they are working correctly)
• T-tube or self-inflating resuscitation bag with valve and assorted size facemasks 00, 01
• Guedel airways sizes 0, 00, 000
• laryngoscopes (with spare bulbs and batteries)
• tracheal tubes, introducers and connectors
• suction apparatus with tubing and catheters
• needles, syringes, scissors, tape, other extras, e.g. umbilical catheterisation pack.
Adaptation for the home includes a basic portable kit that can be utilised effectively. Maddy (1998) provides such an example, where suction, ventilation and oxygen apparatus for both the woman and baby are contained within one bag.
If resuscitation is anticipated the equipment should be prepared in advance of the delivery so that the baby can be delivered onto warmed towels, taken to a resuscitation area with a good heat and light source and where equipment is readily to hand. If resuscitation is unexpected this preparation occurs concurrently with the resuscitative measures used.
Principles of resuscitation
The principles are summed up as ABCD: airway, breathing, circulation, drugs. However, for the newly delivered wet, hypoxic baby, the principles begin with the need to dry thoroughly (except for premature babies <30 weeks gestation), remove the wet towel and cover the baby while assessing the colour, tone, breathing and heart rate of the baby, calling for appropriate help and noting the time (if a stopwatch is available, this should be started at the time of birth or at the beginning of the resuscitation period).
Drying the baby provides tactile stimulation and reduces further heat loss and hypoxia. It is important to discard the wet towel and wrap the baby in a warm dry towel. This measure should be undertaken immediately and as the baby is being transferred to the resuscitation area. Babies who are born prematurely (30 weeks and below) should be placed under a radiant heater without being dried and the head and body covered in food-grade plastic wrapping, leaving the face exposed. This has been found to be the most effective way for their body temperature to be maintained (Resuscitation Council UK 2005).
As this is being undertaken the midwife should assess the baby, taking into account the colour of the trunk, lips and tongue, muscle tone, respiratory pattern and heart rate. Blue hands and feet should never be mistaken for cyanosis in the newborn; assessment of cyanosis should be made by observing the baby centrally, even when the baby has pigmented skin. The mucous membranes (inside of the lips), tongue and trunk are alternative sites to assess. The heart rate is assessed by listening with a stethoscope and not by palpating the umbilical cord which can be unreliable. Mildly hypoxic babies usually respond well to drying; if the colour and tone are good, the baby is breathing regularly with a heart rate above 100 beats per minute, no further measures are required and the baby can be returned to his mother. However, if this is not the case, further resuscitation and assistance are required.
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